Postexposure Infant Prophylaxis in High-risk Situations of Human Immunodeficiency Virus Type 1 Transmission

Abstract

To the Editors: We read with great interest the article by Stern and Muniz entitled “Fever and rash in an 8-month-old girl” published in “Your diagnosis, please” section.1 Much progress has been made in recent years in preventing mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV). Postexposure infant prophylaxis (PIP), through administration of antiretroviral drugs to the infant starting within hours of birth, could be important in preventing the infection from viruses that entered the fetus.2 However, cases of perinatal HIV infection still occur, mainly when available preventive interventions are not provided.3,4 The authors described a case of a full-term infant with high risk of HIV infection: the mother was prescribed highly active antiretroviral therapy (HAART) during pregnancy but had not taken the medications consistently and had an HIV viral load of 22,500 copies/mL during her third trimester of pregnancy. The infant was ultimately HIV infected. We want to focus on the role of the PIP in these situations. The authors noted that “AZT was prescribed, but the child did not complete the recommended 6-week course.” In the United States, the Public Health Service Task Force guidelines recommend that infants born to HIV-infected women should receive 6 weeks of oral zidovudine (AZT) alone, irrespective of the risk of transmission.5 However, other guidelines from European countries recommend combination antiretroviral prophylaxis for infants born to mothers with high-level viremia.6,7 Although well-designed studies of combined antiretroviral prophylaxis for infants born to women receiving HAART but with persistent high-level viremia are admittedly lacking, there is increasing evidence in other high-risk situations of HIV transmission suggesting that children born to mothers with high-level viremia, even if receiving HAART, should receive combination antiretroviral prophylaxis. Maternal viral load is considered the best predictor of the risk of vertical transmission of HIV. In the HAART era, MTCT risk is associated with high maternal viral load (for viral load ≥10,000 copies/mL, adjusted odds ratio = 12.1; P = 0.003).8 When women presented at delivery with unknown HIV status, PIP with nevirapine plus AZT reduced transmission of HIV more than did a regimen of nevirapine alone.9 Neonatal PIP with 2 or 3 antiretroviral drugs was also superior to AZT alone for prevention of intrapartum HIV transmission among infants born to women not receiving antiretroviral drugs before labor in a recent study.10 Although higher rates of anemia and neutropenia have been reported with combination antiretroviral PIP, this approach has been well tolerated in full-term infants from cohort studies.11 Therefore, in this high risk of HIV transmission situation, we believe that the use of 2 or 3 antiretroviral drugs could be justified to further reduce the risk of HIV MTCT compared with the reduction in risk achieved by use of AZT alone. Luis M. Prieto, MD Pablo Rojo, MD Paediatrics Department Jose T. Ramos, MD Department of Pediatric Infectious Diseases Hospital Universitario de Getafe Madrid, Spain