Prevalence and Risk Factors for Cytomegalovirus Retinitis Among People Living with HIV in Sub-Saharan Africa in the Antiretroviral Therapy Era: A Systematic Review and Meta-Analysis

Abstract

Cytomegalovirus retinitis has remained an alarming and potentially vision-threatening opportunistic disease in the population living with HIV, especially in cases of extreme immunosuppression. Although the introduction of antiretroviral therapy has led to a drastic decline in the number of cytomegalovirus retinitis cases reported in most parts of the world, the current epidemiology of cytomegalovirus retinitis in sub-Saharan Africa has seemed unusual in early reports, unexpectedly portraying low disease prevalence rates despite the high number of HIV cases in the concerned region. This systematic review and meta-analysis aimed to estimate the pooled prevalence of cytomegalovirus retinitis among people living with HIV in sub-Saharan Africa in the antiretroviral therapy era, and to identify associated risk factors. The search of databases included Medline using the search engine PubMed, Google Scholar, and the African Journals Online database named AJOL. For inclusion, studies must have included an eye examination to verify the presence of cytomegalovirus retinitis. The data was combined using the logit transformation model. Heterogeneity was tested using the I-squared test and the Cochran Q test. A total of ten studies involving 1,931 participants from nine sub-Saharan Africa countries were found eligible. The proportion of cytomegalovirus retinitis varied from 0.34% to 15.8%. Pooled prevalence was found to be 3% (95% CI: 1.6-5.4%) with low to moderate inter-study variation (I² = 17.8%). Substantial variation in the proportion was found in different sub-Saharan Africa regions; it was found to be less than 1% in West Africa, 3-4% in Southern Africa, 7% in East Africa and 6% in Central Africa. Across all studies, the strongest and most consistent risk factors for cytomegalovirus retinitis were profound immunosuppression, particularly CD4 < 50 cells/µL. Antiretroviral therapy-naïve status, poor adherence, and presence of advanced AIDS-defining illnesses were additional contextual risk markers. Cytomegalovirus retinitis is an under-recognized but important source of preventable blindness among people living with HIV. Prevalence in sub-Saharan Africa differed from that in Asian early antiretroviral therapy era cohorts but is relevant in settings where late HIV presentation occurs. Systematic retinal screening in people living with HIV with low CD4 counts < 50 cells/µL and expanded HIV care and treatment services are important to prevent blindness due to cytomegalovirus retinitis.