February 18, 2008

China's diseased pigs afflicted by multiple viruses

More than one type of virus sample was found when a US delegation sampled diseased pigs in China in a two-week visit to the country last December, according to Dick Hesse, Kansas-State University's director of diagnostic virology.

The problem in China's herd appears to be a multifactorial disease complex, Hesse said.

Researchers did find porcine reproductive and respiratory syndrome virus, the disease which killed millions of pigs in China last year. However, not all cases were killed by the same disease. The majority of the samples contained more than one type of virus. Classical swine fever virus, porcine reproductive and respiratory syndrome virus and porcine circovirus 2b were most commonly found in diseased pigs.

China's pig population last year devastated by Blue Ear Disease, resulting in the deaths of millions of pigs. A variant form of porcine reproductive and respiratory syndrome was believed to be the cause of the disease. The investigative team worked with prominent scientists from four research centers that have had extensive experience with the disease.

Hesse said the limited monitoring of animal disease in China and a lack of uniform practices among pig producers has likely allowed such diseases to spread in China, adding that China needs the type of effective vaccines found in the US.

The team helped in the diagnostic aspect and assist Chinese researchers in the technology and techniques to understand and control the disease. Such technology includes real-time polymerase chain reaction (PCR) developed at Tetracore and Kansas-State University, which were used to look for and provide rapid laboratory diagnosis of likely viral agents.