Global prevalence of asymptomatic dengue infections - a systematic review and meta-analysis

The burden of asymptomatic dengue infections is understudied. Therefore, we systematically reviewed the literature to estimate the global prevalence of asymptomatic dengue infections.We searched cross-sectional studies reporting the prevalence of asymptomatic dengue infections from PubMed, Scopus, and Embase. Prevalence of asymptomatic dengue infections was pooled and reported as proportions with a 95% confidence interval (CI). This systematic review protocol was a priori registered in The International Prospective Register of Systematic Reviews (Reg: No. CRD42020218446).We included 41 studies with 131,953 cases in our analysis. The overall pooled prevalence of asymptomatic dengue infections was 59.26% (95% CI: 43.76-74.75, I2 = 99.93%), with 65.52% (95% CI: 38.73-92.32, I2 = 99.95%) during outbreaks and 30.78% (95% CI: 21.39-40.16, I2 = 98.78%) during non-outbreak periods. The pooled prevalence among the acutely infected individuals was 54.52% (95% CI: 17.73-46.76, I2 = 99.91%), whereas, among primary and secondary asymptomatic dengue infections, it was 65.36% (95% CI: 45.76-84.96, I2 = 98.82) and 48.99% (95% CI: 27.85-70.13, I2 = 99.08%) respectively.The majority of dengue cases are asymptomatic and may play a significant role in disease transmission. Public health strategies aimed at dengue outbreak response and mitigation of disease burden should include early detection of asymptomatic cases.