CHINA: A brief posting on a Chinese government website yesterday confirmed that two strains of the deadly avian influenza virus, H5N1, were isolated from pigs in China last year for the first time, according to a translation made available in Geneva by the World Health Organisation.
"We have no additional information on the types of samples taken but pigs, we know, are a type of mixing vessel for flu viruses and this changes the pandemic equation," said Dr Karl Stohr, director of the WHO Influenza Programme.
The fear is that pigs could become the conduit for a new influenza strain which would raise the prospect of a pandemic among humans. No vaccine is yet available to combat such an outbreak, though work is under way on developing one in the United States based on the genetic make-up of the H5N1 virus.
The Chinese Ministry of Agriculture has offered no further explanation as to the methodology used in isolating the strain or the specific nature of the infection, which was brought to public attention last Friday by Dr Chen Hualan, the head of the China National Avian Influenza Reference Laboratory.
WHO is pressing for more details on the discovery.
According to the Chinese statement, there were no cases identified in pigs in relation to the outbreaks of avian influenza which took place this year when the Chinese Ministry of Agriculture "conducted pathogenic and serological surveillance on 1.1 million specimens of poultry and pigs.
The result of surveillance showed that no H5N1 was detected in pigs." Dr Stohr said there was no active influenza surveillance of pigs in China, beyond random testing whenever there was an outbreak of avian influenza in poultry.
He said there was also little understanding of which human influenza viruses were circulating in pigs