Climate change and rapid urbanization are reshaping how dengue spreads in low- and middle-income countries, according to a systematic review published this week in PLOS Neglected Tropical Diseases.
Dengue virus is spread by Aedes mosquitoes.
Researchers led by a team from Georgetown University reviewed 65 studies published from 2020 to 2024 that looked at the effects of climate and urbanization on dengue transmission.
Sixty-five percent of the studies tied rising temperatures to increased disease risk. “Warmer conditions were associated with accelerated viral replication, higher mosquito biting rates, and extended transmission seasons,” write the researchers.
Urbanization, deforestation enable mosquito spread
More than one-third of the studies linked urbanization to higher dengue risk. Many of those studies “identified unplanned urban growth, population density, and inadequate water or sanitation infrastructure as critical enablers of mosquito breeding and sustained transmission,” the researchers note.
Urban heat islands, deforestation, and the expansion of urban areas were also found to amplify transmission risk.
Several studies reported the emergence of dengue in areas that were previously considered low risk or unaffected.
In addition, the findings suggest that dengue is expanding into new areas. “Several studies reported the emergence of dengue in areas that were previously considered low risk or unaffected, including highland and temperate regions, as rising temperatures enabled mosquito vectors to survive in new environments,” the authors write.
Although some countries have adopted innovative response strategies, the authors say better early warning systems, climate-informed vector-borne disease planning, and investments in urban infrastructure are needed as climate change reshapes dengue’s transmission patterns.