Dear Doc,
This summer the mosquitos are feasting on me! Is there a reason I get bit more than other people? Does this put me at risk for any diseases?

Reader,
Those six-legged biting pests, mosquitos, have been around since the Jurassic period, making them 200 million years old! Today, there are more than 3,500 species of mosquitoes, with about 175 species living in the U.S. Mosquito is Spanish for “little fly.” These little flies can fly at speeds up to 1.5 miles per hour, beat their wings 500 times per second (think buzzing sound), and live an average of two months.

Only female mosquitos bite humans and animals. The females need protein for their eggs, and must take a blood meal in order to reproduce. A female mosquito can drink up to three times her weight in blood! Don’t worry if you are a sanguivoriphobe (one who fears vampires or other blood eaters), it would take 1.2 million bites to drain the 5 liters of circulating blood from your body.

After the female has bitten you and removed some of your blood, some saliva from the mosquito remains in the bite area. The proteins from the saliva evoke an immune response resulting in a raised, irritating, itchy bump, otherwise known as a mosquito bite. The vast majority of bites in the U.S. do not cause any significant disease. However, if the mosquito that bit you is carrying a parasite or virus, that parasite or virus may be transmitted to you and could rarely cause a significant illness.

In fact, mosquitoes are the deadliest animals on earth! Mosquitos transmit the parasite that causes malaria. More than 400 million cases and 1 million deaths due to malaria are reported annually throughout the world. The disease is confined to tropical climates and not typically found in the U.S. Mosquitoes may also spread dengue fever, yellow fever, and viruses that may cause encephalitis (inflammation of the lining of the brain). Mosquitos also carry heartworm, which may be fatal to your dog.

In the U.S., West Nile virus (WNV), spread by the mosquito, has been on the rise. It first appeared in the U.S. as a health scare in NY State in 1999 with 62 confirmed cases. As of 2014, there have been over 36,000 cases of symptomatic WNV reported. Some 15,000 or so have resulted in a significant neurologic disease. It is estimated that at least 1.5 million infections of WNV have occurred but fortunately the vast majority, 82%, are completely asymptomatic. About 1 in 5 people who are infected will develop a fever with other nonspecific symptoms such as fatigue. Less than 1% of infected people develop the serious, sometimes fatal, neurologic illness.

So why are these mosquitos choosing to feed on you? Sweat helps mosquitoes choose their victims. Your skin produces more than 340 chemical odors, and some of them smell like lunch to mosquitoes. They are fond of octenol, a chemical released in sweat. Also, if your skin has higher amounts of cholesterol, folic acid, and certain bacteria you may be targeted. Skin lotions and perfumes also attract some mosquitos. Mosquitos use heat sensors to locate your body and attack. Mosquitos can detect carbon dioxide (CO2) from 75 feet away and use this as a guide to the humans they will be biting! (Humans breathe in oxygen and exhale carbon dioxide). Larger individuals produce more (C02), which is why mosquitoes are more attracted to biting adults over small children. Pregnant woman are also at increased risk, as they produce and exhale a higher level of CO2. After your exercise routine, the panting out of CO2 may be inadvertently alerting the mosquito of a nearby meal. Finally the Journal of the American Mosquito Association (no, I did not make that magazine up), has reported that downing just one beer can increase the risk of being bit!

Using a DEET chemical based repellant has been proven to be safe and effective in protecting from bites. Endorsed by the Centers for Disease Control (CDC), DEET doesn’t mask our smell or jam the insect’s senses but rather gives off an odor that mosquitoes simply don’t like. A product containing 10 percent DEET can protect you for up to 90 minutes. Two other repellents, picaridin and lemon-eucalyptus oil, have also proven effective and are also recommended by the CDC. Some prefer picaridin, as it is odorless.

You are likely to stay attractive to mosquitos, but hopefully, by using an insect repellant you can protect yourself from future bites and possible illness.
Stay healthy and remember the quote by Christine Todd Whitman, “Anyone who thinks that they are too small to make a difference has never tried to fall asleep with a mosquito in the room. “

Dr. Nagpaul is a medical doctor and is board-certified in Internal Medicine. He currently is the Medical Director at Newark-Wayne Community Hospital, DeMay Living Center and Wayne County Public Health. This column is meant to be educational and not intended to be used to make individual treatment decisions. Prior to starting or stopping any treatment, please confer with your own health care provider. To send questions, please email Dr. Nagpaul at Arun.Nagpaul@rochesterregional.org and put “Ask a Doc” in the subject line.