Watch those mosquitoes

Philip J. Goscienski, M.D.

March 2013

Malaria couldn't happen here, could it? Almost all the cases of malaria that are discovered in the United States occur in persons who acquired it elsewhere but that could change. Given the right circumstances a mosquito can dine on an infected immigrant and transmit the disease to someone who has never left the United States.

The likelihood of getting malaria in this country is vanishingly small and nothing to worry about but it makes sense to take precautions to avoid mosquito bites anyway. That's because there are other mosquito-borne diseases that are not so rare, including several types of encephalitis.

Last year, 2012, was a bad one for West Nile virus. It was recognized more than a half-century ago in the West Nile region of Uganda, hence its name, and has steadily spread throughout the world. It arrived in New York City in 1999 and since then it has spread to almost every state.

The good news is that only about one person in five who is infected by the West Nile virus becomes ill. It causes non-specific symptoms such as fever, chills, sweating, muscle aches and headache, like many other viral illnesses, so the diagnosis is usually missed. Only about one victim in 150 develops severe disease involving the brain. Although the fatality rate is low there were so many infections in 2012 that more than 40 persons died.

The risk of mosquito-borne diseases rises dramatically among travelers to tropical or sub-tropical countries. Visitors to Africa, India and the Caribbean should take active precautions to prevent infection.

Most mosquitoes don't feed throughout the day but are most active at dawn and dusk, so stay indoors at those times whenever possible.

Mosquitoes are attracted by fragrances, including perfume, after-shave lotion, hair spray and other scented chemicals that humans wear to attract each other. Learn to use them sparingly, if at all, in areas where malaria, dengue (a painful but rarely fatal disease), yellow fever and various types of encephalitis are known to occur.

In tropical countries you'll feel like wearing short pants, short-sleeved shirts and sandals but they make you mosquito bait. Keep as much of your skin covered as possible and consider using mosquito repellent that is designed for use on clothing. Ask your travel agent if you'll need a mosquito net at night.

Finally, nothing works better than DEET to keep your skin unattractive to those critters.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.