The United States has seen an unusually high number of mosquito-borne disease cases this year. The most commonly transmitted mosquito-borne diseases in the US this year include the West Nile virus, eastern equine encephalitis (EEE), and St. Louis encephalitis. Public health officials are also closely monitoring cases of dengue fever and chikungunya in the eastern and southwestern regions of the country as well. While the high amount of documented EEE cases is higher than ever in the northeast this year, the southwest is seeing the highest amount of West Nile cases in documented history.
Between January 1st and September 24th of this year, 543 people in 46 states contracted the West Nile virus from bites inflicted by infected mosquitoes, according to officials with the Centers for Disease Control and Prevention. Of these victims, 156 contracted the disease from Culex mosquito species in Arizona, making Arizona the state with the highest number of people who have contracted the West Nile virus this year. Arizona has also seen 16 West Nile-related fatalities this year, and Culex mosquitoes remain active well into the fall season in the state. This is an alarming statistic considering that Arizona normally sees only 20 or so West Nile cases per year.
According to experts, West Nile is a preventable disease, as the virus is spread by urban-dwelling Culex mosquito species that rely on stagnant water sources in residential yards and urban areas in order to breed. Removing standing water and containers from properties would not only dramatically reduce the number of disease-carrying mosquitoes in the urban environment, but it would also prevent large numbers of Culex mosquitoes from congregating on residential properties where they transmit diseases most frequently. In Arizona, both Culex tarsalis and Culex quinquefasciatus transmit the West Nile virus to humans, and these two species are more commonly known as the western encephalitis mosquito and the southern house mosquito, respectively.
The western encephalitis mosquito dwells in rural areas where they are not often encountered by humans, but the southern house mosquito dwells primarily in residential and urban areas where females lay their eggs on the surface of stagnant water that has collected in a variety of containers, such as beer cans, bottle caps, gutters, kiddie pools, children’s toys, flower pots, neglected swimming pools, open septic tanks, storm drains, and culverts. Since this species maintains a habitat within 1 to 5 miles from their breeding source, these dangerous mosquitoes are always present around homes, and they are most active around dawn and dusk.
Do you worry about contracting mosquito-borne disease when you spend time outdoors?