Norovirus is the main causative agent of global acute gastroenteritis cases and outbreaks.Since 2013, China’s other infectious diarrhea disease outbreaks are dominated by outbreaks of norovirus, especially since 2014, the outbreaks of norovirus have increased dramatically, significantly higher than the level of previous years.
What is norovirus?
Norovirus, also known as norovirus, is a virus of the genus Norovirus in the human cupriovirus family. It is a group of virus particles with similar morphology and slightly different antigenic properties.
Norovirus infectious diarrhea is endemic throughout the world, with infections occurring throughout the year, mainly in adults and school-aged children, with a high incidence during the cold season. In the United States, 60-90% of all non-bacterial diarrhea outbreaks each year are caused by norovirus. Similar results have been reported in developed countries such as the Netherlands, the United Kingdom, Japan, and Australia. In China, the detection rate of norovirus in children under 5 years of age with diarrhea is about 15%, and serum antibody level surveys indicate that norovirus infection is also very common in the Chinese population.
What are the symptoms of Norovirus?
The main symptoms are nausea, vomiting, fever, abdominal pain and diarrhea. Vomiting is common in children, and diarrhea is common in adults, with 4 to 8 episodes of diarrhea in 24 hours, and the stools are watery or watery, without mucus, pus or blood. Patients with primary infection have significantly more vomiting symptoms than those with secondary infection, and some infected patients show only vomiting symptoms. In addition, headache, chills and muscle pain can be seen, and dehydration can be seen in severe cases. The longer duration of the disease and the more severe cases also have a longer detoxification time, and the contagiousness can last up to two days after the disappearance of the symptoms. The immunization period is short and the disease can be repeated.
Is norovirus contagious?
It has been included in the category C infectious diseases “other infectious diarrheal diseases (infectious diarrheal diseases other than cholera, bacterial and amoebic dysentery, typhoid fever and paratyphoid fever)” in our country for reporting and management.
Sources of infection: Patients, latently infected persons and virus carriers are the main sources of infection.
Transmission: Norovirus is transmitted from person to person, through food and water. Human-to-human transmission can occur through the fecal-oral route (including ingestion of aerosols produced by feces or vomitus), or through indirect contact with the environment contaminated by fecal matter. Foodborne transmission occurs through the consumption of norovirus-contaminated food. Contamination can occur when food is contaminated by norovirus-infected catering workers during meal preparation and serving, or when food is contaminated with norovirus-containing human excreta or other substances (e.g., water, etc.) during the process of food production, transportation, and distribution.
Susceptible population: The population is generally susceptible to norovirus.
Norovirus prevention
1、Cut off the way of transmission
Viral diarrhea is the main means of transmission for the “fecal – oral” transmission, the source of infection is mostly light patients or asymptomatic carriers, so the main preventive measures are to do a good job of food and drinking water, and strengthen the patients, close contacts and their direct contact with the environment management and other work, and actively cut off the infectious pathway of the disease.
2、Control the source of infection
Already sick patients should be isolated for treatment, should rest at home until the symptoms disappear after 3 days, so as not to spread the disease to the surrounding population. Disinfect the vomit and diarrhea of patients, suspected patients and contaminated articles and toilets. Patients with mild symptoms can be isolated at home or in situ at the institution where the outbreak occurred; those with severe symptoms need to be sent to healthcare institutions for isolation and treatment according to intestinal infectious diseases, and the healthcare institutions should do a good job of infection control to prevent nosocomial transmission.
3、Avoid the disease entering by mouth
Do not eat raw and cold food and uncooked and boiled food, especially the ban on raw food shellfish and other aquatic products; on some of the cold dishes placed for a long time is best to eat less or not eat, drinking water boiled before drinking, do not drink raw water.
4、 Thoroughly cooked food
Avoid eating food that is not thoroughly cooked. Norovirus will die if it is exposed to a high temperature of more than 80℃ for 30 seconds. Therefore, it can be prevented by thoroughly cooking food, especially seafood and shellfish.
In our daily life, we carry out publicity on the prevention and control of norovirus infection to raise the awareness of the community, and develop healthy living habits such as washing hands frequently, not drinking raw water, separating raw and cooked food, and avoiding cross contamination.