Real - Time Polymerase Chain Reaction Compared to Nested Polymerase Chain Reaction and Enzyme - Linked Immunosorbant Assays for Detecting Cytomegalovirus Infection in Children

Abstract

Background: Patients with impaired immunity e.g. (use of immunosuppressant therapy, or chemotherapy) are at increased risk of Cytomegalovirus (CMV) infection. Diagnosis of this viral infection is faced with many difficulties in such patients. Objectives: This study aims to compare between ELISA, nested PCR, and real-time PCR in order to set up a highly sensitive applicable assay for detecting CMV in high risk children. Methodology: This study was conducted from September 2015 to May 2016. Two ml blood sample were collected from each of 366 children with suspected CMV infection. CMV specific IgM and IgG were determined in the sera using ELISA. CMV DNA was detected in the plasma using nested PCR. Quantitative real-time PCR was used to determine the viral load. Results: The highest prevalence (50%) of CMV IgM seropositivity was reported from patients suffering from fever of unknown origin. Using the molecular methods, CMV was detected only in patients suffering from malignant hematological disease and receiving chemotherapy, where 83.7% and 67.4% of patients with malignant hematological disease were positive for CMV by real-time and nested PCR respectively. In comparison to real time PCR, nested PCR was 80.5% sensitive and 100% specific; ELISA IgM was 22.2% sensitive and 84.24% specific, where ELISA IgG was 0% sensitive and 71.82% specific for the detection of CMV infection in high risk children. Conclusion: PCR is more sensitive and specific technique for detection of CMV infection in high risk children. Moreover, quantitative real-time PCR is superior to nested PCR as it can define threshold levels needed to guide treatment