Microbiology Taxonomy The International Committee on Taxonomy of Viruses (ICTV) established Astroviridae as a viral family in 1995. There have been over 50 astroviruses reported, although the ICTV officially recognizes 22 species. The genus Avastrovirus comprises three species; Chicken astrovirus (Avian nephritis virus types 1 - 3), Duck astrovirus (Duck astrovirus C-NGB), and Turkey astrovirus (Turkey astrovirus 1). The genus Mamastrovirus includes Bovine astroviruses 1 and 2, Human astrovirus (types 1-8), Feline astrovirus 1, Porcine astrovirus 1, Mink astrovirus 1 and Ovine astrovirus 1. Avastrovirus Phylogenetic tree of astroviruses and the species infected by them Avastrovirus 1-3 are associated with enteric infections in turkeys, ducks, chicken and guinea fowl. In turkey poults 1–3 weeks of age, some symptoms of enteritis include diarrhea, listlessness, liver eating and nervousness. These symptoms are usually mild but in cases of poult enteritis and mortality syndrome (PEMS), which has dehydration, immune dysfunction and anorexia as symptoms, mortality is high. Post mortem examination of the intestines of infected birds show fluid filled intestines. Hyperplasia of enterocytes is also observed in histopathology studies. However, in contrast to other enteric viruses, there isn't villous supply. Mamastrovirus Mamastroviruses often cause gastroenteritis in infected mammals. In animals, gastroenteritis is usually undiagnosed because most astrovirus infections are asymptomatic. However, in mink and humans, astroviruses can cause diarrhea and can be fatal. The incubation period for Mamastrovirus is 1–4 days. When symptoms occur, the incubation period is followed by diarrhea for several days. In mink, symptoms include increased secretion from apocrine glands. Human astroviruses are associated with gastroenteritis in children and immunocompromised adults. 2-8 \% of acute non-bacterial gastroenteritis in children is associated with human astrovirus. These viral particles are usually detected in epithelial cells of the duodenum. In sheep, ovine astroviruses were found in the villi of the small intestine. 1975: Madeley and Cosgrove named the 20-30 nm viral particle Astrovirus based on the star-like EM (electron microscopy) appearance
Microbiology Taxonomy The International Committee on Taxonomy of Viruses (ICTV) established Astroviridae as a viral family in 1995. There have been over 50 astroviruses reported, although the ICTV officially recognizes 22 species. The genus Avastrovirus comprises three species; Chicken astrovirus (Avian nephritis virus types 1 – 3), Duck astrovirus (Duck astrovirus C-NGB), and Turkey astrovirus (Turkey astrovirus 1). The genus Mamastrovirus includes Bovine astroviruses 1 and 2, Human astrovirus (types 1-8), Feline astrovirus 1, Porcine astrovirus 1, Mink astrovirus 1 and Ovine astrovirus 1. Avastrovirus Phylogenetic tree of astroviruses and the species infected by them Avastrovirus 1–3 are associated with enteric infections in turkeys, ducks, chicken and guinea fowl. In turkey poults 1–3 weeks of age, some symptoms of enteritis include diarrhea, listlessness, liver eating and nervousness. These symptoms are usually mild but in cases of poult enteritis and mortality syndrome (PEMS), which has dehydration, immune dysfunction and anorexia as symptoms, mortality is high. Post mortem examination of the intestines of infected birds show fluid filled intestines. Hyperplasia of enterocytes is also observed in histopathology studies. However, in contrast to other enteric viruses, there isn't villous supply. Mamastrovirus Mamastroviruses often cause gastroenteritis in infected mammals. In animals, gastroenteritis is usually undiagnosed because most astrovirus infections are asymptomatic. However, in mink and humans, astroviruses can cause diarrhea and can be fatal. The incubation period for Mamastrovirus is 1–4 days. When symptoms occur, the incubation period is followed by diarrhea for several days. In mink, symptoms include increased secretion from apocrine glands. Human astroviruses are associated with gastroenteritis in children and immunocompromised adults. 2–8 \% of acute non-bacterial gastroenteritis in children is associated with human astrovirus. These viral particles are usually detected in epithelial cells of the duodenum. In sheep, ovine astroviruses were found in the villi of the small intestine. 1975: Madeley and Cosgrove named the 20–30 nm viral particle Astrovirus based on the star-like EM (electron microscopy) appearance
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1-3
1–3
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2-8
2–8
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20-30
20–30