Pilot Study For Surveillance Of Congenital Cytomegalovirus

Objective:Congenital Cytomegalovirus (CMV) infection is the most prevalent congenital infection worldwide. Epidemiology and clinical outcomes are known to vary with socio-economic background, but few data are available from China. First, this study evaluated CMV birth prevalence, seroprevalence, clinding findings and risk factors at birth. Reliable methods to screen newborns for congenital CMV infection are needed for identification of infants at increased risk of hearing loss. Then, we compared the dried-saliva and dried blood spots (DBS) specimens with the liquid-saliva specimens to determine the diagnostic accuracy of dried-saliva and DBS specimens for newborn CMV screening. At last, we compared two commercial CMV-IgG ELISA kits.Methods:In the first part, between March2011and February2012, infants born at5Shandong hospitals had saliva specimens collected. A total of4800infants consecutively born were screened for the presence of CMV in saliva with the first two weeks. Meanwhile, the DBS specimens were collected and tested the presence of anti-CMV IgG antibodies. Neonatal clinical findings were recorded two. The second, results of liquid-saliva PCR assay were compared with DBS PCR assay (March2011to December2011) and dried-saliva PCR assay (November2011to February2012). Then488DBS specimens were selected and tested by two ELISA kits, the indicator include sensitivity, specificity and positive and negative predictive values were calculated.Results:Congenital CMV infection was confirmed in42/4800infants (0.9%;95CI:0.6%-1.1%) according to testing of liquid-saliva specimens. The seroprevalence of CMV-lgG antibodies in newborns is95.6(4589/4800,95%CI:95.0%-96.2%). Six (14.3%;95%CI:4.8-26.2) infants had at least one clinical finding suggestion of CMV infection. Sensorineural hearing loss was found in2/41(4.9%,95%CI:0-12.2, one of infection infants was not tested for hearing screening). Of1086newborns screened with the use of the dried-saliva PCR assay,1079were negative for CMV, and4infants (0.4%) had positive results on both liquid and dried saliva PCR assay. The sensitivity and specificity of the dried-saliva PCR assay were66.7%and99.7%, respectively, and the positive and negative predictive values were57.1%and99.8%, respectively. Of3945newborns screened by means of the DBS PCR assay,6were positive for CMV, whereas35(0.9) were found to be CMV-positive on liquid-saliva PCR assay. Sensitivity and specificity of the DBS PCR assay were14.3%and99.2%, respectively. The positive and negative predictive values were83.3%and99.2%, respectively. A total of488DBS specimens were screened CMV-IgG antibodies using both the SeraQuest and Abnova ELISA kit. The sensitivity and specificity of the Abnova kit were98.9%and78.6%, respectively, and the positive and negative predictive values were99.3%and68.8%, respectively.Conclusions:The CMV birth prevalence was evaluated by this first large newborn screening study. Real-time PCR assays of dried-saliva specimens showed high sensitivity and specificity for detecting CMV infection and should be considered potential screening tools for CMV in newborns. However, among newborns, CMV testing with DBS real-time PCR compared with liquid-saliva PCR had low sensitivity, limiting its value as a screening test.