The Ohio Department of Health has confirmed that several mosquitos, trapped in Union County, have tested positive for West Nile Virus.
The Union County Health Department received notification from the Ohio Department of Health Thursday afternoon that five mosquito samples tested positive for West Nile Virus. All five samples were from the same trapping site near a stream in the southern part of Marysville.
Union County now joins 54 other Ohio counties reporting West Nile Virus activity.
Health Commissioner Jason Orcena said Ohio has seen “a high level of West Nile Virus activity this year.”
“There has been an increase in West Nile Virus positive mosquitoes across the state for the past several weeks,” Orcena wrote in a release announcing the findings. “We assume the mosquitoes in our county are also likely carrying the virus. This positive sampling confirms that assumption.”
Officials also confirmed that at this time, no human cases of West Nile Virus have been reported in Union County. Officials said there has been one case of La Crosse Encephalitis, another disease transmitted by the bite of an infected mosquito, reported in Union County. In Ohio, there have been eight reported human cases of West Nile Virus, 11 human cases of La Crosse Encephalitis, and two human cases of Unspecified California virus.
Mary Salimbene Merriman, epidemiologist for the Union County Health Department also urges residents to talk to their doctor if they are experiencing symptoms of West Nile Virus or La Crosse Encephalitis.
Only a healthcare provider can diagnose West Nile virus infection. A blood or cerebrospinal fluid sample may be collected for laboratory testing. There is no specific treatment for West Nile virus infection, and care is based on symptoms.
According to the Ohio Department of Health, about 80 percent of people who are infected with West Nile virus will not show any symptoms at all, but there is no way to know in advance if you will develop an illness or not. Those who do develop symptoms usually do so between two to 14 days after they are bitten by the infected mosquito.
“Thankfully, most people infected with West Nile Virus do not develop any symptoms,” Salimbene Merriman wrote in the release.
She added that some people can develop a fever accompanied by headaches, body aches, joint pain, vomiting, diarrhea or rash. Those infected with La Crosse Encephalitis usually have a fever, headache, nausea, vomiting, fatigue and lack of energy.”
Officials from the department said people of all ages can get sick with West Nile virus, but adults older than 50 are more at risk for severe disease. Most cases of West Nile virus reported in Ohio are in adults aged 70-79 years, particularly men.
According to the Ohio Department of Health, about one in 150 people infected with West Nile virus will develop severe illness. The severe symptoms may last several weeks, and neurologic effects may be permanent. About one in 10 of those diagnosed with severe illness will die, though that rate is much higher for patients diagnosed with West Nile virus encephalitis and acute flaccid paralysis.
City Manager Terry Emery said Marysville officials were notified Friday of the finding. He said the city has been “pretty aggressive” in trying to curb the spread of the illness.
“Obviously, we have known for several years that West Nile Virus is a concern and a possibility,” Emery said.
Union County mosquitoes have tested positive for West Nile Virus in several previous years, including 2016 and 2015. Neighboring counties including Delaware and Franklin have also had positive mosquito samples this year and in years past.
Emery said that during the summer months, the city sprays for mosquitos on a weekly basis.
“We try to especially treat the parks and the trail system, places where people like to visit outdoors,” Emery said.
He said the city does not get many mosquito related complaints.
“We think we have been pretty successful,” Emery said. “We have not cut back on what we are doing.”
Allison Zandarski, a member of the local health department’s mosquito surveillance team, said Union County Health Department will apply a non-hazardous larvicide to the area in an effort to reduce the mosquito population.
Emery said the public also has a role to play. He said the city focuses allot of effort on educating residents.
“We want to let them know what they can do to eliminate mosquitos around their home and better protect themselves,” Emery said.
According to the Ohio Department of Health, the mosquito that transmits West Nile virus, the northern house mosquito, is found in catch basins, stagnant water in ditches and containers of water with high organic matter, specifically mentioning flowerpot saucers and clogged rain gutters, so people who live or play near these habitats are at increased risk, though officials added, “anyone who spends time outdoors can be at risk for West Nile virus infection.”
The Union County Health Department is also reminding residents to continue taking precautions against mosquito bites.
“Mosquito breeding season continues until the first hard frost of the season. That could be well into October,” Zandarski said. “We encourage everyone to continue using insect repellents, avoid being outdoors during early evening and early morning hours, wear long sleeves and pants when outdoors and remove standing water on your property.”
Union County Health Department officials said they have been trapping mosquitoes from around the county since May. The samples are submitted to the Ohio Department of Health Lab, which identifies the species of mosquito and tests for West Nile Virus. The state then compiles the data as part of the statewide surveillance network.
Those wanting more information on mosquito surveillance efforts or West Nile Virus, are asked to call the Union County Health Department at (937) 642-2053. Union County residents are also encouraged to use the online mosquito reporting tool available at www.uchd.net to report areas with high mosquito activity.