A travel warning is unlikely to be imposed on Beijing if Sars reoccurs on the mainland this winter, as long as a new surveillance system is effective, says WHO China representative Henk Bekedam. Mr Bekedam said the World Health Organisation hoped that a surveillance system, aimed at identifying suspected Sars cases quickly, could help avoid the need for any travel warnings to be issued against Sars-hit areas. Under the system, hospitals have to report any cases with symptoms similar to Sars to the local and national centres of disease prevention and control. 'With the surveillance system ... even if you have 200 cases of Sars, if they are isolated and in the hospitals, there might be no need for a travel warning,' Mr Bekedam said after a media conference marking the first World Suicide Prevention Day yesterday. Trials of the surveillance system, initiated by the Ministry of Health, will begin in hospitals in Guangdong, Shanxi, Hebei and Beijing next week. Mr Bekedam said he expected the system to expand to 10 provinces within a month. Eventually, a national system will be established. Liang Wannian, deputy director of the Beijing Health Bureau, said fever clinics could identify cases more rapidly now that sufficient training had been provided and standard procedures established. It remains unclear, however, how often the Chinese health authorities would pass on the information to the WHO. Mr Bekedam said he was confident the WHO would be informed about suspected cases on a timely basis, but that the WHO would try to work out standard procedures with the authorities on how the information would be passed along, he said. In preparation for the possible return of the deadly virus, dozens of serum samples collected from recovered Sars patients have been stockpiled, a medical expert in Guangzhou said. Zhong Nanshan, the country's foremost authority on Sars, and the director of the Guangzhou Institute of Respiratory Diseases, warned of a return of the illness in winter or spring but said the outbreak would be sporadic and that Guangdong was prepared to deal with it. 'Guangzhou already has mature alert and treatment systems so even if Sars returned it would not be an epidemic. 'It would be a sporadic outbreak,' state media quoted Dr Zhong as saying.