Evaluation of CMV DNA in dried blood spot.

Cytomegalovirus is the primary viral cause of congenital infection. However, diagnosis may be difficult for clinical and technical reasons. Currently, evaluation of CMV DNA on dried blood spot (DBS) is an important instrument to define a congenital infection. The aim of this study was to identify a clinically and technically suitable diagnostic work-flow for CMV DNA evaluation on DBS. Sensitivity was not significantly influenced by storage time of up to 12 months and extraction technique; however, analysis in triplicate was crucial to obtain reliable results. Considering viral load in an infected foetus at risk of developing disease, a threshold value of approximately 10(4) copies/mL was characterized by high operating characteristics for detection of positivity at 12 months on DBS.