‘Alarming’ Increase in AIDS Reported : Epidemic: U.N. agency predicts 6 million cases by the year 2000. Developing countries are hardest hit.

The World Health Organization on Tuesday predicted a cumulative global total of at least 6 million cases of AIDS by the year 2000, with “an alarming rate” of increase of new infections in developing countries.

Also, 15 million to 20 million people around the world could be infected with the human immunodeficiency virus that causes AIDS by the year 2000 because of the soaring rate of new infections in developing countries, WHO said in updating its worldwide AIDS projections.

“If the situation in Africa continues to increase and if we continue to see a rapid rise of infections in Asia and Latin America, then I think these estimates we’re giving are minimum,” Dr. Michael H. Merson, director of the WHO global AIDS program, said in an interview.

The projections are more pessimistic than those of about a year ago. Although WHO initially released similar figures at that time, they were then considered middle-range estimates, rather than the lowest possible.

Six million to 8 million people worldwide--or about one of every 400 adults--are now infected with HIV. Most of them ultimately will become ill “unless therapeutic drugs are developed soon,” WHO said.

The international health organization said that it is “very unlikely” that the global prevalence of AIDS infections will stabilize or level off for at least several decades.

As of this year, about 60% of all global infections had resulted from heterosexual intercourse. WHO predicted that by the year 2000, 75% to 80% of all HIV infections will result from heterosexual intercourse.

In the United States, where there has been a cumulative total of more than 132,000 AIDS cases, the majority of cases have occurred among homosexual and bisexual men.

However, WHO said that heterosexual transmission of AIDS infection is increasing slowly in industrial nations, especially in urban areas with high rates of other sexually transmitted diseases and intravenous drug abusers.

“Large numbers of uninfected IV drug users remain in many areas, and explosive spread might occur among them if they continue their risk behavior,” WHO said.

In North America, WHO estimates, one in every 75 men is HIV infected. In South America, the estimate is one in 125 men; in Western Europe, one in 200.

Among women, WHO estimated that one in 700 women in North America is infected; in South America, one in 500 women; in Western Europe, one in 1,400. In Eastern Europe, Asia and the Pacific region, there are about 50,000 infected women, or one in 20,000, WHO said.

Saying “it is clear that the global balance of HIV infections is rapidly tipping toward the developing countries,” WHO noted that in 1985 about half of the world total of infections were in developing countries. Today, WHO said, the developing world accounts for an estimated 66%, and the figure is expected to reach 80% to 90% by the year 2010.

“The world outlook is increasingly somber,” Dr. June Osborn, a member of WHO’s Global Commission on AIDS, said in an interview. “In particular, we’ve seen a startling emergence of new HIV infections related to intravenous drug use and subsequent sexual spread in Southeast Asia that reminds us of the flash-fire potential everywhere when HIV and illicit drug use are combined.”

The current level of infection is “most acute” in sub-Saharan Africa, WHO said, estimating that about 3.5 million people were HIV-infected by mid-1989. These figures include 1.5 million to 2 million women. WHO estimated that one of every 50 adult men and women in sub-Saharan Africa is now infected with HIV.

Further, as of this year, about 200,000 HIV-infected infants had been born in Africa, and by the end of the decade, “an additional million or more may be expected,” WHO said.

As of mid-1990, more than 250,000 new cases of AIDS have been reported from more than 150 countries, WHO said. But because of under-recognition, under-reporting and delays in reporting, the health organization said that it estimates that nearly 700,000 cases may have already occurred.