Mosquitoes and ticks are showing up with greater frequency. Here’s how to stay safe this summer

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Welcome to summer in the Northern Hemisphere, with all its fun in the sun – and little critters who want to take a bite out of you.

Mosquitoes and ticks can transmit vector-borne illnesses, and they are showing up with greater frequency. What can people do to protect themselves while still enjoying all that the summer months have to offer? And what treatments are available if you or your loved ones get bit?

To find out, I spoke with CNN wellness expert Dr. Leana Wen. Wen is an emergency physician and clinical associate professor at the George Washington University. She previously served as Baltimore’s health commissioner.

Insects can be carriers of diseases like Lyme and West Nile virus. - Ladislav Kubeš/iStockphoto/Getty Images
Insects can be carriers of diseases like Lyme and West Nile virus. - Ladislav Kubeš/iStockphoto/Getty Images

CNN: Let’s start by talking about tick-borne diseases, specifically Lyme disease. What is Lyme, and why is this something people should pay attention to?

Dr. Leana Wen: In the United States, Lyme disease is the most common vector-borne disease and is transmitted by ticks.

People who contract Lyme disease may experience temporary symptoms similar to the flu, such as muscle aches, fever and headache. They also may develop a rash and have joint pain. The concern with Lyme is that some untreated patients progress to having long-term symptoms. These can be severe and debilitating and include ongoing nerve pain, facial paralysis and abnormal heart function.

CNN: When is peak season for Lyme disease?

Wen: We are in peak season now. In areas where the disease is prevalent such as the eastern United States, people can be bitten by blacklegged ticks that carry Lyme disease from spring into fall, according to the US Centers for Disease Control and Prevention. Last year, there were reports that Lyme diagnoses peaked just before the Fourth of July holiday.

CNN: Has the incidence of Lyme disease increased in recent years?

Wen: Yes. The rates of Lyme diagnoses have doubled from 2004 to 2018, with an increase in geographic prevalence, meaning that more areas have a high incidence of this disease compared to before. (Newer data show an even more dramatic increase, though surveillance methodology has improved to capture more diagnoses.) There are a variety of theories as to why this is the case. Most are centered on the influence of climate change — for example, that warmer temperatures expanded the tick habitat and perhaps also sped up tick life cycles. This is the same with other vector-borne diseases, like those carried by mosquitoes, which are also on the rise likely due to rising temperatures.

CNN: What can people do to reduce their odds of contracting Lyme disease?

Wen: The most important step is to prevent tick bites. If you are in an area known to have Lyme, you should wear long-sleeved shirts and pants when hiking. Use insect repellent that contains the ingredient DEET. After the activity, examine carefully for ticks. If you have young children and pets, take the time to examine them as well.

If you find a tick, remove it, save it for identification purposes in a small jar and contact your primary care provider. Early antibiotic therapy can prevent you from developing Lyme disease. Also, if you end up developing symptoms, get tested right away. Antibiotic treatment can reduce the progression to chronic symptoms.

CNN: What about mosquitoes? What diseases can they carry?

Wen: Mosquitoes can transmit a lot of diseases to humans including the West Nile virus, dengue and malaria.

West Nile is the leading cause of mosquito-borne disease in the continental United States. While most people with the illness do not become ill, around 1 in 150 infected people develop a serious illness that can be fatal. In 2023, 47 states reported West Nile cases. In total, there were 2,406 reported instances in the US.

Dengue is another virus transmitted by mosquitoes. Outbreaks are common globally, and occasionally there are cases reported in the US. Most of these cases occur in travelers, but the types of mosquitoes that can spread dengue are found throughout many parts of the US. That means local transmission is possible. In recent years, transmission of dengue by people who have no travel history has happened in states like Florida, Texas, Arizona and California.

Another infection transmitted by mosquito that is far more common in other parts of the world is malaria. If untreated, symptoms can become severe and progress to kidney failure, seizures, coma and death. While most US cases involve travelers who contracted malaria from other parts of the world, locally transmitted cases have occurred, too. Last year, there were such cases reported in Florida, Texas and Maryland.

CNN: You’ve mentioned the US cases of malaria. What should people do who are traveling to other countries known to have these and other mosquito-borne illnesses?

Wen: I advise that people consult the CDC’s comprehensive guide, which includes recommendations for each destination country, and make an appointment with your primary care physician or travel medical clinic. Depending on where you are going, your planned activities and your personal medical history, you may be recommended to have additional vaccines or prophylactic medications.

For instance, if you are going somewhere with a concern for yellow fever, you may need to get that vaccine. If you are traveling to areas with high rates of malaria, you may be recommended to start antimalarial medicines.

CNN: What can everyone do to reduce their chance of getting bitten by mosquitoes?

Wen: Everyone should keep two key steps in mind. The first is to reduce bites. You can do this by covering arms and legs with clothes when possible. Clothing treated with the insecticide permethrin can provide an added layer of protection.

You can also use insect repellent. Make sure to use repellents that are registered with the US Environmental Protection Agency. These will contain active ingredients like DEET and are safe, even for children and pregnant women.

The second key step is source control — meaning to reduce the mosquitoes near you. During peak mosquito season, in the summer and early fall, use screens on windows and doors to reduce the mosquitoes in your home. In addition, it’s crucial to look for standing water in your garden, as these are breeding grounds for mosquitoes. Check for items around your home that could hold water — such as buckets, trash containers, tires and toys— and empty and wash them at least once a week.

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