A new tuberculosis prevention programme for children and the elderly may be launched after signs that the once-widespread disease is lingering in the SAR, a Department of Health official said. A pilot project for 3,000 elderly people was recently launched to screen them for TB, with the results due in a few months. Also under consideration is more widespread preventive treatment for latent TB in children under five and people living with HIV, said the consultant in charge of the department's Tuberculosis and Chest Service, Dr Tam Cheuk-ming. 'From the 1960s to 1980s, the TB rate declined quickly, but in the last decade, the decreasing trend stopped,' said Dr Tam, who recently attended a World Health Organisation (WHO) technical advisory meeting in Osaka for western Pacific countries. Department figures showed there were 404 people with TB per 100,000 in 1960, 254 in 1970, 159 in 1980, 114 in 1990 and 113 in 2000. The Osaka meeting urged Hong Kong, Japan and Singapore to step up TB control. 'TB rates are relatively high in these countries - several times higher than other nations with a similar GDP. Given the right conditions, there is potential that these rates could soar,' the WHO warned. Dr Tam said the incidence of the disease could be due to the ageing population, longer life expectancy, more mobility and overcrowding. He said a large pool of infected people who had not developed TB, but whose disease could reactivate without being diagnosed, was a major reason for the slowdown in the decline. One-third of the Hong Kong population, or two million people, have been exposed to tuberculosis bacilli, he said. 'There is also a recommendation that we should do more research into the other possible reasons for the stagnation and the cost-effectiveness of possible interventions,' Dr Tam said. The department's figures showed the highest TB rate was in Yau Tsim Mong, where 198 people in every 100,000 had TB in 2000. Sai Kung had the lowest rate of 75.6 per 100,000. Dr Tam said it might be that more elderly people lived in the old urban districts of Yau Ma Tei, Tsim Sha Tsui and Mongkok. 'TB is an interesting disease. The germ can stay for a very long period inside the body, the latency period can be very long, from several months to several years and more than decades. When people become old, and their immunity is not good, the germ wakes up and causes trouble,' he said. A total of 7,578 TB cases were reported in 2000 and 7,262 last year. One-third involved people aged over 65.