Norovirus gastroenteritis

　　Patients and asymptomatic carriers are the main sources of infection. During the acute phase, the stool of patients contains a large number of viral particles, which can infect people through contaminated food and drinks, especially shellfish, through the oral route (i.e., fecal-oral transmission), and may also be transmitted through water source contamination or respiratory transmission, often leading to outbreaks. After the disease, it can continue to excrete the virus for 4 to 8 days, and in a few cases, it can last for 18 to 42 days.

　　The peak age of infection of this disease is children under 6 years old, with 12-year-old children more susceptible to infection, and the elderly can also be infected, so it can occur in nurseries or elderly care facilities throughout the year without a clear seasonal peak. Adult cup-shaped virus gastroenteritis (epidemic diarrhea) often presents as a water-type outbreak, and can also be spread through contact with daily life.

　　Cup-shaped virus gastroenteritis generally does not have special complications, but if it is combined with other enterovirus infections, it may cause serious harm to patients if not treated in a timely manner. Therefore, when feeling unwell, it is still necessary to go to the hospital for a disease diagnosis.

　　What are the symptoms of cup-shaped virus gastroenteritis? Briefly described as follows:

　　1. The incubation period of the cup-shaped virus gastroenteritis is 1 to 3 days, with vomiting and diarrhea as the main symptoms. Children primarily present with vomiting, with about half of the children showing upper respiratory symptoms, and a few may have fever and rash. Adults mainly present with diarrhea and watery stools, which may be accompanied by symptoms such as nausea, vomiting, abdominal pain, headache, and general discomfort. The course of the disease is 3 to 5 days.

　　2. The condition of children varies greatly, with infants aged 6 to 24 months showing severe symptoms, while older children are mostly mild or asymptomatic infections. This disease is self-limiting, with a course of about one week. However, a few children may still have malabsorption of disaccharides, especially lactose, in the short term, and diarrhea may last for several weeks, with some cases lasting for several months.

　　3. The incubation period of the cup-shaped virus gastroenteritis in adults is 2 to 3 days, with an acute onset, mostly without fever or only with low fever, mainly presenting with diarrhea, abdominal pain, and bloating. The frequency of diarrhea varies from 3 to 10 times a day, with yellow watery or congee-like stools without pus or blood. Some cases may be accompanied by symptoms such as nausea and vomiting. The course of the disease is 3 to 6 days, and occasionally it can last for more than 10 days. A few patients may develop complications such as intussusception, rectal bleeding, hemolytic uremic syndrome, encephalitis, and Reye syndrome.

　　Currently, there is no vaccine for gastroenteritis caused by cup-shaped viruses. The best way to prevent it is to pay attention to food, drinking water, and personal hygiene. Wash hands frequently before meals, after defecation, or before preparing food; eat thoroughly cooked food; do not drink raw water; do not eat raw or half-cooked shellfish and unclean food; protect water sources. Active treatment should be given to patients with gastroenteritis caused by cup-shaped viruses, strict disinfection and isolation should be implemented, and close contacts and suspected patients should be strictly observed.

　　What examinations should be done for gastroenteritis caused by cup-shaped viruses? Briefly described as follows:

　　1. Pathogenic examination

　　Virus particles can be seen in the stool of patients with gastroenteritis caused by cup-shaped viruses using electron microscopy or immunoelectron microscopy, or the specific antigens in the stool of patients and specific antibodies in the blood of patients can be checked using ELISA or RIA methods.

　　2. Blood routine

　　The total number and classification of peripheral blood white blood cells are mostly normal, with a small number being slightly elevated, and the proportion of lymphocytes increases.

　　3. Stool routine and culture

　　Stool microscopy usually shows no special findings, and a small number of cases may show a small number of white blood cells, and no pathogenic bacteria grow in culture.

　　The dietary principles of gastroenteritis caused by cup-shaped viruses are briefly described as follows:

　　1. Avoid irregular diet. Pay attention to the proportion of sugar, fat, and protein in food, and pay attention to the content of vitamins and other essential nutrients for the body.

　　2. Avoid smoking, alcohol, spicy, and刺激性 foods.

　　3. Avoid cold, hot, and hard foods. Such as cold food and drinks, overly hard and rough foods, fibrous vegetables, and foods fried or grilled with oil.

　　4. Avoid unclean diet. Wash fruits and vegetables before eating, and do not eat spoiled food.

　　In addition, foods or beverages such as chili, mustard, pepper, strong tea, coffee, cocoa, etc. should also be avoided.

　　The gastroenteritis caused by cup-shaped viruses is self-limiting, with a good prognosis and no special treatment is required. Severe cases may require supportive and symptomatic treatment. If patients experience symptoms such as severe abdominal pain and worsening diarrhea, they should seek medical attention in a timely manner.