Increased flooding events could bring more tropical diseases to North America
New research shows how climate change could have an impact on spread of dengue fever.
Disease experts agree more flooding events brought on by severe storms that cause amplified jet streams as our planet warms could increase outbreaks of mosquito-borne diseases in parts of the world that don’t typically see them.
One such disease is dengue fever.
According to associate professor Stephen Barr from Western University, dengue fever can bring flu-like symptoms that are quiet unbearable.
“You have prolonged fever for seven days, your bones feel so painful — like they’re going to break," he told The Weather Network about the possible symptoms.
The disease cannot be transmitted from human to human, according to Barr, as it uses the mosquito as a vector.
Dengue fever is contracted by about 100 million people each year — historically in tropical and sub-tropical regions — and about 40,000 people are expected to die from the disease annually.
The state of Florida reported a case of dengue fever this fall after widespread storm surge flooding from Hurricane Ian, which was a Category 4 storm.
Flooding impacts after Hurricane Ian hit the Gulf Coast of Florida in September 2022. (Jaclyn Whittal)
According to the Center for Disease Control and Prevention in the United States, mosquitoes cannot live through the winds of a hurricane. But mosquito strains that can spread viruses may increase two weeks after a hurricane, especially in areas that experienced more rainfall than usual. Elevated waterborne disease outbreaks have been reported in the weeks following heavy rainfall.
“The research has been around since the 1950s, and only now people are taking it more seriously,” Oliver Brady, associate professor at the London School Of Hygiene and Tropical Medicine, told The Weather Network.
His team used a range of models to measure the potential impact of climate change on the length of the transmission season and population at risk of dengue.
The school’s research team estimates a worst-case scenario would mean the population at risk of the diseases might increase by up to 4.7 billion people (relative to the period 1970-1999), particularly in lowlands and urban areas, if temperatures rise by about 3.7°C by 2100 compared to pre-industrial levels.
The researchers also found there will be a northward shift of the dengue-epidemic belt over central northern Europe and the northern U.S. because of increases in suitability. At present, our temperatures would not allow for the mosquitos to live yearlong in our environment.
“These mosquitos can survive sub-zero temperatures for a certain period of time, but not for prolonged time," said Barr. "If it can acquire certain properties to allow it to survive our winters, it may learn to adapt.”
This more favourable breeding ground for disease carrying mosquitoes will not happen overnight; however, the situation will need to be monitored in the future.
Flooding impacts after Hurricane Ian hit the Gulf Coast of Florida in September 2022. (Jaclyn Whittal)
