A series of studies presented Monday at the 14th Annual Conference on Retroviruses and Opportunistic Infections in Los Angeles suggest that the benefits of breast-feeding in developing countries might outweigh the risk of vertical HIV transmission, the San Francisco Chronicle reports (Russell, San Francisco Chronicle, 2/27).
According to the New York Times, three studies conducted in Africa found that HIV-negative infants who were breast-fed by HIV-positive mothers from birth up to age six months had increased rates of severe diarrhea that resulted in hospitalization or death compared with infants who were breast-fed for longer than six months. Another study found high rates of diarrhea and malnutrition among formula-fed infants in Botswana after a 2006 flood led to water contamination. Following the sewage contamination of the water and the environment, deaths from diarrhea in Botswana were 25 times higher in 2006 than in previous years, according to the Times. A fifth study conducted in Zambia found an increased death rate among infants of HIV-positive women who were breast-fed until age four months. According to the United Nations, about 300,000 infants die annually after becoming HIV-positive through breast-feeding. UNICEF estimates that 1.5 million formula-fed infants die annually from other diseases. The World Health Organization in October 2006 released a statement that recommends HIV-positive women breast-feed exclusively until an infant is six months old unless alternatives are "acceptable, feasible, affordable and safe for both the mother and infant." Several governments in developing nations have followed these guidelines, and some have encouraged HIV-positive women to stop breast-feeding earlier than six months in an effort to reduce the risk of vertical transmission, according to the Times (Altman, New York Times, 2/27). Programs to reduce vertical HIV transmission have not grown at the same pace as other programs that provide HIV-positive people with access to antiretrovirals, and less than 10% of HIV-positive women worldwide have access to the drugs, the Chronicle reports (San Francisco Chronicle, 2/27).
Hoosen Coovadia, a pediatrician at the University of KwaZulu-Natal in South Africa, said that HIV-positive women in countries with an infant mortality rate of 25% or greater should be encouraged to breast-feed exclusively. "Breast milk is a cornucopia of immune factors," Coovadia said, adding, "Breast-feeding should still be promoted, protected and preserved, despite the risk of HIV" (Beasley, Reuters, 2/26). According to Coovadia, it is necessary to make breast-feeding "safer" for HIV-positive women in developing countries to reduce the risk of vertical transmission. Research presented at the conference indicates that measuring HIV-positive women's CD4+ T cell count could make breast-feeding safer because women with higher CD4 counts are less likely to transmit HIV to their infants through breast milk (San Francisco Chronicle, 2/27). Donald Thea, a co-author of the Zambia study, said that HIV-positive infants have a lower mortality rate the longer they are breast-fed. Moses Sinkala, who led the Zambia study, said health officials should "strongly encourage breast-feeding into the second year of life" for HIV-positive infants (New York Times, 2/27). Coovadia said that HIV-positive women who have the "resources to prepare hygienic" formula, such as clean water and access to electricity, should feed their infants with formula (Reuters, 2/26). Michael Thigpen, a CDC epidemiologist, said that official recommendations on breast-feeding should not be changed until the studies are completed, the Times reports (New York Times, 2/27).
Fat Distribution, Cholesterol Studies
Researchers at the conference also presented findings that indicate it might be possible to avoid issues associated with HIV/AIDS treatment regimens and fat distribution, the Los Angeles Times reports. According to the Times, the introduction of antiretroviral therapy in the 1990s came with an unexpected side effect -- the redistribution of body fat that resulted in a thinning of the arms and accumulation of fat in the abdomen, back and neck. This fat redistribution can alter cholesterol levels and potentially increase the risk of heart attacks and stroke, the Times reports. According to three studies presented at the conference, the use of an experimental drug, an existing antiretroviral and a widely used cholesterol drug could help avoid the problems associated with fat redistribution.
- Steven Grinspoon of the Massachusetts General Hospital at the conference reported on an ongoing study of an experimental drug called TH9507, which stimulates the body to produce a growth hormone that burns excess fat. Grinspoon and colleagues conducted the study among 412 participants, half of whom received TH9507 in addition to regular HIV/AIDS therapy. The other half of the participants received a placebo. The researchers found that participants who received TH9507, which is manufactured by Theratechnologies, saw a 15% reduction in fat buildup in the abdomen and back. According to Curtis Cooper of the University of Ottawa, such a fat buildup often prompts HIV-positive people to abandon their drug regimens. The researchers also found that TH9507 reduced blood levels of triglycerides, a major component of cholesterol, by 18%.
- David Wohl of the University of North Carolina-Chapel Hill at the conference presented data that indicate the cholesterol drug ezetimibe -- sold by Merck and Schering-Plough under the name Zetia -- can help reduce cholesterol levels among HIV-positive people. Wohl conducted the study among 48 participants, half of whom received Zetia in addition to their normal HIV/AIDS regimens and half of whom received a placebo. The participants who received Zetia experienced a median 12% decrease in low-density lipoproteins, and those who received the placebo saw a 3% increase in the lipoproteins, the researchers found. The study was funded in part by Merck, according to the Times.
- In a third study presented at the conference, William Cameron of the University of Ottawa examined two groups of treatment-naive, HIV-positive people. One group initially received Abbott Laboratories' Kaletra in combination with other drugs and then only Kaletra. The second group received a standard drug regimen. The researchers found that among participants who received Kaletra, 5% developed abnormal fat distribution, specifically loss of fat in the limbs. Among the participants who received a standard regimen, 34% experienced the abnormal fat distribution, according to Cameron.
Julian Falutz, director of the HIV Metabolic Clinic at McGill University
, said that although the study presentations did not persuade him to recommend immediate changes in drug regimens, he is encouraged by the results (Chong, Los Angeles Times, 2/27).