Viral gastroenteritis is diarrhea caused by viral infection. There are five kinds of viruses, which are Norwalk virus, astrovirus, calicivirus, rotavirus and adenovirus. Most of these viruses exist in the gastrointestinal tract of patients and infected people, and can be excreted with feces and vomit. Therefore, patients with viral gastroenteritis and virus-infected people are the sources of infection of the disease. The virus can be excreted from feces before symptoms appear, and the detoxification time can last for several days or even 2 ~ 3 weeks. After the virus is excreted, it will pollute water, vegetables, fruits, hands and so on. If people eat these food and water contaminated by viruses; You may be infected if you don't wash your hands and eat when you are in contact with viruses or items contaminated by viruses. Different age groups infected with different viruses may be different. For example, group A rotavirus mainly infects infants, with the highest onset age of 6 ~ 12 months, followed by 12 ~ 24 months and 2 ~ 6 months. Other age groups, especially newborns and the elderly, can also be infected when their immunity is low. Infants who are artificially fed are more susceptible to infection than those who are breastfed. Group B rotavirus mainly infects young adults. Group C rotavirus mainly infects children, and the infection rate of adults is relatively low. Adenovirus mainly infects infants under 3 years old, and rarely infects adults.
2. The route of infection is fecal transmission.
The investigation report shows that adult rotavirus infection mainly occurs in the cold season of winter and spring, which is quite different from bacterial diarrhea, and bacterial diarrhea mostly occurs in summer and autumn. For example, from the end of 1982 to the beginning of 1983, an epidemic broke out in Lanzhou and Jinzhou, China. There are more than 30 thousand patients of all ages, but most of them are young and middle-aged. Since then, there have been pandemics in Guangxi, Inner Mongolia, Hunan, Shandong, Hebei, Heilongjiang, Anhui, Fujian and Liaoning. Judging from the above geographical distribution, various climatic conditions prevail in the east, west, south and north. Because the virus is relatively stable in the external environment, it can survive for 7 months at room temperature, is acid-resistant, can not be destroyed by gastric acid, can be stored for a long time at MINUS 20℃, and can not be inactivated at 50℃ in the presence of magnesium sulfate, which lays the foundation for its pollution and epidemic. The mode of infection is fecal-oral transmission. People can eat food or water contaminated by the feces of patients with this disease, and even shake hands with patients with this disease. The possibility of respiratory tract infection cannot be ruled out, and preventive measures should be taken against the above infection routes.