It’s summer again — time for picnics, lazy days by the beach, camping, long evening walks, and barbecuing in the backyard. It’s also a good time to review what’s going on with West Nile virus — the disease that is transmitted by those pesky mosquitoes that come with the season.
At the moment, there have been 22 states with reports of infected mosquitoes, birds, or other animals: Arkansas, California, Florida, Idaho, Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Nebraska, New York, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, Utah, West Virginia, Wisconsin, and Wyoming. According to the Centers for Disease Control (CDC), so far there are already four people with severe neurologic symptoms due to West Nile, who reside in Colorado, Mississippi, and Texas.
Known as a “flavivirus,” this potentially dangerous bug is much more common in other parts of the world, such as Africa, West Asia, and the Middle East. In addition to humans, West Nile also infects mosquitoes, birds, and some mammals, such as horses.
Most often, a mosquito will pick up the virus when it feeds on an infected bird. Then, when the mosquito bites a human or another animal, it passes on the disease. On rare occasions, West Nile has been contracted through blood transfusions or organ transplants, and can be passed from a mother to her baby during breast-feeding or pregnancy.
The West Nile virus can cause several different forms of disease. These include diseases that infect a person’s nervous system, such as West Nile encephalitis (inflammation of the brain), West Nile meningitis (inflammation of the spinal cord and the membrane surrounding the brain), and West Nile meningoencephalitis (inflammation of the brain and its surrounding membrane). West Nile fever is also another form of illness that can occur in an infected individual.
One in 150 people with the virus will experience the rare nervous system symptoms, such as high fever, muscle weakness/stiffness, coma, tremors, vision loss, etc. The less serious symptoms of West Nile fever, experienced by 20% of those infected, include fever, headache, fatigue, body aches, and rash. Eighty percent of people who’ve contacted the West Nile virus will have no symptoms or complications at all.
It’s important to know that West Nile virus, while more easily transmitted during the summer months, can be present in the warmer states throughout the year.
The severity of this year’s summer/fall season is dependent on the weather — how hot and dry it is will definitely have an impact on the spread of the disease, as these conditions spur the growth of the virus inside the mosquito. Most likely, the hard-hit Gulf Coast region could be one of the worst areas for West Nile this year, as the destruction left behind provides a great breeding ground for the virus-toting mosquitoes.
In addition, the rate that the virus spreads from the insects to birds other than crows — such as the house sparrow and the robin — and to mosquitoes again will influence the number of human cases that occur. This last bit is especially concerning because these birds won’t die as quickly from the virus, meaning they’ll be around longer and travel further, potentially spreading the disease even more.
Even though most people infected with the disease will not have any symptoms, this does not mean you shouldn’t take it seriously. In the past seven years, almost 800 people have died from the severe forms of West Nile, with an additional 8,300 experiencing one of the devastating forms affecting the nervous system.
Just remember that anyone is at risk — not just children, the sick, or the elderly. Make sure that you and your family follow the proper preventive measures, so you can enjoy the summertime without too much worry.