HomeMy WebLinkAboutMemo - Mail Packet - 09/10/2024 - Memorandum from Ryan Vincent re: West Nile Virus (WNV) – Weekly UpdateNatural Areas Department
1745 Hoffman Mill Road
PO Box 580, Fort Collins, CO 80522
970-416-2493
rvincent@fcgov.com
CC: Dean Klingner, Community Services Director; Mike Calhoon, Parks Director; Katie Donahue, Natural Areas
Director; Matt Parker, Natural Areas Ecological Stewardship Manager
MEMORANDUM
Date: September 4, 2024
To: Mayor and City Councilmembers
Through: Kelly DiMartino, City Manager
Tyler Marr, Deputy City Manager
From: Ryan Vincent, Natural Areas Sr. Supervisor
Subject: West Nile Virus (WNV) – Weekly Update
BOTTOM LINE
• Based on this week’s data, the Larimer County Department of Health and
Environment (LCDHE) does not recommend spraying for adult mosquitos at this
time.
• Data continue to show a much higher than average mosquito infection rate in the
NE quadrant. While the high infection rate is concerning, it is important to remember
that the vector index (VI) is a combination of infection rate and abundance. Thus, despite
an increasing infection rate, the current VI in the NE quadrant decreased slightly from
last week due to low abundance.
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BACKGROUND
Current Vector Index Information
Week 35 of 37 VI Threshold: Previous Week VI: Current VI:
FC – Zone NW NA 0.00 0.00
FC – Zone NE NA 0.32 0.27
FC – Zone SE NA 0.09 0.00
FC – Zone SW NA 0.05 0.00
FC – Citywide NA 0.11 0.06
Floating Zone 0.75 0.49 0.46
• Four traps detected WNV this week (all in the NE quadrant), down from seven last week.
• The 5-trap floating zone with the highest vector index (0.46) was located between
College Avenue and Timberline Road, and between Vine Drive and Drake Road.
• As of Aug. 28, the Colorado Department of Public Health and Environment reported 30
West Nile virus cases, which includes 2 deaths, 13 cases with neurologic symptoms,
and 12 hospitalizations. Larimer County has 3 of these cases.
• Citywide public outreach is ongoing and includes social media posts, utility bill inserts,
and other advertising. Staff center outreach information on the “4Ds”:
✓ Drain standing water.
✓ Dress in long pants and sleeves to deter biting.
✓ Defend with EPA-approved repellant.
✓ Dusk & Dawn – avoid outdoor activities during this high mosquito activity time.
• City staff, Vector Disease Control International (VDCI), and Colorado State University
are implementing WNV prevention measures, including larval treatments, trapping, and
testing.
• VDCI sprayed Willow Springs HOA last week and plans to spray Countryside this week.
NEXT STEPS
Trapping and testing will continue for two weeks with staff presenting weekly memos.
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