Chikungunya, named for theungunya, meaning “to twist up” in the Kimakondé language due to its characteristic joint pain, is categorized by the World Health Organization as one of the neglected tropical diseases. It is caused by a virus that is transmitted by mosquitoes of the Aedes genus. Symptoms encompass a high fever, muscle and back pain, headache, fatigue, nausea, and a skin rash.
According to estimates from the European Centre for Disease Prevention and Control, approximately 33,000 Chikungunya cases, including nine fatalities, were recorded globally by 2026, with the majority occurring in South America. Currently, the virus is not endemic to Europe or North America; reported cases there are limited to individuals who have traveled to tropical or subtropical areas.
However, a team of researchers from China, in a new study published in Frontiers in Cellular and Infection Microbiology, suggests this situation is likely to change by the year 2100.
“Currently, 139 countries or regions—representing 21.3% of the world’s land area—are risk zones for Chikungunya virus transmission. But we show that under climate change models, the virus will spread further north into temperate regions, specifically into northeastern North America, Central Europe, and East Asia,” stated Ye Xu, a co-author of the study from Zhejiang University of Chinese Medicine in Hangzhou, China.
Until recently, Chikungunya was primarily transmitted by Aedes aegypti mosquitoes, the same vector for yellow fever, a species prevalent in tropical urban settings.
Yet, when scientists examined the widely publicized 2005–2006 epidemic across Réunion, Mauritius, the Comoros Islands, and parts of India—which led to approximately 266,000 infections and at least 254 deaths—they identified a novel mutation (‘E1-A226V’) in the virus’s DNA. This mutation made it more adept at utilizing an alternative vector: the Asian tiger mosquito, Aedes albopictus.
In this research, Xu and his colleagues modeled the ecological requirements of the Chikungunya virus and its two mosquito vectors, utilizing tens of thousands of georeferenced records of their global occurrences. They projected how their current habitats might transform from the present day through 2100, based on 16 climate scenarios developed by the IPCC.
These scenarios, referred to by names such as “green shift,” “regional rivalry,” and “fossil-fueled development,” outline five distinct pathways for global socioeconomic advancement. The researchers also integrated 16 variables into their climate models, including wind speed, elevation, precipitation, and minimum and maximum temperatures.
The scientists’ objective was to pinpoint emerging regions at high risk for Chikungunya infection, thereby allowing public health officials ample time to prepare for future outbreaks.
“Our findings indicate that climate change influences the spread of Chikungunya primarily by altering the habitats of the virus’s mosquito vectors. In our study, the Asian tiger mosquito played a particularly significant role, accounting for over 70% of the projected virus expansion,” observed co-author Yang Wu from Guangzhou Customs Technology Center.
“Because this mosquito can tolerate colder temperatures better than the yellow fever mosquito, warming temperatures may enable it to establish itself in areas that were previously too cold. When suitable mosquito species are present, the likelihood of local Chikungunya transmission increases,” Wu explained.
The precise geographical spread of the disease varied depending on the chosen climate scenario, but north-central Europe, northeastern North America, and East Asia consistently emerged as future hotspots. Consequently, the authors recommend that these regions implement mosquito surveillance systems and relevant public health measures by the year 2040.
“The public should not panic, but health systems need to prepare in advance,” Xu cautioned. “For instance, public health officials can act now by monitoring Aedes mosquitoes, training doctors for rapid Chikungunya recognition, enhancing mosquito control measures, and developing rapid response plans before outbreaks occur. These steps are especially crucial in temperate regions where this disease has not previously been a routine public health concern.”
Mitigating further global warming and investing in fundamental preparedness can reduce the probability of the virus’s eventual spread escalating into major epidemics.
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