The World Health Organization said on 5 July that the global outbreak of severe acute respiratory syndrome (SARS) had been contained, but it urged health authorities across the world not to be complacent, because the world was not yet free of the disease. WHO removed Taiwan, where the last SARS case was detected and the patient isolated on 15 June, from a list of areas of recent transmission that travellers are advised to avoid. WHO officials said the patient in Taiwan had passed two consecutive incubation periods of 10 days without passing on the disease, the WHO criterion defining the end of the outbreak. Since then no new cases have been reported. However, they warned that in the absence of a vaccine and a cure the possibility of seasonal recurrence of SARS could not be ruled out. It remains unclear whether patients without symptoms can infect other people, and scientists are still working on a diagnostic test to detect cases in the early stages. Without such a test the next flu season could trigger panic again. Gro Harlem Brundtland, WHO's director general, said the SARS outbreak was over but the fight would go on. There were still nearly 200 patients with SARS in hospitals, she said, and she urged authorities to be vigilant in case cases had slipped through the surveillance net. "We have only known about this disease since February. It spread rapidly to 30 countries on all five continents and affected 8439 people, killing 812," Dr Brundtland said. "But today, due to an unprecedented global collaboration in public health, the World Health Organization can say that the SARS outbreaks have been contained worldwide." A great deal more is now known about SARS than in November 2002, when an unfamiliar respiratory disease was first detected in Guangdong and carried by Dr Liu Jianlun, a 64 year old doctor, from the southern Chinese province to Hong Kong. The global outbreak can be traced to the night he spent in Hong Kong's Metropole Hotel on 21 February 2003, when he passed the virus to at least 16 other guests on the same floor. It then fanned out across the world, leading to outbreaks in Singapore, Toronto, and Hanoi, as well as in Hong Kong itself. Scientists now know that the SARS virus belongs to the coronavirus family, which includes the common cold virus, that its maximum incubation period is probably 10 days, and that one person can infect a great number of people in a short space of time. They know it originated in Guangdong but are still not sure whether, as preliminary studies indicate, it jumped species from the civet, a member of the cat family, or the racoon dog, both of which are delicacies in the cuisine of southern China.