|
Post-acute Infection Syndrome
Post-acute infection syndromes (PAISs) or post-infectious syndromes are medical conditions characterized by symptoms attributed to a prior infection. While it is commonly assumed that people either recover or die from infections, long-term symptoms—or sequelae—are a possible outcome as well. Examples include long COVID (post-acute sequelae of SARS-CoV-2 infection, PASC), Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and post-Ebola virus syndrome. Common symptoms include post-exertional malaise (PEM), severe fatigue, neurocognitive symptoms, flu-like symptoms, and pain. The pathology of most of these conditions is not understood and management is generally symptomatic. Symptoms and signs PAIS symptoms are often non-specific and similar despite diverse prior infections. Symptoms commonly included in definitions of PAIS include post-exertional malaise, severe fatigue, neurocognitive and sensory symptoms, flu-like symptoms, unrefreshing sleep, muscle pain, and jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Conditions
A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are associated with specific signs and symptoms. A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergies, and autoimmune disorders. In humans, ''disease'' is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person affected, or similar problems for those in contact with the person. In this broader sense, it sometimes includes injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors, and atypical variations of structure and funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poliovirus
Poliovirus, the causative agent of polio (also known as poliomyelitis), is a serotype of the species '' Enterovirus C'', in the family of '' Picornaviridae''. There are three poliovirus serotypes, numbered 1, 2, and 3. Poliovirus is composed of an RNA genome and a protein capsid. The genome is a single-stranded positive-sense RNA (+ssRNA) genome that is about 7500 nucleotides long. The viral particle is about 30 nm in diameter with icosahedral symmetry. Because of its short genome and its simple composition—only a strand of RNA and a nonenveloped icosahedral protein coat encapsulating it—poliovirus is widely regarded as the simplest significant virus. Poliovirus is one of the most well-characterized viruses, and has become a useful model system for understanding the biology of RNA viruses. Replication cycle Poliovirus infects human cells by binding to an immunoglobulin-like receptor, CD155 (also known as the poliovirus receptor or PVR) on the cell surface. Inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore is considered a mechanism of innate immunity, whereas adaptive immunity is specific to each pathogen. Inflammation is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out damaged cells and tissues, and initiate tissue repair. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. However inflammation can also have negative effects. Too much inflammation, in the form of chronic inflammation, is associated with variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoimmunity
In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an " autoimmune disease". Prominent examples include celiac disease, diabetes mellitus type 1, Henoch–Schönlein purpura, systemic lupus erythematosus, Sjögren syndrome, eosinophilic granulomatosis with polyangiitis, Hashimoto's thyroiditis, Graves' disease, idiopathic thrombocytopenic purpura, Addison's disease, rheumatoid arthritis, ankylosing spondylitis, polymyositis, dermatomyositis, and multiple sclerosis. Autoimmune diseases are very often treated with steroids. Autoimmunity means presence of antibodies or T cells that react with self-protein and is present in all individuals, even in normal health state. It causes autoimmune diseases if self-reactivity can lead to tissue damage. History In the later 19th century, it was believed that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giardia
''Giardia'' ( or ) is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada that colonise and reproduce in the small intestines of several vertebrates, causing the disease giardiasis. Their life cycle alternates between a binucleated motile trophozoite and an infective, metabolically inert, environmentally resistant tetranucleate cyst. Cysts are transmitted between hosts through the fecal-oral route, contaminated water and/or food. ''Giardia'' were first seen by the Dutch microscopist Antonie van Leeuwenhoek in 1681 under the light microscope. The genus is named after French zoologist Alfred Mathieu Giard. Characteristics ''Giardia'' trophozoites are 12–15 μm long and 5–9 μm wide and have a shape of a pear bisected lengthwise. Like other diplomonads, ''Giardia'' has two transcriptionally operational nuclei that contain an equal number of well-defined chromosomes and replicate synchronously with the cell division. The cytoskeleton of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia
''Borrelia'' is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of ''Borrelia'' cause relapsing fever, and are transmitted by ticks or lice, depending on the species of bacteria. The genus is named after French biologist Amédée Borrel (1867–1936), who first documented the distinction between a species of ''Borrelia anserina'' and the other known type of spirochete at the time, ''Treponema pallidum''. This bacterium must be viewed using dark-field microscopy, which make the cells appear white against a dark background. ''Borrelia'' species are grown in Barbour-Stoenner-Kelly medium. Of 52 known species of ''Borrelia'', 20 are members of the Lyme disease group (with an additional 3 proposed), 29 belong to the relapsing fever group, and two are members of a genetically distinct third group typically found in reptiles. A proposal has been made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxiella Burnetii
''Coxiella burnetii'' is an obligate intracellular bacterial pathogen, and is the causative agent of Q fever. The genus ''Coxiella'' is morphologically similar to '' Rickettsia'', but with a variety of physiological differences genetically classified as part of the class Gammaproteobacteria (and not Alphaproteobacteria, like ''Rickettsia''). ''C. burnetii'' is a small Gram-negative, coccobacillary bacterium that is highly resistant to environmental stresses such as high temperature, osmotic pressure, and ultraviolet light. These characteristics are attributed to a small cell variant form of the organism that is part of a biphasic developmental cycle, including a more metabolically and replicatively active large cell variant form. It can survive standard disinfectants, and is resistant to many other environmental changes like those presented in the phagolysosome. History and naming Research in the 1920s and 1930s identified what appeared to be a new type of ''Rickettsia'', i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varicella Zoster Virus
Varicella zoster virus (VZV), also known as human herpesvirus 3 (HHV-3, HHV3), is one of nine known herpes viruses that can infect humans. It causes chickenpox (varicella) commonly affecting children and young adults, and shingles (herpes zoster) in adults but rarely in children. As a late complication of VZV infection, Ramsay Hunt syndrome type 2 may develop in rare cases. VZV infections are species-specific to humans. The virus can survive in external environments for a few hours. VZV multiplies in the tonsils, and causes a wide variety of symptoms. Similar to the herpes simplex viruses, after primary infection with VZV (chickenpox), the virus lies dormant in neurons, including the cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia. Many years after the person has recovered from initial chickenpox infection, VZV can ''reactivate'' to cause shingles. Epidemiology Chickenpox Primary varicella zoster virus infection results in chickenpox (varicella), whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influenza A Virus Subtype H1N1
Influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus (IAV). Some human-adapted strains of H1N1 are endemic in humans and are one cause of seasonal influenza (flu). Other strains of H1N1 are endemic in pigs ( swine influenza) and in birds (avian influenza). Subtypes of IAV are defined by the combination of the antigenic H and N proteins in the viral envelope; for example, "H1N1" designates an IAV subtype that has a type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein. All subtypes of IAV share a negative-sense, segmented RNA genome. Under rare circumstances, one strain of the virus can acquire genetic material through genetic reassortment from a different strain and thus evolve to acquire new characteristics, enabling it to evade host immunity and occasionally to jump from one species of host to another. Major outbreaks of H1N1 strains in humans include the 1918 Spanish flu pandemic, the 1977 Russian flu pandemic and the 2009 swine fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxsackie B Virus
Coxsackie B is a group of six serotypes of coxsackievirus (CVB1-CVB6), a pathogenic enterovirus, that trigger illnesses ranging from a mild febrile rash to full-fledged pericarditis and myocarditis ( coxsackievirus-induced cardiomyopathy). The genome of Coxsackie B virus consists of approximately 7,400 base pairs. Geographic distribution The various members of the Coxsackie B group were discovered almost entirely in the United States, appearing originally in Connecticut, Ohio, New York, and Kentucky, although a sixth member of the group has been found in the Philippines. However, all six serotypes have a global distribution and are a relatively common cause of gastrointestinal upset. The name reflects the first isolation from Coxsackie, New York. Transmission Infections are most commonly spread by the Fecal-oral route, emphasizing the importance of good hygiene, especially hand-washing. Oral-oral and respiratory droplets can also be means of transmission. Epidemiology Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross River Virus
Ross River virus (RRV) is a small encapsulated single-strand RNA '' Alphavirus'' endemic to Australia, Papua New Guinea and other islands in the South Pacific. It is responsible for a type of mosquito-borne, non-lethal but extremely debilitating tropical disease known as Ross River fever, previously termed "epidemic polyarthritis". There is no known cure, and it can last in the host's system for up to 20 years. The virus is suspected to be enzootic in populations of various native Australian mammals, and has been found on occasion in horses. Classification and morphology Taxonomically, Ross River virus belongs to the virus genus '' Alphavirus'', which is part of the family ''Togaviridae''. The alphaviruses are a group of small enveloped single-strand positive-sense RNA viruses. RRV belongs to a subgroup of "Old World" (Eurasian-African-Australasian) alphaviruses, and belongs to the SF antigenic complex of the genus Alphavirus. The virions (virus particles) themselves contai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Nile Virus
West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family ''Flaviviridae'', from the genus ''Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The virus is primarily transmitted by mosquitoes, mostly species of ''Culex''. The primary host (biology), hosts of WNV are birds, so that the virus remains within a "bird–mosquito–bird" Transmission (medicine), transmission cycle. The virus is genetically related to the Japanese encephalitis family of viruses. Humans and horses both exhibit disease symptoms from the virus, and symptoms rarely occur in other animals. West Nile virus was not named directly after the Nile River, but rather, after the West_Nile_sub-region, West Nile district of Uganda where the virus was first isolated in 1937. Structure Like most other flaviviruses, WNV is an Viral envelope, enveloped virus with icosahedral symmetry. Electron microscope studies reveal a 45–5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
