Among 811 adults with AHD and cryptococcal meningitis recruited into the AMBITION-cm trial, CMV viraemia occurred in half of all participants, and high-level CMV plasma viraemia (>1000 IU ml−1) was associated with double the odds of mortality at 2 weeks (adjusted odds ratio (aOR), 2.31; 95% CI, 1.12−4.75) and 10 weeks (aOR 2.44; 95% CI, 1.33−4.45) after adjustment for potential confounders including ART and CD4 count. This evidence concerns the gene CD4 and mitochondrial DNA depletion syndrome 4a.