Norovirus in Latin America: Systematic Review and Meta-analysis.

BACKGROUND: Noroviruses are increasingly recognized as a major cause of sporadic and epidemic acute gastroenteritis (AGE). Although there have been multiple studies published on norovirus epidemiology in Latin America, no comprehensive assessment of the role of norovirus has been conducted in the region. We aim to estimate the role of norovirus in the Latin American region through a systematic review and meta-analysis of the existing literature.

METHODS: We carried out a literature search in MEDLINE, SciELO and LILACS. We included papers that provided information on the prevalence or incidence of norovirus (including seroprevalence studies and outbreaks), with a recruitment and/or follow-up period of at least 12 months and where the diagnosis of norovirus was confirmed by reverse transcription polymerase chain reaction. The data were pooled for meta-analysis to estimate the prevalence of norovirus AGE and norovirus asymptomatic infection with 95% confidence intervals (CIs).

RESULTS: Thirty-eight studies were included in the review. Overall, the prevalence of norovirus among AGE cases was 15% (95% CI: 13-18). By location, it was 15% in the community (95% CI: 11%-21%), 14% in outpatient settings (95% CI: 10%-19%) and 16% in hospital locations (95% CI: 12%-21%). The prevalence of norovirus among asymptomatic subjects was 8% (95% CI: 4-13). Norovirus GII.4 strains were associated with 37%-100% of norovirus AGE cases, but only 7% of norovirus asymptomatic detections.

CONCLUSIONS: Noroviruses are associated with almost 1 out of every 6 hospitalizations because of acute diarrhea in children younger than 5 years of age in Latin America.