WNV in spray and no-spray cities
back to about west nile virus

Rachael Sumner's analysis of cases of WNV in spray and no-spray cities
is awesome. It's the kind of gritty work, HARD work as I know well, that
really moves things along. My hat off to you, Rachael, thanks for the inspiration.

Patty Clary, Director
Californians for Alternatives to Toxics
315 P Street
Eureka, CA 95501
707-445-5100
http://www.alternatives2toxics.org

The information in this booklet is Part II of a report on the same topic we released on June 8, 2004. It includes additional research to support our argument that the West Nile virus disease burden does not warrant spraying. We have included new, more comprehensive statistical data of seven cities that spray compared to seven that don't. No significant difference in West Nile virus cases exists. You will find other documentation and studies listed in the table of contents.

We request that City Leaders, the media, the Health Board and Nashville
citizens apply pressure and demand Health Department officials to
discontinue non-emergency spraying and better establish what constitutes an
emergency with the assistance of experts in the field of entomology. In
addition, before any emergency spraying takes place, we request that the
media, Health Board, City Leaders and Nashville citizens apply pressure and
demand Health Department officials establish:

* better notification policies.
* better and more meaningful monitoring procedures with full disclosure.
* buffer zones, which take drift into account for those who have opted out.
* improved precautions and information regarding adverse effects and what
one should do if those effects are experienced.
Sincerely,

Rachel Sumner
217 Silo Court, Nashville, TN 37221
646-3220, rachelsumner@e...

Representing the opinions of the No Spray Coalition: BURNT/No Spray
Nashville, EarthMatters Tennessee, BioControlNetwork, Nashville Greenlands,
Foundation for Global Sustainability, plus over 500 Davidson County
residents who have signed petitions requesting the Health Department cease
unwarranted insecticide spraying and focus on less costly, safer, more
effective forms of mosquito control.

Our mission statement is also endorsed by these organizations:
Sierra Club, Alliance for Informed
Mosquito Management, Beyond Pesticides, National Center for
Environmental Health Strategies, TN
and Mid-TN Sierra Club
BURNT/No Spray Nashville, www.nospraynashville.org
616-327-8515, P.O. Box 128555, Nashville, TN 37212-2 -

FOURTEEN CITY/COUNTY STATISTICAL COMPARISION
We are looking at the human cases of West Nile virus in areas that spray
versus those that don't spray to see if there is any significant difference
to help determine if the risks and expenses of spraying are worthwhile.
Populations based on 2000 Census. West Nile virus numbers are confirmed cases from state, city, CDC reports and phone calls. Information was often double checked with a 2nd reference.

SPRAY

1.) Spray=Dallas, Dallas County, TX, population 2,218,899 Human Cases Total
per 100K
WNV 2002 25 1.23
WNV 2003 51 2.3

2.) Spray=Nashville, Davidson County, TN, population 569,891 Human Cases
Total per 100K
WNV 2002 1 0.17
WNV 2003 1 0.17

3.) Spray=Memphis, Shelby County, TN, population 897,472.
In 2002, 71% of the state's West Nile virus cases were in Shelby County
many were in a small area in downtown (this info by Ms. Kristy Gottfried).
87.5% of the cases were in Western Tennessee.
Human Cases Total per 100K
WNV 2002 40 4.46
WNV 2003 10 1.11

4.) Spray?ltimore County, MD, population 754,292 Human Cases Total per 100K
WNV 2002 1 0.13
WNV 2003 16 2.12

5.) Spray=Savannah, Chatham County, GA, population 232,048 Human Cases
Total per 100K
WNV 2002 0 0
WNV 2003 9 3.88

6.) Spray=Columbus, Franklin County, OH, population 1,068,978 Human Cases
Total per 100K
WNV 2002 9 0.84
WNV 2003 4 0.37

7.) Spray=Baltimore City, MD, population 651,154 In 2004, Baltimore City
made the decision to discontinue spraying for mosquitoes.
Human Cases Total per 100K
WNV 2002 5 0.77
WNV 2003 11 1.69

AVERAGE West Nile Cases per 100K=1.37

NO SPRAY

1.) No Spray City=Ft. Worth, Tarrant County, TX, population 1,446,219
Human Cases Total per 100K
WNV 2002 5 0.35
WNV 2003 22 1.52

2. No Spray=Williamson County, TN, population 126,638
Human Cases Total per 100K
WNV 2002 0 0
WNV 2003 1 0.79

3.) No Spray=Rutherford, County, TN, population 182,023
Human Cases Total per 100K
WNV 2002 1 0.54
WNV 2003 1 0.54

4.) No Spray=Sebastian County, AR, population 115,071
Human Cases Total per 100K
WNV 2002 1 0.87
WNV 2003 0 0

5.) No Spray=Montgomery County, MD, population 873,341
Human Cases Total per 100K
WNV 2002 7 0.8
WNV 2003 9 1.03

6.) No Spray=Washington, DC, population 572,059
When I called said, "Spraying does trigger asthma attacks and can trigger
allergy attacks."
Human Cases Total per 100K
WNV 2002 34 5.94
WNV 2003 3 0.52

7.) No Spray=DeKalb County, GA population 665,865
Human Cases Total per 100K
WNV 2002 4 0.6
WNV 2003 1 0.15

AVERAGE West Nile Cases per 100K=0.97

CONCLUSION: The statistics show that there is no significant difference in
the cases of West Nile virus in cities/counties that spray compared to
those that don't spray. Therefore, the risks and the costs of spraying do
not outweigh the benefits. There are no significant benefits for cities
that spray. For the analysis, I first wanted to make sure that the years
within each treatment were not influencing the data. For example, if in
2002 there were more WNV cases for spraying this would pick it up. Which
was good that we see that year (trt), read year within treatment, is not
significant. We do have to consider year a source of variation and we can
average over the two years.

NOTE: This test controls the Type I comparison wise error rate, not the
experiment wise error rate.
Alpha 0.05
Error Degrees of Freedom 26
Error Mean Square 2.081773
Critical Value of t 2.05553
Least Significant Difference 1.121
Means with the same letter are not significantly different.
t Grouping Mean N trt
A 1.3743 14 1
A
A 0.9750 14 2
The GLM Procedure
Dependent Variable: confirmed WNV cases
Contrast DF Contrast SS Mean Square F Value Pr > F
Spray vs No Spray 1 1.11600357 1.11600357 0.54 0.4706
I then ran the program again and included a contrast statement to compare
the two treatments.
THE RESULTS: The difference in West Nile Virus cases for the two treatments (Spray vs. No Spray) are statistically insignificant, which is what we got on the previous page as well.

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