10.34944/DSPACE/5052
(:unkn) unknown
Norovirus infection and acquired immunity in 8 countries: Results from the MAL-ED study
My University
2016
diarrhea
immunity
norovirus
Caliciviridae Infections
Child, Preschool
Cohort Studies
Diarrhea
Feces
Humans
Incidence
Infant
Infant, Newborn
Norovirus
My University
My University
2021-01-27
2016-05-15
2021-01-27
en
Article
1058-4838
1537-6591
27013692 (pubmed)
http://hdl.handle.net/20.500.12613/5070
1210-1217
CC BY-NC-ND
© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. Background. Norovirus is an important cause of childhood diarrhea. We present data from a longitudinal, multicountry study describing norovirus epidemiology during the first 2 years of life. Methods. A birth cohort of 1457 children across 8 countries contributed 7077 diarrheal stools for norovirus testing. A subset of 199 children contributed additional asymptomatic samples (2307) and diarrheal stools (770), which were used to derive incidence rates and evaluate evidence for acquired immunity. Results. Across sites, 89% of children experienced at least 1 norovirus infection before 24 months, and 22.7% of all diarrheal stools were norovirus positive. Severity of norovirus-positive diarrhea was comparable to other enteropathogens, with the exception of rotavirus. Incidence of genogroup II (GII) infection was higher than genogroup I and peaked at 6-11 months across sites. Undernutrition was a risk factor for symptomatic norovirus infection, with an increase in 1 standard deviation of length-for-age z score associated with a 17% reduction (odds ratio, 0.83 [95% confidence interval,. 72-.97]; P =. 011) in the odds of experiencing diarrhea when norovirus was present, after accounting for genogroup, rotavirus vaccine, and age. Evidence of acquired immunity was observed among GII infections only: Children with prior GII infection were found to have a 27% reduction in the hazard of subsequent infection (hazard ratio, 0.727; P =. 010). Conclusions. The high prevalence of norovirus across 8 sites in highly variable epidemiologic settings and demonstration of protective immunity for GII infections provide support for investment in vaccine development.