Diseases Spread by Mosquitoes

Mosquito-borne diseases are becoming more common in the US. Warmer temperatures and increased rainfall create ideal breeding conditions for mosquitoes. These diseases occur in the summer through fall, with the highest number of cases being reported in August and September. They can occur across the US, so we should all be aware of them. Let’s talk about these diseases and how you can protect yourself from them.

• West Nile Virus – This is the most common mosquito-borne disease in the US. It is widespread across the country, but the highest number of cases are seen in states like California, Texas, and Arizona. Symptoms can range from mild flu-like symptoms to severe neurological issues like meningitis and encephalitis (inflammation of the brain). Although it can be fatal, most infected people have only mild to moderate symptoms.
• Eastern Equine Encephalitis (EEE) – This disease is rare but serious. As the name implies, this virus causes brain inflammation and infects horses as well as humans. EEE has a high mortality rate. It is most common in and around freshwater hardwood swamps in the Atlantic Coast and Gulf Coast states and the Great Lakes region. New Hampshire and Massachusetts have both reported deaths from EEE this year.
• Dengue – This disease causes pain, which can be severe, in muscles, joints, bones, and behind the eyes, along with possible nausea, vomiting, and rash. Dengue cases have been increasing, especially in states like Florida and Texas.
• Malaria – Unlike most diseases carried by mosquitoes, malaria is caused by a parasite, rather than a virus. It usually starts with fever and flu-like symptoms, but can progress quickly to kidney failure, seizures, and coma. Malaria can be deadly if not diagnosed and treated quickly. Although previously mostly eradicated in the U.S., there have been recent local cases, particularly in Florida.
• Zika Virus – This infection may cause little to no symptoms for many people, although it can cause severe neurological complications in rare cases. However, the big concern the Zika is that the virus can cause serious birth defects if a pregnant woman is infected. Most cases of Zika virus in the US happen in people who contracted the virus when traveling in Mexico, the Caribbean, or South America, but the mosquito species that carries Zika is present in the US. The virus can also be spread through sex with an infected person.

• Use insect repellent – Choose an EPA-registered insect repellent. Repellents: Protection against Mosquitoes, Ticks and Other Arthropods | US EPA
• Wear protective clothing – Long sleeves, long pants, and socks can help prevent bites.
• Eliminate standing water – Mosquitoes breed in stagnant water, so regularly empty containers like flowerpots, bird baths, and gutters.
• Install screens – Ensure windows and doors have screens to keep mosquitoes out.
• Stay indoors during peak mosquito hours – Mosquitoes are generally most active around dawn and dusk, although some mosquito species will bite throughout the day and night.
• Plan ahead to prevent mosquito bites while traveling Preventing Mosquito Bites While Traveling | Mosquitoes | CDC
• Pregnant women should be extremely cautious about travel to areas south of the US where Zika virus is common. Always check the CDC website for more information on the country you will be visiting. If you are pregnant and your sexual partner travels to one of these areas, you should use condoms for 6 weeks after travel to prevent spread of potential infection.