August 22, 2007

International organisations concerned with China's pig disease outbreaks

Although China has reassured international organizations that it has its pig disease situation under control, experts are worrying that China is hiding what could turn out to be a far more dangerous disease.

China has identified the disease afflicting pigs in the country as blue ear disease or porcine reproductive and respiratory syndrome or PRRS.

Experts are alarmed at the large number of pig deaths in China, saying it is unusually high.

Juan Lubroth, senior officer of infectious diseases at the Food and Agriculture Organization said Chinese scientists told the UN agency the virus has undergone changes and seemed to be more virulent than what was previously described in previous outbreaks elsewhere.

Fatal cases from PRRS in the past mostly involved young pigs, but now it is infecting adult pigs, Chinese scientists said. Moreover, the disease duration is shorter and it has become more contagious. Environmental factors such as temperature and high humidity, along with secondary bacterial infections, may be sparking mutation, they said.

The disease needs to be studied further and scientists have to see whether the virus is acting alone or acting in synergy with some other pathogens, Lubroth said. The unknowns associated with the virus means an independent confirmation from a laboratory specializing on the PRRS virus is essential, he added.

Jia Youling, China's chief vet, however said Monday no such request has been made from international organizations and adds he does not know where to send the samples because he does not know who needs them.

He added that China does not need international help as Chinese experts fully understand the structure of the virus.

Veterinary experts are also investigating a blue ear outbreak in Vietnam, raising concerns that the virus may have spread beyond China's borders.