Sapoviruses detected from acute gastroenteritis outbreaks and hospitalized children in Taiwan.

Background/purpose: Sapoviruses (SaVs) become important pathogens causing both sporadic and outbreaks of acute gastroenteritis (AGE) after rotavirus vaccination era worldwide. SaVs were included in AGE screening items when norovirus and rotavirus were negative in Taiwan CDC since 2008. However, no complete SaV genome sequence of any genotype detected in Taiwan was determined. This study aimed to investigate SaVs infection and complete genome sequences detected in Taiwan.

Methods: This prospective survey, SaVs samples with untyped or weak PCR result were selected for testing the new design qRT-PCR assay from AGE hospitalized children during 2008-2011, 2016-2017 and AGE outbreak in 2012-2014. Those were genetically characterized using long RT-PCR with different primer combinations as well as primer independent deep sequencing and with 5' RACE and 3' terminal region targeting RT-PCR.

Results: Overall, 14 SaV-AGE hospitalized children and 4 SaV-AGE outbreaks were enrolled in this study. In addition to the AGE symptoms, 6 children also showed URI symptoms (cough, pharyngitis, rhinorrhea and nasal congestion). The detected 19 SaVs were classified as eight genotypes (GI.1, GI.2, GI.3, GII.2, GII.3, GII.5, GII.8, and GIV.1) and the complete genome sequence of representative strain for each genotype were determined except GI.3. The GII.3 was the most major genotype following GI.1 and GIV.1.

Conclusion: Our result confirmed that SaV is one of the pathogens detected from Taiwanese AGE patients. Multiple SaV genotype strains would associate with AGE as similar to those detected in different countries/areas. The whole genome of SaV strains detected including rarely reported GII.8 was firstly determined.