Cytomegalovirus viraemia in HIV exposed and infected infants: Prevalence and clinical utility for diagnosing CMV pneumonia

Background: Human cytomegalovirus (HCMV) is an important pathogen in HIV exposed infants with pneumonia. However, the diagnosis of HCMV pneumonia in this setting is challenging due to limited access to bronchoscopy, lung biopsy and direct sampling of the lower respiratory tract. HCMV viraemia is more accessible, but their diagnostic performance in this context has not been studied. Objective: To describe the prevalence of HCMV viraemia and evaluate its clinical utility in HIV exposed infants. Study design: In this cross-sectional study, we performed qualitative and quantitative PCR to detect HCMV viraemia in HIV exposed asymptomatic infants and in infants with severe pneumonia in the Western Cape province of South Africa. Results: 283 asymptomatic HIV exposed infants and 142 HIV exposed infants with severe pneumonia were studied. Infants with pneumonia had a higher prevalence of HCMV viraemia compared to asymptomatic infants (68% vs 24% OR 6.7, 95% CI 4.2-10.8). This increased prevalence remained significant (OR 4.3 95% CI 2.6-7.0) after adjusting for HIV infection. Of the infants with pneumonia, the level of HCMV viraemia was significantly higher in a subset of infants diagnosed with HCMV pneumonia (median HCMV viral load 4.6 vs 2.5 log copies/ml p<0.001). Receiver operator characteristic (ROC) analysis showed the area under the curve was 0.78 (95% CI 0.71-0.86) and a threshold of 4.1 log copies/ml was able to correctly identify 70% of HCMV pneumonia cases. Conclusion: Prevalence and level of HCMV viraemia in sub-Saharan HIV-exposed and infected infants peaks at 3-4 months of age. Quantitative HCMV PCR may be useful in diagnosing HCMV pneumonia. (C) 2013 Elsevier B. V. All rights reserved.