Detection of cytomegalovirus DNA on dried blood spots collected from infants infected with HIV: an in-house method adaptable in resource-limited settings.

ABSTRACT

In countries with limited resources, infants infected with HIV are highly exposed to CMV co-infection which probably represents a major risk factor for disease progression in this population. This study aimed to evaluate the performance of a low cost CMV DNA extraction method from DBS and the feasibility of its implementation in laboratories of 4 countries with limited resources. DNA was extracted from DBS with a cationic resin (chelex 100) and amplified with an "in house" real time CMV PCR. Dilutions of a quantified whole blood sample were spotted on paper to evaluate the 95% detection limit. A DBS quality control panel was analyzed in all laboratories. CMV PCR was compared between DBS and liquid whole blood (gold standard) in 2 populations 418 transplanted patients and 59 infants infected with HIV (median age of 2 months). The CMV PCR 95% detection limit in DBS was 3.87 log10 copies/mL. Its positive and negative predictive values for CMV diagnosis in infants infected with HIV were 100% and 87.5% respectively. Quality control panels gave consistent qualitative results in all laboratories. This assay had high predictive values for CMV diagnosis in infants infected with HIV and its implementation in resource-limited countries with limited resources is feasible.