The Effect of Anti-HIV Drugs on the Amount of HIV in Semen

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The summary below is from the full report titled "Effect of Antiretroviral Therapy on HIV Shedding in Semen." It is in the 15 August 2000 issue of Annals of Internal Medicine (volume 133, pages 280-284). The authors are P.F. Barroso, M. Schechter, P. Gupta, M.F. Melo, M. Vieira, F.C. Murta, Y. Souza, and L.H. Harrison.

What is the problem and what is known about it so far?

Human immunodeficiency virus (HIV) is the cause of AIDS, a potentially deadly illness that interferes with the ability to fight off infection and certain types of cancer. In persons with HIV infection, the virus is found in body fluids, including blood and semen. Sexual contact is the most common way people spread the infection. Although the ability of anti-HIV drugs to lower the amount of virus in the blood is well known, the effect of those drugs on the amount of virus in semen has not been extensively studied. It seems likely that the greater the amount of HIV in a man's semen, the greater his risk for spreading the infection through sexual contact.

Why did the researchers do this particular study?

To measure the effect of anti-HIV drug treatment on the amount of virus in the semen of men with HIV infection.

Who was studied?

The study included 93 men with HIV infection receiving care at a teaching hospital in Rio de Janeiro, Brazil. All men entered the study at the time that they started anti-HIV drugs.

How was the study done?

The researchers examined the men before they began anti-HIV drugs and again after 1, 2, 3, and 6 months of treatment. During each examination, the men completed an interview, a physical examination, and a blood test and provided a semen sample. The researchers measured the amount of virus in blood and semen at each time point in the study.

What did the researchers find?

Before patients started receiving anti-HIV drugs, HIV was detectable in semen in 74% of the men and in blood in 96% of the men. After 6 months of anti-HIV treatment, 33% of the men had detectable virus in their semen and 38% had it in their blood.

What were the limitations of the study?

This study evaluated only 93 men in a single treatment center; the results could be different for men in other locations. The researchers did not find out whether study patients took all of their anti-HIV medicines, so it is not clear whether virus remained detectable in some men because the drugs were not working or because those men were not taking the drugs as prescribed. Also, although virus was still present in the blood and semen of some men during treatment, it is not known whether it was still able to infect other persons.

What are the implications of the study?

Anti-HIV drugs can greatly reduce the amount of virus in blood and semen, which probably lowers the risk for spreading HIV through sexual contact. Despite anti-HIV treatment, however, a substantial number of men will still have virus in body fluids. This means that they can probably still spread the infection.