Dr. Jacqueline Gerhart: Managing Mosquitoes
Madison, Wisconsin - UW Health Family Medicine physician Jacqueline Gerhart writes a column that appears weekly on madison.com and in the Wisconsin State Journal. Columns are re-published here with permission.
Dear Dr. Gerhart: Why is it that mosquitoes bite certain people more than others?
Dear Reader: Wisconsin summers are here. The days are long, the weather is humid and the mosquitoes are ravenous.
The short answer to your question is that genetics may be responsible for up to 85 percent of our individual susceptibility to mosquito bites. A Japanese study argued that those with blood type "O" may be two times more susceptible to mosquito bites. Other studies showed that the more cholesterol, steroids and certain acid molecules present on one’s skin, the more bites they had.
Other than these studies that suggest genetic linkage, I'm unaware of any specific "mosquito-attractant genes." But we do know about environmental and individual factors that attract mosquitoes.
So what draws mosquitoes? Carbon dioxide is the most universally recognized mosquito attractant. When our bodies release carbon dioxide, mosquitoes can sense it up to 35 meters away!
The larger one's skin surface area, the more carbon dioxide released - which is likely why adults get bitten more than kids. Pregnant women also give off about two times the carbon dioxide as a non-pregnant adults, thus making pregnant women about two times more "attractive" to mosquitoes.
When a mosquito senses carbon dioxide, it flies in a zigzag path to locate the source. Once in the general vicinity, they rely on other cues such as sweat, lactic acid and heat to determine where to land.
Some studies show that the concentrations of cholesterol, steroids or certain acids on a person's skin can increase the likelihood of a mosquito bite. Additionally, there is some evidence that cheese and beer influence mosquitoes. It seems people who drink beer or eat stinky cheese are more attractive to mosquitoes.
Hmmm … beer and cheese? Sweat and heat? I would say our culture is a gold mine for mosquitoes - no wonder they love Wisconsin!
Not only are Wisconsinites the perfect prey, our state is a perfect mosquito habitat. They like standing water, marshes and lakes. They like humidity. They love wooded areas.
So how can we keep mosquitoes away? Three principles:
- Repellants or deterrents.
- Reduce the mosquito population.
Barriers include wearing long sleeves shirts, pants, socks and shoes to cover your body. Mosquito nets, porch and window screens and diligent door closing also can help.
Repellants include chemical sprays such as those with DEET or picaridin. You also may try citronella candles or eucalyptus oil. Fans also are a great deterrent. Because mosquitoes aren't very strong fliers, putting a fan near you can help to make it more difficult for a mosquito to fly to your area and land on you.
You also can reduce the mosquito numbers around you by discouraging their breeding. Since mosquitoes like to breed and live in still water, removing any standing water in your yard can reduce their breeding.
And the final answer in population control: If you slap a mosquito and it dies, well, it's not going to bite you again. Similarly, bug lights, traps and natural predators such as fish and dragonflies can reduce the population.
Stay tuned for more research on why some people get more bites than others. In the meantime, keep in mind the above strategies to stay bite-free!
This column provides general health information and is not specific advice intended for any particular individual(s). It is not a professional medical opinion or a diagnosis. Always consult your personal health care provider about your concerns. No ongoing relationship of any sort (including but not limited to any form of professional relationship) is implied or offered by Dr. Gerhart to people submitting questions.
Date Published: 07/24/2013