Bug Off: How to Keep Mosquitoes Away

Mosquitos are mainly known for spreading itchiness and irritation, but they can also carry a host of illnesses. Mosquito-borne malaria, for instance, kills close to 630,000 people every year, mostly children. While many diseases transmitted by mosquitos are not a cause for concern in the US, there have been close to 40,000 cases of West Nile Virus here since 1999, and recently Florida reported cases of both dengue fever and chikungunya, according to the Centers for Disease Control and Prevention (CDC).

Mosquitos transfer viruses from a nonhuman host such as a bird or a chipmunk, and symptoms of an infection may appear anywhere from a few days to a couple of weeks following a bite.

Depending on where you live, the type of activities you enjoy, and when you enjoy them, you may be putting yourself at risk of a harmful bite. As the number of insect-related illnesses continue to rise, it’s more important than ever to be on guard.

Avoiding Mosquitos: Insect Repellant and Clothing

Countless products that claim to repel bugs can be found on the market, but experts from the CDC, the Environmental Working Group (EWG) and the American Academy of Pediatrics (AAP) say the best way to wage war against summer’s biggest little enemies is insect repellent.

Some repellants contain chemicals, while some are made with natural ingredients. They’re available as aerosols, sprays, liquids, creams, and sticks, though the EWG doesn’t recommend using repellents in pressurized aerosol containers as the mist can hurt your eyes and is easy to inhale. To minimize negative side effects from the ingredients in insect repellents, follow the manufacturer’s directions for proper application carefully.

Liquids, lotions, or sprays with the repellant DEET (aka N,N-diethyl-meta-toluamide) are the most effective way to repel mosquitos and other bugs, says the CDC. However, there are side effects associated with the chemical, including skin blisters, blurred speech, and seizures.

West Islip, New York-based Kavita Mariwalla, MD, recommends using products containing at least 20 percent DEET (but no more than 30 percent) for up to five hours of protection. However, the dermatologist and mother does not recommend DEET products for babies and young children: “It’s difficult to gauge how much to apply so the chance of over exposure is higher. The other worry is that young children constantly put their hands in their mouths, and they can ingest it,” she says. To protect little ones, cover strollers and baby carriers with netting.

If you’ll be out in the sun, sunscreen is also important, but the CDC and Mariwalla don’t recommend using products designed to both repel insects and protect against harmful rays: "If you are applying sunscreen the way you should be—a golf-ball size application every three hours—you are probably using too much DEET. Solve the problem by first applying sunscreen and then using bug spray."

If you’re wary of DEET, the CDC also recommends insect repellents containing picaridin (a black pepper derivative), IR3535, or oil of lemon eucalyptus. Read labels and choose a concentration right for the time span you expect to be outdoors.

Mariwalla is also a fan of clothing that is pre-treated with permethrin (a pesticide), but doesn’t recommend the do-it-yourself kits or permethrin sprays: "Permethrin is quite toxic. We use it in cream form to treat scabies—a type of mite—and it can hurt your skin if not used properly."

Bug Off!

There are other ways to help keep the mosquitos away. Try the following:

  • Place a couple of electric fans around your picnic table to keep the mosquitos from joining your backyard feast. They may be pros at spreading disease, but they’re not expert flyers.
  • Eliminate pools of standing water in flowerpots, birdbaths, baby pools, and grill covers—mosquitos like to congregate and multiply in those areas.
  • Avoid outside activities between dusk and dawn. This is peak biting time for mosquitos.
  • Repair damage to window screens to make sure mosquitos stay outside.
  • Seal cracks and holes outside the home, paying close attention to utility and water pipe entry points.
  • Replace weather stripping and repair loose mortar around basement foundations and windows.

What Doesn’t Work

Experts from the EWG and the AAP say the following products do not offer effective protection from tick and mosquito bites. Don’t waste your money on:

  • Ultrasonic devices that give off sound waves designed to keep insects away.
  • Citronella candles.
  • Battery-operated devices that clip to clothing and circulate insect repellent.
  • Eating garlic or taking an extra dose of vitamin B.
  • Wristbands treated with chemical repellents.
  • Outdoor “fogger” insecticides.

Kavita Mariwalla, MD, reviewed this article.


Sources

Kavita Mariwalla, MD, West Islip, NY-based dermatologist. Phone interview. 10 June 2014.

"Protection Against Mosquitos, Ticks and Arthrods." The Centers for Disease Control and Prevention. Accessed 13 June 2014. 

"EWG’s Advice for Avoiding Bug Bites." Environmental Working Group. Accessed 13 June 2014.

"Insect Repellents. Safety and Prevention." American Academy of Pediatrics. Accessed 13 June 2014. 

"Division of Vector-Borne Diseases (DVBD).

"Centers for Disease Control and Prevention. Page last updated July 21, 2014. 
"Diseases and Conditions. Mosquito Bites." Mayo Clinic. Accessed 10 June 2014. 

"Malaria." World Health Organization. Face sheet updated March 2014.

"West Nile Virus: Prevention and Control." The Centers for Disease Control and Prevention.

"West Nile Virus Disease Cases and Deaths Reported to CDC by Year and Clinical Presentation, 1999-2013." ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention.