To monitor and control Vector-Borne Disease, The Clark County Combined Health District (CCCHD) sanitarian staff capture mosquitos and submit the samples to Ohio Department of Health (ODH) where they are identified by species tested for West Nile Virus.  A sample collected from the west side of the City of Springfield this month is the second sample to test positive for the West Nile Virus in Clark County. 

mosquito pbWest Nile Virus (WNV) is an arthropod-borne virus (arbovirus) most commonly spread by infected mosquitoes that can lead to severe fever, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). 

The primary vector in Ohio is the northern house mosquito, Culex pipiens.  Mosquitoes become infected when they feed on infected birds.  Infected mosquitoes can then spread the virus to humans and other animals when they bite.

Approximately 80 percent of people who are infected with WNV 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 three to 14 days after they are bitten by the infected mosquito:

  • Serious symptoms in a few people.  About one in 150 people infected with WNV will develop severe illness.  The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis.  These symptoms may last several weeks, and neurological effects may be permanent.
  • Milder symptoms in some people.  Up to 20 percent of people who become infected will have symptoms that can include fever, headache, body aches, nausea, vomiting and sometimes swollen lymph glands or a skin rash on the chest, stomach and back.  Symptoms can last for a few days to as long as several weeks.
  • The CCCHD has sent an alert to the local medical community to facilitate quicker human diagnosis of West Nile Virus, and will continue to monitor the mosquito population. 


There is no specific treatment for WNV infection, and care is based on symptoms. Residents must be proactive to prevent mosquito bites:

  • When outdoors, use repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol.  Follow the directions on the package.
  • Many mosquitoes are most active from dusk to dawn.  Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
  • Make sure you have good screens on your windows and doors to keep mosquitoes out.
  • Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels.  Change the water in pet dishes, and replace the water in bird baths weekly.  Drill holes in tire swings so water drains out.  Keep children’s wading pools empty and on their sides when they aren’t being used.


CCCHD prevention activities


In order to reduce the number of mosquito breeding sites, The Clark County Combined Health District hosted two scrap tire collection events at locations convenient to residents.  The first event was August 12 at the Health District office in the City of Springfield and the second event was with the cooperation of Tecumseh Local School District at Tecumseh High school in the western end of the county.  The Health District collected and recycled over 7,000 tires with no charge to residents.

The Health District is in process of the second round of nighttime mosquito fogging as a control measure.  The mosquito fogging is targeted for the Cities of Springfield and New Carlisle as well as most of the villages in order to protect as many residents as possible.   While safe for humans and pets, residents who have a concern about fogging may request the fog to not be released in front of their property by emailing the request and their address to This email address is being protected from spambots. You need JavaScript enabled to view it..  ‘

Residents who have a concern about unusually high mosquito population at a specific location are encouraged to contact the Health District.  Sanitarian staff will evaluate and work with residents and local officials to mitigate problematic locations.

For more information contact the CCCHD at 937-390-5600 or go to our website at