Joint surveillance project discovers Aedes Aegypti mosquitoes in southwest Oklahoma

This spring, due to public health concerns surrounding Zika virus, the Oklahoma State Department of Health began a collaborative mosquito surveillance project with Oklahoma State University entomologists to detect the possible presence of Aedes aegypti (yellow fever) mosquitoes in six different Oklahoma communities.

Aedes aegypti are considered the primary mosquito carrier of the Zika virus in South and Central America and the Caribbean where a Zika epidemic is ongoing. There has been no local transmission of the virus confirmed anywhere in the United States.

An early finding of the project has been the identification of a small number of Aedes aegypti mosquitoes in various locations in Altus, Oklahoma.

In previous years, rare collections of Aedes aegypti have been noted in Oklahoma and Comanche counties. This is the first discovery in Jackson County. Oklahoma’s drier weather and lack of dense human population make it a less favorable region for the yellow fever mosquito.

“The presence of Aedes aegypti mosquitoes in Altus does not mean that community or other communities in Oklahoma will have locally originated cases of Zika virus,” said State Epidemiologist Dr. Kristy Bradley. “Gaining a better understanding of the potential locations and density of this mosquito adds to our knowledge and risk assessment for Zika. For local transmission of Zika virus to be possible, mosquitoes must first have to pick up the virus from an infected person to be able to spread it to others.”

Four of the six regions being monitored include communities with proximity to military bases, said Dr. Bruce Noden, a medical and veterinary entomologist at OSU, who is coordinating the project.

“This choice was because of the potential for mosquitoes to be transiently introduced by movement of military supplies. It seems quite unlikely, however, that this current finding came from nearby Altus Air Force Base,” Noden said.

To date, 13 international travel-acquired cases of Zika virus have been confirmed among Oklahomans, none involving a resident of southwest Oklahoma.

Zika virus is primarily transmitted to people through the bite of an infected Aedes mosquito. Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites. They most frequently bite during the daytime, both indoors and outdoors. They are most active during the early morning and late afternoon.

While the Aedes aegypti is associated with the Zika Virus as well as dengue fever and chikungunya, Oklahomans are reminded that the majority of mosquitoes found in the state are not Zika carriers.

The primary concern in Oklahoma is West Nile virus, a mosquito-borne disease spread by the Culex mosquito, causing illnesses, hospitalizations and even death of some persons, especially those over the age of 50 years. Preventive steps are encouraged to reduce the risk of exposure to West Nile virus and other potential mosquito-borne diseases:

• Use an insect repellent containing DEET, picaridin, or IR3535 on exposed skin and clothing when you go outdoors, particularly if you are outside between dusk and dawn when mosquitoes are more likely to bite. Insect repellent with permethrin should be used on clothing only.

• Repair or install window and door screens to keep mosquitoes out of the home.

• Prevent items such as buckets, cans, pool covers, flower pots, children’s toys and tires from holding water so mosquitoes don’t have a place to breed.

• Empty your pet’s outdoor water bowl and refill daily.

• Scrub and refill bird baths every three days.

• Clean leaves and debris from rain gutters regularly to ensure they are not clogged.

For more information on Zika and West Nile Virus, please visit www.ok.gov/health.