HomeMy WebLinkAboutWest Nile Virus : CITY OF PALM DESERT
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REQUEST: Informational Item West Nile Virus
SUBMITTED BY: Gary Rosenblum, Risk Manager
DATE: October 23, 2003
CONTENTS: West Nile Virus Task Force
The appearance of the West Nile Virus (WNV) in the Coachella Valley has generated a
coordinated response between County and local officials to maximize public health
protection. This response is composed of several interconnected activities, some of
which are already being conducted by the City of Palm Desert. This report summarizes
these activities.
Coachella Valley Mosquito and Vector Control District (CVMVCD):
CVMVCD is in an active partnership with the Riverside County WNV Task Force. The
State and County agencies that are part of the WNV Task Force are listed on
Attachment 1. The CVMVCD operates an early warning program that includes trapping
and testing of mosquitoes in numerous locations every 14 days to determine the mix of
mosquito species present, and the presence of disease-causing viruses. For the WNV,
several small flocks of "sentinel chickens" are maintained in areas of potential infection,
and also tested every 14 days for presence of WNV.
CVMVCD also has an active field mosquito abatement program that consists of
identifying mosquito breeding locations and treating them or eliminating them. This is an
ongoing effort. The City of Palm Desert is currently making a significant contribution to
this effort in its jurisdiction as detailed below. This process of locating breeding locations
is tied to a computerized mapping system to provide digital coordination and scheduling
of treatment programs.
Riverside County Department of Public Health (RCDPH):
In the event that the WNV is infecting humans in the Coachella Valley from a local virus
reservoir (as opposed to human WNV infections occurring from exposure to virus
sources outside the Coachella Valley), the RCDPH has established several levels of
triggers for different protocols. The triggers are based on frequency and severity of the
Staff Report
West Nile Virus
October 23, 2003
Page 2 of 3
human WNV infections. In a worst-case trigger, the RCDPH in conjunction with the
WNV Task Force will initiate "aerial fogging" of insecticide in specific "hot spot" locations
where the presence of mosquitoes is concentrated and severe human WNV infections
have occurred.
The "aerial" element of this description does not describe the device used to perform the
fogging, because the protocol is to use ground vehicles such as jeeps. "Aerial" in this
protocol describes the pesticide fogging process, which sprays a mist of pesticide into
the air, in contrast to spraying pesticide into the ground or breeding pools on the
ground.
The Risk Manager has reviewed the toxicology and related information for the
pesticides to be used in this "aerial fogging" (pyrethrin, an extract of the chrysanthemum
plant in a petroleum based carrier), and agrees with the CVMVCD assessment that the
pesticides in this protocol are low in toxicity for the conditions of expected use. This
means that for public safety, basic warnings for simple protections should manage the
risks. It will still be important to actively address the public's concerns through
information awareness programs. The CVMVCD is prepared to assist all Coachella
Valley cities this public awareness process.
City of Palm Desert
The City is currently providing active ongoing assistance to the CVMVDC by reducing
mosquito-breeding water in various locations around the City. Dry wells providing
roadway water drainage collect irrigation overspray and other runoff, which sometimes
become a mosquito breeding location. The current dry well design is based on
protecting ground water from contamination, and keeping silt and debris from clogging
the drainage system. The City owns and operates a vacuum pump trailer that is used
daily in various locations around the City to remove the water silt and debris that
accumulates in the dry wells. Because this activity also interrupts the mosquito
breeding cycle, CVMVCD has on occasion contacted Public Works to target particular
dry wells when necessary.
The City performs regular maintenance of the San Pascual storm channel. The water in
the channel flows very slowly because the grade is very gradual. Plants grow quickly,
which further disrupts the water flow and provides breeding grounds for mosquitoes.
The City's maintenance work interrupts the mosquito breeding in this location as well.
The City provides secondary surveillance for potential mosquito breeding grounds
through existing code enforcement activities. (Mosquitoes are not the primary focus of
code inspections.) Code enforcement is currently active in identifying and citing yard
debris violations. When code enforcement actions result in cleaned up yards, the
secondary benefit is to reduce potential mosquito breeding sites. Code will report
potential breeding sites such as green algae infested pools to CVMVCD so that they
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Staff Report
West Nile Virus
October 23, 2003
Page 3 of 3
can be treated rapidly. CVMVCD will respond to all reports of stagnant water that Code
and other City inspectors may notice.
In the event the WNV begins to create a significant public health impact and aerial
fogging is triggered, the City is prepared to take several steps to mitigate public
response to the announcement. The City is also prepared to provide information
through local media outlets and City-generated media. The City has already provided
detailed information on WNV to all employees twice in the past year and WNV posters
are up in City lunchrooms. WNV prevention brochures published by CVMVCD are in
stock and are already available to the public at the Civic Center brochure locations.
In the event that pesticide fogging is to occur, the locations, times and duration of the
fogging will be released to the media and the Cities many days ahead of time.
According to the CVMVCD, it is likely that there would be over one week lead time from
initial notification to the actual pesticide application. The City would have ample
opportunity to provide additional information releases and warnings, and perform related
public affairs activities before any pesticide applications were to occur in the City.
Submitted By: Depart ent Hea
Gary Rosenblum Homer Croy
Risk Manager ACM for Develo rr nt Services
Approval:
CITY COUNCIL ACTION:
Carlos L. Ort46.(/,/,› APPROVED DENIED
City Manager RECEIVED E OTHER
MEETIT0C, ATE - 3 AYES:
NOES: `eye
ABSENT:
ABSTAIN: e.
VERIFIED BY:
Original on File with
Cit Cl
-* Item S-3 removed for separate discussi n'S tOhenice
received & filed, noting that a special periodic
inspections should be conducted on the San Pascual
Wash due to the standing water issue there.
4-0 (Ferguson ABSENT)
G:\DevServices\Gary Rosenblum\Word Files\Memos\WestNileCouncil.doc
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ATTACHMENT A
West Nile Virus Task Force
• Riverside County Department of Public Health
• Riverside County Fire Department
• California Department of Forestry and Fire Protection
• Riverside County's Emergency Services Division
• Riverside County Department of Environmental Health
• California Department of Health Services
• Riverside County Agricultural Commissioner
• Riverside County Sheriff's Office
• California Highway Patrol
• Riverside County Animal Control Services
• University of California at Riverside
• California Department of Food and Agriculture Animal Health Program
• State Office of Emergency Services