Communicable Diseases Following Natural Disasters: A Public Health Response - PowerPoint PPT Presentation


PPT – Communicable Diseases Following Natural Disasters: A Public Health Response PowerPoint presentation | free to view - id: 12beda-N2U2M


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation

Communicable Diseases Following Natural Disasters: A Public Health Response


To provide an overview of issues relevant to preparedness and response for ... difficulty swallowing, lockjaw, muscle rigidity, spasms. Tetanus ... – PowerPoint PPT presentation

Number of Views:1179
Avg rating:3.0/5.0
Slides: 39
Provided by: utpu1


Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Communicable Diseases Following Natural Disasters: A Public Health Response

Communicable Diseases Following Natural
DisastersA Public Health Response
  • Stephen C. Waring, DVM, PhD
  • Associate Director
  • Center for Public Health Preparedness

Learning Objectives
  • To provide an overview of issues relevant to
    preparedness and response for emergency health
    relief workers
  • To understand the underlying factors favoring
    outbreaks of high morbidity communicable diseases
  • To review characteristics of diseases of greatest
    concern in disasters

Communicable Diseases in Disasters
  • Keys to minimizing morbidity and
  • Adequate preparedness
  • Rapid, coordinated response
  • Sustained recovery

Communicable Diseases in Disasters
  • Timely coordinated intervention efforts require
    continual review and revision of preparedness
    missions at the local, national, and
    international level
  • Greatly facilitated by ongoing government,
    academic, and private organization training and
    education programs

Factors Favoring Disease Outbreak
  • rapid onset and broad impact
  • compromised sources of water
  • displacement of large numbers of people
  • temporary sheltering in crowded conditions
  • inadequate sanitation
  • compromised waste management

Factors Favoring Disease Outbreak
  • potential food shortages
  • malnutrition/malnourishment
  • level of immunity
  • ongoing outbreaks prior to disaster
  • compromised infrastructure
  • depleted supplies
  • susceptibility of population

Epidemiology and Surveillance
  • Must establish disease surveillance system as
    soon as possible
  • Identify key resources
  • local physicians, nurses, health workers
  • functioning hospitals/clinics
  • medical supplies immediately available
  • access to victims
  • roads, waterways, telecommunications, etc.

Epidemiology and Surveillance
  • Pre-impact epidemiologic information
  • baseline (expected) frequencies and distributions
    of disease (incidence, prevalence, and mortality)
  • known risks
  • immunization coverage
  • awareness/education level in community

Epidemiology and Surveillance
  • Establish and distribute protocols
  • laboratory procedures
  • case definitions
  • case management
  • frequency and method of reporting
  • thresholds for every disease with epidemic
    potential above which a response must be
    initiated (epidemic threshold)

Epidemiology and Surveillance
  • Rapid health assessments
  • conducted as soon as possible
  • purpose - assess immediate impact/health needs
  • critical to directing timely decisions and
  • rely on pre-impact information
  • demographic, geographical, environmental, health
    facilities and services, transportation routes,
  • information from key informants
  • visual inspection of the affected area

Epidemiology and Surveillance
  • Rapid epidemiologic assessments
  • planned and completed as soon as possible
    following initial assessments
  • building on the information already acquired
  • provide more detailed analysis of ongoing threats
    and facilitate monitoring of response and
  • require additional resources and multiple skills
    and expertise
  • a valuable tool that has been used in a number of
    post-disaster settings

Epidemiology and Surveillance
  • Surveillance and assessment systems
  • need to be tailored to whatever means available
  • if widespread disruption and displacement,
    information networks should include a variety of
    sources to be effective
  • crucial to have the capacity to initiate field
    investigations immediately to verify potential
  • laboratory protocols, case definitions, and case
    management protocols must be agreed upon and
    distributed to all catchment areas

Epidemiology and Surveillance
  • Frequency and method of reporting
  • usually telephone alert system
  • established as a matter of protocol at the outset
  • should have necessary resources and personnel in
    place to ensure effective monitoring
  • establishment of thresholds for every disease
    with epidemic potential above which a response
    must be initiated (epidemic threshold) should be

Epidemiology and Surveillance
  • Challenges in implementation
  • must be understood and communicated to ensure
    effort will meet expectations
  • considerations for planning/implementation
  • compromises between what is collected and how it
    is to be analyzed
  • competing priorities for same information
  • limitations of resources
  • lack of available information required to produce
    meaningful estimates
  • lack of standardization of collection/reporting

Water-borne Diseases - Diarrhea
  • Diarrhea can be a major contributor to overall
    morbidity and mortality in a disaster due to
  • large scale disruption of infrastructure
  • compromised water quality
  • poor sanitation
  • massive displacement of population into temporary
    crowded shelters
  • common sources of food and water subject to cross

Water-borne Diseases - Diarrhea
  • Cholera
  • spreads rapidly high mortality across all age
  • major global threat and epidemic threat is
    constant in developing countries throughout the
  • rapid recognition and response imperative during
    acute post-disaster phase to prevent epidemic
  • emergence of antibiotic-resistant strains of
    Vibrio cholera complicate efforts in some regions
    and should be considered in preparedness planning

Water-borne Diseases - Diarrhea
  • Dysentery
  • Bacillary dysentery caused by Shigella
  • Fecal-oral transmission from contaminated
  • Suspect if bloody diarrhea present
  • particular concern (along with cholera) due to
    ease of transmission, rapid spread in crowded
    conditions, and immediate life-threatening
  • guidelines on managing outbreak available from

Acute Respiratory Infections
  • Increased risk for pneumonia
  • overcrowding
  • susceptibility
  • malnourishment
  • poor ventilation in temporary shelters
  • Many acute infections involve upper respiratory
    system mild and self-limiting
  • Lower respiratory infections (bronchitis,
    pneumonia) are generally more severe and require

Acute Respiratory Infections
  • Account for up to 20 of all deaths in children
    less than 5 years of age, with majority due to
    pneumonia (WHO)
  • May account for a major portion of overall
    morbidity depending on
  • Region affected
  • Characteristics of displaced population and
    temporary dwellings
  • Early recognition and management are keys to
    avoiding an outbreak

  • Few outbreaks associated with natural disasters
    although possibility remains high
  • Outbreaks prevented through
  • effective early warning system
  • rapid response to suspicious reports
  • availability of vaccine

  • Mt Pinatubo eruption (Philippines) 1991
  • measles accounted for 25 morbidity and 22 of
    mortality among 100,000 people displaced
  • attributed to very low immunization coverage and
    cultural barriers of indigenous tribe that
    represented majority of displaced population
  • Therefore, threat of measles epidemic remains
    high following natural disasters

  • Due to collapsing structures and falling debris
  • Earthquakes and tsunamis inflicts numerous crash
    injuries, fractures, and serious wounds
  • Tetanus expected when immunization coverage is
    low or non-existent
  • Injured and non-immunized should receive
  • prompt surgical and medical care of contaminated
    open wound
  • tetanus immunization and/or immunoglobulin
    depending on vaccination history and seriousness
    of the wound infection

Vector-Borne Diseases
  • Risk usually higher following disasters
    (hurricane typhoon flood, or tsunami)
  • Higher risk due to increase in number and range
    of vector habitats
  • Initially flushed out mosquito breeding sites
    return shortly after waters begin to recede

Vector-Borne Diseases
  • Factors favoring outbreaks
  • changing dynamics of vector
  • displacement of large numbers of people in
    temporary crowded shelters
  • Lag time of up to 8 weeks before onset

Vector-Borne Diseases Malaria
  • associated with serious public health emergencies
    with little warning
  • likelihood of epidemic high when
  • disaster in malaria-endemic area
  • public health infrastructure is disrupted
  • highly vulnerable population exists
  • usually 4-8 weeks after initial impact
  • several weeks duration before peak

Vector-Borne Diseases Malaria
  • Effective control possible in early stages if
    timely response in implementing control measures
  • Morbidity and mortality reduced with early
    diagnosis and treatment
  • If diagnosis delayed, treatment based solely on
    clinical history without demonstration of
  • important considerations for planning
  • emergence of anti-malarial resistance
  • increased transmission potential due to expanding
    range of vector habitats

Vector-Borne Diseases Malaria
  • vectors exclusively Anopheles - breed in stagnant
    fresh or brackish water
  • transmission efficiency dependent on
  • species of mosquito
  • preferred breeding habits
  • prevalence of parasite
  • in endemic areas disruptions may change otherwise
    poor breeding conditions into favorable ones

Vector-Borne Diseases - Dengue
  • spreads rapidly, affects large numbers
  • Dengue hemorrhagic fever (DHF) associated with
    high mortality (particularly children)
  • dramatic increase in incidence over past 20 years
    (100 million cases annually)
  • endemic throughout all tropical regions

Vector-Borne Diseases Dengue
  • transmitted by Aedes mosquitoes, primarily Ae.
  • vector particularly suited for an urban cycle of
  • breeds primarily in containers and other sources
    of standing water
  • breeds in and around human dwellings rather than
    groundwater pools and swamps

Vector-Borne Diseases Dengue
  • Outbreaks contained only through early-warning
    and rapid response
  • Effective vector control critical but challenging
    due to
  • availability of adequate resources
  • appropriate access to breeding habitats

Water-borne Diseases Summary
Vector-borne Diseases Summary
Direct Contact Diseases Summary
  • Immediate concern is rapid detection and response
    to address existing health needs and prevent
  • Factors that also play key roles in controlling
    communicable diseases in disaster setting

  • Emergency response aimed to mitigate adverse
    health effects requires
  • Multidisciplinary approach employing a broad
    range of expertise
  • Identification and attention to those in need of
    immediate threat
  • Multidisciplinary effort forms framework for
  • Requires ongoing preparedness planning,
    education, and training efforts

Closing Comments
  • Resilience of the local people is a key asset in
    recovering from all adversities physical,
    social, and economic
  • Efforts should be made to strengthen community
    resilience in order to ensure a better future for
    those affected

Goal Translate lessons learned into better
preparedness, response, and recovery for the next
disaster certain to follow.
  • CDC. Rapid assessment of vectorborne diseases
    during the Midwest flood--United States, 1993.
    MMWR 199443481-483
  • CDC. Surveillance in evacuation camps after the
    eruption of Mt. Pinatubo, Philippines. MMWR
  • Connolly MA, Gayer M, Ryan MJ, Salama P, Spiegel
    P, Heymann DL. Communicable diseases in complex
    emergencies impact and challenges. Lancet
  • Connolly MA. Communicable disease control in
    emergencies A field manual. Geneva WHO, 2005.
  • Noji EK. The public health consequences of
    disasters. Prehospital Disaster Medicine
  • Toole MJ. Communicable Diseases and Disease
    Control In Noji E, ed. The Public Health
    Consequences of Disasters. New York Oxford
    University Press, 199779-100
  • World Health Organization. Tsunamis Technical
    Hazard Sheet and Natural Disaster Profile WHO,
  • Waring SC, Brown BJ. The threat of communicable
    diseases following natural disasters, a Public
    Health Response, Disaster Manage Response