Mosquito Pool in Lake County Positive for West Nile Virus

The Ohio Department of Health (ODH) has discovered one positive mosquito pool for West Nile Virus (WNV) in Lake County, according to the Lake County General Health District.

A “pool” is a collection of no more than 50 mosquitoes. Although this particular positive pool was collected near the Painesville/Mentor border on June 12, it is likely that positive WNV mosquitoes are present throughout the county, according to LCGHD.

This is confirmation that the WNV threat is present and will likely increase for the rest of the summer. Over the years, it has been common to find a positive WNV mosquito pool during this time of year.

Drought and a high heat index have contributed to a lower local mosquito population this summer compared to last year’s population levels. Despite this, the types of mosquitoes that may be infected with WNV can increase from normal levels, as they are more resistant to drought conditions and more readily spread the virus within the resident bird population, which serves as the host for WNV, according to LCGHD.

Fourteen additional positive Ohio WNV mosquitoes have also been reported in Franklin (10) and Summit (4) counties this season. In 2011, Ohio had 586 WNV positive mosquito pools from 8,436 total pools tested (totaling 290,840 mosquitoes). Twenty-one human WNV cases were reported in Ohio during 2011, including one fatal case and one human WNV case in Lake County in 2011. In 2011, Lake County also experienced a human LaCrosse (LAC) Encephalitis case.

In response to these confirmed positives, the LCGHD, in cooperation with the ODH, will continue surveillance and will continue to find, eliminate, and treat mosquito-breeding sites. Please remember that WNV is constantly present in Lake County and Ohio since 2001 and will continue to be a long-term, public health threat. Do your part to control breeding sites.

Here are some tips for homeowners to reduce the risk of WNV:

• Dispose of tin cans, old tires, buckets, unused plastic swimming pools, plastic covers or other containers that collect and hold water.
• Keep roof gutters unclogged. Clean gutters in the spring and fall.
• Clean and chlorinate swimming pools, outdoor saunas, and hot tubs. Keep them covered when empty.
• Empty and change the water in bird baths, fountains, wading pools, rain barrels, and potted trays at least once a week, if not more often.
• Fill or drain puddles, ditches, and swampy areas and either remove, drain, or fill tree holes and stumps with mortar.
• Contact your local health department with concerns regarding malfunctioning septic systems.
• Get rid of standing water around animal watering troughs.
• Water lawns and gardens carefully to prevent water from standing for several days.
• Avoid being outside at dawn/dusk. If you cannot avoid those times, use an insect repellent.
• Use an insect repellent containing 10% or less DEET (N, N-diethyl-methyl-meta-tolumide) for children – no more than 30% DEET for adults. Use repellents containing DEET according to label instructions.
-Do not use DEET insect repellent on infants or pregnant women.
-Do not allow young children to apply DEET insect repellent themselves. Store out of their reach.
-Apply DEET insect repellent to your hands and then to a child. Do not apply DEET insect repellent directly to a child.
-DEET insect repellent is effective for about four hours. Use small amounts over exposed skin and clothing. Do not use DEET insect repellent for a long period of time.
-Wash treated skin and clothing after returning indoors.

• Wear long sleeved shirts, long pants, and socks if you go outside when mosquitoes are most active (from dusk until dawn).
• Make sure window and door screens are “bug tight”. Repair or replace torn screens.
• Replace outdoor lights with yellow “bug lights”.
• Call the LCGHD if you have a concern about standing water that may be breeding mosquitoes. If it is on private property, permission is needed to enter the property.

Birds act as a reservoir host of WNV, and then mosquitoes become infected by feeding on them. Due to Ohio Department of Health budget cuts, dead birds are no longer being collected and tested for WNV. Residents may report dead bird locations which will be mapped to document potential virus activity.

If any resident has questions concerning mosquito control, WNV, or wishes to report a dead bird location, please call the LCGHD at (440) 350-2543. Additional WNV and mosquito information can be found at:

Ohio Dept. of Health http://www.odh.ohio.gov/odhPrograms/dis/zoonoses/wnv/wnv1.aspx

CDC: http://www.cdc.gov/ncidod/dvbid/westnile/index.htm

LCGHD: http://www.lcghd.org/mosquito

Source: Lake County General Health District, edited by Stefanie A. Toth, editor