HomeMy WebLinkAboutCORRESPONDENCE - PURCHASE ORDER - 9142923Cola
University
Sponsored Programs
Fort Collins, CO 80523-2002
Phone: (970) 491-6355
Fax: (970)491-6147
Proposal Transmittal Information
Date: May 13, 2014
To: Mike Calhoon
City of Fort Collins — Parks Department
Parks Supervisor
413 S. Bryan Avenue
Fort Collins, CO 80521
Via E-Mail: MCalhoon@fcgov.com
Colorado State University submits an original proposal entitled "City of Mosquito Pools for West
Nile Virus, City of Fort Collins 2014." Dr. Lars Eisen is CSU's Principal Investigator.
The Research Administrators assigned to this project are:
Linda Monum
Senior Research Administrator
Sponsored Programs, CSU
Fort Collins CO 80523-2002
Phone (970) 491-0974
Fax (970) 491-6147
linda.monumgcolostate.edu
Tracey Castaneda
Research Administrator
Sponsored Programs, CSU
Fort Collins CO 80523-2002
Phone: (970) 491-1560
Fax: (970) 491-6147
tracey.castaneda@colostate.edu
Please direct questions, correspondence or award documents to the above individual.
Thank you.
Enc: proposal
Melissa Walker
From: Annetta Maestas
Sent: Friday, May 16, 2014 6:46 AM
To: Melissa Walker
Subject: FW: CSU Mosquito Testing Contract 1
Attachments: FtC_WNV_testing_2014 proposal -FINAL -PASS 119718.doe
Good Morning Missy, v'
Please enter a requisition for the amount below. Ifyou have any questions let me know.
Annetta /l9oeseas " .9-�7'�
Accoants Payable Rep MATERIALS AND/OR
cley oFFort Ca//i7s USc SERVICES RECEIVED
700 woad, se. O K T PAY
Fart ccams, co e0521
P7/ 970- 5176 2256
FAX 970-221-6619
From: Mike Calhoon
Sent: Thursday, May 15, 2014 4:02 PM
To: Annetta Maestas
CC: Dawna Gorkowski; Jill Wilson
Subject: CSU Mosquito Testing Contract
Annetta,
Here is the info for the mosquito testing contract with CSU. Will you please put in a req. for $10,000 to CSU and I'll have
Jill Wilson convert into a PO. We will initiate a req. on our end to cover the balance.
Please let me know if there is anything else you need to accomplish this.
Thanks,
Mike
Mike Calhoon
City of Fort Collins -Parks Department
Parks Supervisor
413 S. Bryan Ave.
Fort Collins, Co
80521
(970)416-2079-0
(970)567-7273-C
(970)221-6849-F
1
Project Proposal (PASS #119718)
Testing of Mosquito Pools for West Nile Virus, City of Fort Collins, 2014
BACKGROUND
West Nile virus (WNV) first appeared in Colorado in 2002. Since that time Colorado, particularly the
northern Front Range counties (Larimer, Weld, Boulder), have seen WNV disease cases in humans in
every year. Case data for Fort Collins are not available, but it is reasonable to assume that a significant
proportion of Latimer County cases occurred in Fort Collins (FC) or Loveland (LV) residents. In
Larimer County, the annual number of cases reported has ranged from a high of 546 in 2003 to a low of
a single case in 2011, with a total of 859 cases to date (Table 1). This represents 17% of the total cases
reported in Colorado. In 2013, Larimer County reported 29% of all cases reported from Colorado.
Table 1. Reported west Nile virus infections in humans, 2003-2013, Larimer County and statewide, including severe
(neuroinvasive) and fatal case numbers. Data from Colorado Dept. of Health and Environment, as of 04/2512014 (available
on the Internet at: htto://www.colorado.pov/cs/Satellite/CDPHE-DCEED/CBON/125160776637).
Larimer Coun
Colorado
% of state
Year
County
cases
Neuro-
invasivel
cases
Fatalities
State
cases
Neuro-
invasive
cases
Fatalities
cases reported
by Larimer
County
2002
0
0
0
13
0
0
0.0
2003
546
64
10
2,947
622
66
18.5
2004
17
1
0
291
41
4
5.8
2005
13
2
0
106
1 21
2
12.3
2006
42
7
1
345
65
7
12.2
2007
94
4
0
578
100
7
16.3
2008
13
3
1
71
17
1
18.3
2009
25
10
0
103
35
3
24.3
2010
13
3
0
81
26
4
16.0
2011
1
0
0
7
2
0
1 14.3
2012
8
3
0
131
62
5
6.1
2013
89
17
1
320
90
7
29.0
Total
859
1 106
13
4,973
1,081
106
17.3
Includes encephalitis, meningitis, and flaccid paralysis.
FC responded to the emergence of WNV in 2003 by establishing a surveillance and control program.
The surveillance involves extensive monitoring of potential larval mosquito habitats and weekly
collection and testing of adult Culex mosquitoes for WNV. Primary components of the control portion of
the program are source reduction, larviciding and public education. Adulticiding is reserved as an option
to be used under exceptional levels of WNV activity within FC. Data from the adult trapping and testing
program is essential to deciding if, where, and when adulticiding is necessary in FC: adulticiding was
conducted in 2003, 2007, in restricted zones in 2012, and city-wide in 2013.
From 2003-2008 CDC provided WNV testing of FC mosquito pools at no charge. That service was no
longer available beginning in 2009. Colorado State University (CSU) had been conducting studies of
WNV along the Front Range, including virus testing. Thus, CSU could provide the testing service
previously offered by the CDC at a competitive cost, and has done so successfully from 2009-2013.
Resources available at CSU include trained staff and students, laboratory space in the Infectious
Diseases Annex (IDA), equipment and reagents to perform RT-PCR detection of WNV, and standard
laboratory equipment such as microscopes, freezers, incubators, etc.
PROJECT PROPOSAL
A. Period of contract
The period of this contract shall extend from June I to September 30, 2014. The laboratory testing
component of the project will take place from June 1 to August 31. Funding will continue until September
30 to permit data analyses and preparation of the final project report.
B. Scope of work
1. Work plan
a. Mosquito traps are operated weekly by City's contractor.
b. Mosquitoes are identified by contractor staff and Culex females (Culex tarsalis and C'ulex spp.) are
placed in pools of up to 50 individuals, separated by collection site and collection date. CSU will provide
the City's contractor with standard vials to store and transport the mosquito pools (this eliminates the
time-consuming task of transferring specimens once they arrive at IDA).
c. Contractor delivers the weekly collection of pools to IDA according to an agreed upon schedule —
typically early Thursday afternoon. Contractor provides lists of collections and pool numbers, and list or
operational/non-operational traps for the week, in MS Excel format via e-mail attachment.
d. IDA staff receives specimens and places in appropriate storage/refrigeration to await processing
e. IDA staff conducts spot checks to identify mislabeling, missing pools, etc., then processes pools and
performs RT-PCR testing
f. IDA staff assembles and interprets PCR results.
g. Weekly test results arc combined with data provided by Contractor (see B.l .c, above) to produce tabular
summaries, including comparison to historic patterns of vector and virus activity (see D, below).
h. Reports are sent to City of Fort Collins and to other organizations as needed.
2. Deliverables
a. Up to 1,000 pools will be tested under the contract.
b. Test results will be provided to City by 5 PM Monday of each testing week. Equivocal test results may
result in delayed reporting, as accuracy is crucial to the surveillance process.
i. Specimens must be received by Thursday at 2 PM for results to be available on Monday of the
following week.
ii. Pools will be processed in order of collection date (earliest collections processed first) unless
otherwise requested by the City's coordinator.
iii. To obtain more rapid test results (e.g., when a sudden increase in virus activity is suspected) pools
can be accepted early in the week for expedited testing.
3. Staffing
a. Co-PIs Ebel and Eisen, with support by Chet Moore as needed, will oversee day-to-day operation of the
project, collate and interpret laboratory data, produce reports, and transmit reports to City of Fort Collins
and other agencies as appropriate.
b. Graduate Research Assistant Fauver will receive mosquito pools from contractor and prepare specimens
according to protocol; perform RT-PCR testing; maintain laboratory notebooks documenting dates and
times, pool numbers, results, and other relevant information; prepare summaries of tests; and deliver
these results to the Co-PIs in a timely fashion.
2
C. Budget
The budget covers West Nile virus testing only. It does not include testing for other potential pathogens
of human or veterinary importance.
Personnel
Salary for Co -PI Lars Eisen; 0.125 month
$1,317
Salary for Co -PI Greg Ebel; 0.125 month
$1,324
Salary for GRA Joseph Fauver; 1.2 month (40% effort for 3 mo)
$2,248
Fringe cost for salaries
$723
TOTAL PERSONNEL COST
$5,612
I Suplies cost for testing 1 pool for WNV = $14*; 1,000 pools thus is $14,000 1 $14,000 j
* See cost breakdown below
Indirect Cost
TOTAL BUDGET
Direct Cost
$19,612
Indirect Cost
$6,139
GRAND TOTAL
$25,751
Breakdown for cost ojtesting I mosquito pool for WNV
Procedure
Kit/Product
Cost Each
(Kit/ba)
n
Cost/
piece
# needed/
specimen
Total Cost
for testing
Homogenization
Ball Bearings
$46.00
100
$0.46
1
$0.46
Homogenization
2mLtubes
$53.00
500
$0.11
1
$0.11.
RNA extraction
Ma Max Viral 96 5x
$1,200.80
480
$2.50
1
$2.50
RNA extraction
Chemicals EtOH, etc
$0.25
RT-PCR
Qiagen One Ste
$527.00
100
$5.27
1
$5.27
RT-PCR
Primers
$0.20
Electro horesis
Various (agarose, etbr)
$0.25
Pipette Tips
Various
$3.00
Gloves
Various
$2.00
Purification
96 KF Plate
$145.88
48
$3.04
0.010416661
$0.03
Purification
Deep well plate
$249.20
50
$4.98
0.010416667
$0.05
Purification
KF tip comb
$491.03
100
$4.91
0.010416667
$9.05
TOTAL
1
$14.17
D. Reporting templates
Based on the need to now report data not only for FC citywide but also separately for each of the four
zones the city has been divided into for the purpose of WNV surveillance and mosquito control, CSU
had to generate a new reporting template. This new reporting template is tailored to provide data
relevant to the Level III and IV entomological triggers (see below) for control measures in the "City of
Fort Collins Program Response Guidelines to Mosquito Borne Arboviral Activity (July 2008 edition)".
Level III
• Vector index > 0.5 and increasing
• Culex mosquito populations increasing and at or above historical average for that time period
• Mosquito infection rates of> 3.0 per thousand (0.3%) and increasing
Level IV
• Vector index > 0.75.
• Culex mosquito population above historical average for that time period
• Sustained mosquito infection rates of> 5.0 per thousand (0.5%)
The new reporting format comprises a set of 6 tables to address the current week (la, 2a, 3a) and
to provide seasonal and historical context (1b, 2b, 3b) (see full table formats on following pages)
• Table la. Vector Index for current week
• Table 1 b. Vector Index for All Culex by week from June -August
• Table 2a. Vector abundance for current week
• Table 2b. Vector abundance for All Culex by week from June -August
• Table 3a. WNV infection rate per 1,000 females for current week
• Table 3b. WNV infection rate per 1,000 females for All Culex by week from June -August
Additionally, the weekly reporting will include the MS Excel spreadsheet completed with WNV
infection data.
4
Table 1a. Vector Index for current week
Mean abundance of
females per traD night'
Estimate for proportion of
females infected with WNV2
Vector Index
Week:
Cx.
pipiens
Cx.
tarsalis
Cx.
pipiens
Cx.
tarsalis
Cx.
I lens'
Cx.
tarsa/is°
All
Culex'
FC —Zone 1
FC — Zone 2
FC — Zone 3
FC — Zone 4
FC —Ci ide
LV
'From Table 2a (CDC light trap catches only).
2Derived from the data presented in Table 3a for estimated infection rate per 1,000 females (CDC light trap and
gravid trap catches combined).
3Vector Index for Cx. pipiens= (Mean abundance of Cx- pipiensfemales per trap night) x (Estimate for proportion
of all Cx. pipiens females infected with WNV).
'Vector Index for Cx. tarsalis= (Mean abundance of Cx. farsalisfemales per trap night) x (Estimate for proportion
of all Cx. tarsalisfemales infected with WNV).
'Vector Index for All Culex = (Vector Index for Cx. pipiens) + (Vector Index for Cx. tarsalis).
Table 1 b. Vector Index for All Culex by week from June -August
'2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
Table 2a. Vector abundance for current week (CDC light trap catches only)
Week:
Total number
females collected
Number
CDC light
trap nights
Mean abundance of females per
CDC li ht trap ni ht
Cx.
pipiens
Cx.
tarsalis
All
Culex
Cx.
i iens'
Cx.
tarsalis'
All
Culex3
FC—Zone 1
FC — Zone 2
FC —Zone 3
FC —Zone 4
FC — Citywide
LV
'Mean abundance of Cx. pipiens females per CDC light trap night = (Total number Cx. pipiensfemales collected) /
(Number CDC light trap nights).
2Mean abundance of Cx. tarsa/is females per CDC light trap night = (Total number Cx. tarsalis females collected) /
(Number CDC light trap nights).
3Mean abundance of All Culexfemales per CDC light trap night = (Total number All Cu/exfemales collected) /
(Number CDC light trap nights).
Table 2b. Vector abundance for All Culex by week from June -August
'2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
Table 3a. WNV infection rate per 1,000 females for current week (CDC light trap and gravid trap
catches combined)
Total number individuals
examined
Total number pools
examined
Total number
WNV-infected pools
Estimate for WNV
rate per 1,000 females'
infection
Week:
Cx.
Pipiens
Cx.
I farsafis
All
Culex
Cx.
i iens
Cx.
tarsafis
All
Culex
Cx.
pipiens
Cx.
tarsafis
All
Culex
Cx.
pipiens
Cx. 1
tarsafis
All
Culex
FC — Zone 1
FC — Zone 2
FC—Zone 3
FC — Zone 4
FC—Citywide_
LV
'Maximum likelihood estimate (MLE) for WNV infection rate per 1,000 females calculated using the CDC;
PooledlnfRate 4.0 plug-in for Excel.
Table 3b. WNV infection rate per 1,000 females for All Culex by week from June -August
�1��Curremt
Historical
2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
E. Reference material
Vector Index
CDC. 2013. West Nile Virus in the United States: Guidelines for Surveillance, Prevention,
and Control. 4th Revision, June 14, 2013.
httv://www.edc.gov/westnile/resources/pdfs/wnvyuidelings pdf
The Vector Index is described on pages 63-66 (Appendix 2) in this document.
VECTORINDEX
To express the arbovirus transmission risk posed by a vector population adequately, information from all three
parameters (vector species presence, vector species density, vector species infection rate) must be considered.
The Vector Index (VI) combines all three of the parameters quantified through standard mosquito surveillance
procedures in a single value. The VI is simply the estimated average number of infected mosquitoes collected
per trap night summed for the key vector species in the area. Summing the VI for the key vector species
incorporates the contribution of more than one species and recognizes the fact that WNV transmission may
involve one or more primary vectors and several accessory or bridge vectors in an area.
The Vector Index is expressed as:
Vector Index = NIP,
igspccic5
Where: N=AverageDensit. (number per trap night for a given species)
P =Es ti ma ted nfecti OrRa to (proportion of the mosquito population WNV positive)
Maximum likelihood estimate for WNV infection rate per 1,000 females
To account for uneven pool sizes (can range from 1-50 mosquitoes), we calculate a maximum likelihood
estimate (MLE) for WNV infection rate per 1,000 females using the CDC PooledInfRate 4.0 plug-in for
Excel.
CDC. 2014. PooledhifRate, version 4.0
http://www.cdc.gov/westnile/resourcei)ages/mosqSurvSoft.htinl
Project Proposal (PASS #119718)
Testing of Mosquito Pools for West Nile Virus, City of Fort Collins, 2014
BACKGROUND
West Nile virus (WNV) first appeared in Colorado in 2002. Since that time Colorado, particularly the
northern Front Range counties (Latimer, Weld, Boulder), have seen WNV disease cases in humans in
every year. Case data for Fort Collins are not available, but it is reasonable to assume that a significant
proportion of Latimer County cases occurred in Fort Collins (FC) or Loveland (LV) residents. In
Larimer County, the annual number of cases reported has ranged from a high of 546 in 2003 to a low of
a single case in 2011, with a total of 859 cases to date (Table 1). This represents 17% of the total cases
reported in Colorado. In 2013, Latimer County reported 29% of all cases reported from Colorado.
Table 1. Reported West Nile virus infections in humans, 2003-2013, Larimer County and statewide, including severe
(neuroinvasive) and fatal case numbers. Data from Colorado Dept. of Health and Environment, as of 04/25/2014 (available
on the Internet at: htti)://www.colorado.pov/cs/Satellite/CDPHE-DCEED/CBON/125160776637).
Larimer County
Colorado
% of state
Year
County
cases
Neuro-
invasive
cases
Fatalities
State
cases
Neuro-
invasive
cases
Fatalities
cases reported
by Larimer
County
2002
0
0
0
13
0
0
0.0
2003
546
64
10
2,947
622
66
18.5
2004
17
1
0
291
41
4
5.8
2005
13
2
0
106
21
2
12.3
2006
42
7
1
345
65
7
12.2
2007
94
4
0
578
1 100
7
16.3
2008
13
3
1
71
17
1
18.3
2009
25
10
0
103
35
3
24.3
2010
13
3
0
81
26
4
16.0
2011
1
0
0
7
2
0
14.3
2012
8
3
0
131
62
5
6.1
2013
89
17
1
320
90
7
29.0
Total
859
106
13
4,973
1,081
106
17.3
Includes encephalitis, meningitis, and flaccid paralysis.
FC responded to the emergence of WNV in 2003 by establishing a surveillance and control program.
The surveillance involves extensive monitoring of potential larval mosquito habitats and weekly
collection and testing of adult Culex mosquitoes for WNV. Primary components of the control portion of
the program are source reduction, larviciding and public education. Adulticiding is reserved as an option
to be used under exceptional levels of WNV activity within FC. Data from the adult trapping and testing
program is essential to deciding if, where, and when adulticiding is necessary in FC: adulticiding was
conducted in 2003, 2007, in restricted zones in 2012, and city-wide in 2013.
From 2003-2008 CDC provided WNV testing of FC mosquito pools at no charge. That service was no
longer available beginning in 2009. Colorado State University (CSU) had been conducting studies of
WNV along the Front Range, including virus testing. Thus, CSU could provide the testing service
previously offered by the CDC at a competitive cost, and has done so successfully from 2009-2013.
Resources available at CSU include trained staff and students, laboratory space in the Infectious
Diseases Annex (IDA), equipment and reagents to perform RT-PCR detection of WNV, and standard
laboratory equipment such as microscopes, freezers, incubators, etc.
PROJECT PROPOSAL
A. Period of contract
The period of this contract shall extend from June l to September 30, 2014. The laboratory testing
component of the project will take place from June I to August 31. Funding will continue until September
30 to permit data analyses and preparation of the final project report.
B. Scope of work
1. Work plan
a. Mosquito traps are operated weekly by City's contractor.
b. Mosquitoes are identified by contractor staff and Culex females (Culex tarsalis and Culex spp.) are
placed in pools of up to 50 individuals, separated by collection site and collection date. CSU will provide
the City's contractor with standard vials to store and transport the mosquito pools (this eliminates the
time-consuming task of transferring specimens once they arrive at IDA).
c. Contractor delivers the weekly collection of pools to IDA according to an agreed upon schedule —
typically early Thursday afternoon. Contractor provides lists of collections and pool numbers, and list of
operational/non-operational traps for the week, in MS Excel format via e-mail attachment.
d. IDA staff receives specimens and places in appropriate storage/refrigeration to await processing
e. IDA staff conducts spot checks to identify mislabeling, missing pools, etc., then processes pools and
performs RT-PCR testing
f. IDA staff assembles and interprets PCR results.
g. Weekly test results are combined with data provided by Contractor (see B.I .c, above) to produce tabular
summaries, including comparison to historic patterns of vector and virus activity (see D, below).
h. Reports are sent to City of Fort Collins and to other organizations as needed.
2. Deliverables
a. Up to 1,000 pools will be tested under the contract.
b. Test results will be provided to City by 5 PM Monday of each testing week. Equivocal test results may
result in delayed reporting, as accuracy is crucial to the surveillance process.
i. Specimens must be received by Thursday at 2 PM for results to be available on Monday of the
following week.
ii. Pools will be processed in order of collection date (earliest collections processed first) unless
otherwise requested by the City's coordinator.
iii. To obtain more rapid test results (e.g., when a sudden increase in virus activity is suspected) pools
can be accepted early in the week for expedited testing.
3. Staffing
a. Co-Pls Ebel and Eisen, with support by Chet Moore as needed, will oversee day-to-day operation of the
project, collate and interpret laboratory data, produce reports, and transmit reports to City of Fort Collins
and other agencies as appropriate.
b. Graduate Research Assistant Fauver will receive mosquito pools from contractor and prepare specimens
according to protocol; perform RT-PCR testing; maintain laboratory notebooks documenting dates and
times, pool numbers, results, and other relevant information; prepare summaries of tests; and deliver
these results to the Co-Pls in a timely fashion.
C. Budget
The budget covers West Nile virus testing only. It does not include testing for other potential pathogens
of human or veterinary importance.
Personnel
Salary for Co -PI Lars Eisen; 0.125 month
$1,317
Salary for Co -PI Greg Ebel; 0.125 month
$1,324
Salary for GRA Joseph Fauver; 1.2 month (40% effort for 3 mo)
$2,248
Fringe cost for salaries
$723
TOTAL PERSONNEL COST
$5,612
Suplies cost for testing 1 pool for WNV = $14*; 1,000 pools thus is $14,000 $14,000
*,See cost breakdown below
I Indirect Cost 1 $6.139 1
TOTAL BUDGET
Direct Cost
$19,612
Indirect Cost
$6,139
GRAND TOTAL
$25,751
Breakdown for cost of testing 1 mosquito pool for WNV
Procedure
Kit/Product
Cost Each
(Kit/bag)
n
Cost/
piece
# needed/
specimen
Total Cost
for testing
Homogenization
Ball Bearings
$46.00
100
$0.46
1
$0.46
Homogenization
2mL tubes
$53.00
500
$0.11
1
$0.11
RNA extraction
Ma Max Viral 96 5x
$1,200.80
480
$2.50
1
$2.50
RNA extraction
Chemicals EtOH, etc)
$0.25
RT-PCR
Qia en One Ste
$527.00
100
$5.27
1
$5.27
RT-PCR
Primers
$0.20
Electro horesis
Various (a arose, etbr)
$0.25
Pipette Tips
Various
$3.00
Gloves
Various
$2.00
Purification
96 KF Plate
$145.88
48
$3.04
0.010416667
$0.03
Purification
Deep well plate
$249.20
50
$4.98
0.010416667
$0.05
Purification
KF tip comb
$491.03
100
$4.91
0.010416667
$0.05
TOTAL
$14.17
D. Reporting templates
Based on the need to now report data not only for FC citywide but also separately for each of the four
zones the city has been divided into for the purpose of WNV surveillance and mosquito control, CSU
had to generate a new reporting template. This new reporting template is tailored to provide data
relevant to the Level III and IV entomological triggers (see below) for control measures in the "City of
Fort Collins Program Response Guidelines to Mosquito Borne Arboviral Activity (July 2008 edition)".
Level III
• Vector index > 0.5 and increasing
• Culex mosquito populations increasing and at or above historical average for that time period
• Mosquito infection rates of > 3.0 per thousand (0.3%) and increasing
Level IV
• Vector index > 0.75.
• Culex mosquito population above historical average for that time period
• Sustained mosquito infection rates of> 5.0 per thousand (0.5%)
The new reporting format comprises a set of 6 tables to address the current week (i a, 2a, 3a) and
to provide seasonal and historical context (1 b, 2b, 3b) (see full table formats on following pages)
• Table la. Vector Index for current week
• Table 1 b. Vector Index for All Culex by week from June -August
• Table 2a. Vector abundance for current week
• Table 2b. Vector abundance for All Culex by week from June -August
• Table 3a. WNV infection rate per 1,000 females for current week
• Table 3b. WNV infection rate per 1,000 females for All Culex by week from June -August
Additionally, the weekly reporting will include the MS Excel spreadsheet completed with WNV
infection data.
El
Table 1a. Vector Index for current week
Mean abundance of
females per trap night'
Estimate for proportion of
females infected with WNV'
Vector Index
Week:
Cx.
pipiens
Cx.
tarsalis
Cx.
pipiens
Cx.
tarsalis
Cx.
pipiens3
Cx,
tarsalis°
All
Culex5
FC - Zone 1
FC - Zone 2
FC - Zone 3
FC - Zone 4
FC - Citywide
LV
'From Table 2a (CDC light trap catches only).
2Derived from the data presented in Table 3a for estimated infection rate per 1,000 females (CDC light trap and
gravid trap catches combined).
3Vector Index for Cx. pipiens= (Mean abundance of Cx. pipiensfemales per trap night) x (Estimate for proportion
of all Cx. pipiens females infected with WNV).
4Vector Index for Cx. tarsalis= (Mean abundance of Cx. tarsalisfemales per trap night) x (Estimate for proportion
of all Cx. tarsalisfemales infected with WNV).
SVector Index for All Culex = (Vector Index for Cx. pipiens) + (Vector Index for Cx. tarsalis).
Table 1 b. Vector Index for All Culex by week from June -August
FC - Zone 1
FC - Zone 2
FC - Zone 3
FC -Zone 4
FC - Citywide
Week
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
LV
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
Table 2a. Vector abundance for current week (CDC light trap catches only)
Week:
Total number
females collected
Number
CDC light.
trap nights
Mean abundance of females per
CDC light trap night
Cx.
pipiens
Cx.
tarsalis
All
Culex
Cx.
pipiensr
Cx.
tarsalis2
All
Culex3
FC - Zone 1
FC - Zone 2
FC - Zone 3
FC - Zone 4
FC - Citywide
LV
Mean abundance of Cx. pipiensfemales per CDC light trap night = (Total number Cx. pipiensfemales collected) /
(Number CDC light trap nights).
2Mean abundance of Cx. tarsalis females per CDC light trap night = (Total number Cx. tarsalis females collected) /
(Number CDC light trap nights).
3Mean abundance of All Culexfemales per CDC light trap night = (Total number All Culexfemales collected) /
(Number CDC light trap nights)
Table 2b. Vector abundance for All Culex by week from June -August
FC -Zone 1
FC - Zone 2
FC - Zone 3
FC -Zone 4
FC - Citywide
Week
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
LV
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
Table 3a. WNV infection rate per 1,000 females for current week (CDC light trap and gravid trap
catches combined)
Total number individuals
examined
Total number pools
examined
Total number
WNV-infected pools
Estimate for WNV infection
rate per 1,000 females'
Week
Cx.
pipiens
Cx.
tarsalis
All
Culex
Cx.
pipiens
Cx.
tarsalis
All
Culex
Cx.
pipiens
Cx.
tarsalis
All
Culex
Cx.
pipiens
Cx.
tarsalis
All
Culex
FC — Zone 1
FC — Zone 2
FC — Zone 3
FC — Zone 4
FC — Citywide
LV
'Maximum likelihood estimate (MLE) for WNV infection rate per 1,000 females calculated using the CDC
PooledlnfRate 4.0 plug-in for Excel.
Table 3b. WNV infection rate per 1,000 females for All Culex by week from June -August
FC — Zone 1
FC — Zone 2
FC — Zone 3
FC — Zone 4
FC — Citywide
Week
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
Current
year
Historical
average'
LV
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
'2006-2013 (2003-2005 were excluded due to changes in trap locations from 2006 onwards).
E. Reference material
Vector Index
CDC. 2013. West Nile Virus in the United States: Guidelines for Surveillance, Prevention,
and Control. 4th Revision, June 14, 2013.
http://www.cdc.vov/westnile/resources/odfs/wnvguidelines.pd
The Vector Index is described on pages 63-66 (Appendix 2) in this document.
VECTORINDEX
To express the arbovirus transmission risk posed by a vector population adequately, information from all three
parameters (vector species presence, vector species density, vector species infection rate) must be considered.
The Vector Index (VI) combines all three of the parameters quantified through standard mosquito surveillance
procedures in a single value. The VI is simply the estimated average number of infected mosquitoes collected
per trap night summed for the key vector species in the area. Summing the VI for the key vector species
incorporates the contribution of more than one species and recognizes the fact that WNV transmission may
involve one or more primary vectors and several accessory or bridge vectors in an area.
The Vector Index is expressed as:
Vector Index = I NrPi
i=species
Where: 'IN =AverageDensib. (number per trap night for a given species)
P=Estimated nfectiorRate(proportion of the mosquito population WNV positive)
Maximum likelihood estimate for WNV infection rate per 1,000 females
To account for uneven pool sizes (can range from 1-50 mosquitoes), we calculate a maximum likelihood
estimate (MLE) for WNV infection rate per 1,000 females using the CDC PooledInfRate 4.0 plug-in for
Excel.
CDC. 2014. PooledlnfRate, version 4.0
http://www.cdc.gov/westnile/resourcepages/mosgSurvSoft.html