Fears of the return of SARS

China is rushing to quell public fears after confirmation on 5 January of the first naturally acquired case of severe acute respiratory syndrome (SARS) since the disease was contained in July last year.

The patient, a television producer from the southern province of Guangdong, became ill on 16 December. He was isolated in hospital in the provincial capital of Guangzhou, and is now making a good recovery.

In the wake of that case, there were also concerns earlier this week about the emergence of SARS in the Philippines, where a domestic maid returned home for a holiday after working in Hong Kong and showed suspicious symptoms of the disease. But tests have shown that the patient, known as MD, is suffering from bacterial pneumonia instead. Her condition is currently improving.

"The country's Department of Health and Hong Kong's Ministry of Health are in close coordination, and the re-classification of MD from a SARS suspect case to simply pneumonia will not mean that we will be letting our guard down," says Philippine health secretary Manuel Dayrit. "We will continue to be vigilant in ensuring that SARS does not enter any of our countries."

In China, a quarantine has been extended to 81 of the SARS patient's contacts, all of whom have remained healthy. "The system of identification and contact-tracing seems to be working," says Julie Hall, the Communicable Disease Surveillance and Response Coordinator for China at the World Health Organization (WHO).

The case was confirmed by tests carried out at two laboratories in Hong Kong and one in Beijing, which found a sharp rise in the patient's production of antibodies to the SARS virus. Researchers at the University of Hong Kong also say that the patient's virus is a close genetic match to samples taken from masked palm civets (Paguma larvata) and other animals in the markets in and around Guangzhou.

On the basis of these results, provincial officials plan to kill some 10,000 civets currently held for sale as food.

But experts are questioning this strategy. "Raccoon dogs, badgers, ferrets, house cats and rodents can all carry the SARS virus," says Albert Osterhaus, a virologist at Erasmus University in Rotterdam, the Netherlands. "A more comprehensive approach is needed."

DAVID CYRANOSKI