Are dried blood spots useful as a specimen for the detection of cytomegalovirus in various clinical settings?

Abstract

Congenital cytomegalovirus (CMV) infection is a common infection in neonates with potentially negative effects on morbidity and mortality. Diagnosis of congenital CMV infection is often based on sampling urine or saliva and the use of polymerase chain reaction (PCR) analysis of CMV DNA. However, the collection of these specimens is unreliable, while retrospective diagnosis of CMV infection at birth cannot be achieved. The use of dried blood spots (DBS), which are routinely collected at birth, may facilitate CMV diagnosis based on PCR techniques, potentially advancing possible screening programmes and retrospective diagnosis of the condition. This systematic literature review aimed to evaluate the clinical utility of DBS samples for the diagnosis of congenital CMV infection. A systematic search strategy resulted in a total of 17 studies eligible for inclusion, comprising both retrospective and prospective methodologies. Overall, the findings suggested a high sensitivity and specificity for DBS samples when analysed using PCR, although these values varied according to sample size and context of investigation. The use of DBS in screening contexts was associated with a lower sensitivity than would be optimal in practice. Therefore, while further data are needed to overcome limitations with the extant data set, the routine use of DBS for CMV screening cannot be recommended, while retrospective diagnosis of CMV infection in infants or children with a high clinical index of suspicion may be justified.