PERFORMANCE OF HIV DRUG RESISTANCE EARLY WARNING INDICATORS AND ASSOCIATED PROGRAM FACTORS IN LESOTHO DURING THE DOLUTEGRAVIR ERA

HIV drug resistance (HIVDR) remains a major threat to the long-term effectiveness of antiretroviral therapy (ART) programs, particularly in settings where routine resistance testing is limited. Although dolutegravir (DTG)-based regimens have improved treatment durability, programmatic factors such as poor adherence, treatment interruptions, and inadequate monitoring continue to increase the risk of HIVDR. The World Health Organisation (WHO) recommends HIVDR Early Warning Indicators (EWIs) to monitor program performance and identify vulnerabilities associated with the emergence of HIVDR. This study assessed HIVDR EWI performance and examined facility-level factors associated with program performance in Lesotho during the DTG era. Methods: A cross-sectional assessment was conducted using routinely collected ART program data from 74 facilities across all ten districts of Lesotho during the 2023 reporting period. Four WHO HIVDR EWIs were assessed: total attrition from ART (ART.2), viral load suppression (ART.3), viral load testing coverage (ART.6), and on-time antiretroviral drug pick-up as an adherence proxy (ART.13). Descriptive analyses summarised facility performance, while multivariable linear regression models examined facility- and district-level factors associated with attrition and adherence outcomes. Results: On retention in care, 97% of facilities met the WHO target for attrition. For adherence performance, 88% of facilities did not meet the target for on-time antiretroviral drug pick-up. For viral load suppression, 55% of facilities met the WHO threshold, while only 5% achieved the target for viral load testing coverage. In addition, 45% of facilities could not be classified for viral load-related indicators because of missing viral load data. Multivariable regression analysis identified significant district-level variation in adherence. Compared with facilities in Mokhotlong, facilities in Leribe, Mafeteng, Maseru, Qacha’s Nek, Quthing, and Thaba-Tseka had lower adherence levels, with these differences statistically significant. Hospitals recorded higher adherence levels than clinics. Attrition showed limited associations with facility characteristics. Compared with facilities in Mokhotlong, facilities in Quthing and Thaba-Tseka had lower attrition rates. Conclusions: Lesotho's ART program demonstrated strong retention in care but important weaknesses in treatment continuity, viral load monitoring, and routine program information systems. The coexistence of high retention and poor adherence suggests that continued engagement in care does not necessarily translate into uninterrupted treatment exposure. Variation in performance across districts and facility types further indicates that local service delivery conditions influence program outcomes and HIVDR risk. Overall, the findings suggest that while ART scale-up has been successful, key systems required to sustain long-term treatment effectiveness have not strengthened at the same pace. Strengthening adherence support, improving monitoring systems, and integrating routine EWI monitoring with laboratory-based HIVDR surveillance should be prioritised to safeguard the effectiveness of ART in the DTG era.