Prevalence and determinants of virological failure among adult antiretroviral treatment experienced HIV-1 patients in South Omo, Ethiopia

Background: Virological failure (VF) is a challenge which hinders the success of the antiretroviral treatment (ART) program. Although viral load is the preferred method used to detect and confirm treatment failure, research into its prevalence and determinants is limited. Objective: This study was conducted to determine the prevalence of virological failure and its determinants among HIV-1 infected adults, who experienced first line ART in South Omo, Ethiopia. Methods: A cross-sectional study was conducted on patients attending ART clinics at Jinka Zonal hospital and four rural health centers found in South Omo. A total of 253 adult patients who were on ART for ≥ 6 months were recruited sequentially from January 2015-December 2016. In addition to the socio-demographic and clinical data, 10 ml of blood was collected for the CD4+ T cell count and the viral load measurements. CD4+T cell count was conducted using the FACS Caliber flow cytometer and the viral load was estimated using a quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR). Samples with a VL ≥1000 copies/mL were considered as virological failure. Logistic regression analysis was used to identify correlates of virological failure. Results: The median duration of ART was 51 months. About 61% of the participants were females with a mean age of 33.5 years. Majority of the participants (70%) were taking the tenofovir (TDF) based ART, while 30% were taking a zidovudine (AZT) based regimen. Majority (71.9%) of the participants started ART in WHO III/IV stage, with a median base line CD4 count of 239 cell/μL. More than 40% of the participants reported poor ART adherence, and 11% had immunological failure. From a total of 253 patients, 206(81.4 %) [95%CI: 76.7-86.2] had viral suppression, while 47 (18.6%) [95%CI: 13.8-23.3] had virological failure with a mean viral load of 185,506 copies/mL (95%CI: 39083-408100). None of the virological failures were switched to second line ART. According to the multivariate logistic analysis, active tuberculosis (aOR=13, 95% CI= 3.46-29.69), immunological failure (aOR=3.61, 95% CI=1.26-10.39), opportunistic infections (aOR=8.39, 95% CI= 1.75-40.19), and poor adherence were significantly associated with VF among the study participants. Conclusion: The study revealed a considerable prevalence of virological failures with the associated risk indicators. Based on the results and the difficulty faced, of being unable to place patients who were treatment resistant in second line ART, indicates that immunological and clinical criteria are poor biomarkers of drug switching.