ABSTRACT
Background: Group A rotavirus has been recognized as a leading cause of severe diarrheal disease in infants and young children worldwide and accounts for 20-25% of children diarrheal deaths per year. Defining the viral agents related to diarrhea will assist in providing an accurate estimate of disease burden within a community and will also be useful to assess the impact of vaccination whenever they become available. Epidemiological and molecular studies in many countries show complex patterns of change from year to year in the genotype of rotaviruses that cause diarrhea in children from the same geographical area. These data can be useful to select areas for vaccine trials and to serve as a baseline for identification of new strains, should they emerge
Objectives: To investigate the role of group A rotavirus in acute diarrhea among infants and children under three years of age attending or admitted to Assiut Pediatric University Hospital and to compare between the strip test and Enzyme Immune Assay [EIA] in diagnosis of rotavirus infection using the Reverse Transcriptase-Polymerase Chain Reaction [RT-PCR] as a gold standard, beside defining the genotype of the detected strains using multiplex-PCR
Methods: 88 children under the age of three years, presenting with acute diarrhea to Assiut Pediatric University Hospital between December 2005 and April 2006, were examined for group A rotavirus antigen in stool by a quick strip test and EIA. RT-PCR was also performed as a reference test. Twelve children of matched age and sex, without diarrhea, were also included [control group]. All rotavirus positive samples by RT-PCR were also subjected to genotyping by multiplex PCR using a cocktail of primers specific for the most common genotypes of rotavirus in human [G1, G2, G3, G4, G8 and G9]
Results: Out of the 88 patients, 33 were rotavirus positive by strips [37.5%], 42 were rotavirus positive by EIA [47.7%] and 44 were positive by RT-PCR [50%]. All control samples were negative by the three methods. 28 samples were positive by both strips and EIA and 44 samples were negative by both methods, whereas discordant results were obtained in 19 samples. Using the RTPCR as a reference test, it was found that the strips failed to detect 13 out of 44 positive samples, while the EIA failed to detect nine out of these 44 positive samples. The sensitivity and specificity of strips versus RT-PCR were 70.5% and 95.5%, respectively, whereas those of EIA were 86.4% and 91%, respectively. Genotyping by multiplex PCR revealed that all the detected strains belong to G3 genotype
Conclusion: The rate of infection with group A rotavirus among children with acute diarrhea differs according to the method used for detection [37.5% by strips, 47.7% by EIA and 50% by RTPCR]. The strips are more rapid, simple and specific than EIA, yet the EIA remains more sensitive in detecting rotavirus antigen in stool. All rotavirus strains detected belong to G3 genotype