Norovirus causes acute infectious diarrhoea and is at its peak from October to March. So, what are the symptoms of norovirus infection? Once someone around me is infected with norovirus, how to protect against it? How can I tell if I have diarrhea if I have norovirus or another virus? Today, experts in infectious diseases at Peking Union Medical College Hospital explained in detail five things you should know about norovirus -
What are the symptoms of norovirus infection?
In 1968, students at an elementary school in the town of Novak in the United States developed a mass outbreak of acute gastroenteritis, the cause of which was not known at the time. It wasn't until 1972 that the causative agent — an RNA virus — was identified from the feces of patients at the time. Because the first patient was in the town of Nowak, the virus was named Novavirus, also known as norovirus.
Norovirus infection occurs more often in autumn and winter and usually presents with nausea, vomiting, abdominal pain, and diarrhea. Children are prone to vomiting, while adults have diarrhea, and the stool is mostly loose and watery, without mucopurulent blood. In addition, fever, headache, and muscle pain are common symptoms, and dehydration due to diarrhea may also occur. Of course, some patients may also have mild symptoms or even no clinical manifestations, that is, hidden infections.
What is the incubation period and transmission route of norovirus?
Norovirus has a short incubation period, only 24~48 hours, transmitted through the fecal-oral route, and only a very small amount of virus is required to cause illness. Patients, recessive infections, and healthy carriers can all be sources of infection.
Norovirus is excreted mainly in the patient's stool, but also through vomit. When food and water are contaminated with norovirus and ingested by healthy people, epidemics can occur. As a result, norovirus often causes outbreaks in schools, nurseries, nursing homes, hospitals, factories and communities.
Someone around me is infected with norovirus, how can I protect against it?
There is currently no vaccine for norovirus infection, so paying attention to personal hygiene and dietary safety is an important means of prevention.
1. Good hand hygiene. Hand hygiene should be paid attention to, because alcohol and rinse sanitizer have no inactivating effect on norovirus, so soap and water should be used to wash hands carefully in accordance with the "seven-step handwashing method", and the effective hand rubbing time should exceed 15 seconds, especially after using the toilet and changing diapers to pay attention to hand washing to avoid illness from entering the mouth.
2. Environmental disinfection. When norovirus cluster infection occurs, disinfection should be done, and the use of chlorine-containing disinfectant solution focuses on disinfecting surfaces contaminated with the patient's vomit and excreta.
3. Self-management. If patients have symptoms of vomiting and diarrhea, after the diagnosis of norovirus infection, do not insist on going to school or work, especially food workers should pay more attention. Patients should use a special toilet or toilet as much as possible, and cover the toilet lid to flush.
Ordinary people should pay attention to their physical health within 48 hours after contact with patients, and once similar symptoms appear, they should immediately go to the hospital for virus screening to avoid transmission to more people.
Confirmed patients should be isolated within 72 hours after the symptoms completely disappear, mild patients can be isolated at home, and severe patients should be isolated in medical institutions according to the standards of intestinal infectious diseases.
There are students on campus who have symptoms such as vomiting, how should other children be protected?
Many diseases can manifest as symptoms of vomiting, so when should norovirus be suspected?
In autumn and winter, when children have diarrhea, loose stools, vomiting and other symptoms, especially when there are 3 or more children at the same time, it is necessary to consider that it is norovirus, usually their feces, blood routine examination will not have special findings, if you need to confirm the diagnosis, need to be pathogenic examination.
When norovirus infection is suspected, schools should take the following measures:
1. Students with symptoms are requested to seek medical attention as soon as possible, isolate at home under the guidance of a doctor, and resume school after all symptoms disappear for 3 days;
2. Do a good job of environmental disinfection, and use chlorine-containing disinfectant to focus on disinfecting the surfaces contaminated by patients' vomit and excrement;
3. Carry out health education: instruct teachers and students to carry out hand hygiene and cleaning (running water + soap), monitor symptoms (diarrhea, vomiting, fever, etc.), report to the doctor in time when there are symptoms, do not drink raw water in diet, and thoroughly wash vegetables and fruits.
If you have diarrhea and other symptoms, do you have nororo or other viruses?
Norovirus is an intestinal RNA virus that mainly manifests digestive symptoms such as diarrhea and vomiting. The new coronavirus is a respiratory-transmitted virus, most of which manifest respiratory symptoms such as fever, cough, sore throat, and diarrhea symptoms are relatively mild. In most cases, the two are easy to distinguish, and a few are difficult to distinguish, and it is necessary to leave stool, vomit, throat swabs and other specimens for etiological examination to identify.
There are some commonalities in viral infections, such as fever, poor appetite, muscle and joint pain, examination of general white blood cells and inflammatory indicators are not high, especially like influenza, respiratory syncytial virus, new coronavirus these respiratory viruses, after infection from the symptoms are difficult to distinguish, to accurately identify diagnosis or need to go to the hospital for etiological testing to determine the cause, for the next step of treatment.
Author: Liu Xinchao
Assistant Director of Department of Infectious Diseases, Peking Union Medical College Hospital, attending physician. Good at: Diagnosis and treatment of fever of unknown origin, infectious diseases, HIV.
Audit expert: Li Taisheng
Director of the Department of Infectious Diseases of Peking Union Medical College Hospital, doctoral supervisor, enjoy the special allowance of the State Council. He is currently the chairman of the Infectious Diseases Branch of the Chinese Medical Association. He has been committed to the clinical and translational research of infectious diseases for more than 30 years, created a comprehensive diagnosis and treatment model of AIDS suitable for China's national conditions, and made important contributions to the clinical diagnosis and treatment of major infectious diseases "AIDS" and "SARS" in mainland China. During the new crown epidemic, he served as an expert in the national medical treatment team for responding to the new coronavirus pneumonia; He was selected as the leading talent of the national high-level talent special plan, the first batch of scientific and technological innovation leading talents of the national "10,000 people plan", and the "list of the top 2% of the world's top scientists in 2022". He has won many commendations such as the Sevia Award of the French Academy of Medical Sciences, the Wu Yang Medical Pharmacy Award, young and middle-aged experts with outstanding contributions to national health, advanced scientific and technological workers in the national fight against SARS, and national advanced workers. He has published 180 SCI papers and cited more than 10,000 times.
Executive Producer/Wu Peixin