An expert warns: diseases transmitted by mosquitoes are becoming a global phenomenon

The expansion of vector-borne diseases, particularly mosquito-borne diseases such as malaria and dengue, has been a rapid global phenomenon in the past 80 years. As a result of global warming and urbanization, regions in northern Europe, Asia, North America, and Australia that were previously unaffected are now at risk. ICREA Professor Rachel Lowe, leading the global health resilience group at the Barcelona Supercomputing Center in Spain, will present a research review at this year’s Escmid Global Congress in Barcelona, emphasizing the changing global threat of vector-borne diseases and the need for improved surveillance and early warning systems.

Climate change resulting from global warming has facilitated the expansion of disease vectors responsible for transmitting and spreading malaria and dengue. This poses a significant challenge, as areas with immunologically naive populations and underprepared healthcare systems are susceptible to outbreaks. Longer warm seasons allow for a wider seasonal window for the spread of mosquito-borne diseases, leading to more frequent and complex outbreaks.

Previously, dengue was primarily limited to tropical and subtropical regions due to the adverse impact of frigid temperatures on mosquito larvae and eggs. However, longer warm seasons have enabled the fastest spreading mosquito-borne viral disease in the world. Dengue-carrying mosquitoes have invaded 13 European countries, with projected local spread in France, Italy, and Spain in 2023. The number of dengue cases reported to the WHO has increased eight-fold in the last two decades.

Professor Lowe’s recent research in the Caribbean revealed that drought conditions followed by warmer temperatures and excessive rainfall increase the likelihood of dengue outbreaks. Climate change-related droughts and floods contribute to increased virus transmission, while stored water provides additional breeding grounds for mosquitoes. It is crucial to assess future risks and prepare contingencies for vector-borne disease outbreaks based on lessons learned from previous outbreaks.

Projections indicate that limiting global warming to 1°C could still result in an additional 2.4 billion people at risk of malaria and dengue by 2100 compared to the period 1970-1999. However, if high carbon emissions and population growth continue, the number could rise to 4.7 billion. With the challenges of addressing climate change, it is anticipated that cases and potential fatalities from dengue and malaria will increase in continental Europe. Efforts must focus on enhancing surveillance and implementing early warning and response systems to effectively allocate resources, control outbreaks, and save lives.

Researchers are utilizing a combination of insect surveillance and climate forecasts to predict the occurrence of epidemics and target interventions in high-risk areas. Professor Lowe’s project employs a powerful supercomputer to analyze weather patterns, identify mosquito breeding sites with drones, and gather information from local communities and health officials. The goal is to provide communities with adequate time to prepare and protect themselves.