Foreskin removal may slow HIV spread

June 10, 2000


Circumcision is such an effective means of reducing the risk of HIV transmission that a worldwide program to circumcise teenage boys should be undertaken to slow the AIDS epidemic, Australian researchers say.

Those conclusions are largely based on African studies, where most HIV transmission is through heterosexual contact. It is not known how circumcision affects the rate of HIV infection among homosexuals.

"In light of the evidence . . . circumcising males seems highly desirable, especially in countries with a high prevalence of HIV infection," Dr. Roger Short, a professor of obstetrics and gynecology at the University of Melbourne, said in Friday's edition of the British Medical Journal.

"Circumcision at puberty, as practiced by many Muslim communities, would be the most immediately effective intervention for reducing HIV transmission since it would be done before young men are likely to become sexually active," he writes.

Short said neonatal circumcision should be practiced more widely, but that approach would take 15 to 20 years to affect HIV-AIDS rates.

A review of medical literature by the Australian team revealed that circumcised men are less likely to contract HIV-AIDS during unprotected sex. Their rates of contracting other sexually transmitted diseases also are markedly lower.

The most dramatic evidence of the protective effects of circumcision was published earlier this year in the New England Journal of Medicine.

Researchers tracking hundreds of Ugandan couples, in which one partner was infected and the other not, reported that there was not a single new infection in the group with circumcised males. In the group with uncircumcised males, however, the new infection rate was 29 percent over a 30-month period.

Uncircumcised men are particularly susceptible because, during intercourse, the foreskin is pulled down the shaft of the penis, "and the whole inner surface of the foreskin is exposed to vaginal secretions, providing a large area where HIV transmission could take place," according to the study.

The only "exposed" area of a circumcised penis is the urethral opening and it contains few Langerhans' cells.

Biologically, women are more susceptible to HIV infection because the vaginal area has an abundance of receptors. The risks are doubly great for those who practise anal intercourse, because of tearing.

The Australian researchers suggest that most circumcised males who do become infected with HIV-AIDS likely have another sexually-transmitted disease or practise anal intercourse, creating lesions that provide routes of transmission.

The research on how HIV is transmitted should provide a boost not only for proponents of circumcision but for promoters of the so-called invisible condom, a gel or spray that is applied to the penis or vagina to create a chemical barrier. The invisible condom works by preventing HIV from binding with CD4 and CCR5 cells.

Dr. Short said, in the short term, that the chemical method "might be more effective and acceptable than any mechanical barrier or surgical intervention." In other words, now that the biology of transmission is better understood, the invisible condom could serve as a stop-gap measure for those who oppose circumcision or condom use.