Astroviruses: Overview and Emerging Disease

Astroviruses are single-stranded, positive-sense possessing a star-like appearance, 28–30 nm in diameter, RNA viruses in the family Astroviridae which have been known to cause food-borne non-bacterial acute gastroenteritis also known as stomach flu in humans affecting the gastrointestinal route. This is caused by intake of contaminated food and water or getting in touch with contaminated sources. This is transmitted through the faecal-oral route and is responsible for causing diarrheal illness more commonly in infants and young children less than age group of 5 years. The old-aged and the less immune system person are also known to get affected by the astroviruses. In contrast to mink and humans, animals remain asymptomatic to the astrovirus. The effect of this virus may last up to 2–3 days and does not require any sort of medical treatment. The symptoms of astrovirus infection include nausea, vomiting, mild fever, loss of appetite, dehydration, and headache but its less severe than rotavirus and norovirus. Although these viruses may reside in gastrointestinal tract for approximately 2 months, the infectivity of the astrovirus can be reduced by using methanol or alcohol disinfection. Human astrovirus consists of 8 serotypes (1–8), and among them, serotype 1 is the most common type present in nearly 50% of the countries. There may be several types of astroviruses such as Avian astroviruses in poultry and Mamastroviruses for dogs. There have been several methods to detect the astroviruses infection such as electron microscopy (EM), cell culture methods, enzyme-linked immunosorbent assays, and RT-polymerase chain reaction (RT-PCR). This review provides the information on phylogenetic classification and structural organization of astroviruses along with their pathogenesis and immunological response to this pathogen​.