Diagnosis of Noroviruses in Iraqi children suffering from Gastroenteritis by Enzyme linked assay and conventional PCR

Abstract

Background: Noroviruses have been reported to be second to rotaviruses in causing severe childhood gastroenteritis, according to nucleotide sequence analysis of the polymerase or capsid regions, norovirus is classified at least into five genogroups GI–GV, each genogroup is further divided into distinct genotypes. GI, GII, and GIV have been found in humans. Amis: To determine the possible implication of Norovirus in a sample of childhood diarrhea and the efficiency of molecular diagnosis in comparing with ELISA method for the detection of this agent. Methods: Stool samples were collected from 100 patients suffering from diarrhea there age ranged from (6 weeks – 14 years), the stool samples were divided into three portions. The first portion (0.5 mg) was prepared for wet smear preparation, and the second portion was used directly for RNA extraction and directly converted to cDNA and third portion used for ELISA assay, all stored at-20°C. Statistical analysis: The statistical analysis of this study was performed using the statistical package for social sciences (SPSS) program version (19) and Microsoft Excel 2010. Categorical data formulated as count and percentage. Chi-square test was used to describe the association of these data. The level of statistical significant difference is below or equal to 0.05. Results: the study showed that 28 (28%) samples out of 100 samples were positive for G1 Norovirus with a PCR product size of approximated (380) bp and 72 (72%) samples were negative. All samples (n=100) were negative for G2 Norovirus. The highest incidence of the Norovirus cases was in the age group (2-5) years followed by (< 2 years) age group and then (> 5 years) group and there was no statistical significant difference between age and positive Norovirus cases. Conclusions: Norovirus could be included as one of the most important causes of acute gastroenteritis in Iraq.