Seroprevalence of dengue in the general population of a Chinese southwestern border city: a community-based cross-sectional study

Dengue fever poses significant public health concern in tropical and subtropical regions, including areas of China-Myanmar border, in which the population-representative evidence on dengue seroprevalence is limited. A community-based cross-sectional survey was conducted in December 2015 in Ruili, a border city in southwestern China. Participants were selected using a stratified random sampling method. Demographic information, previous clinical and travel history, and environment-related factors regarding dengue were collected by structured interview, with serum samples tested for IgG antibodies using ELISA. Age- and gender-weighted seroprevalence was estimated based on the local demographic distribution. Associated factors for seropositivity were analyzed using logistic regression. The study included 1,616 participants aged 1–95 years, with 58.42% being female. The weighted seroprevalence of Dengue was 4.43% (3.53–5.54). Residents of aged 45–54 years, border communities (adjusted odds ratio 6.39 [95%CI 2.98–13.74]), vector-environment exposed occupations (3.43 [1.34–8.82]), lower educational attainment (0.28 [0.09–0.86]), and high travel frequency to southeast Asia (8.94 [1.67–47.83]) tended to have higher seroprevalence. Moreover, we observed a symptomatic-to-asymptomatic ratio of 1:2.84 for dengue infections. The seroprevalence of Dengue virus was low by 2015 in the study area, where dengue had not achieved widespread local transmission. Targeted interventions, enhanced surveillance, and cross-border collaboration are needed to mitigate dengue transmission in this region.