Updated

India has overtaken South Africa as home to the world's highest number of people infected with HIV/AIDS, as the epidemic in the Asia-Pacific gains ground in some countries and shows some promise of slowing in others, a UNAIDS report found.

With an estimated 5.7 million infections last year, India eclipsed South Africa's 5.5 million. But the country of 1.02 billion people still has a low per capita rate of 0.9 percent among adults and has shown some signs of decline in the hard-hit south.

While HIV prevalence has slowed in Cambodia and Thailand, it is increasing in some countries including China, Indonesia and Vietnam, and there are signs of HIV outbreaks in Bangladesh and Pakistan, the report said.

The report released Tuesday by UNAIDS, estimated that some 8.3 million people were living with the virus in the Asia-Pacific region at the end of 2005, the world's second-highest number of cases after sub-Saharan Africa. UNAIDS is a U.N. program that brings together ten world body organizations to respond to the AIDS crisis.

The report said about 930,000 people were newly infected with HIV in 2005, while 600,000 died of AIDS.

The report, which examined the global AIDS picture, emphasized that factors driving the spread of the virus in Asia vary widely and include unprotected sex, intravenous drug use and an overlap of the two.

In Karachi, Pakistan nearly one in four intravenous drug users tested positive for HIV in 2004, while in India's southern Tamil Nadu state, some sex-worker populations were found to have infection rates of 50 percent.

David Bridger, the regional program adviser for UNAIDS Asia-Pacific, said countries must carefully tailor their responses to meet the diverse epidemics they face.

In India, for instance, more than 80 percent of the 5.7 million reported cases are due to unprotected heterosexual sex. But in the country's northeast, intravenous drug use is fueling the epidemic.

In China, approximately 650,000 people are infected with the virus, with 44 percent of them injecting drug users who share needles, the report said.

HIV is spread by the sharing of needles among intravenous drug users to sex workers who transmit it to the general populace, it said.

Asian countries singled out as having worrying epidemics included Cambodia — even though it has managed to reduce HIV prevalence from higher levels in the late 1990s — and Myanmar.

"The HIV epidemics remain relatively limited in Bangladesh, the Philippines, Indonesia and Pakistan, although each of those countries risks a more serious epidemic if prevention methods are not improved," the report said.