David Heymann says the situation in the western provinces is worrying The Sars outbreak which is still peaking on the mainland remains a big danger to the world even though other places with major outbreaks have brought the disease under control, a senior World Health Organisation executive warned yesterday. In an interview with the South China Morning Post, the WHO executive director of communicable disease David Heymann said the most important task now was not to give Sars a chance to turn into another endemic disease, such as tuberculosis and malaria. 'We think Sars has not peaked in China. The problem in China is not only a problem for Hong Kong but for the world because people travel very rapidly internationally. 'Everywhere with a major outbreak including Singapore, Toronto and Hong Kong, the disease is well contained. The big question is what is going on in China? How can we stop the disease there? Now Taiwan is having a very serious problem. We're very concerned about the western provinces [in China] where we believe the health system is less strong.'' Dr Heymann, speaking from the WHO's Geneva headquarters yesterday, warned that under the current screening at the mainland-Hong Kong border, infected patients could still enter Hong Kong during the incubation period. Dr Heymann said Guangdong was now seeing very few cases each day and the province had done well. 'In the rest of China, we are more worried. We expect there to be screening of passengers at international airports, and we expect they [mainland officials] will detect cases, trace contacts and make sure that the contacts will not become additional sources of spreading the disease.'' China attracted international criticism for covering up the outbreak in the early stages. But Dr Heymann did not wish to dwell on the issue. 'It doesn't do any good to look backward, we are looking forward, and we believe China is a full partner with the WHO. We are becoming more and more satisfied with the information given by the Chinese government.' He said the situation on the mainland would play no part in the WHO's assessment of conditions in Hong Kong, adding that Hong Kong was doing an excellent job. On Tuesday, Dr Heymann held a video conference with Hong Kong Secretary for Health, Welfare and Food Yeoh Eng-kiong and set out three criteria that Hong Kong must meet to have the travel advisory imposed against it as a result of the Sars outbreak lifted. The WHO stressed that the number of new cases must be fewer than five for at least three consecutive days. Hong Kong must have stopped spreading the virus to other nations, which has not happened for two or three weeks, and the mode of transmission must be understood in each case. 'We hope that we can put this disease back in a box and contain it so it doesn't become another endemic disease in the human population like TB and malaria,' Dr Heymann said.