Figure 6. Seasonal variation in rotavirus in tropical and northern temperate zones, by World Bank income groups.

We restricted the analysis to studies conducted in the Northern Hemisphere and the tropical belt (i.e., latitudes 10° North and 10° South of the equator) to avoid falsely representing seasonality by summing monthly prevalence across regions with peak rotavirus detections during opposing seasons (which would result in a bias towards weaker seasonality).