Europe (Washington Insider Magazine)— Rising temperatures have enabled mosquito populations to expand their distribution, increasing the risk of dengue fever spreading to new regions. Infectious disease experts are monitoring this development closely.
Situation in Latin America
Parts of this region are currently witnessing the worst dengue fever outbreak. In the first four and a half months of 2024, a record gain of 238% over the previous year was observed. According to the ‘Pan-American Health Organization’, 4.1 million instances were registered last year.
Cases in the United States
The Centers for Disease Control and Prevention (CDC) of the United States have already registered 1,025 indigenous cases in 3 states since the beginning of the year. They were reported in Puerto Rico , Florida, and the United States Virgin Islands. Last year, however, there were 1,206 cases throughout the year.
Expert Concerns
According to Infobae, Dr. Albert Ko, an epidemiology professor at Yale School of Public Health, is concerned about dengue spreading to previously uninfected parts of North America and Europe. The disease, which was originally isolated to tropical countries, is now carried by Aedes aegypti mosquitos, which are becoming more common in temperate climates.
Presence in Temperate Climates
These mosquitoes have been found in regions like central Argentina, Uruguay, the Bay Area, and Washington, DC. Dr. Tomás Orduna of the Pan American Association of Infectious Diseases noted that Canada and Chile are the only countries in the Americas without indigenous cases of dengue. However, he warned of possible outbreaks in the United States this summer, although effective urban planning could help limit their spread.
European Risk
In Europe, the Aedes albopictus mosquito, another dengue vector, has expanded its range. Climate conditions could lead to more indigenous cases in the coming years. Professor Rachel Lowe of the Barcelona Supercomputing Center has highlighted the potential for global warming and urbanization to cause outbreaks in currently unaffected areas of northern Europe, Asia, North America, and Australia.
Climate Change and Dengue Spread
A 2019 study in Nature Microbiology warned that rising temperatures due to climate change could enhance the spread of the dengue virus in already endemic areas and allow it to reach new regions. Increased temperatures facilitate faster viral amplification and longer mosquito survival, thereby boosting transmission rates.
Ongoing Dengue Cases
Gabriela Paz-Bailey from the CDC in Puerto Rico stated that dengue cases are now detected annually, partly due to climate change. Puerto Rico declared a public health emergency in March after a surge in cases resulted in over 400 hospitalizations.
Implications for North America
Dr. Ko indicated that the dengue situation in Brazil and Argentina could be indicative of future trends in North America. In California, local transmission of dengue was reported for the first time in Pasadena last October. Similar cases have been noted in Arizona, Florida, and Texas.
European Heat Waves and Dengue
Unprecedented heat waves in Europe between June and August 2023 led to indigenous dengue transmission in France, Italy, and Spain. The presence of Aedes albopictus mosquitoes in these countries suggests a risk of more local cases if temperatures continue to rise. Future viral circulation could also affect Canada if global warming persists.