SARS returns to China.

As China confirms its first case of severe acute respiratory syndrome (SARS) since July 2003, and two further suspected cases are hospitalised, the source of the virus remains unclear.

The disease in a 32-year-old photographer from Guangdong province was reported on Dec 22,2003, since which time the man has tested positive for a new strain of the coronavirus and remains in quarantine. Although it is not known exactly how the SARS coronavirus is contracted by human beings, it is believed that handling or eating civet cats and other exotic animals has a role in transmission. The man, however, claims not to have eaten any wild animals before becoming ill, but does admit to touching a rat.

The two suspected cases-both also in Guangdong-are a 20-year-old waitress at a wildlife restaurant and a 35-year-old male shopkeeper, who were reported on Dec 31 and Jan 9, 2004, respectively, and have since been transferred to a designated SARS hospital in Guangzhou, the capital of Guangdong.

At a meeting of the Royal Society (London, UK) on Jan 13, Nan Shan Zhong of the Guangzhou Respiratory Disease Research Institute reported that 76% of palm civets in Guangdong were positive for SARS coronavirus by isolation or PCR in throat swabs or faeces. Still, this does not confirm that civets are the reservoir for human infection. Nevertheless, health officials forged ahead with a cull of all civets in market stalls or on farms in Guangdong between Jan 5 and 10, drowning them in disinfectant or water and incinerating the bodies.

According to Jeffrey Gilbert, a zoonosis expert on the WHO SARS team, there are concerns about the preservation of scientific samples: “If evidence was enough to cause emergency measures to be taken we are effectively disposing of infected material”.

People in southern China eat wild animals as a delicacy. Gail Cochrane, veterinary director of the Animals Asia Foundation, an organisation that has monitored Chinese markets for 20 years on welfare grounds, told TLID that “In the past 15 years there has been a massive growth in these markets as the economy has thrived. Animals are brought in from all over Guangdong”.

As yet there have been no secondary cases of SARS transmission from the confirmed case, and it remains to be seen whether any will materialise by the end of January, when the incubation period for contacts of the confirmed case comes to an end.