Preparing for and Responding to Bioterrorism: Information for the Public Health Workforce

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Preparing for and Responding to Bioterrorism
Information for the Public Health Workforce
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Acknowledgements
This presentation, and the accompanying
instructors manual, were prepared by Jennifer
Brennan Braden, MD, MPH, at the Northwest Center
for Public Health Practice in Seattle, WA, for
the purpose of educating public health employees
in the general aspects of bioterrorism
preparedness and response. Instructors are
encouraged to freely use all or portions of the
material for its intended purpose. The
following people and organizations provided
information and/or support in the development of
this curriculum. A complete list of resources
can be found in the accompanying instructors
guide.
Patrick OCarroll, MD, MPH Project Coordinator
Centers for Disease Control and Prevention
Judith Yarrow Design and Editing Health Policy
and Analysis University of WA Washington State
Department of Health
Jeff Duchin, MD Jane Koehler, DVM,
MPH Communicable Disease Control, Epidemiology
and Immunization Section Public Health - Seattle
and King County Ed Walker, MD University of
WA Department of Psychiatry
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Diseases of Bioterrorist Potential Tularemia
Viral Hemorrhagic Fevers
CDC, AFIP
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Diseases of Bioterrorist Potential Learning
Objectives

• Describe the epidemiology, mode of transmission,
  and presenting symptoms of disease caused by the
  CDC-defined Category A agents
• Identify the infection control and prophylactic
  measures to implement in the event of a suspected
  or confirmed Category A case or outbreak

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Francisella Tularensis

• Causative agent of tularemia
• Non-motile, non-spore-forming gram negative
  cocco-bacillus found in diverse animal hosts
• Studied by U.S. and others as potential BW weapon
  
• Resistant to freezing temperatures, sensitive to
  heat and disinfectants

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Francisella TularensisEpidemiology

• Humans infected by various modes
• Handling contaminated animal tissues or fluids
• Bite of infective deer flies, mosquitoes, or
  ticks
• Direct contact with or ingestion of contaminated
  water, food, or soil
• Inhalation of infective aerosols (most likely BT
  route)
• About 200 cases of tularemia/year in U.S.
• Most in South-central and Western states
• Most in rural areas
• Majority of cases in summer

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Francisella TularensisEpidemiology

• Low infectious dose 10-50 organisms produce
  disease
• Incubation period probably 3-5 days following
  aerosol exposure (range 1-21 days)
• Case fatality rate
• Treated lt1-3
• Untreated 30-60 (pneumonic), 5
  (ulceroglandular)
• Recovery followed by permanent immunity
• No person-to-person transmission

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Tularemia Case Definition

• An illness characterized by several distinct
  forms, including the following
• Ulceroglandular (cutaneous ulcer with regional
  lymphadenopathy)
• Glandular (regional lymphadenopathy with no
  ulcer)
• Oculoglandular (conjunctivitis with preauricular
  lymphadenopathy)
• Oropharyngeal (stomatitis or pharyngitis or
  tonsillitis cervical adenopath)

MMWR 199746(RR-10)
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Tularemia Case definition, cont.

• An illness characterized by several distinct
  forms, including the following
• Intestinal (intestinal pain, vomiting, diarrhea)
• Pneumonic (primary pleuropulmonary disease)
• Typhoidal (febrile illness w/o early localizing
  signs symptoms
• Clinical diagnosis supported by evidence or
  history of a tick or deerfly bite, exposure to
  tissues of a mammalian host of F. tularensis, or
  exposure to potentially contaminated water.

MMWR 199746(RR-10)
most likely BT presentation
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Tularemia Case Definition, cont.

• Laboratory criteria for diagnosis
• Presumptive
• Elevated serum antibody titer(s) to F. tularensis
  antigen (w/o documented 4-fold or greater change)
  in a patient with no history of tularemia
  vaccination OR
• Detection of F. tularensis in a clinical specimen
  by fluorescent assay
• Confirmatory
• Isolation of F. tularensis in a clinical specimen
  OR
• 4-fold or greater change in serum antibody titer
  to F. tularensis antigen

MMWR 199746(RR-10)
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Tularemia Case Classification

• Probable Clinically compatible with lab results
  indicative of a presumptive infection
• Confirmed Clinically compatible with
  confirmatory lab results

MMWR 199746(RR-10)
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Ulceroglandular TularemiaClinical Features

• 75-85 of naturally occurring cases
• General symptoms high fever, malaise, muscle
  aches, headache, chills rigors, sore throat
• Cutaneous papule appears at inoculation site
  concurrent with generalized symptoms
• Papule --gt pustule --gt tender indolent ulcer with
  or without eschar
• Tender regional lymphadenopathy

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Ulceroglandular Tularemia
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Pneumonic TularemiaClinical Features

• Initial clinical picture systemic illness with
  prominent signs of respiratory disease
• Abrupt onset fever, chills, headaches, muscle
  aches, non-productive cough, sore throat
• Nausea, vomiting, diarrhea in some cases
• Mortality 30 untreated lt 10 treated

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Tularemia Treatment Prophylaxis

• Vaccine live attenuated vaccine under FDA review
  availability uncertain
• For known aerosol exposures, 14d oral antibiotics
  recommended
• If covert attack, observe for development of
  fever for 14 days and treat with antibiotics if
  febrile
• Post-exposure antibiotics most effective when
  given w/in 24 hours of exposure

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TularemiaInfection Control

• Standard precautions
• No patient isolation necessary due to lack of
  human-to-human transmission
• Alert lab of suspicion for tularemia

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TularemiaSummary of Key Points

• In naturally occurring tularemia, infection
  virtually always occurs in a rural setting.
  Infection in an urban setting with no known risk
  factors or contact with infected animals suggests
  a possible deliberate source.
• Tularemia is not transmitted person to person.

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TularemiaSummary of Key Points

• The most likely presentations of tularemia in a
  BT attack are pneumonic and typhoidal disease, as
  opposed to cutaneous disease in naturally
  occurring cases.
• Tularemia can be treated and prevented with
  antibiotics.

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Viral Hemorrhagic Fevers

• Diverse group of illnesses caused by RNA viruses
  from 4 families
• Arenaviridae, Bunyaviridae, Filoviridae,
  Flaviridae
• Differ by geographic occurrence and
  vector/reservoir
• Share certain clinical and pathogenic features
• Potential for aerosol dissemination, with human
  infection via respiratory route (except dengue)
• Target organ vascular bed
• Mortality 0.5 - 90, depending on agent

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Viral Hemorrhagic Fevers

• Category A agents
• Filoviruses
• Arenaviruses
• Category C agents
• Hantaviruses
• Tick-borne hemorrhagic fever viruses
• Yellow fever

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Viral Hemorrhagic Fevers Transmission

• Zoonotic diseases
• Rodents and arthropods main reservoir
• Humans infected via bite of infected arthropod,
  inhalation of rodent excreta, or contact with
  infected animal carcasses
• Person-to-person transmission possible with
  several agents
• Primarily via blood or bodily fluid exposure
• Rare instances of airborne transmission with
  arenaviruses and filoviruses
• Rift Valley fever has potential to infect
  domestic animals following a biological attack

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Viral Hemorrhagic Fevers Summary of Agents
Virus Family Virus/Syndrome Geographic occurrence Reservoir or Vector Human-human transmission?
Arenaviridae Junin (Argentine HF) S.America Rodents Lassa Fever yes, via body fluids others not usually
Arenaviridae Machupo (Bolivian HF) S.America Rodents Lassa Fever yes, via body fluids others not usually
Arenaviridae Guanarito (Brazilian HF) S.America Rodents Lassa Fever yes, via body fluids others not usually
Arenaviridae Sabia (Venezuelan HF) S.America Rodents Lassa Fever yes, via body fluids others not usually
Arenaviridae Lassa (Lassa Fever) West Africa Rodents Lassa Fever yes, via body fluids others not usually
Flaviridae Yellow Fever Tropical Africa,Latin America Mosquitoes Yellow Fever blood infective up to 5d of illness Others - No
Flaviridae Dengue Fever Tropical areas Mosquitoes Yellow Fever blood infective up to 5d of illness Others - No
Flaviridae Kyanasur Forest Disease India Ticks Yellow Fever blood infective up to 5d of illness Others - No
Flaviridae Omsk HF Siberia Ticks Yellow Fever blood infective up to 5d of illness Others - No
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Viral Hemorrhagic FeversSummary of Agents
Virus Family Virus/Syndrome Geographic occurrence Reservoir or Vector Human-human transmission?
Bunyaviridae Congo-Crimean HF Crimea, parts of Africa, Europe Asia Ticks Congo-Crimean Hemorrhagic Fever yes, through body fluids Rift Valley Fever, Hantaviruses no
Bunyaviridae Rift Valley Fever Africa Mosquitoes Congo-Crimean Hemorrhagic Fever yes, through body fluids Rift Valley Fever, Hantaviruses no
Bunyaviridae Hantaviruses (Hemorrhagic Renal Syndrome/ Hantavirus Pulmonary Syndrome) Diverse Rodents Congo-Crimean Hemorrhagic Fever yes, through body fluids Rift Valley Fever, Hantaviruses no
Filoviridae Ebola HF Africa Unknown Yes, body fluid transmission
Filoviridae Marburg HF Africa Unknown Yes, body fluid transmission
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Viral Hemorrhagic FeversClinical Presentation

• Clinical manifestations nonspecific, vary by
  agent
• Incubation period 2-21 days, depending on agent
• Onset typically abrupt with filoviruses,
  flaviviruses, and Rift Valley fever
• Onset more insidious with arenaviruses

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Viral Hemorrhagic FeversInitial Symptoms

• Prodromal illness lasting lt 1 week may include

• Dizziness
• Muscle aches
• Joint pain
• Nausea
• Non-bloody diarrhea

• High fever
• Headache
• Malaise
• Weakness
• Exhaustion

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Viral Hemorrhagic FeversClinical Signs

• Edema
• Hypotension
• Shock
• Mucous membrane bleeding

• Flushing, conjunctival injection (red eye)
• Pharyngitis
• Rash

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VHF Surveillance Clinical Identification of
Suspected Cases

• Clinical criteria
• Temperature 101?F(38.3?C) for lt3 weeks
• Severe illness and no predisposing factors for
  hemorrhagic manifestations
• 2 or more of the following
• Hemorrhagic or purple rash
• Epistaxis
• Hematemesis
• Hemoptysis
• Blood in stools
• Other hemorrhagic symptoms
• No established alternative diagnosis

JAMA 2002287 Adapted from WHO
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Viral Hemorrhagic FeversTreatment

• Supportive care
• Correct coagulopathies as needed
• No antiplatelet drugs or IM injections
• Investigational treatments, available under
  protocol
• Ribavirin x 10 days for arenaviridae and
  bunyaviridae
• Convalescent plasma w/in 8d of onset for AHF

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Viral Hemorrhagic Fevers Management of Exposed
Persons

• Medical surveillance for all potentially exposed
  persons, close contacts, and high-risk contacts
  (i.e., mucous membrane or percutaneous exposure)
  x 21 days
• Report hemorrhagic symptoms (slide 47)
• Record fever 2x/day
• Report temperatures ? 101?F(38.3?C)
• Initiate presumptive ribavirin therapy
• Percutaneous/mucocutaneous exposure to blood or
  body fluids of infected
• Wash thoroughly with soap and water, irrigate
  mucous membranes with water or saline

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Viral Hemorrhagic Fevers Management of Exposed
Persons

• Patients convalescing should refrain from sexual
  activity for 3 months post-recovery (arenavirus
  or filovirus infection)
• Only licensed vaccine Yellow Fever
• Investigational vaccines AHF, RV, HV
• Possible use of ribavirin to high risk contacts
  of CCHF and LF patients

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Viral Hemorrhagic Fevers
Infection Control

• Airborne contact precautions for health care,
  environmental, and laboratory workers
• Negative pressure room, if available
• 6-12 air changes/hour
• Exhausted outdoors or through HEPA filter
• Personal protective equipment
• Double gloves
• Impermeable gowns, leg and shoe coverings
• Face shields and eye protection
• N-95 mask or PAPR

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Viral Hemorrhagic Fevers
Infection Control

• Dedicated medical equipment for patients
• If available, point-of-care analyzers for routine
  laboratory analyses
• If unavailable, pretreat serum w/Triton X-100
• Lab samples double-bagged hand-carried to lab
• Prompt burial or cremation of deceased with
  minimal handling
• Autopsies performed only by trained personnel
  with PPE

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Viral Hemorrhagic FeversSummary of Key Points

• A thorough travel and exposure history is key to
  distinguishing naturally occurring from
  intentional viral hemorrhagic fever cases.
• Viral hemorrhagic fevers can be transmitted via
  exposure to blood and bodily fluids.

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Viral Hemorrhagic FeversSummary of Key Points

• Contact and airborne precautions are recommended
  for health care workers caring for infected
  patients.
• Post-exposure management consists of surveillance
  for fever and hemorrhagic symptoms, and possibly
  ribavirin therapy for symptomatic individuals.

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Case Reports

• Tularemia
• Viral Hemorrhagic Fevers

MMWR Morb Mortal Wkly Rep 200150(33)
MMWR Morb Mortal Wkly Rep 200150(5)
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Resources

• Centers for Disease Control Prevention
• Bioterrorism Web page
• CDC Office of Health and Safety Information
  System (personal protective equipment)
• USAMRIID -- includes link to on-line version of
  Medical Management of Biological Casualties
  Handbook
• Johns Hopkins Center for Civilian Biodefense
  Studies

http//www.bt.cdc.gov/
http//www.cdc.gov/od/ohs/
http//www.usamriid.army.mil/
http//www.hopkins-biodefense.org
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Resources

• Office of the Surgeon General Medical Nuclear,
  Biological and Chemical Information
• St. Louis University Center for the Study of
  Bioterrorism and Emerging Infections
• Public Health - Seattle King County

http//www.nbc-med.org
http//bioterrorism.slu.edu
http//www.metrokc.gov/health
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Resources

• Washington State Department of Health
• Communicable Disease Epidemiology
• [phone] OR
• [phone] (24 hour emergency)
• Association for Professionals in Infection
  Control
• MMWR Rec Rep. Case definitions under public
  health surveillance.

http//www.doh.wa.gov
http//www.apic.org/bioterror
199746(RR-10)1-55