Viral load and reverse transcriptase drug resistance mutations in HIV-1 isolated from mothers who transmit the virus to their infants at Kibagabaga Hospital PMTCT Clinic, Kigali, Rwanda

Abstract

Mother to Child Transmission (MTCT) of HIV is the largest source of HIV infection in children below the age of 15 years, affecting five-million infants per year. HIV/AIDS is a disease with known modes of transmission and can therefore be prevented. Studies have shown significant reduction in (MTCT) of HIV for mothers undergoing antiretroviral (ARV) treatment. Although there is expanded access to ARV in Rwanda including in prevention of Mother-to-Child- transmission (PMTCT) programs, a significant number of children born to HIV positive mothers still acquire the virus even with the newly adopted Option B+ program. Several factors have been documented as contributing to MTCT of HIV including high viral loads of the mothers at delivery and during breast feeding as well as underlying drug resistance to ARV regimens used in PMTCT. The increasing incidence of transmitted drug resistance in HIV-1 through heterosexual contact raises concern on the contribution of this problem to MTCT. In Rwanda there is lack of information on population studies regarding the impact of Option B+ program on the trajectory of maternal viral loads during gestation and the emerging transmission of drug-resistant HIV strains especially from mothers to their babies. This cross-sectional study determined the viral load dynamics in mothers under Option B+ treatment program of PMTCT in Kibagabaga Hospital of Rwanda and attempted to document prevalence and types of drug resistance mutations in HIV-1 transmitted from mothers-to-children. We found that 88% of babies testing positive for HIV-1 RNA were below the age of 1 year. Option B+ treatment brought 60% of mothers’ viral load below detection by end of 1st trimester, increasing this percentage to 70% by child birth. The 30% mothers who had detectable viral load by 3rd trimester had minimal reductions in viral load throughout gestation, suggestive of underlying problems, including resistance to Option B+ drug regimens administered. Unfortunately we were only able to successfully sequence and determine drug resistance profiles of 3 HIV-1 isolates, which showed high-level resistance. The problem of transmitted drug resistance in MTCT may be a real challenge and may require drug resistance profiling before initiation of ART triple therapy in pregnant mothers if MTCT of HIV-1 is to be reduced further, or even eliminated.