A contractor loads mosquito control pellets onto a helicopter spreader for aerial spraying at Marine Corps Base Camp Pendleton, California. (Photo by Marine Lance Cpl. Kerstin Roberts) ()
Warmer temperatures bring mosquitoes – and these pesky flying insects present a potential health hazard. Through biting, mosquitoes may transmit serious or even deadly illnesses.
According to experts including the World Health Organization, there's no evidence mosquitoes can transmit the COVID-19 virus. But mosquitoes are to blame for the spread of many other germs. West Nile is the most common virus spread by mosquitoes in the continental United States, according to the Centers for Disease Control and Prevention.
Mosquitoes also spread malaria. About 2,000 cases of this flu-like illness are diagnosed in the United States every year, according to the CDC. It can be severe and even lethal in young children, said Anne Radavich, chief of product development and education in the Entomological Sciences Division of the U.S. Army Public Health Center, or APHC.
Other ailments spread by mosquitoes include the dengue, yellow fever, Zika, and chikungunyaviruses.
"Vaccines are not available for many of the illnesses and diseases that mosquitoes spread," Radavich said. "So the best prevention is to control mosquitoes and eliminate their breeding habitat." June 21-27 marks National Mosquito Control Awareness Week.
The Department of Defense has enacted measures to protect the health of service members in parts of the world where mosquito-borne illnesses are common. Those steps include pretreating uniforms with permethrin, an insecticide that kills or repels mosquitoes. Permethrin also can be applied in the field to clothes and other items, but it should not be applied to skin.
Tests are being conducted on a possible replacement for permethrin, said James English, assistant professor in the Global Public Health Division, Department of Preventive Medicine and Biostatistics, at Uniformed Services University of the Health Sciences in Bethesda, Maryland.
"Permethrin in field uniforms works well to protect from mosquito bites; it's safe; and the formulation used in military uniforms has been providing safe, effective protection against disease vectors for nearly 30 years," English said. "But that doesn't mean we can't find something that works better or lasts longer."
English added that permethrin has been used all over the world against agricultural pests, and that has caused resistance to occur in mosquitoes in some locations.
"If and when we change to a new active ingredient or a new method of protection, it will be because we found something that is more effective, lasts longer in the uniform and doesn't wash out or wear off as quickly; that the method has a better risk profile for the wearer, the environment or the people who apply it; or that the new protection method is the next step in the dance to avoid resistance in the target disease vectors," he said.
Other steps in the DoD repellant system include protecting exposed skin using insect repellents containing DEET, picaridin, or IR3535 as the active ingredient. All three can be used on skin or clothing, Radavich said. These products are available in a variety of forms including liquids, lotions, and sprays.
At home, look for ways to eliminate spots where mosquitoes lay their eggs, experts say. Some mosquitoes breed in outdoor containers with standing water, including flowerpot saucers, birdbaths, and trash can lids.
“They can breed in something as small as a bottle cap with a few drops of water in it,” Radavich said.
Army entomologists invented the Trap-N-Kill. Users place a plastic pesticide strip inside the approximately 8-inch-tall, cylinder-shaped device and then fill with water. Mosquitoes looking for a place to lay their eggs enter through a small hole in the front. The pesticide strip fatally poisons them and any larvae that hatch from the eggs.
Trap-N-Kill became available to DoD personnel through the military supply system starting in 2014. It’s also available through a commercial licensing agreement at civilian retail locations. APHC and the Walter Reed Army Institute of Research jointly hold the patent on the device, Radavich said.
A fact sheet available from APHC offers more information about controlling mosquitoes around the home.
