Reducing the Spread of HIV from Mothers to Infants

March 10, 2011

Adding drugs to the standard zidovudine treatment given to infants born to HIV-positive women can reduce the chances that the child will develop the infection.

A National Institutes of Health study has found that adding one or two drugs to the standard zidovudine (ZDV) treatment given to infants born to HIV-positive mothers can reduce the chances by more than 50% that the child will develop an HIV infection, according to data presented March 2 at the 18th Conference on Retroviruses and Opportunistic Infections in Boston, MA.

The study was conducted at 19 research hospitals in Brazil, South Africa, Argentina and the United States, under contract to the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Additional funding was provided by the NIH's National Institute of Allergy and Infectious Diseases.

An estimated one-fifth of people in the United States who have HIV are unaware they harbor the virus, according to the CDC. From 100 to 200 infants are born with HIV in the U.S. each year, many to women who either were not tested in early pregnancy or who did not receive treatment during pregnancy. Internationally, estimates of HIV testing vary, with only 21% of pregnant women in low- and middle-income countries having been tested during pregnancy.

"To reduce mother-to-child HIV transmission, it's best to begin antiretroviral treatment during pregnancy," said Heather Watts, MD, a medical officer in the NICHD's Pediatric, Adolescent and Maternal AIDS Branch and an author of the study. "However, when treatment during pregnancy isn't possible, our results show that adding one or two drugs to the current regimen provides another important means to reduce the chance for mother-to-child HIV transmission."

The NICHD/HIV Prevention Trials Network 040 study evaluated 1,684 infants born to women whose HIV infections were not diagnosed until they were in labor. The infants were randomly assigned to three groups: those receiving the standard six weeks of therapy with ZDV; those receiving six weeks of ZDV plus three doses of nevirapine (NVP) during the first week of life; and those receiving six weeks of ZDV plus two weeks of lamivudine (3TC) and nelfinavir (NFV). The study results showed that treatment with the two- and three-drug regimens reduced HIV transmission by more than 50%.

"Our results showed conclusively that the two- and three-drug regimens are superior to the standard treatment with zidovudine," said the study's chair, Karin Nielsen-Saines, MD, a clinical professor of pediatrics in the division of infectious diseases at the David Geffen School of Medicine at UCLA and a member of the UCLA AIDS Institute.

Source: UCLA Health System