Surveillance and molecular characterization of human sapovirus in patients with acute gastroenteritis in Brazil, 2010 to 2017

Background: Human sapoviruses (HuSaV) are associated with acute gastroenteritis (AGE), causing sporadic cases and outbreaks in patients worldwide. In Brazil, however, there are few reports describing the prevalence of HuSaV in patients with AGE. Objective: Describing the diversity of HuSaV in Brazil by detecting and molecularly characterizing HuSaV among patients with AGE during an 8-year period (2010-2017). Study design: A total of 3974 stool samples, testing negative for rotavirus (RVA), norovirus (NoV) and human adenovirus (HAdV), were selected and screened for the presence of HuSaV. Nested RT-PCR were performed for a partial region of VP1, sequenced and genetic analyzed for genotyping the positive samples. Results: In the current study, the HuSaV prevalence was determined to be 3.7% (149/3974). A higher prevalence, 5.7% (118/2074), was observed in children under 2 years of age. During the surveillance period, 13 outbreaks were detected: 12 outbreaks in children under 3 years old and one outbreak in adults. Among the 149 HuSaV positive cases, 106 samples (71%) were successfully sequenced. The most prevalent genotype found was GI.1 (44.3%), followed by GI.2 (21.7%), GI.3 (3.8%), GI.6 (2.8%), GII.1 (5.7%), GII.2 (8.5%), GII.3 (2.8%), GII.4 (2.8%), GII.5 (5.7%) and GIV.1 (1.9%). Two GIV.1 strains characterized in this study are, to date, the only strains of this genotype reported in Brazil. Conclusions: The present study elucidated the circulation of HuSaV in Brazil and highlight that HuSaV has not assumed an epidemiological importance in the country after the introduction of the RVA vaccine.

Automated summary

The study revealed a prevalence of 3.7% of human sapoviruses (HuSaV) in Brazil, with a higher prevalence in children. Out of 13 outbreaks detected, 12 occurred in children under 3 years old and one in adults. The most prevalent genotypes found were GI.1 and GI.2, with two GIV.1 strains being the only ones reported in Brazil to date.