Antiretroviral drug therapy in an HIV-positive man or woman
can alone help prevent the transmission of HIV to an
uninfected partner, regardless of counseling, the patient's
use of condoms or other safe-sex practices, AIDS experts at
Johns Hopkins report.
In a study among 205 so-called discordant couples in
Uganda, in which only one member of each heterosexual pair
was infected with HIV, researchers found that not a single
case of transmission from one partner to the other occurred
when the infected man or woman was taking potent anti-HIV
medications to keep the disease in check.
By contrast, 34 men and women became infected among the 185
remaining couples in which neither partner was taking
antiretroviral therapy. The study-group pairs consisted of
126 HIV- positive men and 79 HIV-positive women.
The experts caution that drug therapy should not be
considered a fail-safe strategy in such couples and that
condom use and safe-sex practices are still vitally
important. But the results, they say, show that the drugs
significantly help lower the risk of transmission.
According to lead study investigator and
infectious diseases specialist Steven Reynolds, the
study results show that antiretroviral therapy not only
"treats the HIV-infected member of a discordant couple" but
also plays some role in preventing the virus from
However, he cautions that its preventive role is limited
because of the advanced stage of disease in those being
treated in his study group. In Uganda, as in most
countries, infected people usually do not qualify for
government-funded antiretroviral therapies until the
disease has reached an advanced stage, with a CD4 immune
system cell count of 200 or less.
Reynolds, an assistant professor at the Johns Hopkins
University School of Medicine and a staff clinician at the
National Institute for Allergy and Infectious Diseases,
says that study results showed that HIV transmission in the
treated couples was prevented despite the failure of
counseling to halt unsafe sex practices, such as
extramarital sex or failure to use condoms.
Participants in the study, conducted jointly by Johns
Hopkins and Rakai Health Sciences Program researchers
between 2004 and 2007, came from the Rakai cohort, a
population of 12,000 people in Uganda who are being
monitored to determine how HIV spreads throughout the
country. The researchers based their findings on extensive
interviews with each participant and an annual check-up
during which blood tests were conducted.
Researchers in the study, in addition to Reynolds, are
Frederick Makumbi, Joseph Kagaayi, Gertrude Nakigozi,
Ronald Galiwongo, Thomas Quinn, Maria Wawer, Ronald Gray
and David Serwadda.
The study was presented at the 2009 Conference on
Retroviruses and Opportunistic Infections held Feb. 8 to 11