This study was designed to evaluate serological diagnosis of cytomegalovirus (CMV) infection in cases of neonatal jaundice in comparison to identification of virus DNA using polymerase chain reaction (PCR) and included 45 neonates allocated in two groups according to the presence of clinical jaundice: control group comprised 21 apparently normal and jaundice group comprised 24 neonates with clinically diagnosed jaundice. All neonates were subjected to maternal and perinatal history taking, full clinical examination and clinical evaluation of jaundice, routine laboratory investigations and determination of serum levels of CMV IgM and IgG antibodies using ELISA and identification of CMV DNA using PCR for certain samples.
PCR could identify CMV DNA in only 2 cases (8.3%) of jaundiced neonates. There was a significant (P<0.05) decrease in hemoglobin (Hb) and prothrombin concentration and a significant (P<0.05) increase in serum total and indirect bilirubin in jaundice group compared to control group, but with a non-significant (P>0.05) difference between CMV-positive and negative neonates. In jaundiced neonates, Hb concentration showed a positive significant correlation (r=0.463, P<0.05) with neonatal weight and a negative significant correlation with clinical degree of jaundice and serum total bilirubin, (r=-0.538 & -0.42, respectively, P<0.05). Also, serum total bilirubin showed a positive significant correlation (r=0.542, P<0.05) with clinical degree of jaundice. All control and jaundiced samples were found negative for CMV IgM antibodies, but as regards CMV IgG antibodies, there were one negative, 2 equivocal and 18 positive samples in control group, while in jaundiced group there were 3 negative, 2 equivocal and 19 positive samples. The 8 samples gave negative and equivocal results and 10 positive samples with highest activity index (AI) as estimated by ELISA were examined using PCR technique. All the 8 negative samples were confirmed by PCR as negative, but out of the 10 ELISA positive samples, 8 were found negative by PCR, while in the other 2 samples PCR could define CMV DNA and were surely considered positive. Thus, PCR can diagnose samples positive to and exclude samples negative to CMV with sensitivity of 100% and specificity of 80%.
We can conclude that ELISA combined with PCR raise the detection rate and the diagnostic efficacy of CMV infection in jaundiced neonates. However being an expensive technique, PCR cannot be used as a screening test but can be used as confirmatory test for suspicious serology results.
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