Hong Kong's estimated 200,000 female sex workers have been described as a 'time bomb' in the spread of Sars and other infectious diseases by two doctors in the latest issue of the Hong Kong Medical Journal. They have recommended that the government set up outreach clinics, modelled on similar institutions overseas, so medical workers can take prevention and treatment services to prostitutes, and to keep opening hours suitable for them. The paper was written by William Wong Chi-wai, assistant professor of the Chinese University's department of community and family medicine, and Wun Yuk-tsan, of the Hong Kong College of Family Physicians. They wrote that more doctors should also be trained to raise health issues with prostitute patients. The government and the medical community should also provide free hepatitis B vaccines to sex workers. 'Hong Kong has been avoiding much of the relevant debate [on female sex workers], because mandatory screening and improved treatment access would be regarded by many members of the public as tolerating, if not, legalising prostitution,' they wrote. The women faced 'an occupational hazard' through contact with clients, but social marginalisation and stigmatism had deterred many from seeking proper care and treatment. 'These clashing interests can cause a potential 'time bomb' in the spread of Sars or any other infectious diseases in the community,' the doctors wrote. The two experts said previous studies put the rate of hepatitis B infection among female sex workers at 62 per cent, compared with 33 per cent in the general population. The virus, which can lead to liver cancer, is transmitted through contact with contaminated bodily fluids. The incidences of sexually transmitted diseases among sex workers had been estimated to be 40 per cent for non-specific genital infections, 1.2 per cent for gonorrhoea and 0.1 per cent for HIV, they said. The women's lifestyles affected their well-being. 'The time they spend waiting for clients is usually very long and restricts them from doing any outdoor exercise or cooking at home, while also encouraging unhealthy lifestyles such as smoking and gambling.' Professor Wong told the Post that the new medical charging policy was also deterring sex workers, especially those from overseas, from seeking treatment at government social hygiene clinics.