Japan has been hit by an outbreak of a common stomach virus, prompting the prime minister to call for steps to deal with infections that have reached a record high this winter.

Over 65,600 people throughout the country are thought to have been infected by norovirus between November 27 and December 3, the highest since data was first collected in 1989, according to the National Institute of Infectious Diseases.

Four people living at nursing homes, three in their 90s, died due to the infection which causes severe diarrhoea and vomiting, the Asahi newspaper reported yesterday, saying all but two of Japan's 47 prefectures have issued warnings of a potential epidemic.

"Prime Minister (Shinzo) Abe has given instructions to the relevant ministries to prevent the spread of the infection," Chief Cabinet Secretary Yasuhisa Shiozaki told a news conference.

The Health Ministry says there are no vaccines against the virus and advises people to wash their hands carefully before eating and after using the toilet.

Shares in companies that make products to protect against norovirus have shot up on the Tokyo stock exchange, with hand wash and gargle maker Meiji Seika Kaisha Ltd jumping 11.5 per cent in the past week.

Other beneficiaries include clinical reagents maker Eiken Chemical Co, whose have risen 14.8 per cent in a week.

The ministry said shellfish including oysters should be thoroughly cooked to destroy the virus, as it is often found in such seafood.

Norovirus has caused mass infections in other countries, including the United States, where hundreds of passengers on a cruise ship fell ill to it in two separate incidents in early December and in November.

Source: China Daily