Assessing the risk of dengue virus transmission in a non-endemic city surrounded by endemic and hyperendemic areas.

The cumulative exposure of Hong Kong residents to dengue has so far been low. Coupled with the lack of a spatial relationship between exposed cases and vector intensities, a high risk of local transmission of DENV is not supported. The apparently higher exposure likelihood of females could be explained by past infection in workers from dengue endemic countries, while frequent travel could have exposed older adults to DENV. Continued surveillance, risk assessment, and intensive vector control remain essential to prevent the transformation of a non-endemic to an endemic city.