The global AIDS epidemic is "accelerating dramatically" and there may now be as many as 8 million to 10 million people infected with the virus, according to a World Health Organization report released yesterday.
The revised figures -- which push the toll 2 million higher than the estimates made by WHO just over a year ago -- reflect a continuing worsening of the epidemic in sub-Saharan Africa and an unexpected surge in HIV infections in Asia, where just two years ago AIDS was virtually nonexistent.
"It is now clear that the toll of HIV infection around the globe is worsening rapidly, especially in developing countries," said Michael Merson, director of the WHO Global Program on AIDS. "Furthermore, if HIV prevalence over the next couple of years increases markedly in Asia and Latin America, and continues to expand in sub-Saharan Africa, then our projections -- which are considered conservative -- will need to be revised even further upward."
AIDS experts said that the estimates given by WHO could not be considered definitive, because information on the spread and extent of HIV infection is, in many countries, either scanty or nonexistent. Nonetheless, WHO's figures represent the most complete picture available for the dimensions of an epidemic that has become the leading cause of death in some parts of both the developing and the developed world.
The WHO report identified two areas of specific concern.
The first is sub-Saharan Africa, where WHO epidemiologists estimate the number of people infected with HIV has increased from 2.5 million in 1987 to 5 million today. This means that one in 40 adult men and women in the area is now believed to be infected. Infection is considered a virtual death sentence.
"In 1987, most cases in Africa were in large urban populations," Merson said. "But since then we have been more and more aware that the disease is spreading into rural areas."
Far more dramatic, according to the report, is the mushrooming epidemic in Asia, where the number infected with HIV has gone from virtually zero to 500,000 in the past two years. This includes serious inroads by the virus in Thailand, as well as the first signs of the epidemic in countries such as India. One recent study, for example, showed that 70 percent of the prostitutes in Bombay who came from southern India were infected.
"The rates of increase that we have seen in Asia in the past two years have been even sharper than those we saw earlier in Africa," said Merson. "If the situation continues like this in Asia, we will have another problem there, like we do in Africa, within 10 years."
WHO officials said they were surprised by the extent of the epidemic's growth in Asia. Last year, for example, the organization projected a cumulative total of between 15 million and 20 million HIV infections worldwide by the year 2000. That figure, however, assumed only 1 million to 1.5 million Asian cases by the turn of the century, an assumption that seems unlikely to hold true given that 500,000 are believed to have already occurred.
The revised estimates for worldwide infection come on the heels of reports from WHO earlier this year that the first signs of HIV infection had been reported in Eastern Europe and the Islamic countries of North Africa and the Middle East, areas of the world that until recently were thought to be virtually unaffected by the epidemic.