HomeMy WebLinkAboutMemo - Mail Packet - 9/13/2022 - Memorandum From Matt Parker And Amy Resseguie Re: West Nile Virus (Wnv) -Larimer County Spray Recommendation1745 Hoffman Mill Road
PO Box 580, Fort Collins, CO 80522-0580
MEMORANDUM
Date: September 7, 2022
To: Mayor and City Councilmembers
From: Matt Parker, Sr. Supervisor, Natural Areas
Amy Resseguie, Lead Specialist, Communications & Public Involvement
Through: Kelly DiMartino, City Manager
Tyler Marr, Interim Deputy City Manager
Seve Ghose, Director, Community Services
Mike Calhoon, Director, Parks
Katie Donahue, Director, Natural Areas
Subject: West Nile virus (WNV) – Larimer County Spray Recommendation
Summary:
The Larimer County Department of Health and Environment is recommending a fourth mosquito
treatment application. The recommended treatment area is south of Harmony Road, between
College Avenue and I-25, extending south to Trilby Road and the area north of Fossil Creek
Reservoir (map attached). The vector index value for this area is 0.78.
Based on the recommendation, a treatment will take place on Sunday, September 11 and
Wednesday, September 14.
Current Vector Index:
Week No: 35 Vector Index
Threshold:
Previous Week Vector
Index:
Current Vector
Index:
FC – Zone NW NA 0.18 0.09
FC – Zone NE NA 0.69 0.34
FC – Zone SE NA 0.28 0.70
FC – Zone SW NA 0.55 0.55
FC – Citywide NA 0.47 0.34
Floating Zone 0.75 0.94 0.78
City of Fort Collins
Current Conditions: Eighteen trap locations tested positive across the city; however, six positive
traps were in the area sprayed during the most recent application and therefore the data was
not considered in the current calculation of vector index values. While citywide, infection rates
are slightly below historic average for this time of year, the southeast quadrant shows infection
rates near historic average, and abundance values are 3 times the historic values.
Overnight low temperatures, which drive mosquito reproduction downward this time of year, are
remaining much higher than normal, with some recent nights as high as ten degrees higher than
historic averages. Even though predicted low temperatures are dropping in the next week it will
not effectively reduce the mosquito population to prevent human contraction of WNV.
Process for Spray Recommendations: Current WNV conditions exceed the policy thresholds
identified for adult mosquito spraying applications. When the City’s trapping network shows
WNV activity beyond the threshold of 0.75, the LCDHE makes a recommendation that the City
conduct an application to treat adult mosquitoes. When an application is recommended, areas
of concern will be identified based on data from a minimum of 5 traps. Identified treatment areas
may be sub-zone or may cross zone boundaries.
Outreach and Public Awareness:
With this recent recommendation from the County Health Department, additional communication
will take place, including phone, email and text notifications sent to those who have signed up to
receive such notices. Spray notifications and other outreach materials are shared in both
English and Spanish.
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