Percentage of febrile cases with detectable dengue virus (DENV) viremia who presented as C cases by dengue season. The estimated number of DENV-positive C cases in a dengue season was divided by the total number of febrile cases with detectable DENV viremia during that season (including A/B and C cases) multiplied by 100 to obtain a percentage. Displayed as percentage with 95% confidence intervals.