An international team of scientists including BSC researcher Rachel Lowe published an article in Nature Communications about the effects of climatic and socio-environmental drivers on dengue incidence in Vietnam
“Our results also provide evidence that improving water supply will be important in building resilience to the impacts of climate change on dengue and other emerging mosquito-borne diseases"
Climatic and socioeconomic changes are reshaping patterns of infectious disease worldwide, often with urgent and alarming consequences for public health. These impacts are especially pronounced for Aedes mosquito-borne diseases (e.g., dengue, chikungunya and Zika), whose vectors are specialised for life in the emerging urbanised landscapes of the 21st century.
Dengue is a major and rapidly growing threat to health in tropical and subtropical regions worldwide and is mainly transmitted by Ae. aegypti, a human-adapted mosquito that breeds using water-related features of built environments (e.g., water containers in homes, gutters, drains and sewerage systems). The burden of dengue is rapidly growing, with incidence doubling each decade since 1990 and large outbreaks now occurring in more than 125 countries, which are broadly thought to be consequences of climate change, rapid urbanisation and increasing human mobility. However, we have little understanding of how these factors interact to shape dengue transmission and emergence patterns locally, where outbreak surveillance and control activities can be most effectively implemented.
An international team of researchers, including the ICREA Professor at the Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS) Rachel Lowe, has just published an article in the prestigious journal Nature Communications in which they investigate the interacting effects of climatic and socio-environmental drivers on dengue incidence and emergence in Vietnam. Dengue is a major public health issue in Vietnam, with one of the highest incidence rates in Southeast Asia. In the study, led by researchers at the London School of Hygiene & Tropical Medicine (London, United Kingdom), 23 years of district-level case data spanning a period of significant socioeconomic change (1998-2020) was analysed.
The researchers used statistical models to explore how dengue is related to social, environmental and climatic factors and how these may have contributed to the increasing burden and expansion of dengue in Vietnam.
They found that temperature is the dominant climate driver of geographical and seasonal patterns of dengue. By examining over 70 years of historical climate data for Vietnam, they found that climate warming since 1950 has expanded transmission risk throughout the country, including in several current hotspots where the disease is emerging (e.g. Hanoi and the central regions). In contrast, they found that the effects of precipitation extremes depended strongly on the local socioeconomic conditions, particularly access to piped water, and that forecast tools may need to account for these complexities to inform dengue prevention better.
The researchers also found that rather than cities in general, specific urban characteristics such as water and sanitation infrastructure are the main factors shaping dengue risk over space.
Professor Lowe, leader of the Global Health Resilience group at the Earth Sciences Departament of BSC, states: “Our findings challenge the assumption that dengue is an urban disease, instead suggesting that incidence peaks in transitional landscapes with intermediate infrastructure provision.” She adds: “Our results also provide evidence that improving water supply will be important in building resilience to the impacts of climate change on dengue and other emerging mosquito-borne diseases."
Study lead author Dr Rory Gibb, who is now based at University College London, says: “These findings provide evidence that climate change and mobility are contributing to the expansion of dengue throughout Vietnam, including in the country’s northern and higher-altitude regions.”
In another related paper, also published in Nature Communications, Felipe J. Colón-González (Data for Science and Health Team, Wellcome) and colleagues investigated how the recent global expansion of dengue has been facilitated by changes in urbanisation, mobility, and climate change across South East Asia. In the study, which also counted on BSC Professor Lowe's participation, the authors project future changes in dengue incidence and case burden until the end of the century under the latest climate change scenarios, with a peak in dengue incidence expected by 2050, particularly in areas with low population density.
Further work to forecast dengue in Vietnam, Malaysia and Sri Lanka is ongoing as part of the European Horizon-funded E4Warning project. E4Warning is a holistic approach to improving the understanding of the interplay between humans, mosquitoes, reservoir species, and the environment for a better disease intelligence capable of anticipating and identifying mosquito-borne disease epidemic risks and outbreaks. BSC is one of the Consortium partners of the project.
Citation:
Gibb, R., Colón-González, F.J., Lan, P.T. et al. Interactions between climate change, urban infrastructure and mobility are driving dengue emergence in Vietnam. Nat Commun 14, 8179 (2023). https://doi.org/10.1038/s41467-023-43954-0
Colón-González, F.J., Gibb, R., Khan, K. et al. Projecting the future incidence and burden of dengue in Southeast Asia. Nat Commun 14, 5439 (2023). https://doi.org/10.1038/s41467-023-41017-y
Pictures: Ania Blazejewska, Lý Thị Thùy Trang (Vietnam/CD).
