And while the number of people infected with HIV is rising at the rate of 10,000 new cases around the world each day, the pattern of HIV infection is also changing. Increasingly it is being spread by heterosexuals rather than by homosexual intercourse or drug abuse.
But while the spread of the virus in Thailand, Dr Thomas Quinn, of the US National Institutes of Health, warned there had been a very rapid increase in HIV incidence in India.
India has nearly 1 billion inhabitants and "will require enormous resources to control the disease", he warned, giving rise to concerns that Asia could overhaul Africa as the worst- infected hit area by 2000.
Dr Quinn estimates more than 12 million people have been infected in Africa and 3.5 million in Asia. By 2000, he says there will be 26 million people infected world-wide, of whom 10 million will be in South-east Asia (including India). There are also areas of very high incidence in China.
Dr Anthony Fauci, also from the NIH, said treatment of sexually transmitted diseases (STDs) may be very important in hindering HIV. New evidence suggests that the virus, which infects immune systemcells, can only replicate when those cells are active. If someone contracts an STD it will trigger their immune system to fight the infection and this may have the effect of worsening their HIV state.