Unadjusted associations of DENV illness severity and JEV antibody status.

*<p>Non-hospitalized infections incorporate both non-hospitalized DF and asymptomatic seroconversions.</p>**<p>Non-DHF infections incorporate both non-hospitalized and hospitalized DF and asymptomatic seroconversions.</p>†<p>P-values were calculated using the Mantel-Haenzel chi-square statistic.</p

Factors associated with JEV seropositivity among those experiencing dengue (DENV) infection.

*<p>Refers to first-detected DENV infections in the cohort that occurred during the active surveillance period each year (June 1 – November 1) and had neutralizing antibody data available.</p>**<p>Statistical tests considered the association between variables of interest and the presence or absence of JEV NAbs in the pre-infection sample. p-values were obtained using the Pearson chi-square test for categorical variables, with α = 0.05 as the level of significance. ‘Missing’ categories were not included in statistical comparisons.</p

Duration of DENV illness (days) by JEV NAb status.

*<p>Duration of illness was calculated as the number of days elapsed from first day of febrile illness to the last day that a child reported any fever, muscle or joint pain, headache, nauseas, vomiting, diarrhea, or any signs of bleeding or hemorrhage.</p>**<p>P-values were calculated using 2-way analysis of variance testing (ANOVA), with α = 0.05 as the level of significance.</p

Cohort characteristics associated with symptomatic DENV illness.

*<p>Refers to first-detected DENV infections in the cohort that occurred during the active surveillance period each year (June 1–November 1) and had neutralizing antibody data available</p>**<p>Statistical tests considered the association between variables of interest and the occurrence of symptomatic versus asymptomatic infection. p-values were obtained using the Pearson chi-square test for categorical variables, with α = 0.05 as the level of significance. ‘Missing’ categories were not included in statistical comparisons.</p

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

<p>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.</p