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Approaches to Community Prevention of West Nile Virus Infection. Emily Zielinski-Gutierrez, DrPH Behavioral Scientist Division of Vector-Borne Infectious Diseases Centers for Disease Control & Prevention. Outline. A little health education and behavior change theory

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Approaches to community prevention of west nile virus infection l.jpg

Approaches to Community Prevention of West Nile Virus Infection

Emily Zielinski-Gutierrez, DrPH

Behavioral Scientist

Division of Vector-Borne Infectious Diseases

Centers for Disease Control & Prevention

Outline l.jpg
Outline Infection

  • A little health education and behavior change theory

  • A national perspective on WNV trends

  • Some statistics on WNV protective behaviors

  • Some barriers & opportunities for prevention

    • Lessons from Colorado and elsewhere

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Lots of different theories Infection

  • Theory of Reasoned Action

    • How people decide to take a certain action

  • Health Belief model

    • A person’s behavior can be predicted based upon issues such as perceived susceptibility, perceived severity when making a decision about a particular behavior concerning theirhealth.(Glanz, Lewis, & Rimer, 1990).

  • Transtheoretical model/Stages of Change

    • Precontemplation/ contemplation/ preparation/ action/ maintainence

  • Fear Appeals Theory

    • Some would agree, some not – fear can motivate OR lead to rejection and inaction.

  • And many more


    Slide5 l.jpg

    One Theoretical Basis Infection

    Risk Communication and Education

    Risk Perception

    Environmental Factors

    MediaDisease history

    Local ecology

    Demographic factors

    Socio-cultural factors

    e.g. language, age,

    Income, gender, education

    Risk Assessment


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    Barriers Infectionto Action

    Facilitating Factors for the Action

    Desired Action




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    Communication Infectionwith other strategies can:

    Change human behavior

    Overcome barriers and systemic problems

    Health Communication can:

    • Increase knowledge

    • Increase awareness

    • Prompt action

    • Demonstrate skills

    • Influence attitudes

    • Refute myths

    DHHS/NIH/NCI: Making Health Communication Programs Work

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    Health communication questions with West Nile virus Infection

    • What prevention measures are people using to avoid WNV infection?

    • What are possible reasons that people are not using prevention measures?

    • What communication activities and other interventions might increase use of personal & household prevention?

      • How can communication makes prevention measures more “actionable”/feasible?

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    Plan for the result you want Infection

    • Outcomes:

      • Knowledge about transmission, about risk, about repellents, about prevention

      • Attitudes about personal risk, support of prevention, etc.

    • Impact:

      • Behavior: e.g. increased repellent use, installation of screens

      • Disease reduction: A challenge to measure for WNV/mosquito borne disease

        • Lots of variables ecological and otherwise, serosurveys a huge expensive effort…can use surveillance data for some questions

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    Message + receiver Infection≠ behavior change

    • A message w/o supporting context often insufficient

    • There are reasons that people don’t do things that would otherwise seem to make reasonable sense… find out what those reasons are… and address them in your campaign.

    • If there are significant obstacles (income or poor housing, for example) information alone isn’t often going to be enough to counter that alone.

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    WNV trends Infection

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    A bigger and bigger problem Infection

    # Cases # Deaths # States w/ human cases

    1999 62 7 1

    2000 21 2 3

    2001 66 9 10

    2002 4071 279 39 states +DC

    2003 * 9306 240 45** states+DC

    *As of March 3, 2004. Numbers will change.

    **No human disease reports in 2003 in WA, OR, ME, HI, AK

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    This year… Infection

    • 0ver 9000 human cases reported in the US*

      • Severe disease = more than 2700 (30%)

      • West Nile Fever = more than 6300 (~68%)

        • Only about ~25% of all cases in 2002 were Fever

      • Other/unknown = about 163 (2%)

    * 2003 cases reported to CDC, as of 3 March 2004

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    Who gets sick from West Nile? Infection

    • All ages: 1 mo.–99 years

    • Fever cases tend to be young/middle age adults

    • Severe disease and deaths tend to be people over 50, and especially over 70

    • Kids do get sick, but pretty rarely.

      • Intrauterine infection is possible when a pregnant woman gets infected, but the extent to which this occurs and the health effects on the infant are not yet known.

    * 2003 cases reported to CDC, as of 19 November 2003

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    Percent of Reported West Nile Virus Cases Infection Classified as West Nile Fever, United States, 2003

    Percent of Cases





    * Reported as of 1/29/2004

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    WNND County Level Incidence per Million, United States, 2002*

    Incidence per million




    * Reported as of 4/15/2003

    Wnnd county level incidence per million united states 2003 l.jpg
    WNND County Level Incidence per Million, United States, 2003*

    Incidence per million




    *Reported as of 1/20/2004

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    Human WNV Disease Incidence, by Age Group and Clinical Category, United States, 2003*

    * Reported as of 1/30/2004

    * *Entire US population

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    Prevention: Category, United States, 2003*Who’s doing what?national statistics

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    When it’s warm in your area, do you… Category, United States, 2003*

    • Nationwide: those who report they always/usually…

      • 43.9% look for household standing water

      • 37.6% apply {any} insect repellent

      • 28.5% avoid the outdoors due to mosquitoes

      • 23.9% wear long pants/sleeves

        74.5% doing at least one of the above.

    * Healthstyles national survey, data licensed from Porter-Novelli, conducted July-Aug 2003

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    If it’s repellent, is it DEET? Category, United States, 2003*

    • 40.3% of respondents have repellents containing DEET in the household (another 26.8% not sure)

    • It’s not DEET for everyone:

      • Only 59.3% of repellent “users” confirmed having DEET in the household

    • Other respondents do have DEET, but they don’t use it much

      • 44.6% of those have DEET in the household said that they did NOT always/usually use repellent

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    Regional and Demographic Differences Category, United States, 2003*in Repellent Use

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    Jul-Aug 2003 Category, United States, 2003*

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    West North Central region: Category, United States, 2003*

    38% in 2002, 49% in 2003

    Mountain region:

    23% in 2002, 33% in 2003

    East South Central region:

    39% in 2002

    49% in 2003

    Red = Regionw/more than 10% increase in “Always/Usually Use Repellent” between 2002-2003

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    Age & Repellent Use Category, United States, 2003*

    Bad News:Repellent use (largely) decreases with age

    p < .000; n= 4034

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    Age and DEET in household Category, United States, 2003*

    • Highest age categories may be associated with having children at home

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    Race/ethnicity Category, United States, 2003*

    • Significant differences in having DEET in household by race/ethnicity (p<.000)

      • “White” respondents most likely to have DEET (44.3%), other respondents less so (<33%)

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    Household income Category, United States, 2003*

    • Poorer people in this sample were less likely to report having DEET-based repellent in the household.

    p<.000, n=4008

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    Education Category, United States, 2003*

    • Education level directly related to having DEET in household (p<.000)

      • Non HS graduates <30%, college graduates approaching 50% have DEET

      • Relationship to income bears further attention

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    Barriers and Opportunities Category, United States, 2003*

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    The “Why”: Category, United States, 2003*Qualitative Complementing Quantitative

    • Qualitative research to examine KAP and behavioral factors

      • 2003: Focus group discussions (~12 total) in higher and lower transmission areas [Larimer (high) and El Paso (low) counties]. Data on Cook County forthcoming.

      • 2002: 16 focus groups in Louisiana

      • Topics:

        • Risk perception

        • Attitudes twd mosquitoes, repellents, spraying

        • Information sources and shortcomings

        • Views on responsibility for prevention

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    Barriers: Category, United States, 2003* Questions about DEET

    • Reported infrequent/no use of DEET-based repellents in wk before group

    • Many cited their own sensory experience using repellent

      • smell, feel (“sticky”)

      • skin reactions, “sensitive skin,” I just can’t use that stuff

    • Strong, though often vague, beliefs and feelings about safety of DEET

      • Attribute brain damage, nerve damage, danger to kids

      • Often described by consumers as “something I heard somewhere… read somewhere”

      • Desire for more data, but resources for detailed info often unclear

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    More on repellents Category, United States, 2003*

    • Permethrin never mentioned

    • Use of any repellent on clothing rarely discussed

    • Very little awareness of details about repellent

      • DEET % strength unclear

      • Little about “hierarchy” of alternatives

    • Alternative repellents

      • “They wouldn’t have come up with the other types if there weren’t something wrong with DEET.”

      • Colorado way less interesting than Louisiana

      • Skin-So-Soft & the Avon ladies

      • Trust in “natural” products (regardless)

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    It’s not Category, United States, 2003*all about knowledge or about the bug spray

    • The decision to obtain/use repellent is only partly a function of knowledge about WNV, knowledge about prevention, or attitudes toward products.

      • Assessments of risk

        • Temporal, geographical, control/fear/outrage

      • Perceived impact of prevention efforts

        • Would any of these steps make a difference?

      • Individual cost-benefit analysis

        • What is it costing me to take these preventive measures? (not just $)

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    Conceptual Framework Category, United States, 2003*

    Risk perception was affected by locally- and personally-defined intensity of WNV transmission.

    Some factors that combine to define local intensity of transmission include:

    • - personal knowledge about disease

    • - perception of local ecology

    • - type and credibility of information sources

    • - local government intervention

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    Personal knowledge about disease Category, United States, 2003*

    Information Sources

    Actions of local


    Local ecology

    Locally-defined intensity of transmission

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    Intense WNV Human Disease 2002 & 2003 Category, United States, 2003*















    Population perceives limited mosquito infestation

    Limited experience w/ & some resistance to mosquito control

    Risk perception linked to info from community groups



































    Long history of mosquito infestations and nuisance

    Experience with and general support for mosquito control as a public service

    Risk perception linked to info from community groups

    Includes Fever and neuroinvasive disease as reported to CDC

    > 200 human cases 2003

    > 200 human cases 2002

    > 200 human cases both years

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    Risk: Category, United States, 2003*personal knowledge of disease

    • Knowing some who was ill

      • Increased recognition of WNV Fever cases during 2003*, more residents knew of someone infected

    • Concern about severity of Fever

      • Not the same impact as ND, but people missed school, work, described prolonged headache ache and fatigue

        • “No one told us it was going to be this bad.”

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    Defining Risk: Category, United States, 2003*disease & age

    • No one is “old.”

    • Perspective: participants > 60 y.o. pointed out their experience with other illnesses

      • Lived through polio

      • I had malaria and I figured I must be immune

    • Risk roulette for younger people:

      • “One of my younger neighbors, he thought that he ought to go ahead and get it so he would build up an immunity…”

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    Personal view of disease: Category, United States, 2003*fear and control

    • Concern fueled by sense of powerlessness

      • felt that personal options were limited

      • “I can’t spend time outside anymore”

    • Risk may seem ‘unquantifiable’ to general public

      • hard to make decisions about prevention--what to do, what to give up

    • Difficulty conceptualizing how a single mosquito bite can be fatal or life-changing

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    Defining Risk: Category, United States, 2003* Local Ecology

    • “No mosquitoes here”

      • Public lacks history of dealing with mosquitoes as a nuisance or makes qualitative comparisons to Midwest/elsewhere

        • “I just don’t see where all these mosquitoes can be coming from…”

    • Home as “Safe Zone”

      • Don’t use repellent when “just in the backyard”… some disinclination to regard home as dangerous

        • “Most of us [retirees] who are living here are so happy to be in this particular environment that we think we’ve got it made and… we’re kind of invulnerable to any sort of thing.”

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    Defining Risk: Category, United States, 2003* perception of ecology/local geography

    • “Hyper-localization” of risk

      • Desire to quantify exactly where and when the risk exists

        • People try to downgrade their risk – e.g. that dead bird was 3 blocks from here…

        • “We hear about the deaths… I wish they would go into a bit more history [of where they were bit.]”

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    Defining Risk: Category, United States, 2003*use of outdoors

    • The culture of outdoor recreation

      • Golfing, fishing, walking, gardening

      • Neighborhood visiting in PM (cities, south)

    • Resources

      • People without air-conditioning have a v. different relationship to outdoors

      • Age/quality/preferences in housing stock

        • Again western states very different than South and Midwest

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    Defining Risk: Category, United States, 2003* Info sources

    • People get most of information from media

      • Passive

      • Subject to the vagaries of how issues are covered – to what makes the “front page”

    • Respondents suspicious… media “hypes everything”

      • “I think there was confusion over how much is this really a problem and how much is media hype?”

      • Public’s inherent distrust (or at least ambivalence) regarding the media affected level of concern

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    Defining Risk: Category, United States, 2003*media andcontroversy

    • Adulticiding in Larimer county became major and divisive distraction from other prevention messages

    • On the other hand it keep it in the forefront of people’s minds…

      Hard to know the sum effect

      of controversy.

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    Defining risk: Category, United States, 2003*Info sources

    • Some Hispanic residents reported hearing little to nothing about WNV in the media sources to which they were exposed

      • Some folks may be accessing Univision more than local media

    • “Worry fatigue”:

      • “… it felt like, OK, so this year it’s West Nile, last year was something and next year will be something else to be afraid of.”

    • All areas: People expressed interest in hearing from community representatives, relevant leaders, “people like them”

      • “I figured if it were really important my pastor would have mentioned it.” – urban LA resident

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    Defining risk: Category, United States, 2003*people look at what government is doing

    • Mosquito Control actions can create controversy.

      • The decision to declare a public health emergency also was noted as influencing people’s concern over the issue.

  • Some question whether long-term mosquito control can lead to complacency among citizens and how to combat

  • Local gov’t actions can serve as trigger for citizens

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    Opportunities: Category, United States, 2003* Cues to Action

    • High profile repellent sales in retail locations triggered purchase

      • “[they] had [repellent] right when you walk in the door… we bought some right then, and I don’t know if I would have right then [otherwise]… I thought that was wise and caring.”

      • Approach to bring in private elements of the community

    • Hearing about & knowing people around them who were ill

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    Opportunities Category, United States, 2003*

    • A minority of the US population is using repellent but most are doing something.

      • But important gaps related to population (age, SES) and possible geographic risk factors

      • The “something” might provide limited protection.

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    Opportunities/Future steps Category, United States, 2003*

    • “Socially market” repellents with greater savvy

      • DEET and more effective alternatives

      • Distribution points (where people already go)

      • Encourage industry to look at some of the things people really don’t like about DEET

      • Address safety straight on

    • Use the fact that nearly half the population already report looking for breeding sites

      • Encourage, and evaluate

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    Opportunities: Category, United States, 2003* future steps

    • Identify maintenance vs. emergency strategies

    • A lesson from the Avon ladies

      • Personal messages engage people on a different level than TV, a website or a flyers.

      • Who are your partners?

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    (Final) Opportunities Category, United States, 2003*

    • As WNV epidemiology and ecology evolve, messages must similarly evolve.

    • Local ecology and history w/ mosquitoes important in construction of risk

      • considered in adapting prevention efforts

    • Involve community groups and local officials in prevention messages and planning

      • Supplement media and health department personnel

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    Thank you! Category, United States, 2003*