High prevalence of low-level viremia among infants initiated on antiretroviral drugs following mother-to-child transmission of HIV

Abstract

Background: The number of HIV-positive newborns has greatly decreased. However, complete viral suppression is imperative. We assessed the prevalence of low-level viremia among infants initiated on ART over a period of two years in a Ugandan cohort. Methods: Drug resistance testing among infants at baseline (DRIBS) enrolled infants at the time of treatment initiation. Test. The infants were followed for two years. Viral loads (VL) were measured to monitor the response to therapy. Intensified adherence counseling (IAC) and HIV drug resistance testing were performed. Results: Between June 2018 and October 2023, 100 infants were enrolled and followed up. The non-AIDS-related mortality rate was 4%. The median age at diagnosis was 79 (IQR, 57.75;140.75) days, with 4% of patients diagnosed within 6 weeks after delivery. The median age at the initiation of therapy was 110.5 (IQR, 87.0–162.0) days. The medianbaseline %CD4 was 26 (IQR, 18.75;32), with 9% of the babies being severely immunosuppressed. The median baseline log viral load was 4.44 (IQR, 3.19–5.58). At six months, 33% and 65% of the patients had a VL <50 and <1000 copies/ml, respectively. At 12 months, 39% and 74% of patients had a VL <50 and <1000 copies/ml, respectively. At month 18, 50% and 73% had VL <50 and <1000 copies/ml, respectively, and at 24 months, 74% and 88% had VL <50 and <1000 copies/ml, respectively. The proportions of babies with low-level viremia (LLV) (50-999 copies/ml) at months 6, 12, 18 and 24 were 25%, 30%, 21% and 14%, respectively. Post-IAC VL revealed that of the 58% of babies with a VL <1000 copies/ml, only 23% had a VL <50 copies/ml. Notably, there was a high proportion of LLV (35%) following IAC. Comparedwith mothers post-IAC VL, 42% of mothers had <50 copies/ml, with only 11.5% LLV. K‒M survival estimates showed that while it took 72 weeks for 50% of the mothers and infants to attain a VL less than 1000 copies/ml, it took 96 weeks for the infants to attain a VL <50 copies/ml. Conclusion: Viral suppression is achieved much more slowly in pediatric patients, implying that it might take longer for babies to achieve the third 95. Furthermore, the greater prevalence of LLV in pediatric patients than in mothers has important implications for the response to therapy.