THE GUARDIAN Article
Diseases such as dengue and malaria are expected to reach unaffected parts of northern Europe, America, Asia, and Australia, according to a conference report.
Mosquito-borne diseases are spreading worldwide, particularly in Europe, due to the climate crisis, said an expert. Mosquitoes transmit diseases like malaria and dengue, which have seen a massive rise in prevalence over the past 80 years, as global warming has provided warmer, more humid conditions in which they thrive.
Professor Rachel Lowe, who leads the global health resilience group at the Barcelona Supercomputing Center in Spain, has warned that mosquito-borne disease outbreaks will expand into currently unaffected parts of northern Europe, Asia, North America, and Australia in the coming decades. She will present at the global congress of the European Society of Clinical Microbiology and Infectious Diseases in Barcelona, warning that the world must be prepared for a sharp increase in these diseases.
“Global warming due to climate change means that disease vectors that carry and spread malaria and dengue fever can find a home in more regions, with outbreaks occurring in areas where people are likely immunologically naive and public health systems unprepared,” Lowe said. “The harsh reality is that longer warm seasons will widen the seasonal window for the spread of mosquito-borne diseases and lead to outbreaks that are increasingly frequent and complex to manage.”
Dengue used to be found primarily in tropical and subtropical regions, as freezing nighttime temperatures kill mosquito larvae and eggs. Longer warm seasons and less frequent frosts have made it the fastest-spreading mosquito-borne viral disease globally, and it is taking root in Europe. The Asian tiger mosquito (Aedes albopictus), which transmits dengue fever, had established itself in 13 European countries by 2023: Italy, France, Spain, Malta, Monaco, San Marino, Gibraltar, Liechtenstein, Switzerland, Germany, Austria, Greece, and Portugal.
The insect is thriving; nine of the 10 years most conducive to disease transmission have occurred since 2000, and the number of dengue cases reported to the WHO has increased eightfold in the last two decades, from 500,000 in 2000 to over 5 million in 2019. Lowe said the climate crisis would accelerate this spread as droughts follow floods: “Climate change-linked droughts and floods can lead to increased virus transmission, with stored water providing additional mosquito breeding sites. “Lessons from past outbreaks highlight the importance of assessing future risks of vector-borne diseases and preparing contingencies for future outbreaks.”
She said that if the current trajectory of high carbon emissions and population growth continues, the number of people living in mosquito-borne disease areas would double to 4.7 billion by the end of the century. Lowe added: “With climate change proving so difficult to tackle, we can expect to see more cases and possibly deaths from diseases like dengue and malaria across continental Europe. We must anticipate outbreaks and act to intervene early to prevent diseases from occurring in the first place. “Efforts should focus on improving surveillance with early warning systems and responses, similar to those seen in other parts of the world, to more effectively direct finite resources to the most vulnerable areas to control and prevent outbreaks of disease and save lives.”
The climate crisis is also amplifying the threat of antimicrobial resistance, a separate presentation at the conference will warn. Professor Sabiha Essack, head of the antimicrobial resistance unit at the University of KwaZulu-Natal in South Africa, said the climate crisis was a “threat multiplier” for antimicrobial resistance: “Climate change compromises the ecological and environmental integrity of living systems and allows pathogens to cause more and more diseases. The impact on aquatic systems, food-producing animals, and crops threatens the global food supply. “Human activities associated with population growth and transport, along with climate change, increase antibiotic resistance and the spread of waterborne and vector-borne diseases in humans, animals, and plants.”
