West Nile virus positive mosquitoes found in Portage County, City of Kent taking precautions

Words by Carley Hull. Photo by Rachael Le Goubin. 

The City of Kent and Portage County Health Departments are taking measures to rid the area of mosquitoes after five mosquito pools tested positive for West Nile virus.

The City of Kent Health Department confirmed four positive pools, three in Kent and one in Brimfield, in August. Kent State University labs confirmed a fourth positive Kent mosquito pool last week, but results from the Ohio Department of Health are pending, said City of Kent Health Commissioner Jeff Neistadt.

These are the first West Nile virus positive mosquitoes confirmed in the county.

Eradicating mosquitoes

Portage County Health Commissioner DuWayne Porter said that people need to understand that West Nile virus is endemic and is here in Kent, but there is no need to panic.

West Nile virus first appeared in the U.S. in 1999 in New York, said Ohio Department of Health entomologist Richard Gary.

“They believed [the virus] was going to be carried by migratory birds up and down the East Coast, but in addition to that it spread west,” Gary said. “So we started looking for it here in Ohio, and we saw the first evidence of both birds and mosquitoes testing positive in 2001.”

West Nile virus positive mosquitoes have already been in neighboring counties such as Summit and Cuyahoga counties. Portage county and Kent have not tested their trapped mosquitoes until this year, Neistadt said.

“Mosquitoes can travel 1 to 3 miles, and obviously Kent is a small place as far as size wise,” Neistadt said.

Mosquito spraying in Kent is planned to increase to two times a week and larviciding has increased to keep mosquito larvae from hatching into adults, Neistadt said. Mosquito traps have doubled to eight traps in the four surveillance quadrants of Kent.

“So in any standing water area we have definitely increased our larviciding programs,” Neistadt said. “Any wet areas we put larvicide in to make sure they weren’t hatching into adult mosquitoes.”

Female mosquitos are the ones that bite and therefore transmit the disease. To test the mosquito pools, the female insects are sent to both Kent State University labs and the Ohio Department of Health labs due to time and contract agreements, Neistadt said. It can take anywhere from five to six days for results from the Ohio Department of Health, Gary said.    

West Nile virus awareness

“Unfortunately once we start to find positive pools of mosquitoes it is only a matter of time before transmission,” Neistadt said. “Even with the low transmission rate.”

About 70 to 80 percent of people infected show no symptoms while 1 in 5 people develop symptoms such as fatigue, aches and pains, vomiting, diarrhea and a rash that takes weeks or months to recover, according to the CDC. Less than 1 percent of those infected will die from a neurological illness like encephalitis or meningitis.

This year has been a relatively low transmission year for both mosquitoes and people compared to other years.

“So far this year we’ve seen 11 positive mosquito pools [in Ohio] which sounds like a lot, but this time in 2012, which was an outbreak year for us, we had well over a thousand,” Gary said.

In Ohio, three human infections in Cuyahoga, Muskingum and Hamilton counties have been reported, according to the Ohio Department of Health. Of those infections, a 24-year-old female in Muskingum County and a 78- year-old female in Cuyahoga County have been hospitalized with encephalitis.

These numbers have decreased from the 24 human incidence found in 2013, and the 122 cases in 2012, according to the Ohio Department of Health.

“I can not say for sure, but I do believe weather plays a role [in the low incidence rates],” Gary said. “If you look at the outbreak year’s that we’ve had here in the Midwest they tend to be much hotter years…I know that seems counterintuitive because mosquitoes breed in water, but it has been during these dryer warmer years that we’ve had more [mosquito] outbreaks.”

Neistadt also agreed that this summers cold and rainy weather may have contributed to the low number of human and mosquito infections, but the Kent Health Department has upped their response to treating standing water as there is still a risk of human infection where West Nile virus positive mosquitoes live.

“Be aware that the virus is in the area…” Neistadt said. “Definitely take some precautions really to minimize your risk of exposure to mosquitoes.”