Norovirus Infection and Disease in an Ecuadorian Birth Cohort: Association of Certain Norovirus Genotypes With Host FUT2 Secretor Status

TLDR

Norovirus is the leading cause of gastroenteritis, yet community incidence, immunity patterns, and innate resistance remain poorly characterized. The study followed 194 Ecuadorian children from birth to age 3 to estimate norovirus gastroenteritis incidence, evaluate whether prior infection protects against future infection/disease, and examine associations with FUT2 secretor status. Over three years, 66 % of children experienced at least one norovirus infection (40 % had two), norovirus was found in 18 % of samples with no difference between diarrheal and non‑diarrheal specimens, prior infections did not reduce subsequent risk, and GII.4 infections occurred only in secretor‑positive children while non‑GII.4 infections were more common in secretor‑negative children.

Abstract

Although norovirus is the most common cause of gastroenteritis, there are few data on the community incidence of infection/disease or the patterns of acquired immunity or innate resistance to norovirus.We followed a community-based birth cohort of 194 children in Ecuador with the aim to estimate (1) the incidence of norovirus gastroenteritis from birth to age 3 years, (2) the protective effect of norovirus infection against subsequent infection/disease, and (3) the association of infection and disease with FUT2 secretor status.Over the 3-year period, we detected a mean of 2.26 diarrheal episodes per child (range, 0-12 episodes). Norovirus was detected in 260 samples (18%) but was not found more frequently in diarrheal samples (79 of 438 [18%]), compared with diarrhea-free samples (181 of 1016 [18%]; P = .919). A total of 66% of children had at least 1 norovirus infection during the first 3 years of life, and 40% of children had 2 infections. Previous norovirus infections were not associated with the risk of subsequent infection. All genogroup II, genotype 4 (GII.4) infections were among secretor-positive children (P < .001), but higher rates of non-GII.4 infections were found in secretor-negative children (relative risk, 0.56; P = .029).GII.4 infections were uniquely detected in secretor-positive children, while non-GII.4 infections were more often found in secretor-negative children.