Being diagnosed with an HIV infection may no longer be seen as a "death sentence", but it is still a "life sentence" from which researchers should help patients break free, a French virologist who was pivotal in identifying the virus says. Francoise Barre-Sinoussi cautions that now is not the time to rejoice over the success of treatments that keep HIV infections in check. The next challenge for scientists was to reduce the dosage of preventive and treatment drugs from once a day to once a month in order to allow HIV-positive patients more "freedom", she said. "When one has to take the pill every day and for the rest of theirlife, they will feel that they have lost freedom," she said. Barre-Sinoussi was awarded the Nobel Prize in Physiology or Medicine in 2008, together with her former mentor Luc Montagnier, for the groundbreaking discovery of the human immunodeficiency virus that causes Aids. According to the World Health Organisation, 34 million people are living with HIV. At the end of last year 9.7 million of them were undergoing antiretroviral therapy to stop the virus damaging their bodies. Hong Kong knows of 6,000 HIV cases, with more than 100 new cases reported each quarter. If left untreated, an HIV-infected patient takes about 10 years on average to develop Aids. On a visit to the University of Hong Kong-Pasteur Research Centre to mark the 10th anniversary of its virology course last month, Barre-Sinoussi pointed out that the HIV epidemic was very limited in the city. The government should focus its preventive efforts on homosexuals, who were considered a high-risk group, she said. She suggested the use of a new preventive pill, Truvada, which could cut the risk of transmission to between 42 and 75 per cent if taken before or after intercourse. But the virologist, who is based at the Pasteur Institute in Paris, admitted the drug might not be popular among homosexuals in France as they considered it "too much trouble" to take it so frequently. Those living with HIV rely on antiretroviral therapy to live longer and healthier lives, but they must take the drugs every day for the rest of their lives.