Mosquitoes swarm in North Carolina after Hurricane Florence

While the people of North Carolina are recovering from massive floods caused by Hurricane Florence, they are submerged by another unwelcome visitor. Swarms of them: In a video taken last week, a mother explains how to get her out of a car with her child, surrounded by what appears to be wasps. Dozens hang on their windows.

"These are not wasps, baby, they are mosquitoes," says the woman when her child asks him questions.

Population peaks of bloodthirsty mosquitoes are common after major storms. And as climate change causes more storms like Florence and strengthens their strength, the increased risk of transmitting vector-borne diseases such as Zika, West Nile and the chikungunya virus is a major concern for public health experts.

"This is one of the hottest topics in climate and health today," said Juanita Constible, climate expert at the Natural Resources Defense Council. "And that's partly because the answer depends so much on the mosquito and the disease in question, and where the mosquito and [pathogen] live."

The good news is that, despite their monstrous size and painful bites, the race that invades North Carolina – called Psorophora ciliata, or gallinippers – are known primarily as nuisance mosquitoes. "These are not the ones that transmit pathogens causing disease in humans," said Chris Barker, a specialist in mosquito-borne viruses at UC Davis. "These are often floodable species whose eggs are in the ground when the hurricane arrives." The eggs remain dormant near ponds, streams and other bodies of water. When these areas are flooded, they hatch en masse.

Talk to USA today, The entomologist Michael Reiskind of North Carolina State University said that he had only counted three of these mosquitoes in five minutes before the Hurricane Florence passed. One week after the storm, there were eight during the same period and two weeks later, 50. This is therefore a public health issue as it hampers recovery efforts; To combat them, North Carolina Governor Roy Cooper last week called for $ 4 million in funding to fight mosquitoes in areas hardest hit by the hurricane.

This brings us to other types of mosquitoes, those who are able to transmit diseases to humans. The jury has still not clarified the impact of climate change on their spread, but public health officials are not at risk. After Hurricane Harvey last year, the US Air Force was asked to help Texas coastal areas fight the Culex and Aedes mosquito populations, which may carry West Nile and Zika viruses, respectively. Both diseases are endemic to the region.

And the threat of mosquitoes carrying dengue and Zika loomed in Puerto RicoThe months following hurricanes Maria and Irma created the ideal conditions for an epidemic: pockets of stagnant water, suffocating heat and humidity, power outages and general skepticism about aerial application of insecticide.

Unlike nuisance mosquitoes, these breeds are not populated during floods. In fact, they are first driven out of the urban water system by the storm. But they can come back in force weeks, months, even years after a storm, if stimulus efforts do not help.

Example: A study conducted in 2008 by researchers at Tulane University found that in some areas of Mississippi and Louisiana, West Nile virus cases reported to Centers for Disease Control and Prevention had more than doubled a year after the passage of Hurricane Katrina. Although the researchers refrained from directly blaming the hurricane, they suggested that this increase could be due to the enlargement of the breeding areas of fallen trees and stagnant water on an abandoned property. .

Barker says timing is important. "An early hurricane would have a much greater potential to increase the risk of disease in the continental United States than a hurricane that occurs in late September to early October," he said. "At this point, the weather is cooling down quite rapidly, the mosquito development time and the incubation period of the pathogens are getting longer."

This highlights one of the most important effects of climate change on the spread of vector-borne diseases: rising temperatures that warm the seasons. This can then expand the niche habitat of mosquitoes (and ticks) carrying disease – a little further north – and even speed up the incubation period of this pathogen.

"This extension of the habitat is a combination of climate change and human behavior," said Consilium. "Urbanization can expand the habitats of some mosquito species that prefer cities, so these species will accompany them as people develop. .

In the United States, the proliferation of the Asian tiger mosquito carrying the disease and its Aedes aegypti The cousins, who both thrive in the cities, remain one of the main targets of researchers like Barker. "Currently in California, we have a lot to do with invasive mosquitoes that we do not expect to be here by the year 2000," he said. "In 2011, the Asian tiger mosquito was discovered in the Los Angeles area. In 2013, we also discovered Aedes aegypti in the Central Valley and in the San Francisco Bay Area. Since then, these two species of mosquitoes have continued to spread. "Although, he recalls, their spread can not be blamed on climate change. Tourism, globalization and animal migration also play a role.

So what does it mean for cities? Researchers constantly propose new weapons, as controversial as they are, such as genetic mutation and even artificial intelligence. Constable says that most cities do not do enough. Too many people react to the influx of mosquitoes – through spraying campaigns, for example – and too few are proactive.

This means having a climate adaptation plan and making mosquito-borne diseases one of the top priorities of this plan. It also involves more vigilant surveillance of where mosquitoes appear across the country so that cities are not caught off guard.