Mosquito Control
SUMMER 2013
|
ISSUE 2 .
Mosquitoes remind us that we are not as high up
on the food chain as we think.
— TomWilson
Bayou Trap
4
Management:
Battle for Bayou Country
4
Public Health Emergency
8
Features:
West Nile Virus Fatality
6
Genius in a Bottle
3
Mosquito-Driven Death
6
Ground Zero: Virus Outbreak
10
Education:
Tireless Teenagers
2
Tire Cleanups
2
Resistance Multiplies—Fast
7
I Spell Worry:
W - E - S -T N - I - L - E
At the 2013 annual meeting of the American Mosquito
Control Association, I asked attendees about their
industry concerns. Repeatedly, I heard West Nile virus
(WNV). And more than one said that if ever you knew
someone with West Nile virus, you’d take mosquitoborne illnesses more seriously.
In this issue we present the family of Dema Miller, an
82-year-old WNV fatality. Mrs. Miller died last summer
during the Dallas area WNV outbreak, and is terribly
missed by her husband, son and daughter. eir time,
in talking with me, is their gi to help you head off
tragedy. Aer you read their story, on pg. 6, consider
sharing your copy of Mosquito Control Magazine with
someone who would benefit.
We’ve also included other stories about WNV from the
viewpoints of an elected official who declared a state of
emergency over the illness, and mosquito district managers who dealt with the crisis. e more we know about
WNV, the better positioned we will be to explain our
decisions and ask the public for their cooperation.
Rounding out our summer issue are stories about bottle
assays for resistance management, pg. 3, and mosquito
management in the Iberia Parish of Louisiana, pg. 4.
In other news we conducted a survey to find out what
readers thought about our premiere issue and discovered that we have quite a few fans. anks!
Sara May, a technician for the Warren County, N.J., Mosquito Control District, emailed to ask: “Will you be writing articles on lesser known mosquito control agencies?”
Sara, we really appreciate the reminder that mosquito
control districts come in all shapes and sizes. In our fall
issue, we plan to write about small-sized districts—and
we’ll write about them oen in future issues. at’s a
story idea you presented, and we’re going to run with it.
Readers, we invite you to be a “Sara May,” too. Point us
toward a story lead, and we will follow.
Florrie Kohn, Editor
Mosquito Control Magazine
Summer 2013
Number 2
Readers are encouraged to reprint articles.
Please credit Mosquito Control Magazine.
Mosquito Control Magazine is available
at no charge to qualified subscribers.
To submit story suggestions, comments or
address corrections, contact
[email protected].
An Itch to Improve
Teens plow through mud, filth and a lot of “yuck” to collect truckloads of abandoned tires from around
Union, Missouri. The cleanup clears out a vast wasteland of mosquito habitat.
Photo: Danielle Blair
Cleanups Reduce Habitat
Fewer mosquitoes are lurking about
this summer thanks to a group of
teenagers who gave up part of a
spring weekend to reduce scrap tires
around Union, Mo. The students of the
local Union High School FFA chapter
provided the tire-moving muscle for a
community scrap tire collection—and
raked in about 10,000 used tires.
Teacher Danielle Blair says, “Our students believe in giving back to the
community, and this provides them an
opportunity to apply the environmental knowledge they learned in classes.”
They also had the experience of working with other local organizations on
this project. The collected tires will be
mixed with coal to help fuel a local
power plant.
This community scrap tire event is
part of a national effort to clean up
unsightly piles of abandoned tires
that litter fields, river streams and vacant lots. Reducing mosquito habitat
is a huge benefit provided by these
programs.
Reducing the amount of water that
collects in tire sidewalls and creates a
habitat for mosquitoes is a monumental challenge that can also pay large
public health dividends. Linn Haramis,
vector control manager for the Illinois
Department of Health, uses the example of the Eastern Tree Hole mosquito
(Ochlerotatus triseriatus), which
breeds in water-filled containers and
is a primary vector for La Crosse
encephalitis.
“Near Peoria, Illinois, people used scrap
tires to fill in ravines. The scrap tires
filled with rain water and magnified
the amount of habitat available. At the
same time the numbers of confirmed
La Crosse encephalitis cases went up
in that area,” explains Haramis. He notes
that once the tires were removed, the
number of encephalitis cases in the
area dropped.
Haramis describes scrap tires as both
a solid waste problem and a public
health problem, because of the variety
of diseases mosquitoes can spread.
Twenty years ago, huge stockpiles
of scrap tires were common. Public
tolerance changed after a few massive
tire fires. Many states have implemented programs to reduce stockpiles and find new uses for old tires.
However, experts estimate that each
American, on average, generates one
scrap tire per year—and that tire has
to go somewhere.
e editor may be reached at 314-520-5105.
Mosquito Control Magazine is published four times
yearly by Sybil Jones + Company for Cheminova, Inc.
Information on scrap tire programs by state is available on the EPA website
http://www.epa.gov/osw/conserve/materials/tires/live.htm
Cover Photos: Bayou Trap, Stacy Melton; West Nile Virus Fatality, Debby Steadman; Tireless Teenagers, Danielle Blair.
©2013 Cheminova. Fyfanon (malathion) is a registered trademark of Cheminova, Inc.
SCIENCE
Genius in a Bottle
Simple Bioassay Warns Early of Resistance
Mosquito control officials are measuring the effectiveness of insecticides using what might be
described as a do-it-yourself kit for testing.
Researchers and control district technicians use glass
bottles for this testing known as a bottle bioassay.
The bottles are coated on the inside with pesticides
used in the field to control mosquitoes as an early
warning system to detect mosquito tolerance. The
goal is to keep the small number of public health
insecticides working.
Roxanne Connelly, medical entomologist at the University of Florida Institute of Food and Agricultural
Sciences and president of the American Mosquito
Control Association, investigates mosquito tolerance
to insecticides as an indicator that the mosquito population may be developing insecticide resistance.
“Bottle bioassays are a fairly easy inexpensive technique to measure the response an insect has to a
specific dose of insecticide,” says Connelly. The bioassay uses a specific rate of insecticide, which is called
the diagnostic dose. That dose is the amount of the
product that is needed to kill 100 percent of susceptible mosquitoes.
Connelly measures the amount of time required to kill
the mosquitoes while they are exposed to a specific
dose of an insecticide. The results can be compared
to mosquitoes that are known to be susceptible, or
they can be compared to baseline or historical data
that may already be in place. The information can
indicate whether resistance might be a concern in
a given mosquito population.
The most difficult part of the bottle bioassay is getting the mosquitoes inside the bottle, she explains.
A technician uses a mouth aspirator to remove mosquitoes from a collection cage and then blow them
into the test bottle. The trick is to transfer the mosquitoes rapidly enough to prevent their escape.
“There’s an art to that,” Connelly says.
Mosquito control officials compare the effectiveness
of the insecticide on both wild and lab-raised mosquito populations. They also use an acetone-treated
bottle as a control check.
The U.S. Centers for Disease Control and Prevention
medical entomologists William G. Brogdon and
Janet C. McAllister developed the bottle bioassay
about 15 years ago. Today, the bottle bioassay
is used in Florida, Louisiana and several other
mosquito hotspots in the U.S.
With the bottle bioassay, scientists can have answers
in as little as 15–20 minutes as to the effectiveness
of an insecticide. Mosquitoes that die in that timeframe are still susceptible to the insecticide.
Those that survive
give researchers and
mosquito control officials an early warning of
possible resistance.
Much like mosquitoes flying through the air, identifying resistance can be
a moving target. Generally, resistance means one
insecticide isn’t working
on a specific focal mosquito population. Resistance in a bottle doesn’t
necessarily mean resistance in the wild, Connelly
points out.
“Resistance in an operational setting is generally
indicated when you see a great application that doesn’t work in the absence of mechanical or operational
error or environmental conditions that prevent the
product from reaching the target,” Connelly says.
Every Breath She Takes
How quickly a mosquito species develops resistance
to a certain insecticide depends on a number of
factors, including the rate and frequency of use of
an insecticide and the environment.
Photo: Roxanne Connelly, UF/IFAS
Intern Rachel Linley practices the fine art
of aspirating mosquitoes.
For example, in cotton and rice growing areas where
malathion is frequently used, the agricultural applications require a much higher rate than is used for
mosquito control, mosquitoes that inhabit those
areas are more likely to develop resistance because
of the repeated exposure to malathion, says Connelly.
“I have seen examples where mosquito control
districts use one class of insecticide one year and
another the next year to maintain the effectiveness
of both in rotations,” she adds. Mosquito control
operations are well-advised to rotate between classes
to reduce the potential for resistance development.
She says the mosquito control industry is in need of
new active ingredients, but given the expensive
nature of discovery and marketing, and the not-forprofit nature of public health, that’s not likely.
“Products we use for public health come from development efforts in agriculture,” Connelly says. “The
development and regulatory costs must be supported
by the much larger agricultural markets. Public
health uses come almost by default.”
SUMMER 2013 • MOSQUITO CONTROL MAGAZINE
3
MANAGEMENT
Battle for Bayou Country
Pool Surveillance, Gravid Traps
& Diligent Control
In the 2012 record-breaking year of West Nile virus (WNV) outbreak, one coastal Louisiana
parish beat back hordes of mosquitoes with a proactive monitoring program that often
requires riding and walking the bayous.
Amid the largest outbreak of WNV since 2002, the
Iberia Parish Mosquito Abatement District detected
the mosquito-vectored disease early-on in 2012.
While human infection occurrence was low, with
only three human cases of WNV in a population of
75,000, the potential for human incidence was high,
as indicated by virus activity in mosquito pools.
“If you look at it in terms of what we faced last year,
we had success,” says Herff M.P. Jones, executive
director of the Iberia
Parish Mosquito Abatement District. “However, while it may seem
small on a statistical
scale as a percentage
of the population, we
still had three people
who were affected.
And that is three too
many.”
Battlefield: 574 Square Miles
With the mission to protect the 75,000
citizens of Iberia Parish, eradicating
problem mosquitoes is a full-time
challenge for control chief Herff Jones.
Photo: Stacy Melton
Mosquito season normally runs from May to
December in Iberia
Parish, Jones explains.
In 2012, however, the
season was only one
month shy of a year.
“That set up a scenario for the intensity of WNV
across Louisiana and across the country,” he says.
In 2012, the incidence of mosquito pools that tested
positive for WNV rose to 6 percent in Iberia Parish.
On a yearly average, 1 percent of the mosquito
pools test positive for WNV. A heavy mosquito year
and high levels of virus activity in the WNV vector
population carried over to more human cases of
WNV. Nationally, the U.S. Centers for Disease Control
reported 5,387 human cases of WNV with 243
deaths. Louisiana was one of the 11 states responsible for 85 percent of that total.
With a two-pronged approach revolving around
public health and quality of life for residents inundated with the mosquito as a nuisance and disease
carrier, the Iberia Parish Mosquito Abatement Dis-
4
MOSQUITO CONTROL MAGAZINE • SUMMER 2013
trict emphasizes monitoring to detect and manage
mosquitoes as early and efficiently as possible.
In 2012, the district ramped up its efforts early. And
its first indication of WNV came in the beginning of
May 2012, Jones recalls. Fortunately, early diligence
protected the public.
Jones explains the nuts-and-bolts of the parish’s
mosquito program.
Their first line of defense is surveillance. The district
divides the parish into 20 operational zones, each of
which has one or multiple traps. During the work
week, five full-time and 12–14 part-time employees
check 30 different traps nightly to monitor population diversity, density and virus activity. Although the
Southern house mosquito is the indicated primary
vector of WNV, surveillance of all species is important, for many of them can also play a role in disease
transmission. In addition, monitoring allows nuisance thresholds to be established for control efforts
targeting pestiferous mosquitoes.
In Louisiana, as in much of the South, the Southern
house mosquito, Culex quinquefasciatus, is a
permanent water-breeding mosquito and the
primary vector of WNV. It’s also implicated in Eastern
equine encephalitis and St. Louis encephalitis.
The district employees are trained in the biology
of the primary vector as well as the biology of the
40-plus other mosquito species of Louisiana. Those
employees who spray chemicals are also licensed
through the Louisiana Department of Agriculture
and Forestry. More times than not, district employees are riding ATVs and walking the bayous as well
as the populated areas to monitor juvenile and adult
mosquitoes.
The district uses two types of traps to capture mosquitoes: a gravid trap and a light trap with a CO2
signature. The gravid traps target female mosquitoes that are often looking for rest to process a
blood meal. Sampling these mosquito collections
for virus activity gives the district valuable information used to guide abatement operations, which will
hopefully avert transmission of WNV or encephalitis
to humans or horses—even protect our pets from
heartworms.
of an additional chemistry such as Fyfanon® ULV
mosquito insecticide,” says Jones .
The light traps with their CO2 signature target
mosquitoes looking for a blood meal. “By placing
these traps, we're able to get an indication of various
mosquito population densities, gauge the level of
virus intensity and identify seasonal changes in population diversity,” Jones explains.
Fyfanon would give the district the “security” of an
ace in the hole, Jones says.“For us, Fyfanon is an available, proven effective product for our operational
tool box for adult mosquito control,” he explains.
But getting to the areas to test the mosquito
pools—and spraying if the science-based surveillance calls for it—is not an easy task in a parish with
limited paved infrastructure—roughly 150 miles of
roads in its 368,000 acres of land. Employees venture
off-road on ATVs into the swamps and forests of this
coastal parish to do their nighttime abatement work.
After the samples are collected, they’re sent off for
testing. Last year, the district submitted 160,000
specimens from 2,766 mosquito pools to the state
lab in Baton Rouge.
Having heavy mosquito numbers doesn’t always
mean WNV or encephalitis will be present, Jones
points out. Most mosquitoes only provide residents
with the nuisance of daily biting.
However, the district is always mindful that the
Southern house mosquito is the primary vector for
WNV and several other diseases, Jones says. It's the
main target for the district’s disease control efforts.
“Information from veterinarians, public health officials and from citizens requesting sprays as well as
information from our testing helps us decide how,
when and where we will specifically apply control
measures,” Jones says.
For ultra-low-volume ground control of adult
mosquitoes, the Iberia Parish Mosquito Abatement
District uses three different modes of active ingredients within the synthetic pyrethroid chemical class,
Jones explains.
“Generally, we will use a combination of two or three
of these active ingredients—resmethrin, permethrin
and sumithrin—in a season, depending on the
mosquito density and diversity as well as disease
potential,” he says.
The ultra-low-volume aerial control program uses
the organophosphate insecticide naled. “As we go
forward, we hope to gather data to support the use
This reasoning fits in well with the dynamics at play
in the mosquito control market, notes Jones. There
are limited choices for mosquito control, and
expanding regulatory requirements make it difficult
for manufacturers to support a small niche market
like mosquitoes. Also, there is the proclivity of the
primary vector to build up pesticide tolerance
quickly, he points out.
Fleet of Foggers
“If you took a piece of yarn and pulled it
across a globe, you’d be very close to
Southeast Asia. That’s how bad our
mosquito problems are,” says
Herff Jones, executive director of Iberia
Parish Mosquito Abatement District.
Photo: Stacy Melton
“The rotation of products of different classes of
chemistry is essential to our public health mission,”
Jones says. “Having Fyfanon available makes it
possible for us to do our jobs well.”
Choosing or changing chemistry is an ever complex
decision, he says. Factors include detection of resistance or tolerance to a class of chemistry based on
bottle assays, time of season, target species and virus
load. Virus load describes the circulating virus, the
actual virus detections, the number of mosquito
pools and the incidence of human cases, veterinarianreported animal cases and other mortalities.
To test the effectiveness of a chemistry, Jones uses
the bottle assay method with the Southern house
mosquito as its primary target population.
A 90 percent mortality rate within 15 minutes indicates the active ingredient is working. Mosquitoes
that live past that benchmark indicate varying levels
of tolerance to an active ingredient.“We also do cage
tests with mosquito cohorts belonging to the same
test population to supplement our assessment of
not only the operational functionality of our chosen
active ingredient, but also the effective droplet size
of our aerosol cloud—using a time mortality curve
to illustrate those results,” Jones says.
Last year, the district sprayed almost a half million
acres on the ground and treated almost as many
acres aerially. The number of sprays from the ground
totaled 143, while the aerial assault numbered 32
flights, Jones reports. Spray events are often delayed
due to rain, high winds or temperatures, he points
out, because of label restrictions.
Monitor to Know
Spray system supervisor Patrick Palazzo
checks a gravid trap as part of assessing
the current mosquito population.
Photo: Stacy Melton
SUMMER 2013 • MOSQUITO CONTROL MAGAZINE
5
PEOPLE
Mosquito-Driven Death Hits Home
One Family’s Loss
Perhaps no one in Irving, Texas, hurts as much as
the family of Dema Miller. The 83-year-old woman
died of West Nile virus (WNV)—a mosquito-borne
illness—on August 21, 2012.
Her death came 12 days after Dallas County—home
to Irving and 25 other municipalities—declared WNV
to be a public health emergency. At that time, nine
people had died and more than 100 others were
hospitalized with infection. Emergency declared, the
county launched a massive spray assault to control
mosquitoes.
“Wake up and know mosquitoes
with West Nile virus are here and
they are dangerous,” warns Bill
Miller, at 86, now a widower. “The
virus can take you away in about
10 days. My wife Dema was not a
physically strong person—
healthy, but not strong. I only
knew her 70 years,” he says. “I
wasn’t ready to lose her.”
“My mother didn’t like doctors
and didn’t wear mosquito
repellent,” remembers Dema’s
daughter Debby Steadman.
“She was just like that. She did
what she wanted to do.”
Dema first thought she had
the flu, says Steadman. “She
hurt all over. She said it was like
no other pain she’d ever felt in
her life. ”
Only Memories
Dema Miller’s family are left
with memories and photographs
after her death from West Nile virus.
They’ll tell you, it isn’t enough.
Photo: Debby Steadman
6
Dema’s son Greg Miller finally
took her to the hospital. An emergency room
physician misdiagnosed the illness as flu, rehydrated
her and sent her home.
“She started vomiting again,” says Bill. “About midnight, I noticed she was doing silly things. She kept
picking up the telephone. She would say, ‘I’m trying
to straighten out the numbers on this phone.’ I knew
I had trouble. I got her to bed and she kept playing
with my hair and keeping me awake. Finally at four in
the morning I took her back to the hospital.”
for 10 days. She couldn’t talk, she couldn’t eat, and she
couldn’t do anything but die.”
Steadman, who lives in Valley View, Texas, cries as she
talks about her mother.“She was my best friend. I miss
her every day,” says Steadman. Bill gave away the pet
goldfish. Without his wife, he doesn’t want to tend to
a task as simple as keeping it fed. Greg, who lives
nearby, stops in most days to help his father adjust.
“I saw West Nile virus getting play on the television
and heard the talking about so many people sick, but
I didn’t think it would happen to me. You never do,”
says Bill. He also contracted WNV and lost 40 pounds.
He always wore mosquito repellent when outside.
“I know there’s a big spot of water behind us. I knew
we had an unusual amount of mosquitoes here. I had
called the city a time or two to do something about
it and they didn’t have time to mess with it,” he says.
The Miller family’s assumption is misplaced, says
Walter Ritchie, director of mosquito control for Irving.
“Irving has a very strong vector control program. We
practice year-round mosquito control,” he says. “We
had very few positive traps in comparison to the rest
of the cities in the Dallas area. I felt we did a really
good job.”
Surveillance gravid traps—including one within a
mile of the Millers’ home—were monitored as early
as April.“We trap. We follow the recommendations for
control if the traps are positive,” says Ritchie.
Through the summer, an intensive ground-spray
program targeted areas where traps tested positive. When Dallas County declared the public health
emergency, Irving was part of 18 percent of the
county that elected to use targeted ground spray
rather than more widespread aerial application.
This year, Irving enhanced its control program. A
minimum of 100 female mosquitoes used to trigger
a spray—now it’s 50. “This allows us to control the
population, so we spray even when they’re not
infected,” explains Ritchie. Irving implemented inhouse testing for WNV in mosquitoes in addition to
county and state testing.
“Dad and my brother dragged her to the hospital,”
says Steadman. “She held onto the doorframe of the
house and begged them not to take her. She knew
she wouldn’t come home. She knew she would die.”
While Irving always had a strong communication
strategy, it beefed up its program this year, according
to Ritchie. “We are communicating with the media
more aggressively,” says Ritchie. Spray schedules are
on the city website, and calls to the information hotline are usually answered by a person, not a machine.
Bill described his wife’s bizarre symptoms.“The doctor
said, ‘That’s what West Nile does. It gives you meningitis. It affects your brain,’” recalls Bill. “My wife had it
Three residents of Irving died of WNV in 2012. Ritchie
hopes that knowing WNV can kill prompts the public
to take more individual responsibility.
MOSQUITO CONTROL MAGAZINE • SUMMER 2013
Together and Then Apart
Dema and Bill Miller cherished their dog Max,
who died shortly before both Millers contracted
West Nile virus. While Dema died of WNV,
Bill survived and spends most of his time alone.
Photo: Debby Steadman
“Most of the victims (those who died or became
ill) did nothing to prevent it from happening,”
says Ritchie. A survey done by local hospitals
revealed that more than 60 percent who
contracted WNV in the early part of summer
didn’t apply mosquito repellent. By the end of
summer—with more publicity about the virus—
that number dropped to about 50 percent.
He tells citizens,“West Nile virus is your responsibility, too. You need to self-protect.” Inside the
home, residents can use air conditioning to
lower the temperature, which reduces mosquito
movement or run fans to keep mosquitoes off their
skin. They can apply “natural” mosquito repellents.
And they can follow the Four Ds: DEET, drainage,
avoidance of dusk and dawn, and proper dress.
Widower Bill Miller hopes the spray trucks are out this
summer and that neighborhood children are wearing
repellent. Everyone should wear it, he says.
He misses Dema.
“I’ve never been 86 years old before,” says Bill. “I’ve
never lived by myself and I don’t like it. It’s bad. It’s
just a whole different world. There’s nobody to talk
to, nobody to hug, nobody to love, to be affectionate
with, joke with. It’s bad. I talk to the walls and they
don’t answer.”
SCIENCE
Resistance Multiplies—Fast
Gearing up to produce multiple offspring at once would make any expectant mom hungry. Female mosquitoes are
genetically programmed to eat and reproduce until squashed, eaten, or perhaps, dead of exhaustion. Those annoying,
painfully persistent daytime biters—the female Aedes aegypti and Aedes albopictus— lay 100–800 eggs or more
after each blood meal.
While many female mosquitoes lay eggs one to two times, some
live long enough to lay as many as three broods, says Robert Novak,
infectious disease specialist in the School of Public Health at the
University of South Florida in Miami.
Resistance is best avoided, notes Novak, and it can be reversed by
taking the chemistry out of use and allowing susceptible females
to reintroduce susceptibility into the population.
Half of those larvae will be hungry daughters. Fortunately, says
Novak, the number of eggs a female produces will decrease with
each laying.
In one area of China, Novak says, mosquitoes became resistant to
Bacillus sphaericus, a bacteria-based insecticide. Control districts
switched chemistry and in about a year, they were able to use
B. sphaericus once again.
During mosquito season, a constant supply of new broods presents
a continual challenge for mosquito districts. One worry: insecticide
resistance development.
The bottle assay developed by the U.S. Centers of Disease Control
and Prevention provides mosquito control districts with a straightforward way to detect early signs of resistance.
To protect chemistry, combine insecticides with different modes
of action, advises Novak.“This should be part of a good control program,” he says. “Equally important is to use different chemistry for
larval and adult control.”
“It’s important that a variety of control methods and chemistries
remain available to the mosquito control industry,” notes Amanda
Eade, malathion product manager, Cheminova, Inc. “It goes beyond
the idea of mosquitoes as a nuisance given the insect’s ability to
spread disease.”
Mosquito species that remain near where larvae hatch generally
exhibit resistance faster than those that fly longer distances, he
observes. “When resistant mosquitoes survive a pesticide application, they pass on the resistance genes to their offspring,” says
Novak. With each application, he notes, susceptible mosquitoes die,
and mosquitoes that are resistant breed and expand in number.
While districts manage the mosquitoes, Novak understands that
the public most often simply wants the mosquitoes to quit biting.
A reminder that each blood meal-fueled birth may lead to as many
as 400 more female biters could be just the prompt that motivates
someone to empty a bucket of water and apply the DEET.
SUMMER 2013 • MOSQUITO CONTROL MAGAZINE
7
PUBLIC HEALTH
West Nile Crisis:
Public Health Emergency
A Conversation with Judge Clay Jenkins
A severe outbreak of West Nile virus (WNV) gripped
Dallas, Texas, last summer. On August 9, with nine area
fatalities and more than 100 hospitalized, Judge Clay
Jenkins—the highest serving elected official in Dallas
County—declared a public health emergency certified by the Department of Homeland Security.
The declaration freed up access to state and federal
funds to help control the mosquito population and
gave Judge Jenkins widespread leeway in how to
approach the crisis. Jenkins quickly instituted a countywide spray program that significantly reduced the
incidence of WNV.
The U.S. Centers for Disease Control ranks 2012 as the
second worst year of WNV outbreak in the U.S. with
5,674 human infections reported, including 286
deaths. All told, 1,868 of these cases were in Texas,
with 89 deaths. Without intervention, Judge Jenkins
believes these numbers could have been much
higher.
On Point
Dallas County Judge Clay Jenkins
fields questions from the media
about the West Nile virus.
Photo: Dallas County
MCM: As the elected county judge for Dallas County,
you hold public health emergency responsibility for
the entire county—including 26 municipalities. Are
you surprised that it turned out to be mosquitoes
that would trigger a declared emergency for a population of 2.5 million?
JCJ: I didn’t know we’d have a mosquito emergency.
It fell on me when this became an epidemic to make
the decision to declare a public health emergency and
take the actions that thankfully ended the epidemic.
MCM: With nine fatalities from WNV, and about
100 hospitalizations, you issued a countywide
public health emergency declaration and, almost
overnight, launched an aggressive spray program for
mosquitoes. Did the public understand the urgency?
JCJ: One of the first criticisms: It isn’t a disaster, it
is mosquitoes. My decision to call for aerial spraying
over an area with 2.5 million people was—at
the time—extremely controversial. If it had been
a human threat that had taken lives and put 100
people in the hospital, I don’t think people would
be upset by my taking reasonable precautions.
Mosquitoes are indiscriminate killers. The public
tends to think WNV could never happen to them. We
marginalize victims by saying, ‘They had preexisting
conditions; they were old.’ But we have a girl stricken
8
MOSQUITO CONTROL MAGAZINE • SUMMER 2013
with WNV. She is 15 years old, and the mom still
holds on to the belt of that little girl as she walks
from the couch to the bathroom. I met one patient
on a ventilator, who is a 41-year-old man; another
victim is just now getting to where his limp is not
noticeable. He is 43 years old.
MCM: As WNV began to surface, and people started
to get really sick, how did the public want you to
respond?
JCJ: We had a group that was supportive of spraying
and a small minority strongly opposed. We also had
a sizable group that wanted to discuss the situation
more and have more time to talk, but epidemics don’t
necessarily lend themselves to participatory democracy. It is unfortunate. I would have preferred to have
town hall meetings, but it was not possible in this
situation and as the CDC (U.S. Centers for Disease
Control) report confirms, the decision to act quickly
had a significant impact on the outbreak.
MCM: On August 9, what factors caused you, in your
role as head of Homeland Security for Dallas County,
to decide to elevate WNV to an emergency and
assume responsibility for handling the epidemic?
JCJ: I put together a group to make this decision.
Roger Nasci, chief of the Arboviral Diseases Branch at
the Centers for Disease Control, was on my call. I
asked everybody to give me their best case for what
to do. Everyone goes around with their opinions.
There are 18 of us ranging from elected officials to
scientists to local health professionals to homeland
security chiefs. We get to Roger—he is on speaker—
and finally he says ‘Judge, a delay in action can be
counted in increased human infections and potentially death.’ At the end, I bowed my head, thought
about it and prayed. What stuck in my mind is what
Roger said, and I went with that.
MCM: The fatalities were tragic. But what made you
suspect WNV might get worse and, in fact, be bad
enough to call for a massive intervention?
JCJ: At the time I made the decision—in that room—
we had to make assumptions. Ultimately, looking at
little scraps of evidence, we built a picture of what
might happen if WNV wasn’t stopped. The red dots
on our map, that indicate positive pools, were
expanding rapidly and we already had more than one
room for a second
relevant photo?
Home Turf. While 2.5 million Texans live, work and play in the metropolitan Dallas area, millions and millions of mosquitoes use the city’s rich landscape to breed and feed.
death. We had relatively few people that had been diagnosed with
WNV, but the doctors weren’t really looking for it. We could have
been wrong. None of us, at that moment, was 100 percent sure that
we made the right decision. My advice to the mosquito control
community and elected officials: When you are faced with that
decision, you have to act.
MCM: How fast did the county act?
JCJ: When we announced the emergency, we made the decision to
spray that day. We had planes in the air as quickly as we could get
them here. As fast as we could, we had neighborhoods covering 82
percent of the population of Dallas County sprayed. Each city chose
whether it wanted aerial or ground. Because most chose aerial, it
allowed us to have enough trucks to cover the rest.
MCM: Dallas experienced an urgency driven by fatalities. How can
mosquito control districts raise that same level of urgency with government leaders in communities that haven’t experienced deaths?
JCJ: Relationships need to exist before a crisis. Be bold in talking to
upper administration and elected officials about this public health
crisis. When things go wrong, what you will hear from the elected
officials is, ‘Why didn’t you tell me?’ There is not much of an upside
to being quiet about this mosquito threat.
The WNV epidemic was New York City in 1999, Maricopa County,
Ariz., a few years ago; and in Sacramento a few years before it was
here in Dallas. In an urban area, it is a real threat. Tornadoes happen
every 20 or 30 years, but the conditions for mosquitoes happen
every year.
MCM: There’s always that elephant in the room — budget. With
limited dollars, what ‘sells’ a strong mosquito control program?
JCJ: Mosquito surveillance. If you don’t know where the positive
pools are, then you don’t know where to remediate the water, drop
larvacide or spray. If you don’t have adequate surveillance, which
costs money, the threat of WNV is a ticking time bomb. You need to
point that out. Fight for your budget, particularly for surveillance.
In Dallas County, the hospitalization cost for people sick with WNV
was $8.5 million. We had 20 dead and 398 confirmed cases. Estimates
are about 25,000 individuals were infected in the area and may have
had only mild symptoms. If an administrator sees the real cost—
forget that this is mosquito-borne—think if this were a tornado or
gas explosion. Ask: What would we do to make sure the public was
safer? WNV is a very real threat, and it spans across our country.
MCM: How do you go from having a plan to knowing when to act?
JCJ: It is imperative that in advance each jurisdiction have some
triggers for action that are meaningful to their geography and situation. You want the elected officials to be up to speed ahead of
time, so they can act with some degree of certainty and quickly.
Once you get that first human case of WNV in an urban area, you
can call it an ‘outbreak.’ But it is about to be an epidemic when you
have 2.5 million people living on top of each other.
MCM: One year later, what’s changed for Dallas?
JCJ: The governor today signed Senate Bill 186. If you have abandoned or foreclosed property in your neighborhood and someone
is not maintaining that landscape for drainage and remediating
water dangers—in this situation, we can enter property without
permission for the sole purpose of remediating public health
concerns like mosquito pools. I received word at 1 a.m. that the
governor signed—our crews were out at 5 a.m. to follow through.
To declare the emergency, it helped to have good epidemiology
and surveillance. And now, after last year, we have tripled our
surveillance. We also have contracts in place to access a couple of
dozen extra trucks if needed to ground spray.
MCM: How has this crisis shaped your attitude toward mosquitoes?
JCJ: I saw mosquitoes, before this crisis, as a nuisance. But now I wear
a repellent containing DEET, I use long sleeves and long pants
at dusk and dawn; I follow the four Ds. And I make sure my entire
family follows that protocol as well.
MCM: Do you wish you had that influence on everyone?
JCJ: It is unavoidable that some of your population is not going to
wear repellent. That is why it falls on our mosquito control officers
and elected officials to mitigate the risk of WNV as much as possible.
Repellent is effective outside. When you open your door and the
mosquito comes inside your house and it goes for a blood meal, it
has to feed on you. Saying you won’t spend a whole lot on surveillance and you’ll expect your population to exhibit personal responsibility just won’t get it done. Personal responsibility is a big part,
but it can’t be an excuse for government not to do its job.
SUMMER 2013 • MOSQUITO CONTROL MAGAZINE
9
Ground Zero: Virus Outbreak
Scott Sawlis survived and learned during his summer in the hot seat as head of mosquito
control for Dallas County, Texas, as it moved through the 2012 West Nile virus epidemic.
His advice to other district leaders: “Be mosquito-centric. Have mosquito trapping earlier,
more numerous, and more frequently deployed.”
Surveillance Is King
Sawlis says, “Our goal with mosquito control and
surveillance is to give all stakeholders good decision-making information. If you don’t know, then
it puts stakeholders in a bad position. I liken it to
this: No surveillance, no control; know surveillance,
know control.”
In Dallas County, data from gravid traps helped
leaders decide to implement an expensive aerial
spray program.
Communication Supports
Dallas County Health and Human Services held a
press conference in May 2012 to remind the public
that mosquito season
was starting and that
they should protect
themselves from bites.
It held a second press
conference in July as
West Nile virus (WNV)
cases were identified in
the population.
Laboratory at Work
“You have to know what type of
mosquito, how many, where, when
and what the disease potential is,”
says Scott Sawlis. He holds a
double-ring net, with mosquitoes,
taken from a gravid trap.
Photo: Dallas County
10
Dallas County had 10
confirmed human cases
by July 9, notes Sawlis,
and the public was
notified—through press
conferences and subsequent media coverage.
Some said that Dallas
County should have done more to communicate the
danger of WNV, he observes.“But I’m not sure any organization can meet the expectations of some stakeholders in the smart phone instant everything world,”
says Sawlis. “Organizations don’t function like that.”
No matter how well a message is communicated,
anticipate that some will choose not to listen, he
notes. “There has to be some ownership and
responsibility of individuals to protect themselves
from mosquito-borne diseases. Fifty-nine percent
to 69 percent of the people who contracted West
Nile virus in Dallas County never wore repellent.
There is a fine line between mosquito programs
saying, ‘it’s all on the citizen’ and the citizen saying,
“I pay my taxes. It’s on the county to do this. We
operate in that middle ground.”
MOSQUITO CONTROL MAGAZINE • SUMMER 2013
Anticipate WNV
Recognize that West Nile virus will be an every year
concern for many districts. “We know that in Dallas,
West Nile virus is a part of the ecosystem. It is here,”
says Sawlis. “We want it to be a small outbreak, and
late. That’s really all we want. If it is not, then we see
an atypical event like we did in 2006 and 2012. We
need infrastructure ready to be able to implement
control measures.”
And keep focused. In 2012, once Dallas County
declared a public health emergencey, Sawlis heard
from individuals who weren’t happy. “We knew that
additional control needed to be done and that it
would be aerial,” he says. “There are a small percentage of very vocal individuals who are concerned
about the use of insecticides. I, too, am concerned
and that’s why we follow an integrated mosquito
management program.
“The outbreak required a significant response,” says
Sawlis. “At the end of the day, the folks who are antichemical will never change their minds. They are not
going to change my mind either. I have a duty to the
citizens of Dallas County to detect mosquitoes, to
detect mosquito-borne disease and control them for
the best interests of the community based on science.”
Establish a Voice
He also encourages districts to have one “mouthpiece”
speak for mosquito control. “That mouthpiece needs
to understand the complexity that is mosquito control. If that message does not come out clearly, it can
generate panic. Even in a very small district, put out
traps to be able to see what are the species at what
time of year, do they have any virus, and then you can
communicate that,” he says.
“As a local health department, we have to take care
of the individuals that say ‘Don’t spray,’ and then
those that say ‘You better spray.’ We try to reach out
to the folks in the middle and serve them. We tell our
‘no spray’ that we want to be good stewards to the
environment and use chemicals only when needed.
We tell our ‘got to spray,’ that’s not a realistic expectation (if mosquitoes are only a nuisance).”
“We’ve got to do our due diligence to protect all
of our citizens. Our program in Dallas County is a
disease program. We function to protect public
health,” he says.
Viable, valuable and effective mosquito control for the US
and around the world. Fyfanon (Malathion) has been registered
in the US for mosquito control since 1956. It continues to be a
highly effective adulticide in reducing mosquito populations and in
improving pesticide management programs.
Cheminova—
*OWFTUJOHJOJOOPWBUJWFSFTFBSDIUPTVQQPSUFGmDBDZSBUFSFEVDUJPO
and resistance management for public health and crop protection.
Always read and follow label directions. ©2013 Cheminova. Fyfanon is a registered trademark of Cheminova, Inc.
800-548-6113
www.cheminova-us.com
Looking Back
Good Science—A Powerful Weapon in the Battle Against Mosquito-Borne Disease
Today we fight West Nile virus. In 1937 these scientists examined liver tissue samples, to assess incidences of yellow fever. Throughout the 1880s
U.S. port cities were hit hard—New Orleans, Mobile, Savannah, and Charleston were targets; Memphis suffered terribly in 1878. Yellow fever
epidemics caused terror, economic disruption, and some 100,000–150,000 deaths.
PHOTO: THE NATIONAL LIBRARY OF MEDICINE FROM THE ROCKEFELLER ARCHIVE CENTER
Mosquito
Control
P.O. Box 110566
One Park Drive, Suite 150
Research Triangle Park, NC 27709
PRSRT STD
US POSTAGE
PAID
RALEIGH, NC
PERMIT NO. 2236