BACKGROUND: Tanzania and other resource-limited settings in sub-Saharan Africa have reported progress in scaling up ART usage. However, treatment success among people living with HIV (PLHIV) has not been fully appreciated. In March 2019, Tanzania introduced a WHO-recommended dolutegravir-based combination therapy to its ART program. Therefore, we investigated HIV viral suppression rates, associated factors, and the burden of HIV drug resistance (HIVDR) among PLHIV a year after the introduction of dolutegravir in Tanzania.
METHODS: We conducted a national representative cross-sectional survey from September to December 2020. Adults and children PLHIV from 36 HIV care and treatment centres in Tanzania were recruited. Blood samples, demographic and clinical information were obtained. HIV viral load (HVL) was estimated using the COBAS 8800 TaqMan (Roche Molecular system). Viral suppression was defined at HVL<1000 copies/mL. Independent factors associated with viral suppression were identified using regression analyses (p<0.05). HIVDR genotyping was performed from samples with HVL= 1000 copies/mL. HIV genes (reverse transcriptase, protease, and integrase) were amplified by PCR and directly sequenced. The Stanford HIVDR database was used for HIVDR analysis.
RESULTS: A total of 2039 PLHIV were recruited, with 57.5% being adults and 64.7% of them were females; whereas children contributed 42.5% and 53.5% were females. The viral suppression rates were 96.1% and 89.1%, in adults and children, respectively. Hereby, adults and children on the dolutegravir-based regimen recorded the highest viral suppression rates of 96.4 % and 91.3%, respectively; while the lowest suppression rates were observed in PLHIV on protease inhibitor-based regimen at 78.8% and 85.4%, respectively. In addition, factors including marital status, initial HVL, the current ART regimen, and treatment adherence were independently associated with viral un-suppression status (p<0.05). Furthermore, HIVDR was detected in 71.5% of PLHIV with high viremia (HVL= 1000 copies/mL). Importantly, 5.8 % of participants had dolutegravir drug resistance mutations, including the major drug resistance mutations; Q148K, E138K, G118R, G140A, T66A, and R263K.
CONCLUSIONS: The present findings indicate that dolutegravir-based regimens show promise for treating HIV in Tanzania. However, there are still barriers to optimal treatment outcomes, such as the emergence of dolutegravir HIVDR and adherence among PLHIV in Tanzania.