The race to become the next World Health Organisation director-general looks wide open, with former director of health Margaret Chan Fung Fu-chun holding a slight edge over her two closest rivals because of her international exposure, sources close to the WHO said. But Dr Chan, with the WHO for three years, and its assistant director-general for communicable diseases, has yet to release her election manifesto. Instead, she has opted for a globetrotting, back-breaking campaign tour to cover the 34 member states which hold the votes on the WHO executive board. Her two closest rivals - Japan's Shigeru Omi and Mexico's Julio Frenk - had earlier starts after their candidacies were declared in June. The two countries have pulled out all the stops to support them. Dr Frenk attended last week's international Aids conference in Toronto. He is in the midst of a global campaign tour as well, while Dr Omi has been wooing Africa and Eastern European countries, which might hold the swing votes. Like Dr Chan, both Dr Omi and Dr Frenk - each accompanied by campaign aides on their overseas trips - keep their travel plans secret. Dr Omi, the regional director of the WHO Western Pacific region, which includes the mainland, Hong Kong and Macau, said: 'I have already visited many member states ... I have received positive responses from them.' Dr Chan and Dr Omi have taken leave from their WHO posts, as required by the election rules. Apart from being assistant director-general, Dr Chan was also named the WHO's director-general representative on influenza preparedness. China declared Dr Chan's nomination on July 25. She has only 21/2 months to campaign before the election on November 6 and 9. Nominations close on September 5. Dr Chan has said her globetrotting campaign is being funded by the Chinese government. Her sole campaign aide, senior administrative officer Estrella Cheung King-sing, who arrived in Geneva on Friday, is the only visible Hong Kong government support provided to her. Ms Cheung, a senior administrative officer last posted at the Economic Development and Labour Bureau, said yesterday she would be the only worker in Dr Chan's election headquarters - a room at the Hong Kong Economic and Trade Office in Geneva - and would not be with Dr Chan on her overseas campaigns. Officials from the Ministry of Foreign Affairs and mainland embassies and commissions will accompany her.