Interactions between climate change, urban infrastructure and mobility are driving dengue emergence in Vietnam

Abstract

AbstractDengue is expanding globally, but how dengue emergence is shaped locally by interactions between climatic and socio-environmental factors is not well understood. Here, we investigate the drivers of dengue incidence and emergence in Vietnam, through analyzing 23-years of monthly district-level case data spanning a period of significant socioeconomic change (1998-2020). We show that urban infrastructure factors (sanitation, water supply and long-term urban growth) predict local spatial patterns of dengue incidence, while human mobility is a more influential driver in subtropical northern regions than the endemic south. Temperature is the dominant factor shaping dengue’s geographical distribution and dynamics, and using long-term reanalysis temperature data we show that recent warming (since 1950) has generally expanded transmission risk throughout Vietnam, and most strongly in current dengue emergence hotspots (e.g. southern central regions and Ha Noi). In contrast, effects of hydrometeorology are complex, multi-scalar and dependent on local context: risk increases under both short-term precipitation excess and long-term drought, but improvements in water supply largely mitigate drought-associated risks except under extreme conditions. Our findings challenge the assumption that dengue is an urban disease, instead suggesting that incidence peaks in transitional landscapes with intermediate infrastructure provision, and provide evidence that interactions between recent climate change and mobility have contributed to dengue’s ongoing expansion throughout Vietnam.