Usefulness of blood and urine samples collected on filter paper in detecting cytomegalovirus by the polymerase chain reaction technique

A rapid test for the diagnosis of congenital CMV infection is still needed. This study evaluated the usefulness of dried blood and urine samples colle cted on filter paper for detecting cytomegalovirus (CMV) by the polymerase chain reaction (PCR) assay compared with the use of liquid urine. Samples w ere obtained from 332 infants aged 1-7 days. Liquid urine samples were coll ected into bags, cultured in human fibroblasts, and processed using a multi plex PCR technique. Dried urine samples were obtained by placing a piece of filter paper in contact with the infant's genitals. The heels of neonates were punctured and capillary blood was blotted onto filter paper and dried. Dried blood and urine specimens were analyzed by multiplex PCR and nested- PCR assays. A diagnosis of congenital CMV infection was established by isol ating the virus, and by detecting viral DNA in the liquid urine. Of the 332 liquid urine samples collected from 332 neonates. seven (2.1%) were positi ve for CMV and 325 were negative. by both cell culture and PCR assay. In dr ied samples, CMV DNA was detectable only with a nested PCR assay. Compared with known CMV infection status, 5/7 (71.4%) neonates were positive for con genital CMV infection using dried blood samples. All 325 uninfected neonate s were negative. In the dried urine samples. 4/4 CMV-infected infants gave positive tests, and all 262 uninfected infants were negative. Although furt her improvements in sample collection and/or processing are still needed, P CR testing on dried urine or blood collected on filter paper is a promising approach in the diagnosis of neonatal CMV infection. (C) 2001 Elsevier Sci ence B.V. All rights reserved.