Detection of Cytomegalovirus in Urine Dried on Filter Paper

摘要

Urine is the best specimen for the diagnosis of congenital cytomegalovirus, but collection and processing of liquid urine are impractical for screening. Urine dried on filter paper was processed by the same convenient, low-cost method used by newborn screening to test blood spots and showed high sensitivity and specificity. Congenital cytomegalovirus (cCMV) infection is a leading cause of disability worldwide, occurring in approximately 0.4%-0.6% of live births [1]. There has been an increasing interest in universal newborn screening for cCMV due to the benefits of antiviral treatment and early intervention for hearing loss which improve outcomes. The best method for CMV screening remains unclear with saliva, urine, and dried blood spots (DBS) under investigation. Saliva and urine specimens both provide excellent sensitivity for diagnostic testing. Saliva swabs are convenient to collect, store, and transport. However, saliva testing lacks infrastructure for processing, and typically 8%-15% of positive results can be false-positive most likely from CMV in breast milk, requiring that saliva results are confirmed with urine testing [2-4]. DBS are already collected on nearly all newborns and show high specificity for CMV testing but to date have not shown adequate sensitivity. Urine testing offers better sensitivity and specificity than saliva and remains the gold standard specimen for diagnosing cCMV [4-6]. However, liquid urine is difficult to collect and, like saliva, has no infrastructure for large-scale testing. The present study examined whether urine dried on filter paper could be processed with the same streamlined procedures used for DBS in newborn screening.