Neglected tropical diseases (NTDs) are a diverse group of tropical infections that are common in low-income populations in developing regions of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, and the

Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North America, North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. ...

. They are caused by a variety of pathogens, such as

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es,

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, protozoa, and parasitic worms (

helminths Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as ...

). These diseases are contrasted with the "big three" infectious diseases (

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...

, and

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. ...

), which generally receive greater treatment and research funding. In sub-Saharan Africa, the effect of neglected tropical diseases as a group is comparable to that of malaria and tuberculosis. NTD co-infection can also make HIV/AIDS and tuberculosis more deadly. Some treatments for NTDs are relatively inexpensive. For example, the treatment for schistosomiasis is US$0.20 per child per year. Nevertheless, in 2010 it was estimated that control of neglected diseases would require funding of between US$2 billion and $3 billion over the subsequent five to seven years. Some pharmaceutical companies have committed to donating all the drug therapies required, and mass drug administration efforts (for example, mass deworming) have been successful in several countries. While preventive measures are often more accessible in the developed world, they are not universally available in poorer areas. Within

developed countries A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...

, neglected tropical diseases affect the very poorest in society. In the United States, there are up to 1.46 million families, including 2.8 million children, living on less than two dollars a day. In developed countries, the burdens of neglected tropical diseases are often overshadowed by other public health issues. However, many of the same issues put populations at risk in developed as well as developing nations. For example, other problems can stem from poverty which exposes individuals to the vectors of these diseases, such as lack of adequate

housing Housing, or more generally, living spaces, refers to the construction and assigned usage of houses or buildings individually or collectively, for the purpose of shelter. Housing ensures that members of society have a place to live, whether ...

. Twenty neglected tropical diseases are prioritized by the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

(WHO), though other organizations define NTDs differently.

Chromoblastomycosis Chromoblastomycosis is a long-term fungal infection of the skin and subcutaneous tissue (a chronic subcutaneous mycosis). It can be caused by many different types of fungi which become implanted under the skin, often by thorns or splinters. Ch ...

and other deep

mycoses Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ...

, scabies and other ectoparasites, and snakebite envenomation were added to the list in 2017. These diseases are common in 149 countries, affecting more than 1.4 billion people (including more than 500 million children) and costing developing economies billions of dollars every year. They resulted in 142,000 deaths in 2013—down from 204,000 deaths in 1990.

Reasons for neglect

The importance of neglected tropical diseases has been underestimated since many are asymptomatic and have long incubation periods. The connection between death and a neglected tropical disease that has been latent for a long period of time is not often realized. Areas of high endemicity are often in geographically isolated areas, making treatment and prevention much more difficult. These diseases have been overlooked because they mainly affect the poorest countries of the developing world and because of the recent emphasis on decreasing the prevalence of

, and

. Far more resources are given to the "big three" diseases (HIV/AIDS, tuberculosis, and malaria) because of their higher mortality and public awareness rates. Neglected tropical diseases do not have a prominent cultural figure to champion the cause.

Stigma

Neglected tropical diseases are often associated with social stigma, making their treatment more complex. Public health research has only recently begun to focus on stigma as a component of the issue. From the 1960s onward, approximately one citation a year related to social stigma. In 2006, there were 458. Disease control is greatly affected by this stigma, as it decreases help-seeking and treatment adherence. Disease control programs, starting as early as the 1980s, have begun to integrate stigma mitigation into their offerings. In India, the

leprosy Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria '' Mycobacterium leprae'' or '' Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve d ...

program prioritized the message that "leprosy is curable, not hereditary" in order to inspire optimism in highly affected communities. The goal was to make leprosy a disease "like any other", so as to reduce stigma. At the same time, medical resources available in the area were optimized to fulfill the curable promise made.

Economic incentives

Neglected tropical diseases are not commercial, and consequently, patents and profit play no role in stimulating innovation. Like all non-commercial areas, these diseases are the responsibility of governments and philanthropy (including industry philanthropy). Currently, the pharmaceutical industry views research and development as highly risky. For this reason, resources are not often put into the field of NTDs (as diseases of the poor) and new chemical products are often expensive. A review of public and private initiatives found that of the 1393 new chemical products that were marketed in the period between 1975 and 1999, only 16 were related to tropical diseases and tuberculosis. The same review additionally found that there was a 13-fold greater chance of a drug entering the market being for

central nervous The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all ...

system disorders or

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

than an NTD. Due to a lack of economic incentives for the pharmaceutical industry, successful NTD treatment programs have often relied on donations. The Mectizan Donation Program has donated over 1.8 billion tablets of ivermectin. While developed countries will often rely on government-run and private partnerships to fund such projects, developing nations frequently have significantly lower per-person spending on these diseases. A 2006 report found that the Gates Foundation funded most extra activity to counter these diseases.

Developed nations

Since 2008, the concept of "neglected diseases of poverty" has been developed and explored. This group of diseases overlaps with the neglected tropical diseases, which also pose a threat to human health in developed nations. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

alone, there are at least 12 million people with these neglected parasitic infections. They make up a hidden disease burden among the poorest of wealthy societies. In developed nations, lack of knowledge in the healthcare industry and lack of conclusive diagnostic tests perpetuate the neglect of this group of diseases. In the United States, high rates of parasitic infection can be distributed along geographic, racial, and socio-economic lines. Within the African-American community, there may be up to 2.8 million cases of

toxocariasis Toxocariasis is an illness of humans caused by the dog roundworm (''Toxocara canis'') and, less frequently, the cat roundworm ('' Toxocara cati'').https://academic.oup.com/ajcp/article/142/suppl_1/A104/1771175 Eosinophilic Pseudoleukemia Due to T ...

. Rates of toxocariasis, trichomoniasis, and other neglected infections occur in the United States at the same rate as in

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

. Within the

Hispanic The term ''Hispanic'' ( es, hispano) refers to people, cultures, or countries related to Spain, the Spanish language, or Hispanidad. The term commonly applies to countries with a cultural and historical link to Spain and to viceroyalties for ...

community, neglected infections are concentrated near the US–Mexico border. Vector-borne illnesses are especially high, with some rates approaching those of Latin America. Chagas disease was found in the US as early as the 1970s. However, in the developed world, diseases that are associated with poverty are often not addressed comprehensively. This may be due to a lack of economic incentives and public policy failings. Here, a lack of awareness prevents effective policy generation and leaves healthcare services unequipped to address the issue. Additionally, there is little effort put into taking and maintaining large data sets on neglected diseases in the United States and other developed nations. The first summit on the issue was held by the Adler Institute on Social Exclusion in the United States in 2009. In Europe, a similar trend is seen. Neglected tropical diseases are concentrated in eastern and southern Europe, where poverty levels are the highest. The most prevalent diseases in this region are ascariasis,

trichuriasis Trichuriasis, also known as whipworm infection, is an infection by the parasitic worm '' Trichuris trichiura'' (whipworm). If infection is only with a few worms, there are often no symptoms. In those who are infected with many worms, there may ...

, zoonotic helminth infections, and visceral leishmaniasis. Migration paths to Europe, most notably to Spain, have brought diseases to Europe as well. As many as 6,000 cases of Chagas disease have been introduced via this method. In response to a growing awareness of the burden on these populations, the European Centre for Disease Prevention and Control has laid out ten public health guidelines. They cover a variety of topics, from health education and promotion to community partnerships and the development of a minority healthcare workforce.

List of diseases

There is some debate among the WHO,

CDC The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georg ...

, and

infectious disease An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...

experts over which diseases are classified as neglected tropical diseases. Feasey, a researcher in neglected tropical diseases, notes 13 neglected tropical diseases: ascariasis,

Buruli ulcer Buruli ulcer () is an infectious disease characterized by the development of painless open wounds. The disease is limited to certain areas of the world, most cases occurring in Sub-Saharan Africa and Australia. The first sign of infection is a ...

, Chagas disease, dracunculiasis, hookworm infection, human African trypanosomiasis, Leishmaniasis,

, lymphatic filariasis, onchocerciasis, schistosomiasis, trachoma, and

. Fenwick recognizes 12 "core" neglected tropical diseases: the same as above, excluding hookworm. These diseases result from four different classes of causative pathogens: (i) protozoa (for Chagas disease, human African trypanosomiasis, and leishmaniases); (ii)

(for Buruli ulcer, leprosy, trachoma, and yaws), (iii)

or metazoan worms (for cysticercosis/taeniasis, dracunculiasis, echinococcosis, foodborne trematodiases, lymphatic filariasis, onchocerciasis, schistosomiasis, and

soil-transmitted helminthiasis Soil-transmitted helminthiasis is a type of helminth infection (helminthiasis) caused by different species of roundworms. It is caused specifically by those worms which are transmitted through soil contaminated with faecal matter and are therefo ...

); and (iv)

es (dengue and chikungunya, rabies). The World Health Organization recognizes the twenty diseases below as neglected tropical diseases. The

's 2010 report dedicated to neglected tropical diseases offers an expanded list including dengue,

rabies Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...

yaws Yaws is a tropical infection of the skin, bones, and joints caused by the spirochete bacterium ''Treponema pallidum pertenue''. The disease begins with a round, hard swelling of the skin, in diameter. The center may break open and form an ulc ...

cysticercosis Cysticercosis is a tissue infection caused by the young form of the pork tapeworm. People may have few or no symptoms for years. In some cases, particularly in Asia, solid lumps of between one and two centimetres may develop under the skin. Aft ...

echinococcosis Echinococcosis is a parasitic disease of tapeworms of the ''Echinococcus'' type. The two main types of the disease are ''cystic echinococcosis'' and '' alveolar echinococcosis''. Less common forms include ''polycystic echinococcosis'' and ''u ...

, and foodborne trematode infections.World Health Organization. Working to overcome the global impact of neglected tropical diseases: first WHO report on neglected tropical diseases. 2010. ND=Not DeterminedHotez PJ, Molyneux DH, Fenwick A, Ottesen E, Ehrlich Sachs S, Sachs JD. Incorporating a rapid-impact package for neglected tropical diseases with programs for HIV/AIDS, tuberculosis, and malaria. ''PLoS Med'' 2006 Jan;3(5):e102.Hotez PJ, Molyneux DH, Fenwick A, Kumaresan J, Sachs SE, Sachs JD, et al. Control of neglected tropical diseases. ''N Engl J Med'' 2007 Sep 6;357(10):1018-1027.

Buruli ulcer

is caused by the bacterium '' Mycobacterium ulcerans''. It is related to the family of organisms that cause

and

, but ''Mycobacterium ulcerans'' produces a toxin, mycolactone, that destroys tissue. The prevalence of Buruli ulcer is unknown. The risk of mortality is low, although secondary infections can be lethal. Morbidity takes the form of deformity, disability, and skin lesions, which can be prevented through early treatment and treated with antibiotics and surgery. It is found in Africa, Asia, and Latin America.

Chagas disease

Chagas disease is also known as

American trypanosomiasis Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by '' Trypanosoma cruzi''. It is spread mostly by insects in the subfamily '' Triatominae'', known as "kissing bugs". The symptoms change over the ...

. There are approximately 15 million people infected with Chagas disease. Morbidity rates are higher for immuno-compromised individuals, children, and the elderly, but can be very low if treated early. Chagas disease does not kill victims rapidly, instead causing years of debilitating chronic symptoms. It is caused by a

vector-borne In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen to another living organism; agents regarded as vectors are organisms, such as parasites or microbes. The first major discovery of a disease ve ...

protozoa and spread by contact with ''

Trypanosoma cruzi ''Trypanosoma cruzi'' is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood o ...

''-infected feces of the triatomine ( assassin) bug. The protozoan can enter the body via the bug's bite, skin breaks, or mucous membranes. Infection can result from eating infected food and coming into contact with contaminated bodily fluids. There are two phases of Chagas disease. The acute phase is usually asymptomatic. The first symptoms are usually skin

chancre A chancre ( )chancres
thefreedictionary is a painless

s, unilateral purplish orbital oedema, local lymphadenopathies, and

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

accompanied by a variety of other symptoms depending on the infection site. The chronic phase occurs in 30 percent of total infections and can take three forms, which are asymptomatic (most prevalent), cardiac, and digestive lesions. Chagas disease can be prevented by avoiding insect bites through insecticide spraying, home improvement, bed nets, hygienic food, medical care, laboratory practices, and testing. It can be treated with medication, although these may have severe side effects. It can be diagnosed through a serological test, although the test is not very accurate.

Dengue and chikungunya

There are 50–100 million dengue virus infections annually. Dengue fever is usually not fatal, but infection with one of four serotypes can increase later susceptibility to other serotypes, resulting in a potentially fatal disease called severe dengue. Dengue fever is caused by a flavivirus, and is spread mostly by the bite of the ''

Aedes aegypti ''Aedes aegypti'', the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito can be recognized by black and white markings on its l ...

'' mosquito. No treatment for either dengue or severe dengue exists beyond

palliative care Palliative care (derived from the Latin root , or 'to cloak') is an interdisciplinary medical caregiving approach aimed at optimizing quality of life and mitigating suffering among people with serious, complex, and often terminal illnesses. Wit ...

. The symptoms are high fever and flu-like symptoms. It is found in Asia, Latin America, and Northern Australia.

Chikungunya Chikungunya is an infection caused by the ''Chikungunya virus'' (CHIKV). Symptoms include fever and joint pains. These typically occur two to twelve days after exposure. Other symptoms may include headache, muscle pain, joint swelling, and a r ...

is an arboviral disease transmitted by '' A. albopictus'' and '' A. aegypti'' mosquitoes. The virus was first isolated from an outbreak in Tanzania in 1952. Chikungunya virus is a member of the genus '' Alphavirus'' and family ''Togaviridae''. The word "chikungunya" is from the Makonde language and means "that which bends up", referring to the effect of the debilitating joint pain on the patient. Symptoms, generally appearing 5–7 days after exposure, can be confused with dengue and include fever, rash, headache, joint pain, and swelling. The disease mainly occurs in Africa and Asia.

Dracunculiasis

Dracunculiasis is also known as Guinea-worm disease. In 2019, 53 cases were reported across four countries, a substantial decrease from 3,500,000 cases in 1986. It is not fatal, but can cause months of inactivity. It is caused by drinking water contaminated by

water fleas The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms). Over 1000 species have been recognised so far, with many more ...

infected with guinea-worm larvae. Approximately one year after infection, a painful blister forms and one or more worms emerge. Worms can be up to 1 metre long. It is usually treated by World Health Organization volunteers who clean and bandage wounds caused by worms and return daily to pull the worm out a few more inches. Dracunculiasis is preventable by water filtration, immediate case identification to prevent the spread of disease, health education, and treating ponds with larvicide. An eradication program has been able to reduce prevalence. , the four endemic countries are Chad, Ethiopia, Mali, and South Sudan.

Echinococcosis

The rate of

is higher in rural areas, and there are more than one million people infected currently. Untreated alveolar echinococcosis is fatal. It is caused by ingesting parasites in animal feces. There are two versions of the disease: cystic and alveolar. Both versions involve an asymptomatic incubation period of several years. In the cystic version, liver cysts cause abdominal pain, nausea, and vomiting while cysts in the lungs cause chronic cough, chest pain, and shortness of breath. In alveolar echinococcosis, a primary cyst develops, usually in the liver, in addition to weight loss, abdominal pain, general feeling of ill health, and signs of liver failure. Surgery and drugs can both be used to treat echinococcosis. It can be prevented by deworming dogs, sanitation, proper disposal of animal feces, health education, and livestock vaccination. Cystic echinococcosis is found in the eastern portion of the Mediterranean region, northern Africa, southern and eastern Europe, the southern portion of South America, and Central Asia. Alveolar echinococcosis is found in western and northern China, Russia, Europe, and northern North America. It can be diagnosed through imaging techniques and serological tests.

Yaws

There are limited data available on the prevalence of

, although it primarily affects children. The mortality risk is very low, but the disease causes disfigurement and disability if untreated. The most common symptom is skin lesions. It is a chronic bacterial infection, transmitted by skin contact, and caused by the spirochete

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

'' Treponema pallidum pertenue''. It is treated with antibiotics and can be prevented through improved hygiene and sanitation. Yaws is most prevalent in the warm, moist, tropical regions of the Americas, Africa, Asia, and the Pacific.

Foodborne trematodiases

The foodborne trematode infections include clonorchiasis, opisthorchiasis,

fascioliasis Fasciolosis is a parasitic worm infection caused by the common liver fluke '' Fasciola hepatica'' as well as by '' Fasciola gigantica''. The disease is a plant-borne trematode zoonosis, and is classified as a neglected tropical disease (NTD). ...

, and paragonimiasis. These infections are all zoonotic, primarily affecting domestic or wild animals, but can also be transmitted to humans. They are acquired by eating food, such as raw fish, contaminated with the larval stages of the parasites. At least 40 million people are thought to be infected. Fasciola hepatica

Human African trypanosomiasis

African trypanosomiasis (African sleeping sickness) is a somewhat rare protozoal disease as there are fewer than 10,000 cases currently. Human African trypanosomiasis is

and spreads through the bite of the tsetse fly. The most common symptoms are fever, headache, lymphadenopathy, nocturnal sleeping pattern, personality changes, cognitive decline, and coma. The disease is always fatal if untreated. The current forms of treatment are highly toxic and ineffective as resistance is spreading. It is diagnosed through an inexpensive serological test. Trypanosoma African life cycle CDC

Leishmaniasis

The three forms of leishmaniasis, a protozoal disease, are visceral ( Kala-azar), cutaneous, and mucocutaneous. There are an estimated 12 million people infected. It is fatal if untreated and 20,000 deaths from visceral leishmaniasis occur annually. It is a

disease that is caused by the bite of

sandflies Sandfly (or sand fly) is a colloquial name for any species or genus of flying, biting, blood-sucking dipteran (fly) encountered in sandy areas. In the United States, ''sandfly'' may refer to certain horse flies that are also known as "green ...

. At least 90 percent of visceral leishmaniasis occurs in Bangladesh, Brazil, Ethiopia, India, South Sudan, and Sudan. Cutaneous leishmaniasis occurs in Afghanistan, Algeria, Brazil, Colombia, Iran, Pakistan, Peru, Saudi Arabia, and Syria. Around 90 percent of mucocutaneous leishmaniasis occurs in Bolivia, Brazil, and Peru. The only method of prevention is a vaccine that is under development and prevention of sandfly bites. Diagnosis can be made by identifying clinical signs, serological tests, or parasitological tests. Leishmaniasis can be treated with expensive medications.

Leprosy

According to recent figures from the WHO, 208,619 new cases of

were reported in 2018 from 127 countries. It is most prevalent in India (69% of cases), Brazil, Indonesia, Nigeria, the Democratic Republic of the Congo, Madagascar, and East Africa, from Mozambique to Ethiopia, with the highest relative incidence in India, Brazil, and Nepal. There are one to two million individuals currently disabled or disfigured due to past or present leprosy. It is caused by bacteria and transmitted through droplets from the mouth and nose of infected individuals. Leprosy causes disfigurement and physical disabilities if untreated. It is curable if treated early. Treatment requires multidrug therapy. The BCG vaccine has some preventative effect against leprosy. Leprosy has a 5–20 year incubation period, and the symptoms are damage to the skin, nerves, eyes, and limbs. Leprosy deformities hands

Lymphatic filariasis

Lymphatic filariasis is also known as

elephantiasis Elephantiasis is the enlargement and hardening of limbs or body parts due to tissue swelling. It is characterised by edema, hypertrophy, and fibrosis of skin and subcutaneous tissues, due to obstruction of lymphatic vessels. It may affect the genit ...

. There are approximately 120 million individuals infected and 40 million with deformities. Approximately two-thirds of cases are in Southwest Asia and one-third in Africa. Lymphatic filariasis is rarely fatal. Lymphatic filariasis has lifelong implications, such as lymphoedema of the limbs, genital disease, and painful recurrent attacks. Most people are asymptomatic, but have lymphatic damage. Up to 40 percent of infected individuals have kidney damage. It is a

disease, caused by nematode worms that are transmitted by mosquitoes. It can be treated with cost-effective antihelminthic treatments, and washing skin can slow or even reverse damage. It is diagnosed with a finger-prick blood test.

Onchocerciasis

Onchocerca volvulus emerging from a black fly

Onchocerciasis is also known as "river blindness". There are 20.9 million people infected and prevalence is higher in rural areas. Over 99 percent of cases are in sub-Saharan Africa. It causes blindness, skin rashes, lesions, intense itching, and skin depigmentation. It is a

disease, caused by filarial worm infected blackflies. It can be treated with ivermectin. It can be prevented by insecticide spraying or preventative dosing with ivermectin. The symptoms are generally itching and skin lesions.

Rabies

There are two forms of

: furious and paralytic. There are 60,000 deaths from rabies annually. It is mostly found in Asia and Africa. There is a higher prevalence in rural areas and it disproportionately affects children. Rabies is fatal after symptoms develop. It is caused by a lyssavirus transmitted through wounds or bites from infected animals. The first symptoms are fever and pain near the infected site, which occur after a one to the three-month incubation period. Furious (more common type) rabies causes hyperactivity, hydrophobia, and aerophobia; death by cardio-respiratory arrest occurs within days. Paralytic rabies causes a slow progression from paralysis to coma to death. It can be prevented in dogs by vaccination and cleaning and disinfecting bite wounds ( post-exposure prophylaxis). Rabies is undiagnosable before symptoms develop. It can be detected through tissue testing after symptoms develop.

Schistosomiasis

There are over 200 million cases of schistosomiasis. Approximately 85 percent of cases are in sub-Saharan Africa. The disease can be fatal by causing bladder cancer and hematemesis. ''

Schistosoma ''Schistosoma'' is a genus of trematodes, commonly known as blood flukes. They are parasitic flatworms responsible for a highly significant group of infections in humans termed '' schistosomiasis'', which is considered by the World Health Org ...

'' species have a complex life cycle that alternates between humans and freshwater snails. Infection occurs when the skin comes into contact with contaminated fresh water in which the snails that carry the parasite are living. Symptoms for schistosomiasis are not caused by the worms but by the body's reaction to the eggs. The eggs that do not pass out of the body can become lodged in the intestine or bladder, causing inflammation or scarring. Children who are repeatedly infected can develop anemia, malnutrition, and learning difficulties. The symptoms are usually haematuria, bladder obstruction,

renal failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

bladder cancer Bladder cancer is any of several types of cancer arising from the tissues of the urinary bladder. Symptoms include blood in the urine, pain with urination, and low back pain. It is caused when epithelial cells that line the bladder become ma ...

, periportal fibrosis, bladder fibrosis, liver fibrosis, portal hypertension, cervical lesions, ascites, and esophageal varices. Inexpensive praziquantel can be used to treat individuals with schistosomiasis, but cannot prevent reinfection. The cost of prevention is US$0.32 per child per year. Mass deworming treatment with praziquantel, better access to safe water, sanitation, and health education can all be used to prevent schistosomiasis. Vaccines are under development. It can be diagnosed through a serological test, but it often produces false negatives.

Soil-transmitted helminthiasis

Adult ascaris worms being removed from the bile duct of a patient in South Africa

Soil-transmitted helminthiasis Soil-transmitted helminthiasis is a type of helminth infection (helminthiasis) caused by different species of roundworms. It is caused specifically by those worms which are transmitted through soil contaminated with faecal matter and are therefo ...

is the most prevalent neglected tropical disease. The three major worm species responsible for

are ''

Ascaris ''Ascaris'' is a genus of parasitic nematode worms known as the "small intestinal roundworms", which is a type of parasitic worm. One species, '' Ascaris lumbricoides'', affects humans and causes the disease ascariasis. Another species, ''Ascar ...

'' ( roundworms), '' Trichuris'' ( whipworm), the hookworms '' Necator americanus'' and ''

Ancylostoma duodenale ''Ancylostoma'' is a genus of nematodes that includes some species of hookworms. Species include: : ''Ancylostoma braziliense'', commonly infects cats, popularly known in Brazil as ''bicho-geográfico'' : ''Ancylostoma caninum'', commonly infect ...

'', and '' Strongyloides stercoralis''. There are 1.5 billion people currently infected. Soil-transmitted heminthiasis occurs in sub-Saharan Africa, the Americas, China, and east Asia. The mortality risk is very low. The most common symptoms are anemia, stunted growth, intestinal problems, lack of energy, and compromised physical and cognitive development. Infected children often fall behind in schooling. The severity of symptoms depends on the number of worms in the body. Parasitic worms are generally transmitted via exposure to infected human feces and soil that are spread in the environment, for example, due to open defecation. The most common treatment is medicine. It can be prevented through hygienically prepared food and clean water, improved

sanitation Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation syste ...

, periodic deworming, and health education. The World Health Organization recommends mass deworming without prior diagnosis.

Taeniasis/cysticercosis

Cysticercosis Cysticercosis is a tissue infection caused by the young form of the pork tapeworm. People may have few or no symptoms for years. In some cases, particularly in Asia, solid lumps of between one and two centimetres may develop under the skin. Aft ...

is a tapeworm larvae infection, while

taeniasis Taeniasis is an infection within the intestines by adult tapeworms belonging to the genus '' Taenia''. There are generally no or only mild symptoms. Symptoms may occasionally include weight loss or abdominal pain. Segments of tapeworm may be ...

is infection with adult tapeworms. Both are found in Asia, Africa, and Latin America, particularly on farms in which pigs are exposed to human excrement. Cysticercosis is the most common preventable cause of

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...

in the developing world. Cysticercosis occurs after ingestion of contaminated food, water, or soil. Cysts and lesions can cause headaches,

blindness Visual impairment, also known as vision impairment, is a medical definition primarily measured based on an individual's better eye visual acuity; in the absence of treatment such as correctable eyewear, assistive devices, and medical treatment� ...

seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with lo ...

hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary i ...

, meningitis, and

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

. Neurocysticercosis, or the parasitic infection of the nervous system, can be fatal. Taeniasis is not fatal. It is usually contracted after eating undercooked contaminated pork. Taeniasis has mild symptoms, including abdominal pain, nausea, diarrhea, or constipation. Drugs are used to treat both diseases. Infection can be prevented through stricter meat-inspection standards, livestock confinement, improved hygiene and sanitation, health education, safe meat preparation, and identifying and treating human and pig carriers.

Trachoma

There are 21.4 million people infected with trachoma, of whom 2.2 million are partially blind and 1.2 million are blind. It is found in Africa, Asia, Central, and South America, the Middle East, and Australia. The disease disproportionately affects women and children. The mortality risk is very low, although multiple re-infections eventually lead to blindness. The symptoms are internally scarred eyelids, followed by eyelids turning inward. Trachoma is caused by a micro-organism that spreads through eye discharges (on hands, cloth, etc.) and by "eye-seeking flies". It is treated with antibiotics. The only known prevention method is interpersonal hygiene.

Chromoblastomycosis and other deep mycoses

Scabies

Snakebite envenoming

Snakebite was added to the list in 2017, after years of criticism of the WHO by activists for not making it a priority. The greatest burden of snakebite morbidity is in India and Southeast Asia. Globally, there are an estimated 421,000 envenomings each year (about 1 in 4 snakebites) and 20,000 deaths, but snakebites often go unreported.

Effects for patients

Social effects

Social stigma

Several NTDs, such as

, cause severe deformities that result in social stigma. Stigma is considered to be the "hidden burden" of neglected tropical diseases and is not accounted for in measures such as

disability-adjusted life year The disability-adjusted life year (DALY) is a measure of overall disease burden, expressed as the number of years lost due to ill-health, disability or early death. It was developed in the 1990s as a way of comparing the overall health and life ex ...

s (DALYs). Other NTDs that carry heavy social stigma include onchocerciasis, lymphatic filariasis,

plague Plague or The Plague may refer to: Agriculture, fauna, and medicine *Plague (disease), a disease caused by ''Yersinia pestis'' * An epidemic of infectious disease (medical or agricultural) * A pandemic caused by such a disease * A swarm of pes ...

, leishmaniasis, and Chagas disease. Lymphatic filariasis, for example, causes severe deformities that can result in denial of marriage and inability to work. Studies in Ghana and Sri Lanka have demonstrated that support groups for patients with lymphatic filariasis can increase participants' self-esteem, quality of life, and social relations through social support and providing practical advice on how to manage their illness. The social effects of neglected tropical diseases have been shown to affect men and women in different ways. Men are socially stigmatized in a way that detrimentally affects their economic prospects. Women are more likely to be affected in the areas of marriage and family.

Mental health

A 2012 review found that infection with a neglected tropical disease predisposes individuals to poor mental health. This is partially due to the social stigma that surrounds NTDs, but is also likely caused by the subsequent lack of access to health and social services. Overall, being a member of the infected community was found to cut individuals off from multiple aspects of society via civic rights, educational opportunities, and employment. A high prevalence of post-traumatic stress disorder (PTSD) and depression was found in those affected with snakebite survivors. There is a need for more research be directed to understanding the psychological aspects of neglected tropical diseases in order to fully untangle their co-effects and on how they can be dealt with better in health systems in countries where mental health professionals are scarce.

Gender

NTDs disproportionately affect women and children. There is also the added risk of hookworm infection during pregnancy and the potential to transfer diseases such as Chagas during pregnancy. A study in Uganda found that women were more easily able to obtain treatment because they had fewer occupational responsibilities than men and were more trusting of treatment, but ignorance of the effects of medicines on pregnant women prevented adequate care. The paper concludes that gender should be considered when designing treatment programs in Uganda. Additionally, women often bear a heavier social stigma in relation to the pressure to marry.

Economic effects

The cost of treatment of some of these diseases, such as Buruli ulcer, can amount to over twice the yearly income of an average household in the lowest income quartile, while for the highest income quartile, the burden is slightly less than the average household income. These enormous financial costs often cause deferral of treatment and financial ruin, but there is inequality between the wealthy and poor in terms of economic burden. These diseases also cost the government in terms of health care and lost worker productivity through morbidity and shortened life spans. In Kenya, for example, deworming is estimated to increase average adult income by 40 percent, which is a benefit-to-cost ratio of 100. Each untreated case of Trachoma is estimated to cost US$118 in lost productivity. Each case of schistosomiasis causes a loss of 45.4 days of work per year. Most of the diseases cost the economies of various developing countries millions of dollars. Large-scale prevention campaigns are predicted to increase agricultural output and education levels. The low cost of treatment for NTDs can be attributed to the large scale of the programs, free provision of drugs by pharmaceutical companies, delivery modes of drugs, and the unpaid volunteers who distribute the drugs. The economic burden of NTDs is undervalued and therefore the corresponding economic effect and cost-effectiveness of a decreased prevalence of NTDs is underestimated. The investment return on measures to control neglected tropical diseases is estimated to be between 14 and 30 percent, depending on the disease and region.

Health effects

Coinfection

Coinfection Coinfection is the simultaneous infection of a host by multiple pathogen species. In virology, coinfection includes simultaneous infection of a single cell by two or more virus particles. An example is the coinfection of liver cells with he ...

is a major concern with neglected tropical diseases, making NTDs more damaging than their mortality rates might portray. Because the factors that support neglected tropical diseases (poverty, inadequate healthcare, inadequate sanitation practices, etc.) support all NTDs, they are often found in overlapping distributions. Helminth infections, as the most common infection of humans, are often found to be in multi-infection systems. For example, in Brazil, low socioeconomic status contributes to overcrowded housing. In these same areas, connection by '' Necator americanus'' and ''

Schistosoma mansoni A paired couple of ''Schistosoma mansoni''. ''Schistosoma mansoni'' is a water-borne parasite of humans, and belongs to the group of blood flukes ''Schistosoma'' is a genus of trematodes, commonly known as blood flukes. They are parasiti ...

'' is common. The effect of each worm weakens the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

of those infected, making infection from the other easier and more severe. For this reason, coinfection carries a higher risk of mortality. NTDs may also play a role in infection with other diseases, such as

, and

. The ability of helminths to manipulate the immune system may create a physiological environment that could exacerbate the progression of

. Some evidence from

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northe ...

, and

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

has shown that helminth infections raise the risk of malarial infection.

Prevention, treatment and eradication

On the Road to Eliminating Neglected Tropical Diseases in Cote d'Ivoire (29464931444)

Prevention and eradication are important because "of the appalling stigma, disfigurement, blindness, and disabilities caused by NTDs." The possibility of eliminating or eradicating dracunculiasis,

, lymphatic filariasis, onchocerciasis, trachoma, sleeping sickness,

visceral leishmaniasis Visceral leishmaniasis (VL), also known as kala-azar ( Hindi: kālā āzār, "black sickness") or "black fever", is the most severe form of leishmaniasis and, without proper diagnosis and treatment, is associated with high fatality. Leishmanias ...

, and canine

within the next ten years was the principal aim of the

London Declaration on Neglected Tropical Diseases The London Declaration on Neglected Tropical Diseases was a collaborative disease eradication programme launched on 30 January 2012 in London. It was inspired by the World Health Organization roadmap to eradicate or prevent transmission for negl ...

, which is a collaborative effort involving the WHO, the

World Bank The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Inte ...

, the Bill & Melinda Gates Foundation, the world's 13 leading pharmaceutical companies, and government representatives from the US, UK, United Arab Emirates, Bangladesh, Brazil, Mozambique, and Tanzania. It was launched in January 2012. While the current era has had a noticeable uptick in biological research into neglected tropical diseases, prevention may be supplemented by social and development outreach. Spiegal and his coauthors advocated for this to take the form of a "social offset". Social offset entails the delegation of some of the funding for biotechnological research to social programs. The attempts to alleviate some of the surrounding factors (such as poverty, poor sanitation, overcrowding, poor healthcare, etc.) that greatly exacerbate the conditions brought on by neglected tropical diseases. Projects such as these also strengthen the goal of sustained eliminations rather than quickly addressing symptoms.

Policy initiatives

There are many prevention and eradication campaigns funded, for example, by the World Health Organization, US Agency for International Development,

Bill and Melinda Gates Foundation The Bill & Melinda Gates Foundation (BMGF), a merging of the William H. Gates Foundation and the Gates Learning Foundation, is an American private foundation founded by Bill Gates and Melinda French Gates. Based in Seattle, Washington, it was l ...

, and UK

Department for International Development , type = Department , logo = DfID.svg , logo_width = 180px , logo_caption = , picture = File:Admiralty Screen (411824276).jpg , picture_width = 180px , picture_caption = Department for International Development (London office) (far right ...

Sustainable Development Goal 3 Sustainable Development Goal 3 (SDG 3 or Global Goal 3), regarding " Good Health and Well-being", is one of the 17 Sustainable Development Goals established by the United Nations in 2015. The official wording is: "To ensure healthy lives and pr ...

has this target to eradicate NTDs: "By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other

communicable diseases An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

."United Nations (2017) Resolution adopted by the General Assembly on 6 July 2017, Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development
A/RES/71/313

WHO Roadmap of 2012

In 2012, WHO published an NTD "roadmap", which contained milestones for 2015 and 2020 and specified targets for eradication, elimination, and intensified control of the different NTDs. For example: * NTDs planned to be eradicated: dracunculiasis (by the year 2015), endemic treponematoses (yaws) (by 2020) * NTDs planned to be eliminated globally by 2020: blinding trachoma,

human African trypanosomiasis African trypanosomiasis, also known as African sleeping sickness or simply sleeping sickness, is an insect-borne parasitic infection of humans and other animals. It is caused by the species ''Trypanosoma brucei''. Humans are infected by two typ ...

, and lymphatic filariasis * NTDs planned to be eliminated in certain regions: rabies (by 2015 in Latin America, by 2020 in Southeast Asia and the western Pacific), Chagas disease (transmission through blood transfusion by 2015, intra-domiciliary transmission by 2020 in the Americas), visceral leishmaniasis (by 2020 in the Indian subcontinent), onchocerciasis (by 2015 in Latin America), and schistosomiasis (by 2015 in the eastern Mediterranean region, the Caribbean, Indonesia, and the Mekong River basin, by 2020 in the Americas and western Pacific) * NTDs planned to be eliminated in certain countries: human African trypanosomiasis (by 2015 in 80 percent of areas in which it occurs), onchocerciasis (by 2015 in Yemen, by 2020 in selected countries in Africa), and schistosomiasis (by 2020 in selected countries in Africa) * Intensified control with specific targets for 2015 and 2020 are provided for these NTDs: dengue,

buruli ulcer Buruli ulcer () is an infectious disease characterized by the development of painless open wounds. The disease is limited to certain areas of the world, most cases occurring in Sub-Saharan Africa and Australia. The first sign of infection is a ...

cutaneous leishmaniasis Cutaneous leishmaniasis is the most common form of leishmaniasis affecting humans. It is a skin infection caused by a single-celled parasite that is transmitted by the bite of a phlebotomine sand fly. There are about thirty species of '' Leish ...

and

/hydatidosis, foodborne trematode infections, and soil-transmitted helminthiases

Others

The U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

priority review voucher Priority review is a program of the United States Food and Drug Administration (FDA) to expedite the review process for drugs that are expected to have a particularly great impact on the treatment of a disease. The priority review voucher program ...

is an incentive for companies to invest in new drugs and vaccines for tropical diseases. A provision of the Food and Drug Administration Amendments Act (HR 3580) awards a transferable "priority review voucher" to any company that obtains approval for a treatment for one of the listed diseases. The voucher can later be used to accelerate the review of an unrelated drug. This program is for all tropical diseases and includes medicines for malaria and tuberculosis. The first voucher given was for

Coartem Artemether/lumefantrine, sold under the trade name Coartem among others, is a combination of the two medications artemether and lumefantrine. It is used to treat malaria caused by ''Plasmodium falciparum'' that is not treatable with chloroquine. I ...

, a malaria treatment. It does not use or define the term "neglected", though most of the diseases listed are often included on lists of neglected diseases. The prize was proposed by

Duke University Duke University is a private research university in Durham, North Carolina. Founded by Methodists and Quakers in the present-day city of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco and electric power industrialist Jam ...

faculty Henry Grabowski, Jeffrey Moe, and David Ridley in their 2006 ''Health Affairs'' paper "Developing Drugs for Developing Countries". In 2007, United States Senators Sam Brownback (R-KS) and

Sherrod Brown Sherrod Campbell Brown (; born November 9, 1952) is an American politician serving as the senior United States senator from Ohio, a seat which he has held since 2007. A member of the Democratic Party, he was the U.S. representative for Ohio ...

(D-OH) sponsored an amendment to the

Amendments Act of 2007. President George W. Bush signed the bill in September 2007.

Deworming treatment

Deworming Deworming (sometimes known as worming, drenching or dehelmintization) is the giving of an anthelmintic drug (a wormer, dewormer, or drench) to a human or animals to rid them of helminths parasites, such as roundworm, flukes and tapeworm. Pur ...

treatments in infected children may have some nutritional benefit, as worms are often partially responsible for malnutrition. However, in areas where these infections are common, there is strong evidence that mass deworming campaigns do not have a positive effect on children's average nutritional status, levels of blood haemoglobin, cognitive abilities, performance at school, or survival. To achieve health gains in the longer term, improvements in

and hygiene behaviours are also required, together with deworming treatments. The effect of mass deworming on school attendance is disputed. It has been argued that mass deworming has a positive effect on school attendance. The long-term benefits of deworming include a decrease in school absenteeism by 25 percent and an increase in adult earnings by 20 percent. A systematic review, however, found that there is little or no difference in attendance in children who receive mass deworming compared to children who did not. One study found that boys were enrolled in primary school for more years than boys who were in schools that did not offer such programs. Girls in the same study were about a quarter more likely to attend secondary school if they received treatment. Both groups went on to participate in more skilled sectors of the labor market. The economic growth generated from school programs such as this may balance out the actual expenses of the program. However, the results of this study are disputed (i.a. due to a high risk of bias in the study), and the positive long-term outcomes of mass deworming remain unclear.

Integration of treatment

Inclusion of NTDs into initiatives for

, and

, as well as integration of NTD treatment programs, may have advantages given the strong link between these diseases and NTDs. Some neglected tropical diseases share common vectors (sandflies, black flies, and mosquitos). Both medicinal and vector control efforts may be combined. A four-drug rapid-impact package has been proposed for widespread proliferation. Administration may be made more efficient by targeting multiple diseases at once, rather than separating treatment and adding work to community workers. This package is estimated to cost US$0.40 per patient. When compared to stand-alone treatment, the savings are estimated to be 26–47%. While more research must be done in order to understand how NTDs and other diseases interact in both the vector and the human stages, safety assessments have so far produced positive results. Many neglected tropical diseases and other prevalent diseases share common vectors, creating another opportunity for treatment and control integration. One such example of this is malaria and lymphatic filariasis. Both diseases are transmitted by the same or related mosquito vectors. Vector control, through the distribution of insecticide-treated nets, reduces human contact with a wide variety of disease vectors. Integrated vector control may also alleviate pressure on mass drug administration, especially with respect to rapidly evolving drug resistance. Combining vector control and mass drug administration deemphasizes both, making each less susceptible to resistance evolution.

Integration with WASH programs

Water, sanitation, and hygiene ( WASH) interventions are essential in preventing many NTDs, such as

. Mass drug administrations alone will not protect people from re-infection. A more holistic and integrated approach to NTDs and WASH efforts will benefit both sectors along with the communities they are aiming to serve. This is especially true in areas that are endemic with more than one NTD. In August 2015, the World Health Organization unveiled a global strategy and action plan to integrate WASH with other

public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...

interventions in order to accelerate the elimination of NTDs. The plan aims to intensify control or eliminate certain NTDs in specific regions by 2020 and refers to the NTD "roadmap" milestones from 2012 that include, for example, eradication of dracunculiasis by 2015 and of yaws by 2020, elimination of trachoma and lymphatic filariasis as public health problems by 2020, and intensified control of dengue, schistosomiasis, and soil-transmitted helminthiases.World Health Organization (WHO) (2015)
Water Sanitation and Hygiene for accelerating and sustaining progress on Neglected Tropical Diseases. A global strategy 2015–2020
. Geneva, Switzerland, p. 26 Closer collaboration between WASH and NTD programmes can lead to synergies. They can be achieved through collaborative planning, delivery, and evaluation of programmes, strengthening and sharing of evidence, and using monitoring tools to improve the equity of health services. Reasons why WASH plays an important role in NTD prevention and patient care include: * NTDs affect more than one billion people in 149 countries. They occur mainly in regions with a lack of basic sanitation. About 2.4 billion people worldwide do not have adequate sanitation facilities. 663 million do not have access to improved drinking water sources. * One leading cause of preventable blindness is trachoma. The bacterial infection is transmitted through contact with eye-seeking flies, fingers, and fomites. Prevention components are facial cleanliness, which requires water for face washing, and environmental improvement, which includes safe disposal of excreta to reduce fly populations. *

Improved sanitation Improved sanitation (related to but distinct from a " safely managed sanitation service") is a term used to categorize types of sanitation for monitoring purposes. It refers to the management of human feces at the household level. The term was co ...

prevents soil-transmitted helminthiases. It impedes fecal pathogens such as intestinal worm eggs from contaminating the environment and infecting people through contaminated food, water, dirty hands, and direct skin contact with the soil. *

and water management can contribute to reducing the proliferation of mosquitoes that transmit diseases, such as lymphatic filariasis, dengue, and

chikungunya Chikungunya is an infection caused by the ''Chikungunya virus'' (CHIKV). Symptoms include fever and joint pains. These typically occur two to twelve days after exposure. Other symptoms may include headache, muscle pain, joint swelling, and a r ...

. Breeding of the '' Culex'' mosquito which transmits filarial parasites is facilitated through poorly constructed latrines. Breeding of the ''

'' and '' Aedes albopictus'' mosquitoes which transmit dengue and chikungunya can be prevented through safe storage of water. *

Feces Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a rela ...

and

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...

that contain worm eggs can contaminate surface water and lead to transmission of schistosomiasis. This can be prevented through improved sanitation. Not only human but also animal (cow, buffalo) urine or feces can transmit some schistosome species. Therefore, it is important to protect freshwater from animals and animal waste. * Treatment of many NTDs require clean water and hygienic conditions for healthcare facilities and households. For

guinea worm ''Dracunculus medinensis'', or Guinea worm, is a nematode that causes dracunculiasis, also known as guinea worm disease. The disease is caused by the female which, at up to in length, is among the longest nematodes infecting humans. In contr ...

, or

, wound management is needed to speed up healing and reduce disability. Lymphatic filariasis causes chronic disabilities. People who have this disease need to maintain rigorous personal hygiene with water and soap to prevent secondary infections. * NTDs that lead to permanent

disabilities Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be cognitive, developmental, intellectual, mental, physical, ...

make tasks such as carrying water long distances or accessing toilets difficult. However, people affected by these diseases often face stigma and can be excluded from accessing water and sanitation facilities. This increases their risk of poverty and severe illness. Clean water and soap are essential for these groups to maintain personal hygiene and dignity. Therefore, additional efforts to reduce stigma and exclusion are needed. In this manner, WASH can improve the quality of life of people affected by NTDs. * In a

meta-analysis A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting m ...

, safe water was associated with significantly reduced odds of ''

'' infection, and adequate sanitation was associated with significantly lower odds of infection with both ''S. mansoni'' and '' S. haematobium''. * A systematic review and meta-analysis showed that better hygiene in children is associated with lower odds of trachoma. Access to sanitation was associated with 15 percent lower odds of active trachoma and 33 percent lower odds of '' C. trachomatis'' infection of the eyes. * Another systematic review and meta-analysis found a correlation between WASH access and practices and lower odds of

infections by 33 to 77 percent. Persons who washed their hands after defecating were less than half as likely to be infected as those who did not. Traditionally,

preventive chemotherapy Mass deworming, also called preventive chemotherapy, is the process of treating large numbers of people, particularly children, for helminthiasis (for example soil-transmitted helminths (STH)) and schistosomiasis in areas with a high prevalence of ...

is used as a measure of control, although this measure does not stop the transmission cycle and cannot prevent reinfection. In contrast, improved sanitation can.

Pharmaceutical market

Biotechnology Biotechnology is the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services. The term ''biotechnology'' was first used ...

companies in the developing world have targeted neglected tropical diseases due to a need to improve global health. Mass drug administration is considered a possible method for eradication, especially for lymphatic filariasis, onchocerciasis, and trachoma, although drug resistance is a potential problem. According to Fenwick,

Pfizer Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfize ...

donated 70 million doses of drugs in 2011 to eliminate trachoma through the International Trachoma Initiative. Merck has helped The African Programme for the Control of Onchocerciasis (APOC) and Oncho Elimination Programme for the Americas to greatly diminish the effect of onchocerciasis by donating ivermectin. Merck KGaA pledged to give 200 million tablets of praziquantel over 10 years, the only cure for schistosomiasis. GlaxoSmithKline has donated two billion tablets of medicine for lymphatic filariasis and pledged 400 million deworming tablets per year for five years in 2010. Johnson & Johnson has pledged 200 million deworming tablets per year.

Novartis Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-lo ...

has pledged leprosy treatment, and EISAI pledged two billion tablets to help treat lymphatic filariasis.

NGO initiatives

Non-governmental organizations that focus exclusively on NTDs include the

Schistosomiasis Control Initiative The SCI Foundation (SCI), or the Schistosomiasis Control Initiative, is a non-profit initiative that works with governments in sub-Saharan African countries to develop sustainable programmes against parasitic worm infections (schistosomiasis and ...

Deworm the World The Deworm the World Initiative is a program led by a nonprofit Evidence Action that works to support governments in developing school-based deworming programs in Kenya, India, Ethiopia, and Vietnam. Deworm the World works with the Schistosomias ...

, and the END Fund. Despite under-funding, many neglected diseases are cost-effective to treat and prevent. The cost of treating a child for infection of soil-transmitted helminths and schistosomes (some of the main causes of neglected diseases) is less than US$0.50 per year when administered as part of school-based mass deworming by Deworm the World. This programme is recommended by Giving What We Can and the Copenhagen Consensus Centre as one of the most efficient and cost-effective solutions. The efforts of the Schistosomiasis Control Initiative to combat neglected diseases include the use of rapid-impact packages: supplying schools with packages including four or five drugs, and training teachers in how to administer them.

Health Action International Health Action International (HAI) is a non-profit organization based in The Netherlands. Established in 1981, HAI works to expand access to essential medicines through research, policy analysis and intervention projects. The organization focus ...

based in Amsterdam worked with the WHO to get snakebite envenoming on the list of neglected tropical diseases.

Public-private initiatives

An alternative to the profit-driven drug development model emerged in 2000 to address the needs of these neglected patients. Product development partnerships (PDPs) aim at implementing and accelerating the research and development (R&D) of safe and effective health tools (diagnostics, vaccines, drugs) to combat neglected diseases. Drugs for Neglected Disease initiative (DNDi) is one of these PDPs that has already developed new treatments for NTDs. The

Sabin Vaccine Institute Sabin Vaccine Institute (Sabin), located in Washington, D.C., is a nonprofit organization promoting global vaccine development, availability, and use. Through its work, Sabin hopes to reduce human suffering by preventing the spread of vaccine-pre ...

, founded in 1993, works to address the issues of vaccine-preventable diseases as well as NTDs. They run three main programs: Sabin Vaccine Development,

Global Network for Neglected Tropical Diseases The Global Network for Neglected Tropical Diseases is an advocacy initiative of the Sabin Vaccine Institute dedicated to raising the awareness, political will, and funding necessary to control and eliminate the most common Neglected Tropical Disea ...

, and Vaccine Advocacy and Education. Their product development partnership affiliates them with the Texas Children's Hospital as well as the

Baylor College of Medicine Baylor College of Medicine (BCM) is a medical school and research center in Houston, Texas, within the Texas Medical Center, the world's largest medical center. BCM is composed of four academic components: the School of Medicine, the Graduate S ...

. Their major campaign, End7, aims to end seven of the most common NTDs (

, river blindness,

snail fever Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody st ...

, trachoma, roundworm, whipworm, and hookworm) by 2020. Through End7, college campuses undertake fundraising and educational initiatives for the broader goals of the campaign. WIPO Re:Search was established in 2011 by the World Intellectual Property Organization in collaboration with BIO Ventures for Global Health (BVGH) and with the active participation of leading pharmaceutical companies and other private and public sector research organizations. It allows organizations to share their intellectual property, compounds, expertise, facilities, and know-how royalty-free with qualified researchers worldwide working on new solutions for NTDs, malaria, and tuberculosis. In 2013, the Government of Japan, five Japanese pharmaceutical companies, the Bill and Melinda Gates Foundation, and the UNDP established a new public–private partnership, the

Global Health Innovative Technology Fund The Global Health Innovative Technology Fund (GHIT Fund), headquartered in Japan, is an international public-private partnership between the Government of Japan (Ministry of Foreign Affairs and Ministry of Health, Labour and Welfare), 16 pharmaceu ...

. They pledged over US$100 million to the fund over five years, to be awarded as grants to R&D partnerships across sectors in Japan and elsewhere, working to develop new drugs and vaccines for 17 neglected diseases, in addition to HIV, malaria, and tuberculosis."Japan in pioneering partnership to fund global health research", by Andrew Jack, ''Financial Times'', 30 May 2013 Affordability of the resulting drugs and vaccines is one of the key criteria for grant awards.

Others

An open-access journal dedicated to neglected tropical diseases called '' PLoS Neglected Tropical Diseases'' first began publication in 2007. One of the first large-scale initiatives to address NTDs came from a collaboration between Kenneth Warren and the Rockefeller Foundation. Ken Warren is regarded as a pioneer in neglected tropical disease research. The Great Neglected Tropical Diseases Network was a consortium of scientists from all over the world, hand-picked by Warren, working to expand the research base in neglected diseases. Many of the scientists that he recruited had not been involved in NTD research before. The network ran from 1978 to 1988. Warren's vision was to establish units within biological labs across the world, dedicated to R&D. By forming a critical mass of scientists in NTD research, he hoped to attract new students into the field. The interdisciplinary group met annually to update the community on research progress. Much of the work done by this group focused on understanding the mechanisms behind the infection. At these informally structured meetings, research partnerships were formed. Warren himself encouraged these partnerships, especially if they bridged the divide between developed and developing nations. Through the Great Neglected Tropical Disease Network, a great number of scientists were brought into the field of

parasitology Parasitology is the study of parasites, their host (biology), hosts, and the relationship between them. As a List of biology disciplines, biological discipline, the scope of parasitology is not determined by the organism or environment in questio ...

Epidemiology

The distribution of neglected tropical disease disproportionally affects about one billion of the world's poorest populations, causing mortality, disability, and morbidity. Lack of funding, resources, and attention can result in treatable and preventable diseases causing death. Factors like political dynamics, poverty, and geographical conditions can make the delivery of NTD control programs difficult. Intersectional collaboration of poverty reduction policies and neglected tropical diseases creates cross-sector approaches to simultaneously address these issues. The six most common NTDs include

soil-transmitted helminths The soil-transmitted helminths (also called geohelminths) are a group of intestinal parasites belonging to the phylum Nematoda that are transmitted primarily through contaminated soil. They are so called because they have a direct life cycle whic ...

(STHs)—specifically roundworms (''Ascaris lumbricoides''), whipworm (''Trichuris trichiura''), and hookworms (''Necator americanus'' and ''Ancylostoma duodenale'')—schistosomiasis, trachoma, and lymphatic filariasis (LF). These diseases affect one-sixth of the world's population, with 90 percent of the disease burden occurring in sub-Saharan Africa. Information on the frequency of neglected tropical diseases is of low quality. It is currently difficult to summarize all of the information on this family of diseases. One effort to do so is the Global Burden of Disease framework. It aims to create a standardized method of measurement. The principle components of the approach involve 1) the measuring of premature mortality as well as disability, 2) the standardized usage of DALYs (

s), and 3) widespread inclusion of diseases and injury causes with the estimation of missing data. However, the DALY has been criticized as a "systematic undervaluation" of disease burden. King asserts that DALY emphasizes the individual too much while ignoring the effects of the ecology of the disease. In order for the measure to become more valid, it may have to take the context of poverty more into account. King also emphasizes that DALYs may not capture the non-linear effects of poverty on the cost-utility analysis of disease control. The Socio-Demographic Index (SDI) and Healthy Life Expectancy (HALE) are other summary measures that can be used to take into account other factors. HALE is a metric that weights years lived and health loss before death to provide a summary of population health. SDI is a measurement that includes lag-distributed income per capita, average education, and fertility rate. Socioeconomic factors greatly influence the distribution of neglected tropical diseases, and not addressing these factors in models and measurements can lead to ineffective public health policy.

Research and development

NTD interventions include programs to address environmental and social determinants of health (e.g., vector control, water quality, sanitation) as well as programs offering mass drug administration for disease prevention and treatment. Drug treatments existReddy M, Gill SS, Kalkar SR, Wu W, Anderson PJ, Rochon PA. Oral drug therapy for multiple neglected tropical diseases: a systematic review. ''JAMA'' 2007 Oct 24;298(16):1911-1924. to confront many of the NTDs and represent some of the world's essential medicines.Trouiller P, Olliaro P, Torreele E, Orbinski J, Laing R, Ford N. Drug development for neglected diseases: a deficient market and a public-health policy failure. ''Lancet'' 2002 Jun 22;359(9324):2188-2194.Cohen J, Dibner MS, Wilson A. Development of and access to products for neglected diseases. ''PLoS One'' 2010 May 12;5(5):e10610. Despite significant health and economic improvements using available medicines,Conteh L, Engels T, Molyneux DH. Socioeconomic aspects of neglected tropical diseases. ''Lancet'' 2010 Jan 16;375(9710):239-247.Chu BK, Hooper PJ, Bradley MH, McFarland DA, Ottesen EA. The economic benefits resulting from the first 8 years of the Global Programme to Eliminate Lymphatic Filariasis (2000–2007). PLoS Negl Trop Dis. 2010 Jun 1;4(6):e708.Merck Mectizan Drug Donation Program http://www.mectizan.org/Villa S, Compagni A, Reich MR. Orphan drug legislation: lessons for neglected tropical diseases. ''Int J Health Plann Manage'' 2009 Jan-Mar;24(1):27-42. the low number of new compounds being researched and developed for NTDs is an ongoing and significant challenge.Chirac P, Torreele E. Global framework on essential health R&D. Lancet. 2006 May 13;367(9522):1560-1. The dearth of candidates in the pharmaceutical company drug pipelines is primarily attributed to the high costs of drug development and the fact that NTDs are concentrated among the world's poor.Trouiller P, Torreele E, Olliaro P, White N, Foster S, Wirth D, et al. Drugs for neglected diseases: a failure of the market and a public health failure? ''Trop Med Int Health'' 2001 Nov;6(11):945-951. Other disincentives to investment include weak existing infrastructure for distribution and sales as well as concerns regarding intellectual property protection. However, the major stakeholders in NTD drug development—governments, foundations, pharmaceutical companies, academia, and NGOs—are involved in activities to help address the research and development shortfall and meet the many challenges presented by neglected tropical diseases.Liese B, Rosenberg M, Schratz A. Programmes, partnerships, and governance for elimination and control of neglected tropical diseases. ''Lancet'' 2010 Jan 2;375(9708):67-76. Initiatives include public-private partnerships, global R&D capacity building, priority vouchers to speed drug approval processes, open source scientific collaborations, and harmonization of global governance structures concerning NTDs. The diseases considered neglected tropical diseases vary. Some researchers no longer consider

, HIV, and

to be neglected due to the amount of public attention and increased funding they have received. Outside "The Big Three", the seven most prevalent neglected tropical diseases in order of their global prevalence are ascariasis,

, hookworm infection, schistosomiasis, lymphatic filariasis, and trachoma. These seven are among a larger list of thirteen major NTDs: onchocerciasis, leishmaniasis, Chagas disease,

(sleeping sickness), dracunculiasis, and

Deficient market

In their 2002 review of the U.S.

(FDA) databases and the European Agency for the Evaluation of Medicinal Products, Troullier ''et al'' found that 16 out of 1393 new chemical entities were approved for NTDs between 1975 and 1999 (~1%). Cohen ''et al'' revisited the data and using the same methodology found 32 new chemical entities during the time period. In a second analysis using an expanded list of NTDs based on the G-FINDER survey,G-FINDER Database http://www.georgeinstitute.org/about-us/media-centre/g-finder-database-open-public the number was slightly higher, with 46 new drugs and vaccines approved (~3% of the total including HIV drugs). Between 2000 and 2009, there has been some increase with an additional 26 newly approved drugs and vaccines for NTDs. A number of factors are recognized as contributing to the low number. The barrier most reported is the high cost of drug development. Estimates are that pharmaceutical companies' development costs to approval fall between $500 million and $2 billion.Adams CP, Brantner VV. Estimating the cost of new drug development: is it really 802 million dollars? Health Aff (Millwood). 2006 Mar-Apr;25(2):420-8. DiMasi, Hansen, and Grabowski calculated an average of $802 million in the year 2000 dollars.DiMasi JA, Hansen RW, Grabowski HG. The price of innovation: new estimates of drug development costs. J Health Econ. 2003 Mar;22(2):151-85. Furthermore, the time that drugs are approved for use averages seven years out of the twenty years on patent, meaning a tendency for the market to focus on diseases of developed nations where high prices can be used to recoup research and development costs, and subsidize failed R&D efforts. In short, NTD research and development is considered a high investment risk is given that NTDs predominantly affect the poor in low- and middle-income countries.Bethony JM, Cole RN, Guo X, Kamhawi S, Lightowlers MW, Loukas A, et al. Vaccines to combat the neglected tropical diseases. ''Immunol Rev'' 2011 Jan;239(1):237-270. Additional barriers include drug safety regulatory requirements, intellectual property protection problems, and poor infrastructure for distribution and sales. Although drug companies have not invested heavily in NTDs, in several cases, rather than focus on profits, some have decided to donate key drugs to address NTDs. For example, Merck has had a program since the mid-1980s to donate ivermectin (Mectizan) indefinitely to support the global fight against onchocerciasis. GlaxoSmithKline and several other large pharmaceutical companies have donation programs as well. Drug donation, however, does not ameliorate the deficiency of new chemical entities being researched and developed. This is especially of concern with reports of emerging resistance among existing drugs.Tchuem Tchuente LA. Control of soil-transmitted helminths in sub-Saharan Africa: Diagnosis, drug efficacy concerns and challenges. ''Acta Trop'' 2010 Jul 21.Smits HL. Prospects for the control of neglected tropical diseases by mass drug administration. ''Expert Rev Anti Infect Ther'' 2009 Feb;7(1):37-56.

Policy initiatives

Public-private partnerships

Governments, foundations, the non-profit sector, and the private sector have found new connections to help address market deficiencies by providing funding support and spreading both the costs and risks of NTD research and development. The proliferation of public–private partnerships (PPPs) has been recognized as a key innovation in the past decade, helping to unlock existing and new resources. Major PPPs for NTDs include: the

, Norvartis Vaccines Institute for Global Health, MSD Wellcome Trust

Hilleman Laboratories Hilleman Laboratories is a Delhi-based vaccine research organization. The firm is an equal-joint venture between US drug maker Merck & Co Inc and British charitable foundation Wellcome Trust. The research firm is named in the honour of Dr. Ma ...

, Infectious Diseases Research Institute,

Institut Pasteur The Pasteur Institute (french: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccine ...

and INSERM, WIPO Re:Search, and the

International Vaccine Institute The International Vaccine Institute (IVI) is an independent, nonprofit, international organization founded on the belief that the health of children in developing countries can be dramatically improved by the use of new and improved vaccines. Work ...

. Likewise, a number of new academic drug development centers have been created in recent years drawing in industry partners. Support for these centers is frequently traced to the

, the Sandler Foundation, and the Wellcome Trust.Renslo AR, McKerrow JH. Drug discovery and development for neglected parasitic diseases. ''Nat Chem Biol'' 2006 Dec;2(12):701-710.

R&D capacity building in middle-income countries

Growing NTD research and development capacity in middle-income countries is an area of policy interest. A 2009 study of biotechnology companies in India, China, Brazil, and South Africa revealed 62 NTD products in development and on the market out of approximately 500 products offered (~14%). When products to fight HIV, malaria, and TB were included in the analysis, the number increased to 123 products, approximately 25% of the total products offered. Researchers have argued that, unlike most multinationals, small and mid-sized "Global South" companies see significant business opportunities in the development of NTD-related diagnostics, biologics, pharmaceuticals, and services.Frew SE, Liu VY, Singer PA. A business plan to help the 'global South' in its fight against neglected diseases. ''Health Aff'' (Millwood) 2009 Nov-Dec;28(6):1760-1773. Potential actions to improve and expand this R&D capacity have been recommended, including expansion of human capital, increased private investment, knowledge and patent sharing, infrastructure building for business incubation, and innovation support.

Innovation prizes and grants

Competitive innovation prizes have been used to spur development in a range of fields such as aerospace engineering, clean technology, and genomics. The X-Prize Foundation is launching a competition for high-speed, point-of-care diagnostics for tuberculosis. A more widely defined annual "Global Health EnterPrize" for neglected tropical diseases has been proposed to reward health innovators, particularly those based in countries where NTDs represent a serious health burden. The Bill & Melinda Gates Foundation offers the Grand Challenges Explorations Opportunities on a rolling basis. This grant program allows individuals from any organization or background to apply to address priority global health issues. Each project award is $100,000 dollars and is drawn from a Foundation funding pool of $100 million. Awardees have tended to offer research projects on topics that are highly speculative but offer potentially game-changing breakthroughs in global health.

FDA priority review vouchers (PRV)

In 2006, Ridley ''et al'' recommended the development of a

(PRV) in the journal '' Health Affairs''. It gained interest from Senator Sam Brownback of Kansas, who championed its introduction in the FDA Amendments Act of 2007. Under the enacted law, FDA approval of a non-NTD drug can be accelerated through the drug review process if paired with a drug that addresses an NTD. The potential economic benefit to a pharmaceutical company is estimated to be potentially as high as $300 million per drug. Three drugs have earned NTD PRVs to date (December 2014):

(by Novartis, for malaria); bedaquiline (by Janssen, for TB); and

miltefosine Miltefosine, sold under the trade name Impavido among others, is a medication mainly used to treat leishmaniasis and free-living amoeba infections such as ''Naegleria fowleri'' and ''Balamuthia mandrillaris''. This includes the three forms of le ...

(by Knight, for leishmaniasis). However, the success of the PRV system is now under much scrutiny, given that Knight benefitted by $125 million from the sale of a PRV earned from a drug (miltefosine) that was largely researched and developed by the WHO. Médecins Sans Frontières are now pressuring Knight to guarantee to supply miltefosine at cost price, thus far without success. The PRV isn't limited to the pairing of drugs within a single company as it can be transferred between companies. Companies with NTD drug candidates in their pipelines but without a blockbuster drug are able to sell their vouchers, producing financial returns. In the EU, similar priority review incentives are now under consideration to increase the speed of regulatory pricing and reimbursement decisions. However, PRVs have been criticized as being open to manipulation and possibly encouraging errors through too rapid regulatory decision-making.Kesselheim AS. Drug development for neglected diseases – the trouble with FDA review vouchers. ''N Engl J Med'' 2008 Nov 6;359(19):1981-1983.

Open source collaboration initiatives

Several companies and scientific organizations are participating in open-source initiatives to share drug data and patent information over the web, and facilitate virtual collaboration on NTD research. One rich area to explore is the wealth of genomic data resulting from the sequencing of parasite genomes. These data offer opportunities for the exploration of new therapeutic products using computational and

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized so ...

collaboration methods for drug discovery.Kar S. Opinion: Open innovation: an answer for neglected diseases. ''Future Med Chem'' 2010 Sep;2(9):1411-5.Ortí L, Carbajo RJ, Pieper U, Eswar N, Maurer SM, Rai AK, Taylor G, Todd MH, Pineda-Lucena A, Sali A, Marti-Renom MA. A kernel for open source drug discovery in tropical diseases. ''PLoS Negl Trop Dis'' 2009;3(4):e418. The Tropical Disease Initiative, for example, has used large amounts of computing power to generate the protein structures for ten parasite genomes. An open-source drug bank was matched algorithmically to determine compounds with protein interaction activity, and two candidates were identified. In general, such methods may hold important opportunities for off-label use of existing approved drugs.

History

In 1977,

Kenneth S. Warren Kenneth S. Warren (June 11, 1929 – September 18, 1996) was an American scientist, physician, educator and public health advocate. He was an expert on tropical disease, in particular schistosomiasis. Warren was born in Brooklyn, New York City ...

, an American researcher, invented the concept of what is now "neglected tropical diseases".

References

External links

WHO – Control of neglected tropical disease

''PLOS Neglected Tropical Diseases''

United Nations World Health Organization

India’s neglected tropical diseases

Neglected tropical disease targets must include morbidity

Global health policy and neglected tropical diseases: Then, now, and in the years to come
{{Portal bar, Medicine Human diseases and disorders Infectious diseases Tropical diseases Sanitation

Reasons for neglect

Stigma

Economic incentives

Developed nations

List of diseases

Buruli ulcer

Chagas disease

Dengue and chikungunya

Dracunculiasis

Echinococcosis

Yaws

Foodborne trematodiases

Human African trypanosomiasis

Leishmaniasis

Leprosy

Lymphatic filariasis

Onchocerciasis

Rabies

Schistosomiasis

Soil-transmitted helminthiasis

Taeniasis/cysticercosis

Trachoma

Chromoblastomycosis and other deep mycoses

Scabies

Snakebite envenoming

Effects for patients

Social effects

Social stigma

Mental health

Gender

Economic effects

Health effects

Coinfection

Prevention, treatment and eradication

Policy initiatives

WHO Roadmap of 2012

Others

Deworming treatment

Integration of treatment

Integration with WASH programs

Pharmaceutical market

NGO initiatives

Public-private initiatives

Others

Epidemiology

Research and development

Deficient market

Policy initiatives

Public-private partnerships

R&D capacity building in middle-income countries

Innovation prizes and grants

FDA priority review vouchers (PRV)

Open source collaboration initiatives

History

See also

References

External links