Clinical severity of dengue infections by strata of preexisting DENV and JEV immunity.

The proportions of dengue (DENV) infections resulting in symptomatic illness (1a), hospitalized illness (1b), and dengue hemorrhagic fever (1c) are shown. Data are stratified by preexisting DENV immunity (naïve [DENV -], monotypic [DENV 1+], multitypic older and younger than 10 years of age [DENV >1+]) and preexisting Japanese encephalitis virus (JEV) neutralizing antibodies (NAbs) (positive [+] or negative [-]). The JEV NAb positive groups are indicated by hash lines for each stratum of DENV immunity. Odds ratios (ORs) estimate the odds of being experiencing the disease severity of interest (dengue hemorrhagic fever [DHF], hospitalized illness [Hosp], or symptomatic illness [Sx]) in the presence of JEV NAbs over the odds of experiencing the disease severity of interest in the absence of JEV NAbs. Values in parentheses indicate the 95% confidence intervals for the ORs. Error bars indicate the 95% confidence intervals for proportions.