Summer in the United States means more time outdoors, and the annual tradition of fighting mosquitoes. This year, however, a mild winter and a wet spring has made the mosquito problem far worse than previous years. Complicating matters is the relatively new presence of a mosquito that carries some of the worst diseases imaginable. And this summer could see the worst breakout of mosquito-borne diseases ever.
In an interview with Business Insider, Durland Fish, professor emeritus of epidemiology at the Yale School of Public Health, predicts mosquito-borne diseases will only get worse as the world gets smaller and warmer. That not only includes diseases Americans are familiar with, like the West Nile virus, but more exotic diseases that before were limited to other countries, like Zika.
Fish explains why we are seeing an increase in mosquitoes and the diseases they carry.
“If they go through an extra life cycle, there’s going to be more mosquitoes,” he said. “If they’re transmitting a disease, the incidence of the disease is going to be higher.”
In addition to that, Fish says that six or seven new species of mosquito have recently been introduced to Florida, two within the past year. More and different types of mosquitoes increase the chances that a new disease could appear.
It’s not just climate, either. Environmental change and globalization have also made it easier for diseases to spread, something that is seen with mosquitoes and with creatures like ticks, too. In general, says Fish, diseases seem to be emerging at an increasing rate.
“The trend is pretty frightening,” he says. “We didn’t seem to have these scares 30 or 40 years ago.”
The diseases mosquitoes carry can be potentially life-changing and deadly.
The U.S. Centers for Disease Control list these major diseases carried by mosquitoes, along with their symptoms.
- West Nile virus. Symptoms include extreme fever. Less than 1% of those infected develop a serious, sometimes fatal, neurologic illness.
- Malaria. Symptoms include fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. 1,500 people in the United States get malaria each year.
- Chikungunya virus. Major symptoms include fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash. It is rarely found in the United States.
- Dengue. Symptoms include high fever, with additional symptoms including severe headache, pain behind the eyes, joint pain, pain in bones and muscles, rash, and bleeding.
- Zika virus. Symptoms include fever, rash, joint pain, and red eyes. In pregnant women, Zika can cause neurological damage and microcephaly, a particularly small head and underdeveloped brain.
Zika and dengue are carried by only two types of mosquitoes, and one, the Asian tiger mosquito, has seen a dramatic increase in its population in the United States in the past couple of years.
Scientists think that the Asian tiger mosquito — one of two mosquitoes that carries Zika, dengue, and yellow fever — first arrived in Texas in shipments of used tires in 1987. Since then, they’ve spread inexorably across the country.
The Asian tiger mosquito (Aedes albopictus) — prefers less populated areas and is as likely to bite humans as animals, but it carries many of the same diseases and is a more effective breeder. Unlike aegypti, which can’t survive harsh northern winters, albopictus has overwintered as far north as Connecticut. There are concerns that range will expand with climate change.
Aedes mosquitoes are particularly well-adapted to life alongside humanity. They evolved to breed in the notches and holes in trees, but they’ve adapted to the nooks and crannies we leave scattered around our homes and cities. They lay their eggs on the sides of containers next to tiny pools of water, and their eggs can survive dried out for months. If that container is moved, so is a generation of mosquito.
This map shows the counties in the United States where the Asian tiger mosquito has been found. The map only shows where they have been found over the years, and it is possible that it may not be present in all of these areas today. However, the resilience of the Asian tiger mosquito also means it may be in far more areas, but not yet identified.
While treatment of Zika, West Nile, and other mosquito-borne diseases vary, the prevention, of course, is the same.
The Center for Disease Control suggest Americans take these precautions when spending time outside.
- Reduce sources of standing water.
- Wear long-sleeved shirts and long pants.
- Use EPA-registered insect repellents on exposed skin and clothing, as directed on the product labels.
If you feel any of the symptoms listed above, particularly if the symptoms are uncommon for you or feel different from past illnesses, consult a doctor immediately.
Please pass along this information to your family and friends, and in addition, share it on social media. It could save a life!