Prevalence and predictors of virologic failure among HIV patients on antiretroviral therapy in Makueni County: a cross-sectional study

Abstract

Background: The growing number of people on antiretroviral therapy in Kenya has led to a decrease in HIV morbidity and mortality. However, virologic failure (VF) threatens to reverse these gains. In Makueni County, existing data indicate challenges in achieving viral load (VL) suppression among persons living with HIV (PLHIV). Few studies have been carried out investigating VF in the region despite its high incidence of HIV infections. Methods: An analytical cross-sectional study was conducted among PLHIV in Makueni County to investigate the determinants and estimate the prevalence of VF. The prevalence of VF and its associated 95% exact binomial confidence interval was estimated, and a mixed-effects logistic regression model used to evaluate the relationship between the predictors and VF. Results: The estimated period prevalence of VF between October 2018 and June 2019 was 13.2% (95% CI: 12.7%–13.8%). Being 15 years or older (aOR=0.53; 95% CI: 0.44 – 0.645) and having blood samples tested for reasons other than baseline VL measurement was associated with lower odds of VF: breastfeeding mothers (aOR=0.1; 95% CI: 0.01 – 0.97); clinical failure (aOR=0.08; 95% CI: 0.01 – 0.44); confirmation of VF (aOR=0.2; 95% CI: 0.07 – 0.62); no VL data (aOR=0.06; 95% CI: 0.01 – 0.31); routine VL (aOR=0.04; 95% CI: 0.01 – 0.12); drug substitution (aOR=0.03; 95% CI: 0.01 – 0.08). Taking ABC-based, AZT-based, or other non-TDF-Based regimens increased the odds of VF (aOR=1.61; 95% CI: 1.34 – 1.94), (aOR=1.75; 95% CI: 1.52 - 2.01), and (aOR=1.55; 95% CI: 0.99 - 2.44) respectively. Conclusion: This study showed that over 13% of HIV patients on ART in Makueni County had VF between October 2018 and June 2019. The significant risk factors associated with VF were found to be age lower than 15 years, taking a non-TDF-based ART regimen, and blood sampling for baseline VL measurements.