Cleopatra may not have had to contend with West Nile virus as she floated on her royal barge, but North Americans do. For the past 13 years, this mosquito-borne infection has been an ever-increasing problem: 2012 is one for the record books in Canada and the U.S. WNV caused more than 44 deaths before September.

What is it? WNV comes from being bitten by a mosquito that has bitten an infected bird. Almost 80 percent of the time, it causes no symptoms; 20 percent of folks with WNV have a mild, flu-like reaction, swollen lymph glands or a rash. But for 1 out of 150 people, the result is high fever, headache, neck stiffness, coma, tremors, convulsions, vision loss, numbness and paralysis -- and brain and nerve damage may be permanent.

Who’s at risk for serious problems? The elderly and those with a chronic disease or a weak immune system are most vulnerable.

How can you protect yourself? Put screens on windows and doors; eliminate standing water (in kiddie pools, flowerpots, clogged rain gutters). Wear long sleeves and pants, especially at dawn and dusk, and use insect repellant 100 percent of the time (no excuses) on clothing and exposed skin. Try oil of lemon eucalyptus for kids 3 or older, or citronella; 30 percent DEET is the most effective repellant. It’s safe for adults and children over 2 months. Use mosquito netting on infant carriers and strollers.

If you do get it? There is no cure for WNV, but quick treatment for symptoms minimizes risk of long-term complications.

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Medical Officer at the Cleveland Clinic Wellness Institute. For more information go to