The report says women living with HIV have increased globally with the sharpest rise in East Asia, followed by Eastern Europe and Central Asia.
Now nearly half of all those infected with the virus that causes AIDS are women, up from 41 percent in 1998. In Sub-Saharan Africa, nearly 60 percent of infected adults are women.
Early in the AIDS epidemic, far more men than women were infected with HIV.
In cities around the world on Tuesday the United Nations Program on HIV/AIDS and the World Health Organization released a report detailing the spread of the disease. The report says women are more susceptible to HIV infection than men, with male-to-female transmission during sex about two times as likely to occur as female-to-male transmission.
Doctor Swarup Sarkar, from the UNAIDS Southeast Asia and Pacific Intercountry Team says women in many developing countries are particularly vulnerable to HIV infection through sexual violence, the sex industry and unfaithful partners.
"Some of the current strategies we practice which is not necessarily effective for women because many women do not have control; being faithful for a married woman may not solve their problem of prevention of HIV if they get it from their husbands, and condom use is often not controlled by women," said Dr. Sarkar.
According to the report, an estimated 39 million people are infected with HIV, up from 37 million in 2002.
Although the report says there have been modest declines in HIV infection rates in East Africa, the epidemic is far from being reversed there.
There is cause for hope. The report says that many countries could prevent massive epidemics if they immediately begin to educate the public, encourage condom use and help protect sex workers. It encouraged governments in such countries as the Philippines and Bangladesh to adopt the aggressive methods used in Thailand, which cut its infection rate by more 85 percent in the 1990's.
Southern Africa continues to be the worse hit region, with as many as 25 percent of adults infected.
The Caribbean is the second worst affected region in the world; AIDS is the leading cause of death there among adults aged between 15 and 44.
The report says that in the past two years, HIV infections rose 50 percent in East Asia, largely because of growing epidemics in China, Indonesia, and Vietnam. Central Asia also is seeing a rise in cases.In North America and Europe, the report says an increasing number of people are becoming infected through unprotected heterosexual sex. Eastern Europe in particular faces a surge of cases among young adults.