Study Backs Estimate of Up to 1.5 Million AIDS Carriers

Federal health officials, in a confidential report to President Reagan on the extent of AIDS infection in the country, said the latest evidence indicates that 1 million to 1.5 million Americans carry the AIDS virus, consistent with their previous estimates, The Times has learned.

“The existing data indicate there is no reason to revise the figures at this time,” said one Public Health Service official, who asked not to be identified. Further, he said, the current information “does not suggest that the estimate is too low.”

First Step in Plan

The report, a copy of which was obtained by The Times, is the first step of an ambitious plan by federal health officials to more accurately determine to what extent the AIDS virus has spread throughout society. The information will guide policy-makers and the health care community in planning how to combat the epidemic.

This first report, scheduled to be delivered to the President on Nov. 30, will be followed by a more extensive study of 30 target areas, which is beginning now. That project will study 20 AIDS high-risk areas--including Los Angeles, San Francisco and New York--and 10 low-risk areas. Blood samples will be collected and tested from sexually transmitted disease and drug treatment clinics, hospitals, colleges and prisons.

The early report summarizes all available data, including an extensive survey of state health departments, federal agencies and medical research institutions conducted last month by the Centers for Disease Control and the National Institute on Drug Abuse.

The report said that several methods of calculation all point to a national infection prevalence of between 1 million and 1.5 million, bracketed by “outer range” estimates of 276,000 to 1,750,000.

The Public Health Service official dismissed published reports during the weekend that predicted the report would scale down estimates of nationwide infection to about 600,000. “At the present time, we just don’t have enough information to be able to say the figure is below 1 million,” he said.

The report acknowledged that “considerable concern has been expressed” about heterosexually active persons “in the absence of other (AIDS) risk factors in both partners” but said that “currently, the prevalence of . . . infection in such persons remains very low on a national basis in comparison with persons with specific risk behavior or known sexual exposure to persons at increased risk.”

The report said that homosexual and bisexual men continue to be the major group at increased risk for infection. “While the highest levels (of infection) have been noted . . . in San Francisco, the geographic distribution . . . is otherwise fairly even without major concentration in any particular region,” the report said.

The report said that the prevalence of infection in intravenous drug abusers “shows marked geographic variation,” unlike that in homosexual and bisexual men. About two dozen studies in 15 cities from 10 states show that prevalence “varies widely, with levels as high as 50% to 75% in New York City and its East Coast environs” to levels below 5%, with only a few exceptions, “in most other areas of the country,” the report said.

Many Hemophiliacs Infected

There is an extremely high prevalence of infection among the country’s estimated 18,000 hemophiliacs, the report said, stemming from the use of contaminated clotting factor concentrates prior to 1985, before the heat treating of such products began.

The infection of hemophiliacs “tends to be uniform in its geographic distribution throughout the United States,” the report said. About 70% of persons with hemophilia A and 35% of those with hemophilia B, a less severe form of the disease, are believed to be infected, the report said.

As for the regular heterosexual partners of infected individuals, a few studies estimate that infection levels among the study populations vary from about 10% to about 50%.

“It is not clear whether these differences reflect different levels of infectiousness of source partners from the various risk groups or . . . differences in the frequency of sexual exposure (or) the duration of infection in the source partner,” the report said. “Recent evidence suggests that infectiousness increases with the deterioration of the source partner’s immune system.”

Life after testing positive for the AIDS virus. Part V, Page 1.