HomeMy WebLinkAboutMemo - Mail Packet - 09/17/2024 - 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 10, 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 does not recommend spraying for adult mosquitos at this time.
• Data indicate that WNV infection rates are higher than average in the NW, NE and
SE quadrants for this time of year. However, low mosquito abundance keeps the
vector index below the 0.75 threshold for spraying.
BACKGROUND
Current Vector Index Information
Week 36 of 37 VI Threshold: Previous Week VI: Current VI:
FC – Zone NW NA 0.00 0.06
FC – Zone NE NA 0.27 0.15
FC – Zone SE NA 0.00 0.09
FC – Zone SW NA 0.00 0.00
FC – Citywide NA 0.06 0.09
Floating Zone 0.75 0.46 0.42
Docusign Envelope ID: 957178F6-70E8-4FAD-B712-2377AD8D53A9
BACKGROUND CONTINUED
• Five traps detected WNV this week (2 in SE, 2 in NE, 1 in NW), up from four last week.
• The 5-trap floating zone with the highest vector index (0.42) was located between Lemay
Avenue and Ziegler Road, and between Horsetooth Road and Carpenter Road.
• As of Sept. 5, the Colorado Department of Public Health and Environment reported 41
WNV cases, which includes 2 deaths, 19 cases with neurologic symptoms, and 14
hospitalizations. Larimer County has 3 of these cases.
• Citywide public outreach will continue through the remainder of the testing season on
social media.
• City staff, Vector Disease Control International (VDCI), and Colorado State University
are implementing WNV prevention measures, including larval treatments, trapping, and
testing.
• VDCI provided the August report, available at fcgov.com/westnile/local-data. Key points
include:
o Temperatures were 2-4°F above normal.
o Precipitation is at 58% of the seasonal average (April 1 to Aug. 31).
o There were 1,168 site inspections, with larvicide applied at 446 locations, including
142 storm drains.
NEXT STEPS
Trapping, testing, and weekly memos will continue for one more week.
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Docusign Envelope ID: 957178F6-70E8-4FAD-B712-2377AD8D53A9