Window Screens Simple But Critical Tool to Combat West Nile Virus

Window Screens Helped Eliminate Malaria by Early 1950s

Window screens have been part of the average American home for more than 60 years. But in some areas, particularly newly constructed and older neighborhoods, screens can be few and far between. In newer homes some homeowners choose not to not have screens installed because they just don’t like the way they look. In older homes, occasionally screens have been removed, but more often than not they have long since fallen out.  Failure to install or replace window screens is a concern to the Contra Costa Mosquito & Vector Control District because window screens are an important way to protect public health, and the fact is, screens have been preventing disease for decades.

Prior to the invention of the earliest form of modern air conditioning in the 1920s, open windows and doors provided the best chance of air flowing through a home during hot weather. But flying insects could easily enter the home as well.  The solution: window screens. Train companies became the first to use window screens on train cars in the 1860s as a way to keep embers and insects away from passengers. Soon after, with the ability to manufacture screens for mass distribution, window screens started appearing on buildings and slowly, but surely, on private homes.

In the book, Med School by Clifton K. Meador, MD, Dr. Meador recounts the stories told to him by a medical school professor who’d worked in the Southeastern United States in the 1930s where nearly one-third of the residents suffered from malaria. In one story, the professor explained that the reason so many people were sick with the mosquito-borne illness was because there were no screens on many windows, so mosquitoes easily flew into homes, biting and infecting residents.

In response to the epidemic, public health agencies joined forces to educate the public about the importance of window screens as a way to prevent mosquito-borne illness. According to the Centers for Disease Control and Prevention (CDC), this effort, in conjunction with the Tennessee Valley Authority’s efforts to reduce the number of places where mosquitoes could lay their eggs, effectively eliminated malaria in the region by the late 1940s.  Dr. Meador writes, “I don't know of a more dramatic and successful story of the use of science and education to eliminate disease on such a wide scale.”

By 1951, the CDC reports malaria was effectively eliminated from the United States, but other mosquito-borne illnesses would follow. Today, West Nile virus threatens the health of Contra Costa County residents, while a mosquito that can transmit dengue fever is in Southern California, and the yellow fever mosquito is just two counties away from Contra Costa County. The fact is, just as the risk of new mosquitoes bringing new diseases to our county is a part of life, so is using properly installed and fully functioning window screens whenever windows are open.

Homes with air conditioning have the option of keeping windows closed to keep mosquitoes and other insects out, however many homes that were built even as late as the 1980s and ‘90s were not built with air conditioning. And according the U.S. Energy Information Administration, more than half of homes belonging to low income families do not have central air, leaving open windows as the primary source of cooling. So if, you’re among the millions of Americans who keep windows open to provide cool air, be sure to put a screen on it to keep potential disease-transmitting mosquitoes out of your home today and well into the future.

August, 2013

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