Antiretroviral therapy does not reduce risk of HIV transmission

For married couples in which one partner is HIV-positive and the other is HIV-negative, antiretroviral therapy (ART) does not reduce the risk of transmitting HIV to the uninfected partner, according to a study from China in the October issue of JAIDS: Journal of Acquired Immune Deficiency Syndromes. JAIDS is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

The new research raises questions as to the real-world effectiveness of the so-called Test-And-Treat strategy—treating HIV-positive persons with ART drugs in an effort to prevent new cases of HIV infection.

HIV Transmission Rate Is Relatively Low…
Led by Dr. Lu Wang of the Chinese Center for Disease Control & Prevention, Beijing, the study included 1,927 married couples in the city of Zhumadian, Henan Province, China. The couples were initially "serodiscordant," meaning that one partner had HIV while the other did not. Zhumadian has a high rate of HIV disease related to infected blood products from paid plasma donors during the early 1990s. All infected persons have free access to medical monitoring and treatment, including ART drugs.

The initially seronegative spouses were monitored regularly for "seroconversion"—that is, conversion from HIV-negative to HIV-positive. Factors associated with a higher or lower risk of HIV transmission were analyzed.

The seroconversion rate was relatively low: over a median follow-up of three years, 4.3 percent of spouses became HIV-positive. The seroconversion rate increased over time, however.

The risk of HIV transmission was higher for couples who reported more frequent sexual activity and especially for those who said they did not always use condoms. Risk was also higher for spouses who scored lower on a psychological questionnaire. The results suggest that education—particularly on the need for consistent condom use—may play an important role in preventing transmission from HIV-positive persons to their HIV-negative partners. Efforts to target psychosocial factors may also be helpful.

…But Antiretroviral Drug Treatment Doesn't Lower the Risk
Just as important, the use of ART did not lower the risk of HIV transmission to the initially HIV-negative spouse. Risk did appear lower for couples in which the HIV-positive spouse did not switch his or her ART regimen during follow-up.

The lack of effect of ART may have important implications for HIV prevention strategies. An idea that has gained momentum in recent years is "Test and Treat" strategy—identifying as many HIV-positive people as possible and treating them with ART medications to reduce their likelihood of transmitting the infection. In theory, this strategy provides the possibility of "treating our way out of the epidemic," according to an editorial by Dr. Myron S. Cohen of UNC Center for Infectious Diseases.

The new results from Zhumadian provide an "Important, surprising and cautionary" look at how "Test and Treat" may work, according to Dr. Cohen. In previous studies, ART significantly lowered the rate of HIV transmission in serodiscordant couples, who generally received close medical follow-up. In contrast, the Chinese study shows no reduction in HIV transmission—even though all couples had access to health care services, including ART drugs.

A formal research trial is being performed to see if ART reduces HIV transmission over five years in a large group of serodiscordant couples. Meanwhile, the new study raises a critical question: Will ART reduce HIV transmission from treated people to their sexual partners under "real life" conditions? Dr. Cohen concludes, "It would seem more than wise to try to answer this question before we fully deploy a 'Test and Treat' strategy, expecting to detect a benefit to the general population."