HomeMy WebLinkAboutMemo - Mail Packet - 07/30/2024 - 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
MEMORANDUM
Date: July 23, 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
SUMMARY
The City of Fort Collins’ network of 53 traps has detected WNV-positive mosquitoes for the first
time this season. Two positive traps were located in the NE quadrant of the city and one in the
SE quadrant.
WNV activity, measured as a vector index, is well below the City’s policy threshold for which
spraying for adult mosquitos would be recommended. Vector indexes are currently below
average in the northwest and southwest quadrants of the city but increasing in the northeast
and southeast.
The abundance of mosquitos that can carry and spread WNV, Culex tarsalis and pipiens, are
currently below average for this time of the year in all quadrants.
This is the first in a series of weekly memos providing up-to-date information on the level of
WNV found in the community and information about mosquito spraying.
PROCESS FOR SPRAY RECOMMENDATIONS
The Larimer County Department of Health and Environment (LCDHE) will recommend spraying
for adult mosquitos when the vector index from a minimum of five adjacent traps exceeds the
policy threshold of 0.75. City staff will notify Council before any public announcements
concerning adult mosquito treatments are issued. If the LCDHE makes a recommendation to
spray, communication will take place through email and text notifications to those who have
opted in to receive them, as well as broad communication through the City’s various external
communication channels. Community members can sign up for alerts through nocoalert.org.
Docusign Envelope ID: 1EBFEBB6-7F90-4854-A4FE-EB5F0A3DDBE4
CURRENT VECTOR INDEX
The floating zone with the highest current vector index was located between Lemay and I-25,
and between Drake and Mountain Vista in the northeast quadrant of the city.
ADDITIONAL INFORMATION
• Preventative WNV management actions are in full swing with larval treatments, trapping,
and testing.
• Public outreach is underway including social media posts, utility bill inserts, and other
advertising. Outreach information is centered on the “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.
• There have been five human cases of WNV reported in Colorado as of July 22; none in
Larimer County.
• The following HOAs have begun spraying for nuisance mosquitos: Lindenwood, Willow
Springs, Countyside, and Greenstone.
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Week No: 29 Vector Index
Threshold:
Previous Week Vector
Index:
Current Vector
Index:
FC – Zone NW NA 0.00 0.00
FC – Zone NE NA 0.00 0.24
FC – Zone SE NA 0.00 0.07
FC – Zone SW NA 0.00 0.00
FC – Citywide NA 0.00 0.08
Floating Zone 0.75 0.00 0.42
Docusign Envelope ID: 1EBFEBB6-7F90-4854-A4FE-EB5F0A3DDBE4