BEIJING, July 27 -- Doctors are yet to find specific drugs to treat the disease that has killed 24 farmers in Southwest China, officials said yesterday.

    The Ministry of Health has blamed Streptococcus suis, a bacteria carried by pigs, for the disease, which broke out on June 24 in the cities of Ziyang and Neijiang in Sichuan Province.

A mysterious disease patient receives medical treatment in a hospital in Ziyang of Sichuan Province July 25.  (Xinhua)

    The number of human cases has risen to 117, including 76 confirmed and 41 suspected infections. Among these, 21 patients are in a critical condition.

    At the moment doctors are relying on heavy doses of antibiotics to treat patients, but with the death toll mounting it is clear this approach is unsatisfactory.

    "The Chinese Centre for Disease Control and Prevention is conducting drug sensitivity tests to find a more effective treatment," said Ministry of Health spokesman Mao Qun'an.

    But despite the lack of a reliable treatment, experts believe the outbreak can be dealt with effectively.

    The pig-to-human infection can be prevented if people refrain from slaughtering, processing or eating infected pigs, said Chen Huanchun, vice-president of Huazhong (Central China) Agricultural University.

    Chen, also a member of the expert group set up by the Ministry of Agriculture to conduct on-the-spot investigations, said the bacteria can only infect people through open wounds or if they digest the infected meat.

    Pork prices have dropped 20 per cent in Ziyang, said Cao Jingli, a government employee in Ziyang.

    Mao said China has been reporting the situation to the World Health Organization every day, but as yet there has been no response.

    Chen said the Guangzhou Animal Biological Medicine Plant is working on a vaccine to protect pigs from the disease, and is expected to produce a viable inoculation in about a week.

    After a two-to-three-day safety test, the vaccine will be used widely among pigs, said Chen.

    The infected farmers and pigs are scattered among 73 villages around the two cities. So far no epidemic has been reported in other regions of Sichuan or in the rest of the country.

    Investigations suggest the infected pigs had been raised by at least 300 different farms, all with poor sanitary conditions, experts said.

    No infected pigs have been found in large- or medium-sized breeding farms, according to a statement from Sichuan Province.

    Experts said they are searching for the reason for the outbreak as many healthy pigs also carry the bacteria but do not fall ill or transmit the disease.

    In Ziyang and Neijiang, all 469 pigs with the disease have been buried.

    The two cities have also set up 50 temporary checkpoints to stop pigs from being transported outside the infected villages.

    Wang Jian, a 41-year-old farmer in Panshi Village in Danshan Town, Ziyang, is worried that his four pigs will not survive the epidemic.

    "If they die, it would mean a loss of 2,400 yuan (US$296), or one-quarter of my family's annual income," said Wang.

    More than 50 pigs in his village have died from the disease.

(Source: China Daily)