Cases of Tamiflu-resistant influenza are increasing in Hong Kong as they have been in the United States, early on in the peak flu season, the city's top disease expert says. There were 28.1 cases of flu-like illnesses for every 1,000 consultations for the week ending January 3, slightly up from the previous week, the Centre for Health Protection said. The centre monitors flu outbreaks by keeping track of private clinics designated as part of a sentinel surveillance system. Thomas Tsang Ho-fai, the centre's controller, said laboratory tests showed 90 per cent of flu-like illnesses were caused by the H1N1 virus, which has been shown to be resistant to the antiviral Tamiflu in the US. Just a few cases were of the A/H3N2 or B viruses. The flu has also stricken world tennis women's No1, Serbia's Jelena Jankovic, who had to withdraw from the JP Group Classic tournament at Victoria Park. The dominant circulating strains in Hong Kong have mimicked those in the United States. Dr Tsang said yesterday that Tamiflu, the antiviral of choice, was not being routinely given by local doctors and hospitals. Vaccination is the best protection against seasonal flu, especially for those more vulnerable, such as the elderly. Food and Health Secretary York Chow Yat-ngok yesterday urged the elderly, those with chronic illnesses and young children to get their vaccinations now, rather than wait to the end of the flu season. He said the risk of bird flu has increased this winter. 'We expect that the risk will continue to be reasonably high this winter, judging from the recent outbreaks in various countries including in Hong Kong.' Dr Tsang and Dr Chow were speaking after watching an exercise to evaluate the city's contingency plans for handling suspected human cases of the H5N1 virus at a clinic. Late last week, the Atlanta-based US Centres for Disease Control and Prevention announced that Tamiflu, the Roche Holding drug for flu, could not fight more than half of the H1N1 strain that had been analysed in the US. Joseph Bresee, the CDC's chief of influenza epidemiology and prevention, said 72 of the 73 H1N1 viruses the agency had tested were Tamiflu-resistant. Hong Kong's flu peak season typically occurs from January to March, with a second, milder, peak during the summer. Under the city's pandemic preparedness plan, people suspected of having the H5N1 bird flu will be first taken to designated clinics. At yesterday's exercise at the Shau Kei Wan Jockey Club Clinic, two people suspected of having the H5N1 flu - an adult and a boy - were taken by ambulance to the Pamela Youde Nethersole Eastern Hospital. Eighty-four staff took part in the four-hour exercise. Also attending were observers from the Ministry of Health and the French consulate, and provincial health representatives from the mainland. Meanwhile, Dr Tsang also said jacuzzi and sauna bath owners should follow guidelines for the proper maintenance of their facilities to prevent the spread of legionnaire's disease. Club Siena, a private clubhouse in Discovery Bay, was temporarily closed after a 38-year-old man who had used it was confirmed to have the water-borne disease. High levels of the bacteria were found in the clubhouse jacuzzi, as the bacteria usually proliferates in warm waters, Dr Tsang said.
