Norovirus

Norovirus is a virus that can cause acute gastroenteritis. Its main symptoms are nausea, vomiting, fever, abdominal pain and diarrhea, which is highly contagious. At present, there are no specific antiviral drugs, mainly symptomatic or supportive treatment.

What is norovirus?

Norovirus, also known as purulent virus, is a virus that causes non-bacterial acute gastroenteritis. Can be abbreviated as NV. The most common symptoms after infection with norovirus are diarrhea, vomiting, nausea, or accompanied by fever, headache and other symptoms. Vomiting and nausea are more common in children, diarrhea is more common in adults and vomiting is rare. The course of disease is usually 2-3 days. This disease is self-limited and has no sequelae after recovery.

Norovirus-infected diarrhea is prevalent all over the world, which can occur all year round, mainly affecting adults and school-age children, and it is high in cold season. This virus is widely spread in the world. Data show that the detection rate of norovirus in children with diarrhea under 5 years old in China is about 15%. The investigation of serum antibody level shows that norovirus infection is also very common in China.

Norovirus symptoms

1, onset time: the incubation period is 24-48 hours, generally not more than 96 hours.

2. The course of disease development

The clinical manifestations are similar to other viral gastroenteritis, and the onset is sudden. The main symptoms are fever, nausea, vomiting, spasmodic abdominal pain and diarrhea. It can only have vomiting or diarrhea, or it can vomit first and then diarrhea, so it is also called norovirus infectious diarrhea.

Adult diarrhea is more prominent, and children vomit more. The feces are yellow and watery, ranging from several times to ten times a day, without pus and mucus. May be accompanied by low fever, sore throat, runny nose, cough, headache, myalgia, fatigue and loss of appetite.

If the course of disease is long and the condition is serious, the detoxification time is also long, and the infectivity can last for two days after the symptoms disappear. The immune period of this disease is short, and it can be repeatedly infected.

3, norovirus infection check

There was no abnormality in routine laboratory examination, and no pathogenic bacteria grew in the culture. 24-48 hours after onset, stool was examined by immunoelectron microscope and virus particles were found.

Norovirus therapy

What medicine does norovirus take? At present, there are no specific antiviral drugs and vaccines for prevention. Vomiting and diarrhea mainly rely on symptomatic treatment or supportive therapy.

1, oral rehydration salts: mild children take oral rehydration salts recommended by WHO. Serious patients, especially young children and the infirm, should be infused in time to correct the imbalance of water, electrolyte and acid-base.

2, daily care: should pay attention to the patient's food hygiene, eat more fresh, digestible, high-calcium food, drink more water, eat less high-fat food, eat less cold food, at the same time pay attention to children's warmth, less crowded public places.

3. Prevention of dehydration: Although most diseases can recover by themselves, doctors remind that dehydration is the main cause of death from Norovirus-infected diarrhea. For severe cases, especially young children and the infirm, timely infusion or oral rehydration should be given to correct dehydration, acidosis and electrolyte disorder.

4. Nutritional therapy: The principle of nutritional therapy for diarrhea is to adjust diet, stop eating high-fat and indigestible foods, reduce the burden on gastrointestinal tract, gradually restore digestive function, supplement vitamins and electrolytes, and avoid abusing antibiotics.

How to deal with norovirus infection

Treatment of vomit/fecal overflow of norovirus infected persons in polluted places;

1. Arrange others to stay away from polluted places.

2. Wear gloves and masks during the whole process of cleaning up vomit.

3. If there is uncovered food near vomiting and diarrhea, all food should be discarded.

4. Before cleaning dirty sheets and clothes, remove solid pollutants, then soak in 1 diluted household bleach (1 household bleach, containing 5.25% sodium hypochlorite and adding 49 parts of water) for 30 minutes before cleaning. If it cannot be soaked in real time, it should be put in a sealed bag and disposed of as soon as possible.

5. Wipe the vomitus/spilled feces from the outside to the inside with a disposable rag, and then use household bleach diluted by 1 to 49 (containing 5.25% sodium hypochlorite 1 household bleach added to 49 parts of clean water) to clean and disinfect the surface of the contaminated area and its vicinity (it is best to disinfect the area within 2m of the edge of the vomitus/spilled feces), especially where it is frequently contacted.

Let the bleach stay on the surface of the polluted place for about 15 to 30 minutes to inactivate the virus, then wash it with clear water and let the surface air dry naturally.

6. Never use a mop to clean up vomit.

7. Disinfected cleaning utensils must be soaked in household bleach diluted by 1 to 49 (containing 5.25% sodium hypochlorite 1 household bleach added to 49 parts of clear water) for 30 minutes, and then thoroughly rinsed before use.

8. Wash your hands thoroughly after all cleaning work is completed.

Norovirus prevention

1, cut off the transmission route

The main transmission route of viral diarrhea is fecal transmission, and the source of infection is mostly mild patients or asymptomatic carriers. Therefore, the main preventive measures are to do a good job in diet and drinking water, strengthen the management of patients, close contacts and their direct contact environment, and actively cut off the transmission route of the disease.

Step 2 control the source of infection

Students who have been ill should be treated in isolation, suspended from classes and rested at home until the symptoms disappear for 3 days, so as not to transmit the disease to their classmates. Disinfect vomit, diarrhea, contaminated articles and toilets of patients and suspected patients.

3, avoid the disease from the mouth.

Do not eat cold and uncooked food, especially raw shellfish and other aquatic products; For some cold dishes that have been placed for a long time, it is best to eat less or not, drink water after boiling, and don't drink raw water.

4. Pay special attention to food hygiene

Strictly implement the Food Hygiene Law of People's Republic of China (PRC), especially strengthen the hygiene management of catering industry (including restaurants, individual restaurants, food stalls around schools, etc.). ), farmers' markets, collective canteens, etc. Food processors should pay strict attention to personal hygiene and be transferred from their jobs as soon as they get sick.

Step 5 cook food thoroughly

Avoid eating food that is not thoroughly cooked. Norovirus will die in 30 seconds in a high temperature environment exceeding 80℃. Therefore, it is preventable to pay attention to thoroughly cooking food, especially seafood and shellfish.

6. Health education

Strengthen publicity and education focusing on the prevention of intestinal infectious diseases, advocate drinking boiled water and not eating raw aquatic products, especially shellfish, wash raw fruits and vegetables, wash hands before and after meals, and develop good hygiene habits.

7. Personal preventive measures

(1) Exercise and improve body resistance.

(2) Pay attention to personal hygiene and wash your hands frequently to prevent infection by virus pathogens.

(3) Do not eat cold food and uncooked food, and reduce eating in off-campus restaurants, especially unlicensed street shops.

(4) In the popular season, go to crowded public places less, eliminate infection channels and reduce infection opportunities.

(5) Patients with diarrhea at home should be actively treated and properly isolated.

(6) As soon as there is any situation, see a doctor immediately and report to the unit and the community.

Norovirus transmission route

Norovirus infection can occur all year round, especially in winter. And humans are the only known hosts. The sources of infection are the sick, the recessive infected and the healthy carriers. The main route of transmission is fecal transmission. In addition, daily contact can also cause the spread of diseases.

The main routes of transmission are:

1, infectious food poisoning, infectious gastroenteritis.

2. Eat raw aquatic animals, such as shellfish and oysters.

3. Vomiting and feces of patients with non-bacterial acute gastroenteritis, or dust infection after drying.

Norovirus high-risk population

1, the disease mostly occurs in schools, families, tourist areas, hospitals, canteens, troops and so on. And it's easy to break out because of eating together, using public tableware or crowded people. But the high temperature of 85℃ can kill norovirus.

2. Norovirus likes cold and is afraid of heat. Winter is the high incidence season of norovirus infection, and people are generally susceptible to norovirus.

3.4- 12-year-old children are more susceptible to infection because of their low resistance and immunity. Norovirus can spread through contaminated water, uncooked food, seafood, shellfish, droplets in the air, etc.

Norovirus is most easily infected by people with weak constitution such as the elderly and children.