HomeMy WebLinkAboutMemo - Mail Packet - 8/25/2020 - Memorandum From Matt Parker, Amy Resseguie, Tyler Marr Re: West Nile Virus Update
City Manager’s Office
PO Box 580
300 LaPorte Ave.
Fort Collins, CO 80522
970.221.6505
970.224.6107 - fax
fcgov.com
MEMORANDUM
Date: August 19, 2020
To: Mayor and City Councilmembers
From: Matt Parker, Supervisor, Natural Areas
Amy Resseguie, Sr. Specialist, Communications
Tyler Marr, Interim Director, Information & Employee Services
Through: Darin Atteberry, City Manager
Kelly DiMartino, Deputy City Manager
John Stokes, Interim Director, Community Services
Mike Calhoon, Director, Parks
Zoe Shark, Interim Director, Natural Areas
Mark Sears, Manager, Natural Areas
Re: West Nile virus (WNV) Update
Summary:
This week’s data shows WNV activity amplifying in the southeastern section of the City. Six
traps tested positive: four in the southeast quadrant, one each in the southwest and northeast
quadrants. Although the season has been quiet, the general trend (abundance, infection rate,
and VI) is still increasing – historically, these measures are decreasing at this time. WNV
management actions are in full swing with larval treatments, trapping, and testing; and public
outreach efforts are currently focused on methods with the highest visibility and impact.
Current Vector Index:
Week No: 33 Vector Index
Threshold:
Previous Week
Vector Index:
Current Vector
Index:
FC – Zone NW NA 0.00 0.00
FC – Zone NE NA 0.00 0.04
FC – Zone SE NA 0.02 0.29
FC – Zone SW NA 0.20 0.11
FC – Citywide NA 0.05 0.16
Floating Zone 0.75 0.26 0.53
Current Conditions: A seven-trap area bounded by Drake Road, Ziegler Road, Harmony Road, and
College Avenue shows a vector index value of 0.53. This is the highest floating zone value this
year.
The SE quadrant of the city remains the focal point of viral activity. Compared to previous years’ data
the timing of WNV presence is generally extending later in the season. Last year’s treatment occurred
on September 8. This is likely influenced by changing climate conditions including overnight low
DocuSign Envelope ID: 92B75A12-8A02-48D0-9581-8A9378EF831F
temperatures lingering at higher values later in the year. Overnight low temperatures are the driving
factor in the seasonal decline of mosquito abundance. Until the overnight lows consistently reach the
low 50s, the rising abundance, infection rate, and thus the vector index may continue to rise against the
historic trend, as indicated in the included chart showing the vector index in the SE quadrant.
Process for Spray Recommendations: If the vector index exceeds 0.75, the Larimer County Health
Department typically makes a treatment recommendation to the City; areas of concern will be identified
based on data from a minimum of five traps. Identified treatment areas may be sub-zone or may cross
zone boundaries.
Outreach and Public Awareness:
Digital, print and radio advertising; street banners; bus bench ads; and social media content are
currently running and will continue through the rest of August. In the event of a localized spike in the
vector index value, door hangers will also be distributed. Outreach materials and messaging are shared
in both English and Spanish.
Outreach information is centered on “4Ds” messaging, which encourages people to Drain standing
water, Dress in long pants and sleeves to deter biting, Defend with EPA-approved repellant, and avoid
the high mosquito activity time between Dusk & Dawn. Please see example below.
DocuSign Envelope ID: 92B75A12-8A02-48D0-9581-8A9378EF831F