HomeMy WebLinkAboutMemo - Mail Packet - 9/7/2021 - Memorandum From Matt Parker, Amy Resseguie And Tyler Marr Re: West Nile Virus (Wnv) Weekly Update- Post Second Treatment 1745 Hoffman Mill Road
PO Box 580, Fort Collins, CO 80522-0580
MEMORANDUM
Date: September 2, 2021
To: Mayor and City Councilmembers
From: Matt Parker, Sr. Supervisor, Natural Areas
Amy Resseguie, Sr. Specialist, Communications & Public Involvement
Tyler Marr, Assistant City Manager
Through: Kelly DiMartino, Interim City Manager
Seve Ghose, Director, Community Services
Mike Calhoon, Director, Parks
Zoe Shark, Interim Director, Natural Areas
Subject: West Nile virus (WNV) Weekly Update Post Second Treatment
Summary:
A second WNV Adult mosquito application was cancelled due to weather on Wednesday,
September 1. The application was planned to mitigate WNV risk in a 7-trap area in the northeast
portion of the city. The area north of Mulberry Avenue, extending to Douglas Road, and from
College Avenue to the east of I-25 presented a vector index value of 1.24 (week 33 data),
exceeding the 0.75 threshold for adult mosquito treatments. Assessment of conditions will
resume with the next data point anticipated on Friday, September 4.
The Culex spp. mosquito infection rate remains higher than the historic average in all quadrants
of the city.
Current Vector Index:
Week No: 34 Vector Index
Threshold:
Previous Week Vector
Index:
Current Vector
Index:
FC Zone NW NA 0.09 0.05
FC Zone NE NA 0.84 0.66
FC Zone SE NA 0.08 0.14
FC Zone SW NA 0.16 0.05
FC Citywide NA 0.26 0.28
Floating Zone 0.75 1.24 0.5
Current Conditions: Culex mosquito abundance is generally declining, although as is typical for
this time of the season, the infection rate within those mosquitos continues to climb. The
infection rate remains above historic averages for all quadrants of the city. Overnight low
temperatures in the low 50s and high 40s are required to slow the reproductive cycle of
City of Fort Collins
mosquitoes, bringing the high threat WNV season to an end. Such temperatures do not yet
show up in the extended forecast.
Spray operations were originally scheduled for the evening of Thursday, August 26; however,
high winds presented conditions outside the label requirements and therefore operations were
postponed.
This most recent set of data shows the first treatment of the season (the SE area of the city,
conducted on August 12 and August 15) continues to suppress the amplification of WNV. The
vector index in the previous treatment area has moved from 0.76 (week 32) to 0.04 (week 33),
to 0.40 (week 34).
Outreach and Public Awareness:
Communication regarding the August 29 and September 1 spray application included news
releases, webpage updates, social media posts, a hotline recording, and phone/email/text alerts
sent through the NoCo Alert (LETA911) system to those people who have subscribed to
receive such alerts. The information shared included details about the spray application timing
and location, as well as general instructions for community members in those areas. Outreach
materials and messaging is shared in both English and Spanish.
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