Prevention and control of infectious diseases in spring | Updated: 2023-03-02
As students are back to school, disease prevention and control centers around the country have noticed that influenza, particularly the influenza A virus, is spreading rapidly in China. In addition, the number of students infected with norovirus has also increased.

What is norovirus infection and what is influenza? How can we prevent them? Wang Guiqiang, director of the Department of Infectious Diseases at Peking University First Hospital, answers some of the most frequently asked questions.
Q: What is norovirus? What are the symptoms after infection?
Wang: Norovirus belongs to the caliciviridae family. The symptoms after infection are mainly vomiting and diarrhea, as it is an infectious disease afflicting the digestive system of the human body. The main source of infection is ingesting food or water contaminated by the virus. Norovirus can also be transmitted through aerosol, close contact and other ways, such as physical contact between primary school and kindergarten children.
Vomiting and diarrhea can cause a large amount of electrolyte and water loss in the human body. Therefore, it is necessary for the infected patient to rehydrate, rest, and drink sugar and salt solutions or use rehydration salt.

Q: When do I need to see a doctor after being infected with norovirus? 
Wang: If children and elderly people suffer from weakness, dry mouth and eyes after being infected with norovirus, it may indicate hypotension. Their blood pressure should be measured, and the patient should go to the hospital and seek medical help.
If you're at home, you can drink some light salt water, because norovirus infection mainly causes diarrhea and vomiting, resulting in a large amount of electrolyte and water loss in the human body. For the elderly with basic diseases, severe water loss may induce shock, they should be closely monitored.
Norovirus mainly affects the digestive system. Therefore, the safe management of food and water is top priority. Maintaining hand hygiene and washing hands before meals are equally important. Once infection is detected in places where people gather, such as nurseries and primary schools, it is necessary to immediately check whether food and water sources have been contaminated, and the canteen and other key areas must be double-checked and thoroughly disinfected to prevent the spread of the virus.

Q: What is influenza? What is the difference between influenza and the common cold?
Wang: Influenza is an acute respiratory infectious disease caused by the influenza virus. The difference between influenza and the common cold mainly lies in etiology and severity.
First, their etiology is different. There are many pathogens that can cause cold-like symptoms, while influenza is caused by the influenza virus. 
Second, influenza symptoms are more severe than the common cold. Influenza can cause persistent high fever, sore muscles and joints in the whole body, and in serious cases, the influenza virus can cause pneumonia. At the same time, influenza is likely to aggravate the conditions of the elderly with basic diseases. Some patients may develop secondary infections, such as respiratory tract infection, and secondary bacterial infection.
Third, in terms of treatment, there are special therapeutic medicines for influenza. It is recommended that antiviral medicines be administered as early as possible. Although influenza is a self-limiting disease, early use of medicines can shorten the course of the disease, alleviate symptoms and reduce the risk of developing into severe cases. 
Common cold is usually treated according to symptoms. The sufferers need to drink more water and get enough rest.
Q: When do I need to see a doctor if I have influenza?
Wang: If you experience a persistent high fever, shortness of breath, and aggravation of basic diseases, you should go to the hospital. For the elderly with basic diseases in particular, it is suggested that when they have fever, cough, headache and fatigue, they should seek medical help. If they are diagnosed with influenza, they should use antiviral medicines as soon as possible to avoid further deterioration. It is recommended that vulnerable groups get influenza vaccination every year.
Frequent ventilation, wearing masks and maintaining hand hygiene are all effective ways to prevent influenza. In winter and spring, it is recommended that you wear masks in places where people gather or in confined spaces.