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Study says circumcision may protect against HIV Ulysses Torassa EXAMINER MEDICAL WRITER |
Jan. 31, 2000
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Studies in AIDS-ravaged Africa have found that people with very low levels of HIV in their blood are unlikely to infect others - suggesting that drug therapies or vaccines that suppress the virus could significantly reduce its spread. The research also gives compelling evidence that circumcision may be protecting many men from contracting the disease. At the same time, surveys in the United States show that the introduction of powerful AIDS drugs has made people less concerned about HIV and, in some cases, led them to act more recklessly. The studies, presented here Sunday at the seventh Conference on Retroviruses and Opportunistic Infections, pointed up both the promise and the pitfalls of antiretroviral therapy in the next stage of the epidemic. "AIDS has changed. It's not the same disease anymore," said Kevin De Cock, former director of the Centers for Disease Control and Prevention's division of HIV/AIDS Prevention and Surveillance and Epidemiology. "With the advent of highly active antiretroviral therapy, it makes sense to focus on the infected population much more in our prevention efforts." African studies The two African studies in Uganda and Zambia examined how heterosexual couples infect one another. Although given counseling and condoms, most continued to practice unsafe sex, and a large percentage of people in each group became infected from their partners. People whose partners had fewer than 1,500 copies of the virus in their blood (according to standard measures) escaped infection. As the volume of virus rose to as high as 50,000 copies, infection rates rose dramatically. Because expensive AIDS drugs are generally not available in Africa, the differences in virus levels occurred naturally. It remains to be shown conclusively that drug-induced reduction of virus in the blood has the same effect, although many researchers believe that it does. "Our data provides a lot of hope," said Thomas Quinn of Johns Hopkins University in Baltimore, who led the Ugandan study. Besides antiretrovirals, the virus also may be suppressed by vaccines, which would be cheaper and easier to administer in developing countries. While low levels of virus in the blood usually mean the virus also is low in semen, the correlation is not perfect. Michelle Roland of UC-San Francisco said she knows of at least one woman who was infected after unsafe sex with her partner, who was thought to have an undetectable amount of virus in his blood. Drugs worth side effects Although antiretroviral drugs are notoriously difficult to take and have many side effects, their existence already has led many people in high-risk groups to drop their guard against HIV, according to a new CDC survey. In a poll of 1,976 HIV-negative people in seven states, the agency found that 31 percent said they were less concerned about the disease, and 17 percent were less careful about drug and sexual practices because of the therapies. The survey polled nearly equal numbers of heterosexuals recruited from sexually transmitted disease clinics, injection drug-users and gay men. The CDC's Stan Lehman, who presented the study, acknowledged that it makes sense for people to be less worried about HIV because of the drugs, but he remained concerned about behaviors. The survey also found that among gay men, those less concerned about HIV were having more unprotected receptive anal sex, the riskiest sexual behavior. Meanwhile, another possible protection against HIV is getting more attention among HIV researchers at the conference: circumcision. In the Ugandan study of 415 couples, Quinn and his colleagues found that none of the 50 men who were circumcised picked up the virus no matter how much virus their partners had in the blood. Quinn called the finding highly provocative and said it has been backed by other recent research that has yet to be published. "In at least the high-risk individuals, circumcision could be associated with a 40 percent reduction in transmission," he said. Disparities explained The finding could partially account for why the disease has spread so rapidly in sub-Saharan Africa, where circumcision rates are low. It also could help explain why studies of female-to-male transmission of HIV in the United States find that it is less frequent here, where circumcision is common. The African studies found that men and women were equally likely to transmit the virus to their heterosexual partners. The CDC's De Cock said he was skeptical of earlier data that suggested circumcision helped protect against infection, but now he has changed his mind. Quinn said the effect is biologically plausible because the foreskin that is removed in circumcision is very soft and prone to tiny lacerations that could allow the virus to enter the bloodstream more easily.
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