Incidence of common opportunistic infections among HIV-infected children on ART at Debre Markos referral hospital, Northwest Ethiopia: a retrospective cohort study

Background Opportunistic infections (OIs) are the leading cause of morbidity and mortality among children living with human immunodeficiency virus (HIV). For better treatments and interventions, current and up-to-date information concerning occurrence of opportunistic infections in HIV-infected children is crucial. However, studies regarding the incidence of common opportunistic infections in HIV-infected children in Ethiopia are very limited. Hence, this study aimed to determine the incidence of opportunistic infections among HIV-infected children on antiretroviral therapy (ART) at Debre Markos Referral Hospital. Methods A facility-based retrospective cohort study was undertaken at Debre Markos Referral Hospital for the period of January 1, 2005 to March 31, 2019. A total of 408 HIV-infected children receiving ART were included. Data from HIV-infected children charts were extracted using a data extraction form adapted from ART entry and follow-up forms. Data were entered using Epi-data (TM) Version 3.1 and analyzed using Stata (TM) Version 14. The Kaplan Meier survival curve was used to estimate the opportunistic infections free survival time. Both bi-variable and multivariable Cox proportional hazard models were fitted to identify the predictors of opportunistic infections. Results This study included the records of 408 HIV-infected children-initiated ART between the periods of January 1, 2005 to March 31, 2019. The overall incidence rate of opportunistic infections during the follow-up time was 9.7 (95% CI: 8.13, 11.48) per 100 child-years of observation. Tuberculosis at 29.8% was the most commonly encountered OI at follow-up. Children presenting with advanced disease stage (III and IV) (AHR: 1.8, 95% CI: 1.2, 2.7), having "fair" or "poor" ART adherence (AHR: 2.6, 95% CI: 1.8, 3.8), not taking OI prophylaxis (AHR:1.6, 95% CI: 1.1, 2.4), and CD4 count or % below the threshold (AHR:1.7, 95% CI: 1.1, 2.6) were at a higher risk of developing opportunistic infections. Conclusions In this study, the incidence rate of opportunistic infections among HIV-infected children remained high. Concerning predictors, such as advanced disease stage (III and IV), CD4 count or % below the threshold, "fair" or "poor" ART adherence, and not taking past OI prophylaxis were found to be significantly associated with OIs.