The number of encephalitis B infections in Yuncheng in north China's Shanxi Province has risen to 65, according to the latest statistics released by the city's health bureau.

The city wants all children under 15 to receive a vaccination and is also encouraging all adults to be inoculated.

Zhou Ying, the city's top health official, said yesterday the authorities had brought the epidemic under control after adopting a series of emergency measures.

The Shanxi Provincial Health Department has allocated 420,000 encephalitis B vaccines to the city and is preparing another 1 million to meet the growing demand.

So far, four infected people have been cured and have left hospital. Thirty-eight others are still receiving hospital treatment and four are recovering at home.

Since its outbreak on Sunday, the disease has claimed 19 lives in the city.

The epidemic has infected 61 villages near the city. The oldest patient is 80.

Zhou said this year's high temperature and excessive rainfall had resulted in a sharp increase in the number of mosquitoes, which carries the disease.

Zhou said the encephalitis B virus comes from domestic animals, such as pigs, cattle, sheep, horses, chickens and ducks.

It spreads when mosquitoes bite infected animals and then bite a person.

Zhou said the disease has a latent period of between 5 to 15 days, with symptoms such as high fever, headache, vomiting and, in extreme cases, coma.

Zhang Jiemin, an expert from Shanxi Province's Centre for Disease Prevention and Control, said people should not be worried as there was no sign that the outbreak would extend further.

He added that not all those bitten by virus-carrying mosquitoes would automatically be infected. People with poor immunity systems are more likely to become infected.

As the temperature drops and the number of mosquitoes falls, the epidemic will gradually disappear.

Zhang said encephalitis B outbreaks happened occasionally in the province.

30 affected in Nanjing

In Nanjing, capital of east China's Jiangsu Province, about 30 cases of encephalitis B infections had been reported since the first patient was confirmed on July 20, according to local newspaper Contemporary Express.

All patients are children under 12, according to Yao Wenhu, head of the infectious diseases department at the No 2 Hospital in Nanjing, the only hospital allowed to deal with the outbreak in the city.

The number is similar to those in previous years, a dean surnamed Lu with the Nanjing Municipal Disease Prevention and Control Centre said.

Lu said that as the 30 patients come from three provinces, this was not a major outbreak.

Except for three patients from the suburbs, the infected children are from rural areas in neighbouring Anhui and Zhejiang provinces.

"Most infected children had already caught the encephalitis B virus in their hometowns before coming to Nanjing, where their parents work," said Lu.

Lu refused to reveal whether any of the patients had died, saying that only two or three were in a critical condition, while the others had fully recovered or were stable.

The period between the middle of July and the middle of August is the prime time for encephalitis B, when the weather provides good breeding conditions for mosquitoes, said Lu.

(China Daily August 17, 2006)