Hill County mosquitoes could transmit Zika

Twenty-nine percent of Hill County’s mosquitoes could transmit the Zika virus, a new study suggests.

Hill County Weed District Supervisor Terry Turner said a new study by researchers at the University of North Dakota found that Aedes vexans, a type of mosquito indigenous to North America and the second-most plentiful of all the species in Hill County, has the capability of transmitting Zika.

Researchers, in an Entomology Today article dated May 12, said the Ae. vexans mosquito can serve as a “potential vector” for Zika virus because of its wide geographic distribution, often extreme abundance and aggressive human biting activity.

However, author Josh Lancette writes, capabilities does not translate to certain outbreak. He cites Professor Jefferson Vaughn of medical entomology and arthropod-transmitted diseases:

“There are other things at play. For instance, Zika virus is a primate virus, therefore a mosquito would have to feed twice on a human during its lifetime in order to become infected and then transmit Zika virus. Although the Ae. vexans mosquito bites people, studies indicate it prefers to feed on larger animals such as livestock and deer,” Vaughn says.

Turner said Thursday the total mosquito population, comprising 13 species in the county, has dwindled drastically in Hill County since the mosquito district was implemented in 2004. Mosquito district workers went from finding 4,000 mosquitoes in traps to 250 mosquitoes as of late.

The upcoming weed control district mill levy, he said, could be the difference between going back to a mosquito population akin to what it was before the mosquito district was implemented, and keeping the number low as it is now.

“We would be right back to where we were 15 years ago,” he said, “and we don’t want that, especially with all these viruses popping up.”

The mosquito district uses the same employees as the weed district, so if the numbers fall in the weed district, they do for the mosquito district, too.

Voters will vote May 25 whether to approve the levy. If approved, the cost to property owners with a home of a market value of $100,000 would be $5.40, and to those with a market value of $200,000, it would be $10.80.

Should the levy pass, Turner has said, it would give his department up to about $141,760 a year more to work with — some of which he would use to hire more seasonal workers. He said he would like to have four more workers.

Turner said the district employees use two main approaches to curbing the mosquito population.

The first and most effective tool, he said, are altosid pellets that are put in standing water pools that have tested positive for mosquito presence. The pellets keep the mosquito larvae from maturing into adults.

This is done in the mosquito district, which encompasses a swath of area that begins seven miles west of Havre and stretches to the Blaine County line, and six miles north of Havre and five miles south.

The second step, Turner said, is fogging, which normally happens once the weather gets hot and mosquito eggs hatch and the larvae mature into adults. Before the fogging begins, Turner said, he calls residents who have some allergy to the fog to let them know that it will be happening.

Turner said some people are allergic to the chrysanthemum derivative in the fogging spray, but other than that, there is no harm to fogging. He supported the claim with information from the American Mosquito Control Association.

“Extensive studies have evaluated the risk to people from exposure to mosquito control products. When public health professionals treat outdoor areas with these products, studies show the exposure will not cause harm,” the AMGA says.

Turner cited a list of practical steps people can take to mitigate mosquito presence and possible health concerns. The common denominator in all the steps comes down to eliminating standing water.

Get rid of old tires in the area; check the rain gutters and eliminate water, repair drippy faucets; change bird bath water; dump the children’s swimming pools — those are all steps that would help, Turner said.

A pool of water large enough to fill a coffee cup could produce 250 mosquitoes, and a five-gallon bucket could support 10,000, Turner said.

People also can avoid mosquito bites with dressing and defending.

The American Mosquito Control Association recommends that people wear light-colored, loose-fitting clothes to help prevent mosquito bites. Some species of mosquitoes in the United States are attracted to darker-colored clothing and most can bite through tight-fitting loose-weaved clothing.

Environmental Protection Agency-approved mosquito repellent also can prevent bites. Experts consider products including DEET, the abbreviation for the chemical name N,N-diethyl-meta-toluamide, the most effective.

The Mosquito Control Association also lists other substances including picaridin, oil of lemon eucalyptus and IR3535 as effective repellents.

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Online: Mosquito Control Association website: http://www.mosquito.org/