Epidemiology of Sapovirus Infections in a Birth Cohort in Peru

Background. Sapovirus is one of the primary viral causes of acute gastroenteritis (AGE), especially where rotavirus vaccination has been implemented. Te 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 1 nondiarrheal stools collected trimonthly from children up to age 2 years (n = 1669) were tested for sapovirus detection. Viral shedding duration was determined by testing additional weekly samples (n = 440) collected before and afer a sapovirus-positive sample. Results. Te incidence of sapovirus infection in the frst and second years of life was 4.3 and 11.1 per 100 child-months, respectively. By age 2 years, 82% of children had at least 1 sapovirus infection, and 64% had at least 1 sapovirus-associated diarrhea episode. Te median shedding period was 18.5 days. In 112 of 175 infections, 14 genotypes from 4 genogroups (GI, GII, GIV, and GV) were determined. Among genogroups, GI were more frequently found in symptomatic infections than in asymptomatic infections (odds ratio, 3.1; 95% confdence interval, 1.3-7.4). Fify-nine children had serial sapovirus infections, but only 3 had repeated infection of the same genotype. Conclusions. Sapovirus was frequently detected in children with AGE at the community level during the frst 2 years of life. Serial sapovirus infections by multiple genotypes in a child suggest genotype-specifc immunity from each infection, which needs to be taken into account for vaccine development.