Prevalence and Genetic Diversity of Norovirus in Acute Gastroenteritis Cases in the Southwest Province of Turkey

AIMS: Noroviruses may cause both epidemic and sporadic acute gastroenteritis globally. Thus, this study evaluated the prevalence of norovirus in stool samples of hospitalized patients with acute gastroenteritis in Aydin, Turkey using enzyme-linked immunoassay (ELISA) and real-time reverse transcription-polymerase chain reaction (rRT-PCR) and genotyped positive samples to detect which genotypes have currently circulated. METHODS: This retrospective descriptive study collected 92 stool samples from patients with acute gastroenteritis symptoms from Aydın Adnan Menderes University Hospital from September 2017 to May 2019. The samples were tested using the commercial Third Generation Ridascreen norovirus ELISA and rRT-PCR. Positive samples were genotyped by sequencing of conventional positive RT-PCR products followed by phylogenetic analysis. RESULTS: Of the 92 samples, 5 (5.4%) using ELISA and 12 (13%) using rRT-PCR tested positive for norovirus. All positive samples were genogroup II (GII). Two norovirus positive samples were genotyped successfully using DNA sequencing of the nested conventional PCR products. One sample (GII/Hu/TR/2019/Aydin25) could be categorized as GII.3 and the other (GII/Hu/TR/2019/Aydin20) as GII.13. CONCLUSION: rRT-PCR testing of stool samples is more sensitive than Ridascreen ELISA. Data from our study provide protocols for how to study norovirus epidemiology.