The disease is believed to be caused by Streptococcus suis and the first case was reported in June 2005 in Sichuan province of China. The infected persons were mostly farmers and butchers, who handled infected pigs or people who handled the contaminated pork products. According to investigations in China, the infected pigs are thought to have come from up to 300 different farms, which were then spread across 70 areas in and around the two cities of Ziyang and Neijiang. No cases have been reported outside these areas. Till now no person to person transmission was reported. The death doll from this rare disease has killed 24 people in southwest china with more than 117 people feared infected.
Chinese health officials report that the disease is caused by known bacteria from pigs, though the size and virulence of the outbreak has baffled the World Health Organization. "It's never occurred in an outbreak this big before," WHO spokesman Bob Dietz told AFP. "We're accustomed to seeing only one or two cases. We're not accustomed to this large number of people getting infected. And we don't understand why that is."
The first recorded human case of S. suis was in Denmark in 1968. Only 200 cases have been reported since then, excluding the current outbreak. Symptoms of the disease include high fever, nausea, vomiting and hemorrhage.
The high mortality rate is worrying - nearly one third confirmed cases have since died. Sichuan is China's second largest pork producing province. All 469 infected pigs have been buried and pork exports have been suspended from the areas involved. The Chinese Health Ministry is urging people not to process or slaughter infected animals in an effort to contain the spread.
(Source: The New Scientist)