A team of international experts from WHO recently conducted a joint investigative mission in Guangdong Province, China, along with colleagues from the Ministry of Health of China, the Ministry of Agriculture of China, the Chinese Centre for Disease Control and Prevention and the Guangdong Centre for Disease Control and Prevention.
The overall aim of the mission was to try to identify the sources of infection in the SARS case of a 32-year-old television producer, as well as two other cases -- a young waitress and a 35-year-old businessman. All three are located in the city of Guangzhou.
The joint mission, from January 9 to 16, 2004, did not yield a definite source of infection in any of the cases, and the investigation continues. Still, there were several intriguing findings, including some pertaining to possible animal reservoirs of the SARS coronavirus. These were shared with the media at a briefing on Friday, January 16. However, some media reports have over-simplified these findings, and WHO would like to take the opportunity to clarify the situation.
Civet cats: WHO environmental experts took samples from cages that originally housed civet cats at an animal market as well as the restaurant where the waitress worked. A number of these samples tested positive for traces of the SARS coronavirus. This would add to recent studies by scientists in Guangdong Province, China, and Hong Kong, SAR, that point to the civet cat as a reservoir of the SARS coronavirus. However, it is still unclear exactly if or how civets transmit the SARS coronavirus to humans.
It is also possible that other animal species are reservoirs and may be able to transmit the SARS coronavirus, but these species have not been conclusively identified so far. Much more study needs to be done on animal reservoirs of the SARS coronavirus, and WHO encourages China and the international community to fund and conduct such research as a matter of importance.
Investigation continues: The conclusion of the latest joint mission does not mean that the investigation into the source of infection in these three cases is over. Some media reports have suggested that, but we would like to reiterate that the investigation continues. So far, there is no indication as to what caused the infection in the first case, the television producer. Nor is there a clear answer in the third case, the businessman. There is strong circumstantial evidence in the second case, the waitress, linking civet cats to her infection - but, once again, further research is needed.
A "milder" or "different" disease? : There is no conclusive evidence so far that these three cases represent a "milder" disease or a new strain of SARS. It is true that the three patients have displayed milder symptoms than some of the more severe cases during the 2003 outbreak.
However, these are only three cases, and do not represent the spectrum of cases seen in 2003. There were relatively mild cases during the 2003 outbreak as well. These three people are young, and it was seen last year that many younger patients recovered faster too.
As to whether these three cases represent a new strain of SARS, experts from WHO are of the opinion that there are no conclusive findings so far that support this.
WHO will continue to monitor the situation, and will provide updates as necessary.