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Friday, May 6, 2016

Ag Corner

Tuesday, July 24, 2007

Local West Nile Virus Threat Statistically Minimal

So far the West Nile Virus (WNV) has been fairly quiet on the news front this year. With the dry summer mosquitoes have been minimal but recent rains can change numbers quickly. Wet weather patterns for a short period of time can spur breeding populations since 5-10 days is a complete life cycle for this pest. Also local areas with ideal mosquito habit (like old tires with water, standing water, etc.) may have high mosquito numbers despite times when current weather patterns would not encourage high populations.

It is important to remember that WNV statistically is estimated to only infect one percent of all mosquitoes while secondly only one to two percent of people who are infected with a WNV mosquito bite will experience a serious illness.

A Purdue website http://www2.agriculture.purdue.edu/agcom... with links to the Center for Disease Control and the Indiana State Board of Heath is a good place to go for tracking weekly progression of WNV cases. As of July 17, Indiana had no reports of human WNV while a total of two Indiana counties (Marion and Vanderburgh) had WNV reports, 18 and 1 respectively, in mosquitoes. Furthermore no animal reports had occurred in Indiana. This is down significantly from previous years at this time of year. Kentucky and Michigan reported no infections though the virus was found in blood collected from blood donors.  Illinois reported two human cases while Ohio had reported infections in birds and mammals other than humans with no human infections. Although the risk to the general population is minute, it is important for elderly, young infants/children and those with compromised immune systems to realize that they are at highest risk within the general population.

Although this discussion is devoted to WNV, this pest is also responsible for heartworm in dogs, both human and equine encephalitis, and La Crosse fever.

Transmission of WNV occurs from mosquito bites of infected mosquitoes. Since only female mosquitoes bite, they are the only transmitters of WNV. Certain bird species, especially crows, blue jays, cardinals, robins, falcons and hawks are most likely species for WNV.

If dead for no more than four to six hours, birds can be tested for WNV. Visit http://www.in.gov/isdh/healthinfo/westni... to see a picture directory and information regarding birds that carry the virus. Additional WNV info can be found on this Indiana State Board of Health webpage regarding handling and testing of suspect WNV birds. Once the mosquito has bitten an infected bird, it carries the virus to horses or people when biting those species for blood meals. WNV cannot be transmitted from person to person, person to horse, or vice-versa. Also people are the end of the line for the virus meaning that mosquitoes cannot obtain the virus from a person and carry it to another person or animal. There are 50 different species of mosquitoes in Indiana. Some species feed primarily on birds whereas others feed on both mammals and birds. Here in Clay and Owen counties both types of species exist.

Prevention by ridding standing water in debris, gutters, etc. is the best course of action. Briquettes of insecticide "Bacillus thuringiensis" (also known as Bt) can be used to treat up to 100 square feet of water regardless of depth for up to 30 days. As with any pesticide, always read and follow the label directions. Another information resource for mosquito control products are the local Health Department at 829-5017 in Owen County or 448-9021 in Clay County. Also check out Purdue publication E-240 entitled "West Nile Virus in Indiana" available at the Extension website for Owen or Clay County at www.ces.purdue.edu/counties.htm and click on either Owen or Clay County on the map and go to the link for ag or ANR news columns to find this article and its references.

You can contact the local Purdue Extension Office by calling 829-5020 x14 in Owen County or 448-9041 in Clay County for more information or publication copies regarding this week's column topic or to RSVP for upcoming events. It is always best to call first to assure items are ready when you arrive and to RSVP for programs. While most publications are free, some do have a fee. All times listed are Eastern Time.

Upcoming Events

July 24 Start Your Own Business Workshop, Spencer, 6 p.m.

August 2-5 National Trappers Association Convention, Goshen

August 23 Poison Prevention Workshop, Methodist Hospital, 12:30 p.m.

September 5 Farm Bureau Drainage School, Indy, 9 a.m.

September 18 Riverwatch Training, Bloomington

September 19 Poison Prevention Workshop, Methodist Hospital, 12:30 p.m.

September 27-29 State Master Gardener Conference, Evansville