INTRODUCTION: Norovírus was recently identified as the main cause of outbreaks of acute gastroenteritis of non-bacterial origin worldwide and it is involved in episodes of foodborne origin. In this study, patients with symptoms of acute gastroenteritis were evaluated over a one-year period, in order to evaluate two methods for identifying norovírus (real-time and conventional polymerase chain reaction), along with its incidence, seasonality and predominant genotype. METHODS: After RNA extraction, 50 samples were analyzed using conventional PCR and 365 were analyzed using real-time PCR. All the samples that presented positive results using both methods or discordant results were sequenced. In all, 13 samples were sequenced. RESULTS: Out of the 50 samples tested using both methods, seven presented a positive result from the conventional method and 15 from real-time PCR. Out of the total of 365 samples tested using real-time PCR, 48 were positive. All of the sequenced samples were shown to present norovírus of genogroup II. Regarding the distribution of norovírus-positive sample incidence over the course of the year, higher frequency of positive cases was observed during the southern hemisphere spring, reaching 29.7% in November. CONCLUSIONS: We observed that real-time PCR was more sensitive for identifying norovírus. The incidence of norovírus was 13.2% and genogroup II predominated among the population evaluated, with the greatest infection rate in the southern hemisphere spring.
Norovírus; Acute gastroenteritis; Caliciviridae; Foodborne illness outbreaks
