ABSTRACT
The purpose of this study was to estimate the incidence density and prevalence of dengue virus infection in Australian travellers to Asia. We conducted a multi-centre prospective cohort study of Australian travellers over a 32-month period. We recruited 467 travellers (≥ 16 years of age) from three travel clinics who intended to travel Asia, and 387 (82.9%) of those travellers completed questionnaires and provide samples pre- and post-travel for serological testing for dengue virus infection. Demographic data, destination countries and history of vaccinations and flavivirus infections were obtained. Serological testing for dengue IgG and IgM by enzyme-linked immunosorbent assay (ELISA) (PanBio assay) was performed. Acute seroconversion for dengue infection was demonstrated in 1.0% of travellers, representing an incidence of 3.4 infections per 10,000 days of travel (95% confidence interval [CI]: 0.9-8.7). The seroprevalence of dengue infection was 4.4% and a greater number of prior trips to Asia was a predictor for dengue seroprevalence (p = 0.019). All travellers experienced subclinical dengue infections and had travelled to India (n = 3) and China (n = 1). This significant attack rate of dengue infection can be used to advise prospective travellers to dengue-endemic countries.
