BACKGROUND: Betaherpesviruses are established causes of morbidity and mortality in immunosuppressed patient groups but have been little studied in sub-Saharan Africa, the epicenter of the human immunodeficiency virus (HIV) pandemic. In this region, primary infections with human cytomegalovirus (HCMV) and human herpesvirus type 6 (HHV-6) type 6 are endemic in infancy, but the clinical impact of these infections among pediatric inpatient groups is poorly characterized and assumptive, based largely on data from Western populations. METHODS: We used TaqMan polymerase chain reaction to screen sera from a group of 303 pediatric inpatients aged between 3 weeks and 2 years, at the University Teaching Hospital in Lusaka, Zambia. We report the prevalence of DNAemia and viral loads within this patient group, and evaluate possible clinical associations/risk factors for betaherpesvirus infections in these hospitalized children. RESULTS: We detected betaherpesvirus DNAemia in 59.1% (179/303) of children. HCMV was the most prevalent (41.3%), followed by HHV-6B (20.5%), HHV-7 (20.1%), and HHV-6A (0.3%). HIV infection (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.37-3.90; P = .002), being underweight (OR, 1.82; 95% CI, 1.06-3.12; P = .03), and an admission diagnosis of suspected meningitis (OR, 5.72; 95% CI, 1.07-30.5; P = .041) were independently associated with an increased odds of HCMV DNAemia. Conversely, HHV-6B and HHV-7 DNAemia were not associated with HIV, underweight, or admission diagnosis. Median HCMV viral load was moderately but significantly higher in HIV-infected children. CONCLUSIONS: Highly prevalent HCMV DNAemia was independently associated with HIV infection and being underweight across all age groups, and was also associated with meningitis, with previously underappreciated implications for the health and development of African children.