Investigation of Potential and Real Outbreaks of Smallpox

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Investigation ofPotential and RealOutbreaks of
Smallpox

• Department of Defense
• Smallpox Preparedness Conference
• October 30, 2002

Jeffrey D. Gunzenhauser, MD, MPH COL, MC, US
Army Preventive Medicine Staff Officer OTSG 703-68
1-3160 (DSN 761) jeffrey.gunzenhauser_at_otsg.amedd.a
rmy.mil
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Investigation of Smallpox OutbreaksOBJECTIVES

• 1. Define the major purposes of the Epidemiologic
  Outbreak Investigation
• 2. Describe the purpose of case investigations
• Describe surveillance activities that will occur
  after a case of smallpox is confirmed.
• Be familiar with the CDC forms used in the
  Outbreak Investigation    

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Investigation of Smallpox Outbreaks CDC
REFERENCES
CDC Smallpox Response Plan and Guidelines
(Version 3.0) http//www.bt.cdc.gov/agent/smallp
ox/response-plan/index.asp Guide A
Surveillance, Contact Tracing, and
Epidemiological Investigation Guidelines 1. Pre-
Event Rash Surveillance 2. Smallpox clinical
presentations and differential diagnosis 3. Smal
lpox case definitions 4. Epidemiological (case
and outbreak) investigations 5. Surveillance
following an outbreak 6. Contact
identification, tracing, and surveillance 7. Des
cription of forms 8. Guide A Forms 1 to
11. Annex 4 Suggested Pre-Event Activities for
State Local Health Authorities Annex 7
Checklists for State/Local/CDC Personnel Actions
in a Smallpox Emergency
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Investigation of Smallpox Outbreaks DoD
REFERENCES
DoD Interim Smallpox Response Plan, version 2.2,
14 Jun 02 POC John.Grabenstein_at_otsg.amedd.army.
mil Annex A Surveillance, Contact Tracing, and
Epidemiological Investigation 1. General 2. Mi
ssion 3. Pre-outbreak Rash Surveillance 4. Sma
llpox Clinical Presentations and Differential
Diagnosis (Appendix A-7) 5. Smallpox Case
Definitions and Case Classification 6. Post-Outb
reak Response Epidemiologic Investigation 7. P
ost-Outbreak Surveillance 8. Contact
Identification, Tracing, Vaccination, and
Surveillance 9. Special Situations Appendices
A-1 Surveillance, Contact Tracing, and
Epi-Summary A-8 Case Definitions and Case
Classification A-2 Svc Reportable-Dz Surveillance
Centers A-9 Expected Epidemiological Features of
Smallpox A-3 Training Curriculum-Contact
Tracers A-10 Surveillance Reporting and
Information Flow A-4 Characteristics of Epi
Response Teams A-11 Enhanced Hospital
Surveillance A-5 State Health Law Observed by US
Officers A-12 Classification of Evaluated
Patients A-6 Handout to ID Symptoms of
Smallpox A-13 Contact Identification, Tracking,
Surveillance A-7 Clinical Case Description and
Differential Dx A-14 Forms for Contact ID,
Tracing, Surveillance
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Smallpox Outbreak Response Model
Pre-Event
Post-Event

• Surveillance
• Fever-Rash Illness Surveillance
• Smallpox Case Definition
• Pre-Event Vaccination
• Specified Groups
• Pre-Event Planning / Training
• Global, Regional, and Local
• Command and Control
• Surveillance, Epi and Contact Tracing
• Quarantine and Isolation
• Treatment / Infection Control
• Laboratory support
• Vaccination Operations (Adv Events)
• Decontamination
• Public/Media Preparation
• Facilities identification and prep
• Security Issues

Vaccinate Large Groups
Mass Vaccination
Vaccinate Specified Groups
Identify the Source / Cause
Contacts of Contacts (same thing)
Ring Containment
ID, Trace, Interview, and Vaccinate Contacts
Smallpox Event
Case Detection and Investigation
Case or Agent Confirmation
Containment of Outbreak
Local
Regional
Global
Diagnosis, Treatment, and Infection Control
Vaccination Operations
Isolation and Quarantine
Communication and Media Operations
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Epidemiologic InvestigationMajor Purposes

• The goal of the epidemiologic investigation is to
  collect sufficient information to promptly reduce
  the risk of transmission by means of the
  following activities
• 1. Locate, interview, classify, confirm, and
  isolate cases
• 2. Trace, interview, and vaccinate and place
  contacts under surveillance
• 3. Determine the cause or source of the outbreak
• Three Cs of the Outbreak

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Epidemiologic InvestigationLevels of Response
Local - Implement prepared, local smallpox
response plans. - Execute immediate reporting of
cases. - Maintain primary responsibility for
conducting case investigations. - Designate and
support a Smallpox Response Coordinator - Conduct
case investigations with local resources only
until support arrives at 24 48 hours. - Upon
arrival, attach Smallpox Epi Response Team (SERT)
under the OPCON of local MTF or field medical
unit. Regional - Provide consultative support
to local event responders. - Coordinate local,
state, or federal assistance, as
needed. - Request Smallpox Epi Response Team
assistance immediately upon local confirmation
of a case of smallpox. - Prepare for prior
manning, training, vaccination and resourcing of
SERTs. - SERTs will have capability to vaccinate
some personnel without resupply Global - Joint
staff designation of a DoD Smallpox Coordination
Center. - DoD Coordination Center will
coordinate with CDC, host nations, or the WHO
as needed - DoD will provide support to the
lead federal agency as needed upon request
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Epidemiologic InvestigationConcept of Operations

• Upon recognition of a probable or confirmed case
  of smallpox, local personnel will initiate a case
  investigation immediately. Coordinate with
  appropriate local officials.
• A case investigation may also be initiated for
  suspected cases (with expert consultation),
  depending upon probability of smallpox diagnosis
  and level of suspected threat.
• Local or regional medical personnel will complete
  most case investigations. Regional PM or PH
  personnel, MTFs, and DoD Smallpox Epi-Teams will
  provide consultative and logistical support.
• Case investigations will
• - Establish smallpox diagnoses / case
  classification
• - Identify contacts for tracing, vaccination,
  and surveillance
• - Identify the source of infection
• - Identify unexpected features of the outbreak
• - Formulate the most effective containment
  strategies

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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses - Confirm the diagnosis - For
suspected cases based on clinical presentation,
consult with Infectious Disease physicians and/or
other experts. Submit clinical specimens for
laboratory confirmation. - Identify and
classify cases as suspected, probable, or
confirmed based upon CDC definitions - Impose
isolation of suspected, probable, and confirmed
cases
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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses 2. Identify contacts for tracing,
vaccination, and surveillance - Initiate
contact-tracing within hours of case
confirmation - Collect information on contacts
of contacts - Minimize risk of infection among
investigative personnel by using vaccinated
personnel to the extent possible. In some case
requires local coordination for use of scarce
resources and prior planning to assure pre-event
vaccination of required personnel. - Call upon
outside teams for assistance as
needed. - Follow CDC guidelines in assigning
case and contact numbers
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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses 2. Identify contacts for vaccination
and surveillance 3. Identify most likely source
of initial exposure - Complete this step within
24 hours. Two possible causes
are 1) Intentional release via environmental
release or human vectors 2) Accidental release
or inoculation from research or repository
laboratories - Provide timely notification
where initial exposure or virus release may have
occurred to appropriate authorities (installation
commander, service medical operations center,
local or nearest MTF) - May require extensive
trace-back if beyond the 1st generation of cases.
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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses 2. Identify contacts for vaccination
and surveillance 3. Identify most likely source
of initial exposure 4. Estimate the population
at risk - Identification of the PAR will depend
on the identified source of exposure. - Exposed
persons / contacts may be identified based
on 1) Presence at a specific
location 2) Based upon a mode of
transportation 3) Exposure to a specific
person - The PAR will be placed under
surveillance. Consider offering vaccine to these
persons as well as their household contacts.
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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses 2. Identify contacts for vaccination
and surveillance 3. Identify most likely source
of initial exposure 4. Estimate the population at
risk 5. Identify unexpected features of the
outbreak - Departures from expected incubation
periods - Case occurrence inconsistent with
likely modes of transmission - Secondary cases
occurring in persons with little or no theorized
exposure - Demographic profiles that vary
from an expected distribution - Variations in
case-fatality from an expected 30 - Secondary
attack rates in close contacts that vary from the
expected 58 (38-88) - Deviations from the
expected case reproduction rate of 1-10
cases Note Be familiar with features of
varicella that are similar and those which are
different and may distinguish VZV-associated
outbreaks from those caused by smallpox.
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Epidemiologic InvestigationCase Investigations
Purposes 1. Establish smallpox
diagnoses 2. Identify contacts for vaccination
and surveillance 3. Identify most likely source
of initial exposure 4. Estimate the population at
risk 5. Identify unexpected features of the
outbreak 6. Formulate the most effective
containment strategy - Some options include
installation closure, quarantine, travel
restriction, ban of use of large transport
vehicles, closure of facilities where crowding
may occur - Maintain effective communication to
ensure that decision-makers remain informed of
the status of the evolving outbreak and what
future decisions you are likely to recommend.
Coordinate with security personnel for
assistance. - Recognize when cases are occurring
outside anticipated patterns, requiring expanded
vaccination - Quickly recognize when vaccination
is required in second-order contacts - Anticipate
where and when additional resources are required
to quickly identify, trace, interview, and
monitor contacts - Develop a decision support
matrix that anticipates future actions based upon
anticipated events that may occur
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Epidemiologic InvestigationPost-Event
Surveillance
Once a confirmed case of smallpox has been
identified, immediately initiate active case
surveillance to quickly identify additional
suspected or probable cases of infection. 1. Dist
ribute case definition and case
classifications 2. Increase local awareness of
the CDCs Generalized Febrile Vesicular-Pustular
Rash Illness protocol. 3. Establish redundant
mechanisms for reporting cases 4. Distribute
reporting forms - Form 1A, Core data collects
key information on cases - Form 1B, Monitor
clinical course and outcome of cases 5. Enhanced
hospital-based surveillance (DoD Appendix
A-11) - Refer cases of fever-rash illness to
specified facilities - Designate one employee to
conduct daily active surveillance (maintain
high-risk and moderate-risk case
lists) - Conduct prospective and retrospective
surveillance - Specify support activities within
the ED, Laboratory, Pathology Dept, ICUs, and
Wards
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Epidemiologic InvestigationSmallpox Epi Response
Teams

• Be prepared to support various scenarios
• CONUS-based attack on a military installation
• CONUS-based attack not involving a military
  installation
• CONUS-based attack involving both military and
  civilian settings
• OCONUS attack involving military personnel or
  installations
• Possibly attached under OPCON of
• Unified Command
• Medical command of one of US Armed Services
• Installation commander
• Civilian authority (FEMA, CDC, state health
  department, other)

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Epidemiologic InvestigationSmallpox Epi Response
Teams

• DoD will maintain at least 6 Smallpox Epi
  Response Teams with approximately 12 members.
• Team Composition
• Team leader (1 per team)
• Public health advisor
• Physician-epidemiologist
• Infectious disease physician
• Laboratory scientist
• PM / PH / EH technician
• Communication specialist
• Occupational medicine physician
• Immunization technician
• Team Capabilities
• Confirm or refute reported cases of smallpox
• Confirm or refute substances suspected of being
  smallpox virus
• Estimate disease threat in the context of a
  smallpox outbreak
• Serve as advisors to medical authorities
  concerning response activities
• vaccination, quarantine, medical care, safety
  precautions

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Clinical StaffMakes Diagnosis
Information Flow for an Infectious Disease
Outbreak at a CONUS Installation
CHPPM - DEDS Dir - EPI PGM
OTSG POPM
CDC
Medical Command (MEDCOM)
State Civilian Leaders
Higher Command
CHPPM (AMSA)
State Public Hlth
Regional Medical Command
Higher Command Surgeon
(State, National)
(Local)
MTF Command (DHS)
Installation Command
County Public Hlth
Preventive Medicine
Med Log / Lab
Med Ops / PAO
Case Unit
Installation Ops Center
Local Civilian Leaders
Case Contacts
MEDDAC LNO
MWR
PAO
Unit LNOs
Media
Law Enforcement
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Summary

• The purpose of the epidemiologic outbreak
  investigation is to reduce the risk of
  transmission through efforts focused on cases,
  contacts, and causes.
• Levels of response during a smallpox outbreak
  include local, regional, and global.
• Case investigation is the key activity that
  allows for an appropriately scaled local
  response.
• Post-event surveillance activities include
  efforts to actively identify new cases and
  enhance hospital-based surveillance.
• Smallpox epidemiologic response teams will be
  available within DoD to augment local efforts
  through capabilities and consultation.

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?? Questions ??