Evaluation of screening tests for congenital cytomegalovirus infection.

Although the use of dried blood spots has been proposed for screening of newborns with congenital cytomegalovirus infection, viral loads in blood were significantly smaller than those in urine (P < 0.001), and DNA recovery from dried blood spots using the thermal shock procedure was inefficient. In contrast, our urine-based screening program identified asymptomatic cases with low viral loads in blood.