Evaluation of plasma viral-load monitoring and the prevention of mother-to-child transmission of HIV-1 in three health facilities of the Littoral region of Cameroon

BACKGROUND: Prevention of mother-to-child transmission (PMTCT) has reduced HIV incidence among new-borns. However, PMTCT remains concerning in sub-Saharan Africa due to bottlenecks including viral load (VL) monitoring during pregnancy. We assessed VL coverage and materno-foetal outcomes of pregnancy among HIV-infected women within the Cameroonian context. METHODS: A hospital-based study was conducted among HIV-infected mothers and their babies in three facilities of the Littoral region of Cameroon from January 2019 to May 2021. Maternal VL-coverage was monitored during pregnancy (VL>1000 copies/ml or unknown were classified as MTCT high-risk group); HIV early infant diagnosis (EID) was evaluated by PCR at six-weeks after birth, and EID results were analysed according to maternal VL; p<0.05 was considered statistically significant. RESULTS: Of 135 HIV-infected pregnant women enrolled (median [IQR] age 39 [27–37] years), VL-coverage during antenatal care (ANC) was 50.4% (68/135), with a lower VL-coverage in 2019 (37.5% vs. 61.9%, p = 0.0069). Married women vs. single (61.8% vs. 42.5%, p = 0.0275) and those on treatment before vs. during pregnancy (56.7% vs. 5.8%, p = 0.0043) had a higher VL-coverage, respectively. Among those with known VL, 10.3% (7/68) had high (VL>1000 copies/mL), 22.1% (15/68) had low (50–1000 copies/mL), and 67.6% (46/68) had undetectable (<50 copies/mL) VL, suggesting an overall viral suppression (<1000copies/mL) of 89.7% (61/68). Vaginal delivery was 80.75% (109/135) regardless of VL, including 81.1% (59/74) women in the high-risk group. EID coverage was 88.1% (119/135) and the rate of HIV-1 MTCT was 1.68% (2/119). Both HIV-positive infants were from the high-risk group, had prolonged labour, had vaginal delivery and were breastfed. CONCLUSION: In these Cameroonian settings, VL-coverage remains suboptimal (below 90%) among ANC attendees, and women at high-risk of MTCT mainly have vaginal delivery. Viral suppression rate remains below the target (below 90%) for accelerating the elimination of MTCT. HIV-MTCT persists, and might be driven essentially by poor VL monitoring. Thus, achieving an optimal PMTCT performance requires a thorough compliance to virologic assessment during ANC.