HomeMy WebLinkAboutMemo - Read Before Packet - 8/15/2023 - Memorandum From Matt Parker And Amy Resseguie Re: West Nile Virus (Wnv) – Recommended Adult Mosquito Treatment 1745 Hoffman Mill Road
PO Box 580, Fort Collins, CO 80522-0580
MEMORANDUM
Date: August 15, 2023
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, Deputy City Manager
Dean Klingner, Director, Community Services
Mike Calhoon, Director, Parks
Subject: West Nile virus (WNV) – Recommended Adult Mosquito Treatment
Summary:
The Larimer County Department of Health and Environment is recommending the City of
Fort Collins spray for mosquitoes in an area north of Drake Road on Sunday, August 20.
The recommended spray area carries a vector index of 0.82, exceeding the policy threshold of
0.75, and conforms with the City’s policies for mosquito spraying.
Current Vector Index:
Week No: 32 Vector Index
Threshold:
Previous Week Vector
Index:
Current Vector
Index:
FC – Zone NW NA 0.64 0.53
FC – Zone NE NA 0.10 0.42
FC – Zone SE NA 1.34 0.43
FC – Zone SW NA 0.31 0.27
FC – Citywide NA 0.70 0.45
Floating Zone 0.75 1.34 0.82
Current Conditions: This week is approximately the half-way point within the most active WNV
weeks. The WNV season runs between week 24 (June 11) to week 37 (September 10). Five
more data points remain in the 2023 season. This week’s data shows abundance values in line
with historic population numbers for the first time this season. However, the infection rate is
above historic values.
This week’s data indicates 16 WNV-positive traps, down from 21 last week. Throughout this
season, each of the previous spray zones have shown a decrease in abundance and vector
index value after application. The vector index for the most recent spray zone for which data is
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City of Fort Collins
available (the Aug 6 zone west of College Avenue, from Mulberry Avenue to Carpenter Road) is
currently 0.27, down from 1.06 at the time of recommendation.
Process for Spray Recommendations: When the City’s trapping network shows WNV activity
beyond the threshold of 0.75, the Larimer County Department of Health and Environment
(LCDHE) makes a recommendation that the City conduct an application to treat adult
mosquitoes. When an application is recommended, areas of concern are 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:
Phone, email, and text notifications will be issued on Tuesday to all individuals signed up to
receive such notifications through Larimer Emergency Telephone Authority. A press release will
be issued, and information will be shared through social media. Webpage content will be
updated with the latest vector index values and a map of the planned spray area. All key
communications are shared in English and Spanish.
Throughout the West Nile Virus season, general outreach and education 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. Messaging also encourages community members to opt-in
to receive notification about any future spray events.
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DocuSign Envelope ID: 9B88E85C-1E09-4016-B9D5-A6F351413C71
32College AveCurrent Week:Week Ending Date: 8/13/20232023 West Nile Virus - Mean Culex (Female) Abundance per Trap NightCollege AveDrake RoadDrake Road0.020.040.060.080.0100.0120.0140.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NE Quadrant Abundance vs Historic (Red)Current AbundanceHistoric Abundance0.020.040.060.080.0100.0120.0140.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SW Quadrant Abundance vs Historic (Red)Current AbundanceHistoric Abundance0.020.040.060.080.0100.0120.0140.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SE Quadrant Abundance vs Historic (Red)Current Vector AbundanceHistoric Vector Abundance0.020.040.060.080.0100.0120.0140.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NW Quadrant Abundance vs Historic (Red)Current AbundanceHistoric AbundanceDocuSign Envelope ID: 9B88E85C-1E09-4016-B9D5-A6F351413C71
32College AveCurrent Week:Week Ending Date: 8/13/20232023 West Nile Virus Infection Rate per 1,000 (All Culex)College AveDrake RoadDrake Road0.05.010.015.020.025.030.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NE Quadrant Infection Rate vs. Historic (Red)0.05.010.015.020.025.030.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SW Quadrant Infection Rate vs. Historic (Red)0.05.010.015.020.025.030.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SE Quadrant Infection Rate vs. Historic (Red)0.05.010.015.020.025.030.0Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NW Quadrant Infection Rate vs. Historic (Red)DocuSign Envelope ID: 9B88E85C-1E09-4016-B9D5-A6F351413C71
32College AveCurrent Week:Week Ending Date: 8/13/20232023 West Nile Virus Vector IndexCollege AveDrake RoadDrake Road0.000.100.200.300.400.500.600.700.800.901.00Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NW Quadrant Vector Index vs. Historic (Red)Current Vector IndexHistoric Vector Index0.75 Vector Index Threshold0.000.100.200.300.400.500.600.700.800.901.00Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37NE Quadrant Vector Index vs. Historic (Red)Current Vector IndexHistoric Vector Index0.75 Vector Index Threshold0.000.100.200.300.400.500.600.700.800.901.00Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SW Quadrant Vector Index vs. Historic (Red)Current Vector IndexHistoric Vector Index0.75 Vector Index Threshold0.000.100.200.300.400.500.600.700.800.901.00Week24Week25Week26Week27Week28Week29Week30Week31Week32Week33Week34Week35Week36Week37SE Quadrant Vector Index vs. Historic (Red)Current Vector IndexHistoric Vector Index0.75 Vector Index ThresholdDocuSign Envelope ID: 9B88E85C-1E09-4016-B9D5-A6F351413C71