The case of an Asheville, North Carolina boy who came down with a life-threatening type of encephalitis (swelling of the brain) from a mosquito bite serves as a striking reminder for parents, especially in mosquito-prone regions such as South Florida, about the importance of protecting kids from these pesky — and sometimes disease-carrying — insects.
LoriAnne Surrett told NBC News that she thinks her boy, Noah, was bit by a mosquito while playing outside near the woods. The mosquito reportedly carried the virus that causes La Crosse (LACV) encephalitis. LACV is one of a group of mosquito-transmitted viruses that can cause inflammation of the brain (encephalitis). The boy is recovering at home after several days in an Asheville hospital.
“Taking precautions against mosquito bites is very important for the most vulnerable — very young children and the elderly,” says Tony Tavarez, M.D. , associate medical director, Children’s Emergency Center  at Baptist Children’s Hospital . “That’s partly because they have limited response from their immune systems. Sometimes we get no symptoms or mild symptoms from insect bites, and our immune system takes care of any virus that may be transmitted.”
Wearing protective clothing and applying mosquito repellent, while closely following directions when applying to children, is crucial to avoid potential insect-borne diseases, he says.
“Mosquitoes can bite at any time of day, depending on the species,” says Dr. Tavarez. “The rainy season in South Florida is when they are most active. Parents should also take steps to avoid stagnant water outside the home. Any open container that can fill with rainwater is a breeding ground for mosquitoes.” (See mosquito prevention tips below.)
In the U.S., an average of 63 LACV disease cases are reported each year, according to the U.S. Centers for Disease Control and Prevention (CDC). Most cases of LACV disease have been reported from upper Midwestern, mid-Atlantic and southeastern states, the CDC says. LACV disease cases occur primarily from late spring through early fall.
While the North Carolina mosquito-borne virus is rare in tropical climates, Floridians need to take precautions because mosquitoes are much more plentiful in South Florida, particularly during the rainy season which peaks in September.
Cases of diseases in the U.S. contracted by mosquito, tick or flea bites have tripled from 2004 to 2016, according to new data from the CDC. Such diseases can include dengue, Zika and Lyme disease. Mosquito-transmitted diseases that have struck in South Florida in recent years include dengue, Zika and chikungunya, although local outbreaks have been controlled.
The North Carolina boy’s symptoms included severe headaches, then he began having seizures, his mother said. Most persons infected with LACV have no apparent illness. Initial LACV symptoms in those who become ill include fever, headache, nausea, vomiting, and tiredness. Severe disease (involving encephalitis) occurs most commonly in children under age 16, and is often accompanied by seizures. Coma and paralysis occur in some cases.
Preventing Mosquito Bites
Here are valuable tips from the CDC:
- Protect yourself when traveling: Learn about country-specific travel advice, health risks, and how to stay safe by visiting CDC Travelers’ Health website .
- Use insect repellent: Use an Environmental Protection Agency (EPA)-registered insect repellent with one of the following active ingredients. When used as directed, EPA-registered insect repellents are proven safe and effective. These ingredients are:
– Picaridin, also known as KBR 3023, Bayrepel, and icaridin
– Oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD)
- Cover up: Wear long-sleeved shirts and long pants.
- Keep mosquitoes outside: Stay in places with air conditioning or that use window and door screens. If you are not able to protect yourself from mosquitoes inside your home or hotel, sleep under a mosquito bed net.
- Learn more: Travelers can learn more about mosquito bite prevention in this fact sheet from the CDC .
If You have a Baby or Child
- Always follow product instructions when applying insect repellent to children.
- Spray insect repellent onto your hands and then apply to a child’s face.
- Do not apply insect repellent to a child’s hands, mouth, cut or irritated skin.
- Do not use insect repellent on babies younger than 2 months.
- Dress babies or small children in clothing that covers arms and legs.
- Cover cribs, strollers or baby carriers with mosquito netting.
Stop Mosquitoes From Breeding
- Put away items that are outside and not being used because they could hold standing water. Mosquitoes breed by laying eggs in and near standing water. – As little as one teaspoon or bottle cap of water standing for more than one week is enough for mosquitoes to breed and multiply.
- Keep flower pots and saucers free of standing water. Some plants, such as bromeliads, hold water in their leaves—flush out water-holding plants with your hose once a week.
- At least once a week, empty, turn over or cover anything that could hold water: tires, buckets, toys, pools & pool covers, birdbaths, trash, trash containers, recycling bins, boat or car covers, roof gutters, coolers, and pet dishes.