Diagnosing congenital cytomegalovirus by saliva on Guthrie paper

Abstract

Background: In recent years, interest in universal newborn screening for congenital cytomegalovirus (cCMV) has intensified. consequently, reliable and simple methods of mass screening for cCMV, are essential. Herein, we present a novel approach of using polymerase chain reaction (PCR) in saliva with direct inoculation onto Guthrie paper. Our aim was to determine the diagnostic accuracy of real- time PCR in saliva rolled directly onto Guthrie paper in diagnosing cCMV infection.

Objectives: To evaluate the diagnostic accuracy of real-time PCR analysis of dried saliva on Guthrie paper as a future approach for mass screening of newborns in diagnosing cCMV infection.

Study design: This prospective, blinded study was performed in a tertiary cytomegalovirus (CMV) clinic from May 2018 through January 2019. Forty-two cCMV positive newborns and 41 without cCMV, were enrolled and tested for CMV using PCR from their saliva placed onto Guthrie paper and from their saliva using standard methods. Specificity and sensitivity of dried saliva PCR versus gold-standard methods were analyzed.

Results: Forty-two out of 42 (100 %) CMV positive infants showed positive PCR in the dried saliva on the Guthrie paper. All (100 %) controls exhibited negative PCR results. Congenital CMV infection was identified with a sensitivity of 100 % (95 % C.I. = 91.4%-100.00%) and specificity of 100 % (95 % C.I. = 91.4%-100.00%).

Discussion: CMV testing with saliva real-time PCR on Guthrie paper displayed a high sensitivity and specificity, rendering it a powerful screening test. The accuracy, simplicity of sampling, storage and transportation and the potential reliance on existing logistic resources, establishes this method as a candidate for cCMV universal screening programs.

Keywords: CMV; Guthrie; Saliva; Screening; Universal screening.