Epidemiology of sapovirus infections in a birth cohort in Peru

Abstract

Background

Sapovirus is one of the primary viral causes of acute gastroenteritis, especially in settings where rotavirus vaccination has been implemented. The characteristics and impact of natural infection at the community level, however, have not been well documented.

Methods

Stool samples were analyzed from 100 children randomly selected from a community-based birth cohort study in Peru. All diarrheal and one non-diarrheal stools collected trimonthly from children up to two years of age (n=1669) were tested for sapovirus detection. Viral shedding duration was determined by testing additional weekly samples (n=440), collected before and after a sapovirus positive sample.

Results

The incidence of sapovirus infection in the first and second year of life was 4.3 and 11.1 per 100-child months, respectively. By two years of age, 82% of children had at least one sapovirus infection, and 64% had at least one sapovirus-associated diarrhea episode. The median shedding period was 18.5 days. In 112 of 175 infections, 14 genotypes from four genogroups (GI, GII, GIV and GV) were determined. Among genogroups, GI viruses were more frequently found in symptomatic infections than in asymptomatic infections (OR: 3.1 [CI: 1.3–7.4]). Fifty-nine children had serial sapovirus infections but only three had repeated infection of the same genotype.

Conclusions

Sapovirus was frequently detected in children with acute gastroenteritis at the community level during the first two years of life. Serial sapovirus infections by multiple genotypes in a child suggest genotype-specific immunity from each infection, which need to be taken into account for vaccine development.