The New York Times - October 28, 1986
Erik Eckholm

The gathering concern was evident in the Surgeon General's extraordinary plea last week that children be frankly told about sex, drugs and AIDS.

Although recent studies have shown conclusively that the virus that causes AIDS, or acquired immune deficiency syndrome, can pass between men and women through ordinary intercourse, important questions remain about how easily the virus spreads this way, how often it already has and whether a major epidemic among heterosexuals is likely.

So far, the proportion of the country's AIDS cases attributable to heterosexual contact remains small. Some experts fear that the AIDS virus is spreading insidiously among heterosexuals and that a surge in cases is in store. Because of the estimated average lag of at least five years between a patient's infection with the virus and diagnosis of the deadly disease, the experts note, statistics on current disease patterns could be dangerously lulling.

But senior Federal scientists and many other experts believe the infection is still quite rare among heterosexuals, except for those who use intravenous drugs or who frequently have sex partners who do.

Infection data are sparse. Estimates of the number of Americans carrying the AIDS virus range from half a million to two million, most of them homosexual men or heroin users. Nearly 27,000 AIDS cases have been reported to date; scientists do not know what portion of virus carriers will eventually develop the disease.

Among heterosexuals, most experts agree, sexually active residents of the inner city face the greatest immediate danger. Nowhere is this threat greater than in New York and northern New Jersey, where dirty needles are a constant conduit of AIDS.

Up to now, most heterosexually infected AIDS victims have been the partners of heroin addicts, and most have been black or Hispanic women. This explains why four out of five children who developed AIDS after being infected at birth have been black or Hispanic.

Minority teen-agers and young adults in urban areas already suffer the country's highest rates of venereal disease, observes Dean F. Echenberg of the San Francisco Department of Health. Add in the high incidence of drug abuse and this group seems "ripe for a wildfire heterosexually spread epidemic of AIDs," he warned.

Last week scientists and health officials at a conference, sponsored by the Montefiore Medical Center in the Bronx, on the heterosexual transmission of AIDS agreed that the public at large must be alerted to the rising hazards of unprotected, promiscuous sex. No one dissented when Mervyn Silverman, director of the American Foundation for AIDS Research, said educators should talk "less about risk groups" and "more about risky activities." All applauded New York City's Health Commissioner, Stephen C. Joseph, when he declared: "The day of the condom has returned."

Prevention Among Drug Addicts

But preventive efforts must focus with special intensity, most experts agreed, on intravenous drug addicts and their sex partners, the primary sources of AIDS infection among heterosexuals. No effective attack has been mounted on the spread of AIDS by shared needles.

Health experts also caution against any relaxing of preventive education about "safe sex" among homosexual and bisexual men. Although half the homosexuals in a few cities may already be infected, a majority nationwide are not and some, especially men who only occasionally engage in homosexual acts, may not realize the exceptional danger.

Excluding immigrants from Haiti and Africa, where heterosexual transmission of AIDS is common, the proportion of American AIDS cases traced to heterosexual intercourse with a partner from a known risk group is 2 percent, up from 1 percent in earlier years of the epidemic. Four out of five of these patients are women.

When cases among immigrants are counted, the total share of the country's cases attributed to heterosexual contact is 4 percent.

Only a few American cases are known to have developed from AIDS virus infection that had been passed along so many times that neither partner had any reason to suspect the possible exposure. Such an extended spread of the virus may, however, account for some of the 3 percent of cases with no explained cause, said Dr. Harold Jaffe, chief of AIDS epidemiology at the Federal Centers for Disease Control.

Heterosexual Cases in New York

In New York City, 156, or 2 percent, of the 7,696 AIDS cases totaled as of Sept. 15 were attributed to heterosexual contact. But among cases reported in the first nine months of 1986, the proportion has dropped to below 1 percent. Eighty percent of these patients are black or Hispanic. (Cases of presumed heterosexual origin among immigrants are excluded from these figures.) Of those 156 patients, 154 are women and only 2 are men, leading New York health officials to argue -against the grain of much expert opinion elsewhere - that passage of the virus from female to male in intercourse is extremely rare.

New York officials assert that their data may reflect a more tenacious and accurate investigating procedure. They argue that many apparent heterosexual cases involve men who are concealing past drug use or homosexual acts. But others do not agree that questioning elsewhere has been so lax.

In an effort to clarify what has become an angry debate, Commissioner Joseph announced at the Montefiore conference that he would invite an outside panel of experts to review New York's data and procedures.

Relief on Blood Donor Data

Statistics on the extent of AIDS virus infection among New York heterosexuals remain frustratingly fragmentary. Data from blood donors came as something of a relief to health officials. Blood donations are accepted only from people who deny past homosexual acts and intravenous drug use.

Among 331,000 people who gave blood to the Greater New York Blood Program from April through December 1985, 257, or 0.08 percent had antibodies to the AIDS virus, a sign of infection. Further investigation revealed that 90 percent of these 257 people had prior homosexual or drug experience, or had a sex partner who did. In only 11 cases could the source of infection not be identified.

Blood donors are not, of course, a random sample of the community. More worrisome is the much higher incidence of infection shown in the military's tests of New York City applicants for service. From October last year through July 1986, 84, or 1.06 percent of 7,938 men and 13, or 0.83 percent of 1560 women were found infected. The older the applicant, the more likely the infection; rates did not differ greatly by race.

Military recruits, too, are unrepresentative of the general population. Data were not gathered on the background of the infected applicants, who were rejected for military service, but about a fourth of them sought counseling from the New York Health Department.

Among this subgroup of military applicants, most infections could be traced to homosexual contact or drug use and the proportion attributed to heterosexual relations was "minor" and "not different from normal," reported Mary Ann Chiasson, an epidemiologist at the Health Department. A new survey is planned, she said, for AIDS infection rates among people who visit a clinic for sexually transmitted disease and who agree to blood testing.

Studies Raise Puzzling Questions

Three new studies have highlighted the risk of unprotected intercourse with a virus carrier. They also raise puzzling questions.

Two of the studies, one involving 58 couples at the University of Miami and one of 93 couples at Montefiore, found that half or more of the steady, long-term heterosexual partners of AIDS patients, partners who faced no other discernible exposures, were also infected. The virus seemed to pass as readily from women to men as the reverse, and ordinary vaginal intercourse was a sufficient means.

During the Miami study, 16 AIDS patients continued, despite doctors' warnings, to have unprotected intercourse over periods ranging from one to three years. Thirteen of their partners became infected, for a transmission rate of over 80 percent.

Of 12 AIDS patients and their partners who continued having sex but used condoms, the infection spread in two cases - a far lower rate but still, given the presumed safety of condoms, a "very disturbing finding," observed Dr. Margaret Fischl, the study director. In both these cases the virus spread from man to woman, and Dr. Fischl speculated that oral sex involving semen discharges might be to blame.

A Curious Disparity

These and other studies found dramatic, unexplained differences in the rate of sexual spread depending on how the first partner had become infected. The virus was passed through intercourse far more readily from drug abusers than from people exposed by contaminated blood products.

Reinforcing this curious disparity, a study of 73 spouses of transfusion-associated AIDS victims found that only 5 percent of men and 16 percent of women acquired the virus through sexual intercourse over time. In this, as in the other studies, why the virus spread within some couples and not others was a mystery. Transmission was not correlated with frequency of intercourse, suggesting, said Dr. Thomas Peterman of the Centers for Disease Control, that infectivity may vary among individuals or in the same person over time.

All these studies involved couples who had intercourse repeatedly over an extended period. Available evidence indicates that the likelihood of viral transmission in a single heterosexual encounter "must be quite low, probably less than 1 percent per contact," concluded Dr. Peterman and James W. Curran in an article this week in the Journal of the American Medical Association. Scientists suspect that the virus spreads more easily in anal intercourse, which more often involves tearing of tissue that would aid the entry of the virus into the bloodstream.

Some experts wonder whether trends in Haiti are an ominous harbinger of events in the United States. The spread of AIDS in Haiti has shifted dramatically, reports Dr. Warren D. Johnson Jr. of the Cornell Medical College. Homosexual contact and drug abuse accounted for a majority of cases a few years ago, but now heterosexual intercourse is blamed for more than 80 percent of cases.

So far, however, no evidence indicates the United States is experiencing a similar transition. "It's probably too simplistic to look at trends in Haiti or Africa and conclude we'll have the same problem in a few years," Dr. Jaffe said. "A lot of things in those countries are different," he said, including patterns of sexual promiscuity and the extent to which the AIDS virus is recirculated among the population by contaminated transfusions.

It also appears, many scientists think, that the virus has spread more easily via heterosexual intercourse among Africans and perhaps Haitians than among North Americans. Venereal diseases are more common among heterosexuals in Africa and studies in Africa produce a "strong suspicion," Dr. Jaffe said, that concurrent infection with another sexually transmitted disease renders a person more capable of infecting others, or more susceptible to invasion by the AIDS virus.

The conjecture is that a person with a disease such as syphilis or gonorrhea has more white blood cells - the kind the AIDS virus inhabits - in the genitals and hence may emit more of the virus in intercourse. Also, sores caused by genital herpes would provide a pathway into the bloodstream for the virus.

In any case, the nation's health officials realize that to halt the heterosexual spread of AIDS they must strike a delicate balance. They are urging heterosexuals to make prudent changes in sexual behavior, but they hope to do so without causing unwarranted anxiety or panic.

For anyone who has sex with multiple partners the danger is rising, and it is already great for those whose intimate lives intersect with drug addicts or bisexual men. For now, however, most of the country's heterosexuals apparently face only a slight risk of exposure to AIDS. This contrasts with the plight of homosexual men, among whom the infection is so prevalent that a blanket proscription of unprotected intercourse is entirely credible.

Officials feel they must urge all heterosexuals to be more careful, however, because they know that the accumulation of low individual risks can, under the wrong circumstances, add up to a runaway epidemic.

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