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Middle East respiratory syndrome (MERS) is a viral
respiratory infection Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...
caused by ''
Middle East respiratory syndrome–related coronavirus ''Middle East respiratory syndrome–related coronavirus'' (''MERS-CoV''), or EMC/2012 ( HCoV-EMC/2012), is the virus that causes Middle East respiratory syndrome (MERS). It is a species of coronavirus which infects humans, bats, and camels. Th ...
'' (MERS-CoV). Symptoms may range from none, to mild, to severe. Typical symptoms include
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 ...
,
cough A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ph ...
,
diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
, and
shortness of breath Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...
. The disease is typically more severe in those with other health problems. The first case was identified in June 2012 by Egyptian physician Ali Mohamed Zaki at the Dr. Soliman Fakeeh Hospital in
Jeddah Jeddah ( ), also spelled Jedda, Jiddah or Jidda ( ; ar, , Jidda, ), is a city in the Hejaz region of the Kingdom of Saudi Arabia (KSA) and the country's commercial center. Established in the 6th century BC as a fishing village, Jeddah's pro ...
, Saudi Arabia, and most cases have occurred in the
Arabian Peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plat ...
. Over 2,500 cases have been reported as of January 2021, including 45 cases in the year 2020. About 35% of those who are diagnosed with the disease die from it. Larger outbreaks have occurred in South Korea in 2015 and in Saudi Arabia in 2018. MERS-CoV is a
coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...
believed to be originally from bats. However, humans are typically infected from
camels A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. ...
, either during direct contact or indirectly. Spread between humans typically requires close contact with an infected person. Its spread is uncommon outside of hospitals. Thus, its risk to the global population is currently deemed to be fairly low. Diagnosis is by rRT-PCR testing of blood and respiratory samples. , there is no specific
vaccine A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.
or treatment for the disease, but a number are being developed. 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) recommends that those who come in contact with camels wash their hands and not touch sick camels. They also recommend that camel-based food products be appropriately cooked. Treatments that help with the symptoms and support body functioning may be used. Previous infection with MERS can confer cross-reactive immunity to
SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
and provide partial protection against
COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quick ...
. However,
co-infection 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 hepatiti ...
with
SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
and MERS is possible and could lead to a recombination event.


Signs and symptoms

Early reports compared the
viruses 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 Ivanovsky's ...
to
severe acute respiratory syndrome Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''sev ...
(
SARS Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''seve ...
), and it has been referred to as Saudi Arabia's SARS-like virus. The first person, in June 2012, had a
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 ...
,
cough A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ph ...
,
expectoration Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). In medicine, sputum samples are usually used for a naked eye examination, microbiological investigation of respiratory infections and cytological investigatio ...
, and shortness of breath. One review of 47 laboratory confirmed cases in Saudi Arabia gave the most common presenting symptoms as fever in 98%, cough in 83%, shortness of breath in 72% and
myalgia Myalgia (also called muscle pain and muscle ache in layman's terms) is the medical term for muscle pain. Myalgia is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another li ...
in 32% of people. There were also frequent gastrointestinal symptoms with diarrhea in 26%, vomiting in 21%, abdominal pain in 17% of people. 72% of people required
mechanical ventilation Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move a ...
. There were also 3.3 males for every female. One study of a hospital-based outbreak of MERS had an estimated
incubation period Incubation period (also known as the latent period or latency period) is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the in ...
of 5.5 days (95%
confidence interval In frequentist statistics, a confidence interval (CI) is a range of estimates for an unknown parameter. A confidence interval is computed at a designated ''confidence level''; the 95% confidence level is most common, but other levels, such as 9 ...
1.9 to 14.7 days). MERS can range from asymptomatic disease to severe
pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severit ...
leading to
acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...
(ARDS).
Kidney 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 ...
,
disseminated intravascular coagulation Disseminated intravascular coagulation (DIC) is a condition in which blood clots form throughout the body, blocking small blood vessels. Symptoms may include chest pain, shortness of breath, leg pain, problems speaking, or problems moving parts ...
(DIC), and
pericarditis Pericarditis is inflammation of the pericardium, the fibrous sac surrounding the heart. Symptoms typically include sudden onset of sharp chest pain, which may also be felt in the shoulders, neck, or back. The pain is typically less severe when sit ...
have also been reported.


Cause


Virology

Middle East respiratory syndrome is caused by the MERS coronavirus (MERS-CoV), a species with single-stranded RNA belonging to the genus
betacoronavirus ''Betacoronavirus'' (β-CoVs or Beta-CoVs) is one of four genera (''Alpha''-, ''Beta-'', '' Gamma-'', and '' Delta-'') of coronaviruses. Member viruses are enveloped, positive-strand RNA viruses that infect mammals (of which humans are part). ...
which is distinct from SARS coronavirus and the common-cold coronavirus. Its genomes are phylogenetically classified into two
clades A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English te ...
, Clades A and B. Early cases of MERS were of Clade A clusters (EMC/2012 and Jordan-N3/2012) while new cases are genetically different in general (Clade B). The virus grows readily on Vero cells and LLC-MK2 cells. In November 2012, Egyptian virologist Dr. Ali Zaki sent a virus sample from the first confirmed case in Saudi Arabia to virologist
Ron Fouchier Ronaldus (Ron) Adrianus Maria Fouchier (born 13 October 1966) is a Dutch virologist who is Deputy head of the Erasmus MC Department of Viroscience, headed by Prof. Marion Koopmans. Notability Fouchier is notable for his research on respiratory vi ...
, a leading coronavirus researcher at the
Erasmus Medical Center Erasmus University Medical Center (Erasmus MC or EMC) based in Rotterdam, Netherlands, affiliated with Erasmus University and home to its faculty of medicine, is the largest and one of the most authoritative scientific University Medical Centers in ...
(EMC) in
Rotterdam Rotterdam ( , , , lit. ''The Dam on the River Rotte (river), Rotte'') is the second largest List of cities in the Netherlands by province, city and List of municipalities of the Netherlands, municipality in the Netherlands. It is in the Prov ...
, the Netherlands. The second laboratory-proven case was in London, confirmed by the UK
Health Protection Agency The Health Protection Agency (HPA) was a non-departmental public body in the United Kingdom. It was an organisation that was set up by the UK government in 2003 to protect the public from threats to their health from infectious diseases and envi ...
(HPA). The HPA named the virus the London1_novel CoV 2012.


Transmission


Camels

A study performed between 2010 and 2013, in which the incidence of MERS was evaluated in 310 dromedary camels, revealed high titers of neutralizing antibodies to MERS-CoV in the blood serum of these animals. A further study sequenced MERS-CoV from nasal swabs of
dromedary The dromedary (''Camelus dromedarius'' or ;), also known as the dromedary camel, Arabian camel, or one-humped camel, is a large even-toed ungulate, of the genus '' Camelus'', with one hump on its back. It is the tallest of the three species o ...
camels in Saudi Arabia and found they had sequences identical to previously sequenced human isolates. Some individual camels were also found to have more than one genomic variant in their
nasopharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
. There is also a report of a Saudi Arabian man who became ill seven days after applying topical medicine to the noses of several sick camels and later he and one of the camels were found to have identical strains of MERS-CoV. It is still unclear how the virus is transmitted from camels to humans. The World Health Organization advises avoiding contact with camels and to eat only fully cooked camel meat, pasteurized camel milk, and to avoid drinking
camel urine Camel urine is a liquid by-product of metabolism in a camel's anatomy. Urine from Arabian camels has been used in the Arabian Peninsula as prophetic medicine for centuries, being a part of ancient Bedouin practices. After the spread of MERS-CoV ...
. The Saudi Ministry of Agriculture has advised people to avoid contact with camels or wear breathing masks when around them. In response "some people have refused to listen to the government's advice" and kiss their camels in defiance of their government's advice.


Between people

There has been evidence of limited, but not sustained spread of MERS-CoV from person to person, both in households as well as in health care settings like hospitals. Most transmission has occurred "in the circumstances of close contact with severely ill persons in healthcare or household settings" and there is no evidence of transmission from asymptomatic cases. Cluster sizes have ranged from 1 to 26 people, with an average of 2.7.


Diagnosis

According to
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 ...
, the interim case definition is that a confirmed case is identified in a person with a positive lab test by "molecular diagnostics including either a positive PCR on at least two specific genomic targets or a single positive target with sequencing on a second".


World Health Organization

According to the WHO, a probable case is * a person with a fever, respiratory infection, and evidence of pneumonia or acute respiratory distress syndrome, where testing for MERS-CoV is unavailable or negative on a single inadequate specimen, and the person has a direct link with a confirmed case. * A person with an acute febrile respiratory illness with clinical,
radiological In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visib ...
, or histopathological evidence of pulmonary parenchymal disease (e.g., pneumonia or acute respiratory distress Syndrome), an inconclusive MERS-CoV laboratory test (that is, a positive
screening test Screening, in medicine, is a strategy used to look for as-yet-unrecognised conditions or risk markers. This testing can be applied to individuals or to a whole population. The people tested may not exhibit any signs or symptoms of a disease, or t ...
without confirmation), and a resident of or traveler to Middle Eastern countries where MERS-CoV virus is believed to be circulating in the 14 days before onset of illness. * A person with an acute febrile respiratory illness of any severity, an inconclusive MERS-CoV laboratory test (that is, a positive screening test without confirmation), and a direct epidemiologic link with a confirmed MERS-CoV case.


Centers for Disease Control

In the United States, the
Centers for Disease Control and Prevention 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 ...
(CDC) recommend investigating any person with: * Fever and pneumonia or acute respiratory distress syndrome (based on clinical or radiological evidence) and either: ** a history of travel from countries in or near the Arabian Peninsula within 14 days before symptom onset, or ** close contact with a symptomatic traveler who developed fever and acute respiratory illness (not necessarily pneumonia) within 14 days after traveling from countries in or near the Arabian Peninsula or ** a member of a cluster of people with severe acute respiratory illness (e.g. fever and pneumonia requiring hospitalization) of unknown cause in which MERS-CoV is being evaluated, in consultation with state and local health departments. * Fever and symptoms of respiratory illness (not necessarily pneumonia; e.g., cough, shortness of breath) and being in a healthcare facility (as a patient, worker, or visitor) within 14 days before symptom onset in a country or territory in or near the Arabian Peninsula in which recent healthcare-associated cases of MERS have been identified. * Fever or symptoms of respiratory illness (not necessarily pneumonia; e.g., cough, shortness of breath) and close contact with a confirmed MERS case while the case was ill.


Medical imaging

Chest X-ray A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in me ...
findings tend to show bilateral patchy infiltrates consistent with viral pneumonitis and
acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...
(ARDS). Lower lobes tend to be more involved. CT scans show
interstitial An interstitial space or interstice is a space between structures or objects. In particular, interstitial may refer to: Biology * Interstitial cell tumor * Interstitial cell, any cell that lies between other cells * Interstitial collagenase ...
infiltrates.


Laboratory testing

MERS cases have been reported to have low white blood cell count, and in particular low lymphocytes. For PCR testing, 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) recommends obtaining samples from the lower respiratory tract via
bronchoalveolar lavage Bronchoalveolar lavage (BAL) (also known as bronchoalveolar washing) is a diagnostic method of the lower respiratory system in which a bronchoscope is passed through the mouth or nose into an appropriate airway in the lungs, with a measured amoun ...
(BAL),
sputum Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). In medicine, sputum samples are usually used for a naked eye examination, microbiological investigation of respiratory infections and cytological investigatio ...
sample or
trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...
l aspirate as these have the highest viral loads. There have also been studies utilizing upper respiratory sampling via
nasopharyngeal swab A nasopharyngeal swab is a device used for collecting a sample of nasal secretions from the back of the nose and throat. The sample is then analyzed for the presence of organisms or other clinical markers for disease. This diagnostic method is c ...
. Several highly sensitive, confirmatory real-time
RT-PCR Reverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA (in this context called complementary DNA or cDNA) and amplification of specific DNA targets using polymerase chai ...
assays exist for rapid identification of MERS-CoV from patient-derived samples. These assays attempt to amplify upE (targets elements upstream of the E gene), open reading frame 1B (targets the ORF1b gene) and open reading frame 1A (targets the ORF1a gene). The WHO recommends the upE target for screening assays as it is highly sensitive. In addition, hemi-nested sequencing amplicons targeting RdRp (present in all
coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...
es) and nucleocapsid (N) gene (specific to MERS-CoV) fragments can be generated for confirmation via sequencing. Reports of potential polymorphisms in the N gene between isolates highlight the necessity for sequence-based characterization. The WHO recommended testing algorithm is to start with an upE RT-PCR and if positive confirm with ORF 1A assay or RdRp or N gene sequence assay for confirmation. If both an upE and secondary assay are positive it is considered a confirmed case. Protocols for biologically safe
immunofluorescence Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to spe ...
assays (IFA) have also been developed; however, antibodies against
betacoronaviruses ''Betacoronavirus'' (β-CoVs or Beta-CoVs) is one of four genera (''Alpha''-, ''Beta-'', '' Gamma-'', and '' Delta-'') of coronaviruses. Member viruses are enveloped, positive-strand RNA viruses that infect mammals (of which humans are part). ...
are known to cross-react within the genus. This effectively limits their use to confirmatory applications. A more specific protein-microarray based assay has also been developed that did not show any cross-reactivity against population samples and serum known to be positive for other betacoronaviruses. Due to the limited validation done so far with serological assays, WHO guidance is that "cases where the testing laboratory has reported positive serological test results in the absence of PCR testing or sequencing, are considered probable cases of MERS-CoV infection, if they meet the other conditions of that case definition."


Prevention

While the mechanism of spread of MERS-CoV is currently not known, based on experience with prior coronaviruses, such as SARS, the WHO currently recommends that all individuals coming into contact with MERS suspects should (in addition to standard precautions): * Wear a medical mask * Wear eye protection (i.e. goggles or a face shield) * Wear a clean, non sterile, long sleeved gown; and gloves (some procedures may require sterile gloves) * Perform hand hygiene before and after contact with the person and his or her surroundings and immediately after removal of
personal protective equipment Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, ...
(PPE) For procedures which carry a risk of aerosolization, such as intubation, the WHO recommends that care providers also: * Wear a particulate respirator and, when putting on a disposable particulate respirator, always check the seal * Wear eye protection (i.e. goggles or a face shield) * Wear a clean, non-sterile, long-sleeved gown and gloves (some of these procedures require sterile gloves) * Wear an impermeable apron for some procedures with expected high fluid volumes that might penetrate the gown * Perform procedures in an adequately ventilated room; i.e. minimum of 6 to 12 air changes per hour in facilities with a mechanically ventilated room and at least 60 liters/second/patient in facilities with natural ventilation * Limit the number of persons present in the room to the absolute minimum required for the person's care and support * Perform hand hygiene before and after contact with the person and his or her surroundings and after PPE removal. The duration of infectivity is also unknown so it is unclear how long people must be isolated, but current recommendations are for 24 hours after resolution of symptoms. In the SARS outbreak the virus was not cultured from people after the resolution of their symptoms. It is believed that the existing
SARS Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''seve ...
research may provide a useful template for developing vaccines and therapeutics against a MERS-CoV infection. As of March 2020 there was one ( DNA based) MERS vaccine which completed
phase I clinical trials The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases ...
in humans, and three others in progress all of which are viral vectored vaccines, two adenoviral vectored (
ChAdOx1 ChAdOx1 is an adenoviral vector for vaccines that was developed by the Jenner Institute, University of Oxford. The vector is a chimpanzee adenovirus modified to avoid its replication. Adenoviruses are effective vectors for inducing and boosting ...
-MERS, BVRS-GamVac) and one MVA vectored (MVA-MERS-S).


Treatment

As of 2020, there is no specific
vaccine A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.
or treatment for the disease. Using extra-corporeal membrane oxygenation (ECMO) seems to improve outcomes significantly. Neither the combination of antivirals and
interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten th ...
s (
ribavirin Ribavirin, also known as tribavirin, is an antiviral medication used to treat RSV infection, hepatitis C and some viral hemorrhagic fevers. For hepatitis C, it is used in combination with other medications such as simeprevir, sofosbuvir, pe ...
+ interferon alfa-2a or interferon alfa-2b) nor
corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invol ...
improved outcomes.


Epidemiology

MERS has had a relatively low population-wide reproduction number in previous outbreaks, but such outbreaks have occurred due to superspreading events. Total laboratory-confirmed cases of MERS world-wide per year have been as follows:Epidemic and pandemic-prone diseases Infectious disease outbreaks reported in the Eastern Mediterranean Region in 2018
See 8. Middle East respiratory syndrome (MERS) ''www.emro.who.int'', accessed 29 January 2020


Saudi Arabia

MERS was also implicated in an outbreak in April 2014 in
Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the Ara ...
, where MERS has infected 688 people and 282 MERS-related deaths have been reported since 2012. In response to newly reported cases and deaths, and the resignation of four doctors at Jeddah's King Fahd Hospital who refused to treat MERS patients for fear of infection, the government removed the Minister of Health and set up three MERS treatment centers. Eighteen more cases were reported in early May. In June 2014, Saudi Arabia announced 113 previously unreported cases of MERS, revising the death toll to 282. A hospital-related outbreak in Riyadh in the summer of 2015 increased fears of an epidemic occurring during the annual
Hajj The Hajj (; ar, حَجّ '; sometimes also spelled Hadj, Hadji or Haj in English) is an annual Islamic pilgrimage to Mecca, Saudi Arabia, the holiest city for Muslims. Hajj is a mandatory religious duty for Muslims that must be carried o ...
pilgrimage that was to begin in late September. After a period of few cases, cases began increasing in the middle of the summer. The
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 ...
placed the travel health alert to level 2, which calls for taking enhanced precautions. In May 2019, 14 cases of MERS were reported to the World Health Organisation (WHO) by Saudi authorities, of which five were fatal. All those who died had comorbidities and other relatively serious health problems ranging from only
diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
in one person (aged 35) to complicated combinations of diabetes mellitus,
hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...
and
ischemic heart disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...
in two (65 and 80 years old) and diabetes mellitus, hypertension and nephropathy in another one who was 73 years old. Another patient who died and was 64 years old, had diabetes mellitus and hypertension. All those who died were males and three of them were reported to have had contact with, and exposure to, camels. Among the nine persons who survived were two females who were believed to have had contact with a person infected with MERS, one being a 23-year-old healthcare worker. Of the total 14 cases, four were females and 10 were males. All females survived. Reports of fatal cases were from Riyadh, Jeddah, Madinah and Najran. WHO did not recommend screening of travelers upon arrival or traveling restrictions.


United States

On 2 May 2014, the
Centers for Disease Control and Prevention 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 ...
(CDC) confirmed the first diagnosis of MERS in the United States at Community Hospital in
Munster, Indiana Munster is a suburban town in North Township, Lake County, Indiana, United States. It is in the Chicago metropolitan area, approximately southeast of the Chicago Loop, and shares municipal boundaries with Hammond to the north, Highland to th ...
. The man diagnosed was a health care worker who had been in Saudi Arabia a week earlier, and was reported to be in good condition. A second patient who also traveled from Saudi Arabia was reported in Orlando, Florida on 12 May 2014.


Netherlands

On 14 May 2014, officials in the
Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...
reported the first case had appeared.


South Korea

In May 2015, the first case in South Korea was confirmed in a man who had visited Saudi Arabia, United Arab Emirates and Bahrain. Another man from South Korea, who was travelling to China, was diagnosed as the first case in China. So far, no Chinese citizen has been found infected. As of 27 June 2015, 19 people in South Korea have died from this outbreak, with 184 confirmed cases of infection. There have been at least 6508 quarantined. In 2018 a case was found in South Korea; the patient had recently returned from Kuwait (via Dubai). One study found that severe cases of illness had higher viral loads than milder cases, and that concentrations peaked in the second week of illness.


Philippines

In April 2014, MERS emerged in the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
with a suspected case of a home-bound Overseas Filipino Worker (OFW). Several suspected cases involving individuals who were on the same flight as the initial suspected case are being tracked but are believed to have dispersed throughout the country. Another suspected MERS-involved death in
Sultan Kudarat Sultan Kudarat, officially the Province of Sultan Kudarat ( hil, Kapuoran sang Sultan Kudarat; Maguindanaon: ''Dairat nu Sultan Kudarat'', Jawi: دايرت نو سلطان كودرت; ceb, Lalawigan sa Sultan Kudarat; tl, Lalawigan ng Sul ...
province caused the Department of Health (DOH) to put out an alert. On 6 July 2015 the DOH confirmed the second case of MERS in the Philippines. A 36-year-old male foreigner from the Middle East was tested positive.


United Kingdom

On 27 July 2015, the accident and emergency department at
Manchester Royal Infirmary Manchester Royal Infirmary (MRI) is a large NHS teaching hospital in Chorlton-on-Medlock, Manchester, England. Founded by Charles White in 1752 as part of the voluntary hospital movement of the 18th century, it is now a major regional and natio ...
closed after two patients were treated for suspected MERS infection. The facility was reopened later that evening, and it was later confirmed by
Public Health England Public Health England (PHE) was an executive agency of the Department of Health and Social Care in England which began operating on 1 April 2013 to protect and improve health and wellbeing and reduce health inequalities. Its formation came as ...
that the two patients had tested negative for the disease.


Kenya

In January 2016, a larger outbreak of MERS among camels in Kenya was reported. By 5 February 2016 more than 500 camels had died of the disease. On 12 February 2016, the disease was reported to be MERS. No human cases were identified, although one study found antibodies in healthy humans in Kenya.


Comparisons

The table above provides a comparison between the 2014 Saudi Arabia outbreak and the South Korean outbreak in 2015 of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection.


History

Collaborative efforts were used in the identification of the MERS-CoV. Egyptian virologist Dr. Ali Mohamed Zaki isolated and identified a previously unknown coronavirus from the lungs of a 60-year-old Saudi Arabian man with pneumonia and
acute kidney injury Acute kidney injury (AKI), previously called acute renal failure (ARF), is a sudden decrease in kidney function that develops within 7 days, as shown by an increase in serum creatinine or a decrease in urine output, or both. Causes of AKI are c ...
. After routine diagnostics failed to identify the causative agent, Zaki contacted Ron Fouchier, a leading virologist at the
Erasmus Medical Center Erasmus University Medical Center (Erasmus MC or EMC) based in Rotterdam, Netherlands, affiliated with Erasmus University and home to its faculty of medicine, is the largest and one of the most authoritative scientific University Medical Centers in ...
(EMC) in Rotterdam, the Netherlands, for advice. Fouchier sequenced the virus from a sample sent by Zaki. Fouchier used a broad-spectrum "pan-coronavirus" real-time reverse-transcription polymerase chain reaction (RT-qPCR) method to test for distinguishing features of a number of known
coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...
es (such as OC43, 229E, NL63, and SARS-CoV), as well as for
RNA-dependent RNA polymerase RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to ...
(RdRp), a gene conserved in all
coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...
es known to infect humans. While the screens for known
coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...
es were all negative, the RdRp screen was positive. On 15 September 2012, Dr. Zaki's findings were posted on
ProMED-mail Program for Monitoring Emerging Diseases (also known as ProMED-mail, abbreviated ProMED) is among the largest publicly available emerging diseases and outbreak reporting systems in the world. The purpose of ProMED is to promote communication amon ...
, the Program for Monitoring Emerging Diseases, a public health on-line forum. The United Kingdom's
Health Protection Agency The Health Protection Agency (HPA) was a non-departmental public body in the United Kingdom. It was an organisation that was set up by the UK government in 2003 to protect the public from threats to their health from infectious diseases and envi ...
(HPA) confirmed the diagnosis of severe respiratory illness associated with a new type of coronavirus in a second patient, a 49-year-old Qatari man who had recently been flown into the UK. He died from an acute, serious respiratory illness in a London hospital. In September 2012, the UK HPA named it the
London1 novel CoV/2012 London1_novel CoV/2012 is a coronavirus strain isolated from a Qatari man in London in 2012 who was one of the first patients to come down with what has since been named Middle East respiratory syndrome-related coronavirus (MERS-CoV). The Qatari ...
and produced the virus' preliminary phylogenetic tree, the genetic sequence of the virus based on the virus's RNA obtained from the Qatari case. On 25 September 2012, the WHO announced that it was "engaged in further characterizing the novel coronavirus" and that it had "immediately alerted all its Member States about the virus and has been leading the coordination and providing guidance to health authorities and technical health agencies". The
Erasmus Medical Center Erasmus University Medical Center (Erasmus MC or EMC) based in Rotterdam, Netherlands, affiliated with Erasmus University and home to its faculty of medicine, is the largest and one of the most authoritative scientific University Medical Centers in ...
(EMC) in Rotterdam "tested, sequenced and identified" a sample provided to EMC virologist Ron Fouchier by Ali Mohamed Zaki in November 2012. On 8 November 2012, in an article published in the
New England Journal of Medicine ''The New England Journal of Medicine'' (''NEJM'') is a weekly medical journal published by the Massachusetts Medical Society. It is among the most prestigious peer-reviewed medical journals as well as the oldest continuously published one. His ...
, Dr. Zaki and co-authors from the Erasmus Medical Center published more details, including a tentative name, Human Coronavirus-Erasmus Medical Center (HCoV-EMC), the virus's genetic makeup, and closest relatives (including SARS). In May 2013, the Coronavirus Study Group of the
International Committee on Taxonomy of Viruses The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclatures for viruses. The ICTV has developed a universal taxonomic scheme for viruses, and thus has the means to ap ...
adopted the official designation, the Middle East Respiratory Syndrome Coronavirus (MERS-CoV), which was adopted by WHO to "provide uniformity and facilitate communication about the disease". Prior to the designation, WHO had used the non-specific designation 'Novel coronavirus 2012' or simply 'the novel coronavirus'.


Research

When rhesus macaques were given interferon-α2b and
ribavirin Ribavirin, also known as tribavirin, is an antiviral medication used to treat RSV infection, hepatitis C and some viral hemorrhagic fevers. For hepatitis C, it is used in combination with other medications such as simeprevir, sofosbuvir, pe ...
and exposed to MERS, they developed less pneumonia than control animals. Five critically ill people with MERS in Saudi Arabia with
acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...
(ARDS) and on ventilators were given interferon-α2b and ribavirin but all ended up dying of the disease. The treatment was started late in their disease (a mean of 19 days after hospital admission) and they had already failed trials of steroids so it remains to be seen whether it may have benefit earlier in the course of disease. Another proposed therapy is inhibition of viral
protease A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...
or
kinase In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule don ...
enzymes. Researchers are investigating a number of medications, including using interferon,
chloroquine Chloroquine is a medication primarily used to prevent and treat malaria in areas where malaria remains sensitive to its effects. Certain types of malaria, resistant strains, and complicated cases typically require different or additional medi ...
,
chlorpromazine Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar di ...
,
loperamide Loperamide, sold under the brand name Imodium, among others,Drugs.co Page accessed September 4, 2015 is a medication used to decrease the frequency of diarrhea. It is often used for this purpose in inflammatory bowel disease and short bowel syn ...
,
lopinavir Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir ( lopinavir/ritonavir). It was patented in 1995 and approved for medica ...
,
remdesivir Remdesivir, sold under the brand name Veklury, Text was copied from this source which is © European Medicines Agency. Reproduction is authorized provided the source is acknowledged. is a broad-spectrum antiviral medication developed by the ...
and galidesivir as well as other agents such as
mycophenolic acid Mycophenolic acid (MPA) is an immunosuppressant medication used to prevent rejection following organ transplantation and to treat autoimmune conditions such as Crohn's disease and lupus. Specifically it is used following kidney, heart, and liv ...
,
camostat Camostat is a serine protease inhibitor. Serine protease enzymes have a variety of functions in the body, and so camostat has a diverse range of uses. Camostat is approved in Japan for the treatment of chronic pancreatitis and postoperative reflu ...
and
nitazoxanide Nitazoxanide, sold under the brand name Alinia among others, is a broad-spectrum antiparasitic and broad-spectrum antiviral medication that is used in medicine for the treatment of various helminthic, protozoal, and viral infections. It is ind ...
.


References

{{Authority control 2012 disease outbreaks 2013 disease outbreaks 2014 disease outbreaks 2015 disease outbreaks 2016 disease outbreaks 2017 disease outbreaks 2018 disease outbreaks 2019 disease outbreaks 2012 in Saudi Arabia 2015 in South Korea 21st-century epidemics Atypical pneumonias Bat virome Camels Coronavirus-associated diseases Merbecovirus Syndromes affecting the respiratory system Syndromes caused by microbes Viral respiratory tract infections Wikipedia medicine articles ready to translate Zoonoses