The astroviruses are relatively new, having been discovered in 1975. Their name is derived from the appearance of a star in the center of the virus particle, when viewed at the right angle. Previous attempts at classification grouped astroviruses with caliciviruses, enteroviruses, parvoviruses, and parvo-like particles as small, round viruses (SRVs). The virion is small, 28-30 nm in diameter, with a spherical shape. The genome consists of a 7 kb-long, ssRNA of positive sense. Unlike the caliciviruses, astroviruses do not encode a helicase. Astrovirus 1 represents the most common of 5 serotypes, at least in the United Kingdom, where extensive serotype testing has been conducted. Sketch:
Astrovirus gastroenteritis is a relatively mild form of rotavirus enteritis. Symptoms of diarrhea, vomiting, and abdominal pain generally persist for only a few days. Complications are rare and serious cases are present when the patient, especially infants and the elderly, cannot replace the fluids lost through vomiting and diarrhea. Outbreaks tend to occur where children are in close contact with one another, as in day-care centers, kindergarten, and pediatric wards.
Astrovirus 1 is spread predominantly through the fecal-oral route but can also be transmitted through contaminated food and water, and the sharing of eating utensils. It is endemic throughout the world, attacking frequently in the winter months. After an incubation period of 1-4 days, mild gastroenteritis generally results from astrovirus infection, characterized by diarrhea, vomiting, and abdominal pain lasting several days.
There is no vaccine currently available against any astrovirus. After infection, immunity lasts for several years so by adulthood, most people contract very few astrovirus infections. Astrovirus infection can be prevented by frequent handwashing, disinfection of contaminated surfaces, prompt washing of soiled clothes, and avoidance of contaminated food or water. Game
Go swimming in Lake Lag, lose 2 health points
Star light, star bright The first star I see tonight My stomach hurts with painful might May I not have this what brings me blight