(TNS) — The two types of mosquitoes that can carry Zika — and other viruses — have been reported in Kansas. One type of the mosquitoes has been reported for the first time in 38 Kansas counties, according to a new study by researchers from the Centers for Disease Control and Prevention.
Six researchers examined all of the available county-level mosquito surveillance data to follow up on a study they published last year on the range of the Aedes aegypti and Aedes albopictus mosquitoes.
The “yellow fever mosquito,” Aedes aegypti, mainly stayed in the upper northeast corner of the state, including in Wyandotte, Johnson, Douglas and Shawnee counties.
Closer to Wichita, the Aedes albopictus mosquito, also called the “Asian tiger mosquito,” was more common, reported in 38 Kansas counties. It has been found for three or more years in 22 counties, including Kingman, Sedgwick, Butler and Chase. All of the counties bordering Sedgwick had at least one Aedes albopictus reported between 1995 and 2016.
Sedgwick County was initially put on the Aedes aegypti database in error and was later removed.
‘A smaller place’
Joe Conlon, technical adviser for the American Mosquito Control Association, said he was surprised to see the Aedes aegypti in Kansas.
“Aedes aegypti is generally regarded as a coastal mosquito, even though historically it’s been found in the Ohio River Valley,” Conlon said. “I think what this underscores is people need to be apprised of the fact that these mosquitoes and the diseases they transmit are just around the corner and the world is becoming a smaller place.”
Aedes aegypti prefers to feed on humans, making it the most common transmitter of Zika, dengue and chikungunya.
Both types of mosquitoes have been known to carry West Nile virus.
The Aedes albopictus can also transmit dengue fever and chikungunya. However, the mosquito feeds on animals as well as people, making it less likely to spread the various viruses than the Aedes aegypti. Even when an infected mosquito bites a human, it may be less likely to transmit the disease than the Aedes aegypti, Conlon said.
While Aedes albopictus isn’t the mosquito most known for spreading Zika, the Pan American Health Organization did report that 2016 tests found the Zika virus in Aedes albopictus mosquitoes in Mexico.
The CDC researchers emphasized that the presence of the mosquito in a certain county does not mean it’s abundant in that county and that mosquito-borne transmission of Zika has so far been extremely rare in the continental United States.
The 22 cases of Zika reported in Kansas have all been travel-related. The only documented instances of mosquito-borne Zika in the continental U.S. were in Florida and Texas.
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Zika is a relatively mild illness except when it occurs during pregnancy, when it can cause the birth defect microcephaly. A study of almost 1,500 pregnant women with Zika in the continental United States found that it caused birth defects in about 5 percent of cases.
“I think what this paper is telling us is how important it is state and local jurisdictions have in place these surveillance networks to detect the presence of these mosquitoes,” CDC spokesman Tom Skinner said.
The best way to keep both the Aedes aegypti and Aedes albopictus from breeding is to empty out any containers holding water, Conlon said. That includes trash cans, dishes under flower pots and birdbaths.
“They don’t breed in ponds, they don’t breed in puddles, they don’t breed in ditches,” Conlon said. “Particularly with Aedes aegypti, they breed in man-made containers filled with water.”
People should also scrape the sides of a dish when they empty the water, making sure to remove any mosquito eggs.
Wear long clothing and use mosquito repellent to avoid being bitten. The Aedes aegypti is attracted to dark clothing, so wearing light-colored clothes also helps, Conlon said.
Of the mosquito-borne illnesses, West Nile virus — most commonly transmitted by the Culex mosquito — is considered much more of a threat in this region. The Kansas Department of Health and Environment is now reporting a high risk of West Nile transmission throughout the state, and the virus is suspected in the death of a Jackson County, Mo., boy last month.
Most people infected with West Nile don’t experience any symptoms, according to the CDC. For about 20 percent of people infected, West Nile can cause a fever, headache, joint pains, vomiting, diarrhea or rash. Fatigue can last weeks or months after recovery.
Three cases of West Nile in a human are being investigated now, while one case was confirmed in Barton County.