In January, China identified the contagious pig disease outbreak, till then known as the ‘high- fever disease’, as blue ear disease, or Porcine Reproductive and Respiratory Syndrome (PRRS). The outbreak had begun last May.

Says Jia Youling, head of the veterinary department of the ministry of agriculture:"The 'high-fever disease' was caused mainly by the blue-ear disease virus, but other viruses cannot be ruled out."

According to Jia, the death rate from the 'high-fever disease' accounted for 0.2 percent of the pig population.

The Blue Ear virus was discovered in the United States in 1987 and has since spread worldwide, posing no threat to humans. But it has mutated in China, making it hard to identify and becoming more deadly to pigs, says Jia.

"This variation of Blue Ear disease is a completely new variation," informs Jia. "It is the first time our country and the world has experienced this kind of the disease."

Within three months of the disease being identified, a vaccine was developed; and the ministry authorized 12 factories to produce the vaccine.

Government figures from the Ministry of Agriculture put at 18,597, the number of pigs killed by the disease in the first five months of 2007, with outbreaks found in 22 provinces, or about two-thirds of the country's provinces and regions.