From the Center for Disease Control:

 We ask that this message be passed along to your residents..

 

To date, the spring and summer of 2012 have been relatively hot and dry. In 2011 there was moderate to high precipitation, and a mild winter. As such, the two seasons combined have resulted in the perfect storm for stagnant water /container mosquito breeders, such as Culex pipiens, the primary vector for West Nile Virus in Central Ohio. And, in comparing 2012 with 2011 for Columbus, there was a significant (10 fold) and earlier (~1 month) increase in the number of positive pools (a pool = 50 Culex pipiens mosquitoes) by late July of this year. CDC reported that the first four cases of WNV encephalitis reported to them this year occurred earlier than any other year since 2002. 

 

As of early August, approximately 1 out of 6 pools submitted to the State lab from Columbus were positive for WNV. The CDC WNV guidelines state that a 10 in 1000 (1 in a 100) infection rate in mosquitoes is high. Roughly 1 in 80 mosquitoes are infected with WNV this year. This infection rate of WNV in mosquitoes trapped in the City of Columbus is greater than the "high infection rate as stated in the CDC guidelines".

 

Concern is growing nationwide that a higher than normal human infection is likely this year. Texas is already experiencing this, as it has reported 17 deaths to date due to WNV.  This concern has also been expressed by the Ohio Department of Health.  It is essential that Columbus Public Health mosquito control measures are increased
to reduce human exposure, eliminate breeding sites, and kill infected mosquitoes.

 

In light of this widespread distribution and prevalence of WNV positives, there is no place in the City that does not have nearby positives relative to the flight range of Culex pipiens mosquitoes. Additionally, in accordance with the CDC guidelines corresponding to such infection rates, adulticiding efforts will be increased to eliminate infected mosquitoes. 

 

Please Continue to monitor online Spray Maps in the coming weeks for details on additional areas set to be sprayed.  At this time "No-Spray" requests are continuing to be honored.  If there should be any changes, updated information will be posted on the Online Map. 

 

In addition to WNV concerns, it has come to light in the last several weeks that the Clintonville area has a serious Aedes albopictus, or Asian Tiger Mosquito, breeding issue.  CPH field staff have been surveying the area extensively and have found
the likely culprit is RAINBARRELS.  While rain barrels offer many great qualities, they can make the perfect breeding ground for the Asian Tiger mosquito when not properly screened or maintained. These mosquitoes lay their eggs in water-filled natural and artificial containers like old tires, rain barrels, and clogged gutters; they do not lay their eggs in ditches or marshes. The Asian tiger mosquito usually does not fly more than about 1/2 mile from its breeding site. 

 

Tiger Mosquitoes have been found to carry LaCrosse encephalitis viruses and West Nile virus.  The bite of the Asian tiger mosquito is not particularly irritating to
most people, but they are persistent biters. Because they breed in nearly any sort of water-filled container, they often become very common and bothersome, even in neighborhoods where there are normally few mosquitoes.  Based on complaint  numbers, it is clear to the staff at CPH that the Asian tiger mosquito has become one of the most important nuisance mosquitoes in the City of Columbus. 

 

Because the Asian tiger mosquito is active during the day, "fogging" provides little control from these pesky biters, as this method is generally ineffective due to atmospheric conditions during daylight hours. You can, however, greatly reduce the number of tiger mosquitoes in your area by getting rid of breeding places: 
CPH needs help getting the word out to educated residents. 

 

1.  Remove any water-filled containers like old tires, food containers and buckets from your yard.

2 .   Keep mosquitoes from breeding in bird baths, pet water dishes and plastic wading pools by emptying them at least once a week.

3 .    Roof gutters should be kept clean of fallen leaves and other debris so that water does not collect in them.

4 .   Neighborhood residents should work together to eliminate breeding sites
like abandoned cars, old machinery, drums and other junk in vacant lots.

5 .    Report piles of discarded tires or other accumulations of water-holding junk to local health officials.

6 .   Businesses should cover tires, store them indoors or treat them with an
insecticide labeled by the U.S. Environmental Protection Agency for control of
mosquito larvae.

 

How to screen a rain barrel from mosquitos:  http://www.ehow.com/how_7397874_screen-rain-barrel-mosquitoes.html

 

Weekly spraying map of Columbus:

https://maps.google.com/maps/ms?hl=en&ie=UTF8&split=0&gl=us&ei=y9hDSoftF5eqtgeBlqGnAQ&msa=0&msid=115581560833322729686.00044f8d4490543d085a3&ll=39.955017,-82.926178&spn=0.370021,0.582275&z=11

 

 

>

> LUKE K. JACOBS, MPH, RS

> DIVISION OF ENVIROMENTAL HEALTH

> SECTION CHIEF, DISEASE PREVENTION

> 614-645-0266

> lkjacobs@columbus.gov

> _______________________________

>

> COLUMBUS PUBLIC HEALTH

> 240 Parsons Ave, Columbus, OH 43215

> www.publichealth.columbus.gov