Clark County Mosquito Trapping Reveals Widespread West Nile Virus in the Area

Clark County Mosquito Trapping Reveals Widespread West Nile Virus in the Area

Clark County Combined Health District                                     Charles Patterson, Health Commissioner

529 E. Home Road

Springfield, Ohio 45503

                                                                                                            For Immediate Release

                                                                                                            August 10, 2021


Public Information Office

Nate Smith

937-390-5600 ext. 283

Clark County, Ohio – Nearly a dozen more mosquito samples collected by the Clark County Combined Health District (CCCHD) have tested positive for West Nile Virus (WNV), which is now believed to be widespread throughout the area.
A total of 10 positive samples were collected from areas all over the city of Springfield, and CCCHD advises residents to assume the presence of West Nile Virus in their area and to take steps now to eradicate mosquito habitats along their properties.
The most recent samples add to a growing list of WNV-positive mosquitos that have been identified in Clark County in the last two weeks.
Previously reported mosquito samples positive for WNV were taken from the North Hampton and Catawba areas, as well as the northeast side of Springfield. Mosquitos trapped throughout the county are submitted to the Ohio Department of Health (ODH) as part of our Vector-Borne Disease Program.
The best way to avoid the West Nile Virus infection is to prevent mosquito bites, and the best way to avoid being bitten by a mosquito is to eliminate habits where mosquitos can survive and reproduce.

CCCHD recommends a three-part strategy to combat mosquitos: AVOIDPLANSTOP:


  • Apply repellents on exposed skin registered with the U.S. Environmental Protection Agency (EPA.) 
  • Wear long sleeves and pants or consider staying indoors as much as possible. 


  • If traveling, check ahead of time for travel advisories, and plan accordingly. 
  • Have EPA approved mosquito repellent and longs pants and shirts available to avoid bites.
  • Do outside activities at times when mosquito activity is less.


  • Get rid of mosquito breeding sites by emptying or treating any standing water on your property (even small amounts of standing water can be a breeding site for mosquitos.)  
  • Make sure screens on windows and doors are free of holes or rips. You may also opt to utilize air conditioning instead of open windows if possible.

Residents’ cooperation in getting rid of standing water is the most effective means of reducing the total number of mosquitos and far more effective that spraying. 

In response to the confirmed presence of West Nile Virus, CCCHD is: 

  • Inspecting the affected area and working with property owners to reduce breeding sources by draining stagnant water or treating stagnant water with products containing Bacillus thuringiensis israelensis (Bti.) Bti is safe for humans and pets and only affects the mosquito larvae. 
  • Distributing informational flyers in the affected area.
  • Misting the affected area with Duet® to reduce the adult mosquito population when weather permits. While safe for humans and pets, residents who have a concern about misting may opt out by calling 937-390-5600 or emailing the request and their address to
  • Continuing to monitor the area for West Nile Virus.

West Nile Virus is most commonly spread by infected mosquitoes and 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 develop symptoms usually do so between three to 14 days after they are bitten by the infected mosquito. There is no specific treatment for WNV infection, and care is based on symptoms.

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.

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 or up to several weeks. 

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