Letters to the Editor
To the Editors:
Recently, an article entitled “Optimal Time on HAART for Prevention of Mother-to-Child Transmission of HIV”1 was published in this journal. The study aimed at investigating the optimal time in which antiretroviral therapy should be initiated during pregnancy to maximize prevention of mother-to-child transmission. The study described the situation of HIV-infected women in Lusaka, Zambia. The methods used to achieve the proposed goals are consistent. However, the study did not specify the childbirth delivery methods of the surveyed women and the possible prophylaxis protocols used in the perinatal period, which is a gap in the data.
Approximately, 65% of mother-to-child HIV transmission cases occur during labor and delivery, whereas the remaining 35% of cases occur during pregnancy, with the highest risk in the third trimester.2 The risk of infection is estimated to be between 7% and 22%, if the infected mother breastfeeds the baby. The infection rate can rise as high as 29%, depending on maternal viral load.3 Unfortunately, these aspects were not highlighted in the article.1 In our opinion, this information is essential for the understanding of the results and comparison of the findings with other populations. The prevalence of HIV infection without prophylactic intervention ranges between 25% and 30%.2 However, when the protocol is followed, this rate is reduced to less than 1%.
To prevent maternal transmission of HIV in Brazil, the Ministry of Health recommends the use of antiretroviral drugs starting in the 14th week of pregnancy. Furthermore, HIV-infected pregnant women with unknown or high viral load, or by obstetric indication, should undergo elective cesarean section, and the use of injectable azidothymidine (AZT) is recommended at least 3 hours before the procedure until umbilical cord clamping. In vaginal delivery, AZT should be administered at the beginning of labor and continued until cord clamping. Oral AZT should be given to newborns exposed to infections from birth to 42 days of age. Lactation should be inhibited, and the child nutrition should consist of artificial infant formula. Antiretroviral chemoprophylaxis is recommended for all pregnant women diagnosed with HIV or submitted to rapid HIV testing at delivery with confirmatory results.2
Mother-to-child transmission rates have been progressively reduced in Brazil by using the prevention protocol for maternal transmission. The overall transmission rate is estimated to be 6.4%, based on 2004 data, with some variation across geographical areas. However, there is a difficulty carrying out HIV infection screening tests in the prenatal period. The coverage of HIV testing during prenatal care is estimated to be 96%, but test completion and result disclosure occur in only 62.5% of cases.2 Being aware of the infection does not ensure greater adherence to antiretroviral treatment.
Despite the universal access to comprehensive prevention, care and treatment of HIV infection in Brazil, the access and quality of health care services are uneven, depending on the surveyed region, due to the territorial area of the country and the lack of health information in some strata of the population. Health institutions are not always organized and structured with skilled multidisciplinary teams and referral services available. Sometimes, there is a failure to provide prenatal follow-up care and delay in diagnosis and therapeutic decision-making that affects the prevention success of mother-to-child HIV transmission.
Variables associated with vertical HIV transmission should be standardized and a description of context information and cultural aspects of health care should be provided, enabling comparison between different realities.
1. Chibwesha CJ, Giganti MJ, Putta N, et al.. Optimal time on HAART for prevention of mother-to-child transmission of HIV. J Acquir Immune Defic Syndr. 2011;58:244–248.
2. Connor EM, Sperling RS, Gelber R, et al.. Reduction of maternal-infant transmission of human immunodeficiency virus type 1 with zidovudine treatment. Pediatric AIDS Clinical Trials Group Protocol 076 Study Group. N Engl J Med. 1994;331:1173–1180.
3. Dunn DT, Newell ML, Ades AE, et al.. Risk of human immunodeficiency virus type 1 transmission through breastfeeding. Lancet. 1992;340:585–588.