新宿区 Shinjuku CityHOME

Choose Language

Shinjuku City websiteLeave this page and go to the Shinjuku City website

Menu
Current Page
Shinjuku City Official Website > Foreign Language Top Page > Insurance, Health Maintenance and Welfare > Norovirus Food Poisoning and Infectious Stomach Flu

Norovirus Food Poisoning and Infectious Stomach Flu

Please Be Especially Careful During Winter!

Although cases of norovirus food poisoning and infectious stomach flu occur year-round, they are particularly rampant from early winter to early spring.
Norovirus spreads very easily. Even a small amount of the virus can be transmitted orally via foods, hands or fingers. It multiplies in the human intestinal tract, leading to vomiting, diarrhea and stomach pain. If vomiting and diarrhea persist, it is wise to drink plenty of fluids to avoid dehydration and see a doctor.
It’s a good idea to know the symptoms of norovirus and to be especially careful about taking preventive measures to avoid this disease.

■ Characteristics
1 Even a small amount of the virus can cause disease.
2 In some cases symptoms may be light, and there are also cases in which no symptoms appear (asymptomatic).
3 Regardless of whether symptoms appear or not, a large amount of the virus appears in the stool of an infected person.
4 Most cases of food poisoning are caused by an infected person contaminating food while preparing it.

■ Infection Routes
◎ A person can become infected by eating food contaminated with norovirus.
・This often occurs when an infected person prepares food.
・Other cases include instances when bivalve clams are undercooked and the virus is not killed.
◎ An infected person can transmit the virus to another person via stool or vomit.
・Secondary infection from coming in contact with the stool or vomit of a patient.
・Infection from droplets within the home or a facility.

■ Symptoms
◎Incubation Period
Between 24 and 48 hours from the time of infection to when symptoms appear.
◎Main Symptoms
Nausea, vomiting, diarrhea, stomachache, low-grade fever for one or two days.
In some cases no symptoms may appear, even if a person is infected, and in other cases the symptoms are similar to those of a slight cold.

■ Prevention
Wash your hands carefully after using the toilet, before cooking, and before meals.
Do not prepare food if you are not feeling well.
If you have contact with a stomach flu patient, make sure you dispose of the patient’s waste and/or vomit properly to prevent the disease from spreading.
Heat foods that present a risk of causing norovirus infection thoroughly to their center (90 seconds or more at between 85 and 90℃).
Wash and disinfect cooking utensils thoroughly with hot water or a household chlorine-based bleach) after use.

Inquiries About Food Sanitation
Food Sanitation Section, Sanitation Division (Shinjuku City Office Annex 2, 3F)
Tel: 03-5273-3827
Fax: 03-3209-1441
About Infectious Diseases
Health Consultation Section, Public Health Promotion and Disease Prevention Division (Shinjuku City Office, New Wing of Annex 2, 1F)
Tel: 03-5273-3862
Fax: 03-5273-3820

December 5, 2022