New York: For mothers who are infected with human immunodeficiency virus (HIV) but their immune system is in good health, taking a three-drug antiretroviral regimen during breastfeeding period can essentially eliminate HIV transmission by breast milk to their infants, finds a study. The findings showed that both three-drug maternal antiretroviral therapy and daily infant nevirapine were safe and effective at preventing HIV transmission from mother to child during breastfeeding. "Maternal antiretroviral therapy safely minimises the threat of HIV transmission through breast milk while preserving the health advantages of breastfeeding, as the high infant survival in this study underscores," said Anthony S. Fauci, Immunologist and Director of National Institute of Allergy and Infectious Diseases (NIAID) -- a US-based research organisation. Further, the rate of perinatal transmission in those who continued the regimen was found to be very low - 0.3 per cent at six months of age and 0.6 per cent at one year of age. The longer an HIV-infected mother breastfeeds, the greater the risk for HIV transmission to the infant. Overall, infant mortality in the study was extremely low, with nearly all babies surviving their first year of life, the researchers said. In comparison, in the absence of any intervention, rates of HIV transmission from a HIV-infected mother to her child during either pregnancy, labour, delivery or breastfeeding historically have ranged from 15 to 45 per cent, according to World Health Organisation (WHO). "These findings add to the considerable body of evidence confirming the benefits of antiretroviral therapy for every person living with HIV," Fauci added. Infant mortality in resource-limited countries can be high, but following the therapy, nearly 99 percent of babies lived to see their first birthday. HIV-infected mothers in areas that lack safe, clean water may be encouraged to breastfeed because of the health benefits for the infant and the risk for infants from mixing formula with an unsafe water supply, the study said. Breastfeeding helps prevent malnutrition, and antibodies from breast milk protect babies against potentially life-threatening diarrheal and respiratory infections. "HIV-infected mothers in low and middle income countries, who may not have access to alternative feeding methods, can be reassured that breastfeeding is a safe option for their infants," explained Nahida Chakhtoura from Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) in the US. For the study, the team enrolled 2,431 pairs of HIV-infected mothers and their HIV-uninfected infants at clinical research sites in India South Africa, Malawi, Tanzania, Uganda, Zambia, and Zimbabwe between June 2011 and October 2014. On average, the women were asymptomatic and had relatively high CD4+ cell levels -- a marker of good immune system health. The first group of women used triple-drug antiretroviral therapy daily doses of nevirapine for the infant until 6 weeks after birth. The second group used triple-drug antiretroviral therapy until one week after delivery and daily doses of nevirapine for the infant beginning from the first week after birth and continuing through completion of study follow up. Infant nevirapine also offers a safe and effective alternative if the mother has difficulty adhering to or tolerating antiretroviral therapy, the researchers concluded, suggesting lifelong antiretroviral therapy for all pregnant and breastfeeding women living with HIV. The results were presented at the 8th International Workshop on HIV Pediatrics in Durban, South Africa, recently.