Journal of Medical Virology 84:109–115 (2012) Prevalence of Congenital Cytomegalovirus Infection in Slovenia: A Study on 2,841 Newborns Katarina Rednak Paradiz ˇ, 1 Katja Seme, 2 Evelin Puklavec, 3 Darja Paro-Panjan, 4 and Mario Poljak 2 * 1 Department of Pediatrics, General Hospital Slovenj Gradec, Slovenj Gradec, Slovenia 2 Faculty of Medicine, Institute of Microbiology and Immunology, University of Ljubljana, Ljubljana, Slovenia 3 Gastroenterology Unit, Pediatric Clinic, University Clinical Centre, Maribor, Slovenia 4 Neonatal Unit, University Children’s Hospital, University Medical Centre, Ljubljana, Slovenia Human cytomegalovirus (CMV) is the most fre- quent cause of congenital infection in humans. In the first prevalence study of congenital CMV infection in Eastern and Central Europe, all neo- nates born in a 22-month period in two Slove- nian maternity units (total of 2,841 newborns) were screened prospectively for congenital CMV infection by a real-time polymerase chain reaction (PCR) in urine. In all newborns with positive screening results, plasma and dried blood spots (DBS) collected at birth were tested additionally for CMV DNA. Congenital CMV infection was confirmed by virus isolation from a urine sample collected within the first 2 weeks of life. Congenital CMV infection was identified in four out of 2,841 newborns tested (incidence 0.14%; 95% CI, 0.05–0.39%). In four newborns with confirmed congenital infection, the con- centration of CMV DNA in urine ranged from 4.68 to 8.18 log 10 copies/ml, all four newborns had detectable CMV DNA in plasma taken at birth (1.26–3.34 log 10 copies/ml) and two out of four had detectable CMV DNA in DBS collected during newborn metabolic screening. None of the four newborns with confirmed congenital CMV infection was symptomatic. The study showed that the prevalence of congenital CMV infection at birth in Slovenia is among the low- est in the world and that CMV DNA PCR testing of urine is a suitable and affordable real-time screening strategy for congenital CMV infec- tion. If it is performed in 24 mini-pools, the cost of screening is 1.4 s/newborn and the cost of detecting a single newborn with congenital CMV infection 1,000 s. J. Med. Virol. 84:109–115, 2012. ß 2011 Wiley Periodicals, Inc. KEY WORDS: cytomegalovirus; congenital infection; Slovenia; screening; PCR INTRODUCTION Human cytomegalovirus (CMV) is the most fre- quent cause of congenital infections, which can cause permanent disabilities such as hearing loss, vision loss, and mental retardation [Kenneson and Cannon, 2007]. Although congenital CMV infection is usually asymptomatic and undiagnosed at birth, its cumula- tive effect on morbidity and mortality is of consider- able public health significance; for example, a recent study in the United States identified a total of 777 deaths associated with congenital CMV over the 17-year study period, resulting in 56,355 years of age- adjusted years of potential life lost [Bristow et al., 2011]. Congenital CMV infection is a leading non-genetic cause of sensorineural hearing loss in infants and children [American Academy of Pediatrics, 2007; Engman et al., 2008; Grosse et al., 2008]. Although sensorineural hearing loss can be detected by hearing screening of newborn, a substantial proportion of affected children are missed using this screening approach [Fowler et al., 1997; Foulon et al., 2008]. In contrast, virological screening of newborns for congen- ital CMV infection permits timely identification of children at increased risk of CMV-associated sensori- neural hearing loss, allowing targeted monitoring of affected children in order to intervene at critical stages of acquiring speech and language skills [American Academy of Pediatrics, 2007; Boppana et al., 2010, 2011]. Conventional virus isolation from urine or sali- va is still considered the ‘‘gold standard’’ for identifica- tion of newborns with congenital CMV infection, but *Correspondence to: Prof. Mario Poljak, MD, PhD, Faculty of Medicine, Institute of Microbiology and Immunology, Zalos ˇka 4, 1105 Ljubljana, Slovenia. E-mail: mario.poljak@mf.uni-lj.si Accepted 15 August 2011 DOI 10.1002/jmv.22230 Published online in Wiley Online Library (wileyonlinelibrary.com). ß 2011 WILEY PERIODICALS, INC.