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

Northwest Center for Public Health PracticeUniversity of Washington School of Public Health and Community Medicine

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Preparing for and Responding to Preparing for and Responding to Bioterrorism: Bioterrorism:

Information for the Public Health Information for the Public Health WorkforceWorkforce

UW Northwest Center for Public Health Practice

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Acknowledgements Acknowledgements Acknowledgements Acknowledgements

This presentation, and the accompanying instructor’s manual, were prepared by Jennifer Brennan Braden, MD, MPH, at the Northwest Center for Public Health Practice in Seattle, WA, for thepurpose of educating public health employees in the general aspects of bioterrorism preparedness and response. Instructors are encouragedto 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 instructor’s guide.

Patrick O’Carroll, MD, MPH Project Coordinator Centers for Disease Control and Prevention

Judith YarrowDesign and Editing Health Policy and Analysis; University of WA

Washington State Department of Health

Jeff Duchin, MD Jane Koehler, DVM, MPHCommunicable Disease Control, Epidemiology and Immunization Section

Public Health - Seattle and King County

Ed Walker, MD; University of WADepartment of Psychiatry


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Diseases of Bioterrorist Potential: Diseases of Bioterrorist Potential: Smallpox Smallpox

Diseases of Bioterrorist Potential: Diseases of Bioterrorist Potential: Smallpox Smallpox

CDC, AFIP


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Diseases of Bioterrorist PotentialDiseases of Bioterrorist Potential Learning ObjectivesLearning Objectives

Diseases of Bioterrorist PotentialDiseases of Bioterrorist Potential Learning ObjectivesLearning Objectives

Describe the epidemiology, mode of Describe the epidemiology, mode of transmission, and presenting symptoms of transmission, and presenting symptoms of disease caused by the CDC-defined Category A disease caused by the CDC-defined Category A agents agents

Identify the infection control and prophylactic Identify the infection control and prophylactic measures to implement in the event of a measures to implement in the event of a suspected or confirmed Category A case or suspected or confirmed Category A case or outbreakoutbreak

Describe the epidemiology, mode of Describe the epidemiology, mode of transmission, and presenting symptoms of transmission, and presenting symptoms of disease caused by the CDC-defined Category A disease caused by the CDC-defined Category A agents agents

Identify the infection control and prophylactic Identify the infection control and prophylactic measures to implement in the event of a measures to implement in the event of a suspected or confirmed Category A case or suspected or confirmed Category A case or outbreakoutbreak


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Smallpox Smallpox OverviewOverview

Smallpox Smallpox OverviewOverview

Two strains: variola major and variola minorTwo strains: variola major and variola minor Variola minor – milder disease with case Variola minor – milder disease with case

fatality typically 1% or less fatality typically 1% or less Variola major – more severe disease with Variola major – more severe disease with

average 30% mortality in unvaccinated average 30% mortality in unvaccinated

Person-to-person transmissionPerson-to-person transmission

Two strains: variola major and variola minorTwo strains: variola major and variola minor Variola minor – milder disease with case Variola minor – milder disease with case

fatality typically 1% or less fatality typically 1% or less Variola major – more severe disease with Variola major – more severe disease with

average 30% mortality in unvaccinated average 30% mortality in unvaccinated


Smallpox OverviewOverview


Killed approximately 300,000,000 persons in 20th century

Routine smallpox vaccination in the U.S. stopped in 1972

WHO declared smallpox eradicated in 1980 Vaccine has significant adverse effects No effective treatment

Killed approximately 300,000,000 persons in 20th century

Routine smallpox vaccination in the U.S. stopped in 1972

WHO declared smallpox eradicated in 1980 Vaccine has significant adverse effects No effective treatment

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Person-to-person transmission

Average 30% mortality from variola major in unvaccinated

A single case is considered a global public health emergency

Person-to-person transmission

Average 30% mortality from variola major in unvaccinated

A single case is considered a global public health emergency

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Smallpox Smallpox TransmissionTransmissionSmallpox Smallpox TransmissionTransmission

Infectious dose extremely lowInfectious dose extremely low

Spread primarily by droplet nuclei >aerosols > Spread primarily by droplet nuclei >aerosols > direct contactdirect contact

Maintains infectivity for prolonged periods out of Maintains infectivity for prolonged periods out of hosthost Contaminated clothing and bedding can be infectiousContaminated clothing and bedding can be infectious

Infectious dose extremely lowInfectious dose extremely low

Spread primarily by droplet nuclei >aerosols > Spread primarily by droplet nuclei >aerosols > direct contactdirect contact

Maintains infectivity for prolonged periods out of Maintains infectivity for prolonged periods out of hosthost Contaminated clothing and bedding can be infectiousContaminated clothing and bedding can be infectious

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Smallpox Smallpox TransmissionTransmissionSmallpox Smallpox TransmissionTransmission

Transmission does not usually occur until after Transmission does not usually occur until after febrile prodrome febrile prodrome Coincident with onset of rashCoincident with onset of rash

Slower spread through the population than chickenpox Slower spread through the population than chickenpox or measlesor measles

Large outbreaks in schools were uncommonLarge outbreaks in schools were uncommon

Less transmissible than measles, chickenpox, Less transmissible than measles, chickenpox, influenzainfluenza

Transmission does not usually occur until after Transmission does not usually occur until after febrile prodrome febrile prodrome Coincident with onset of rashCoincident with onset of rash

Slower spread through the population than chickenpox Slower spread through the population than chickenpox or measlesor measles

Large outbreaks in schools were uncommonLarge outbreaks in schools were uncommon

Less transmissible than measles, chickenpox, Less transmissible than measles, chickenpox, influenzainfluenza

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SmallpoxSmallpoxTransmissionTransmissionSmallpoxSmallpox

TransmissionTransmission

Secondary cases primarily household, hospital, Secondary cases primarily household, hospital, and other close contactsand other close contacts

Secondary attack rate 37-87% among Secondary attack rate 37-87% among unvaccinated contactsunvaccinated contacts

Patients with severe disease or cough at highest Patients with severe disease or cough at highest risk for transmissionrisk for transmission

Greatest infectivity from rash onset to day 7-10 of Greatest infectivity from rash onset to day 7-10 of rashrash Infectivity decreases with scab formation and Infectivity decreases with scab formation and

ceases with separation of scabsceases with separation of scabs

Secondary cases primarily household, hospital, Secondary cases primarily household, hospital, and other close contactsand other close contacts

Secondary attack rate 37-87% among Secondary attack rate 37-87% among unvaccinated contactsunvaccinated contacts

Patients with severe disease or cough at highest Patients with severe disease or cough at highest risk for transmissionrisk for transmission

Greatest infectivity from rash onset to day 7-10 of Greatest infectivity from rash onset to day 7-10 of rashrash Infectivity decreases with scab formation and Infectivity decreases with scab formation and

ceases with separation of scabsceases with separation of scabs10


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SmallpoxSmallpoxCase DefinitionCase Definition

SmallpoxSmallpoxCase DefinitionCase Definition

Clinical case definitionClinical case definition An illness with acute onset of fever An illness with acute onset of fever 101101F F

followed by a rash characterized by vesicles followed by a rash characterized by vesicles or firm pustules in the same stage of or firm pustules in the same stage of development without other apparent cause development without other apparent cause

Laboratory criteria for confirmation Laboratory criteria for confirmation (Level C/D* lab)(Level C/D* lab)

Isolation of smallpox virus from a clinical Isolation of smallpox virus from a clinical specimen, specimen, OROR

Identification of variola in a clinical specimen Identification of variola in a clinical specimen by PCR or electronmicroscopyby PCR or electronmicroscopy

Clinical case definitionClinical case definition An illness with acute onset of fever An illness with acute onset of fever 101101F F

followed by a rash characterized by vesicles followed by a rash characterized by vesicles or firm pustules in the same stage of or firm pustules in the same stage of development without other apparent cause development without other apparent cause

Laboratory criteria for confirmation Laboratory criteria for confirmation (Level C/D* lab)(Level C/D* lab)

Isolation of smallpox virus from a clinical Isolation of smallpox virus from a clinical specimen, specimen, OROR

Identification of variola in a clinical specimen Identification of variola in a clinical specimen by PCR or electronmicroscopyby PCR or electronmicroscopy

*initial confirmation of outbreak requires testing in level D lab (I.e., CDC)


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SmallpoxSmallpoxCase ClassificationCase Classification

SmallpoxSmallpoxCase ClassificationCase Classification

Case classification Case classification ConfirmedConfirmed: laboratory confirmed : laboratory confirmed ProbableProbable: meets clinical case definition & has : meets clinical case definition & has

an epi link to another confirmed or probable an epi link to another confirmed or probable casecase

SuspectedSuspected: : Meets clinical case definition but is not Meets clinical case definition but is not

laboratory-confirmed and does not have an laboratory-confirmed and does not have an epi link epi link OROR

Atypical presentation not lab confirmed but Atypical presentation not lab confirmed but has an epi link to a confirmed or probable has an epi link to a confirmed or probable casecase

Case classification Case classification ConfirmedConfirmed: laboratory confirmed : laboratory confirmed ProbableProbable: meets clinical case definition & has : meets clinical case definition & has

an epi link to another confirmed or probable an epi link to another confirmed or probable casecase

SuspectedSuspected: : Meets clinical case definition but is not Meets clinical case definition but is not

laboratory-confirmed and does not have an laboratory-confirmed and does not have an epi link epi link OROR

Atypical presentation not lab confirmed but Atypical presentation not lab confirmed but has an epi link to a confirmed or probable has an epi link to a confirmed or probable casecase

SmallpoxSmallpoxClinical FeaturesClinical FeaturesSmallpoxSmallpox

Clinical FeaturesClinical Features

Prodrome (Prodrome (incubation 7-19 daysincubation 7-19 days)) Acute onset of fever, malaise, Acute onset of fever, malaise,

headache, backache, vomiting, headache, backache, vomiting, occasional deliriumoccasional delirium

Transient red rashTransient red rash ExanthemExanthem (2-3 days later)(2-3 days later)

Preceded by enanthem on Preceded by enanthem on oropharyngeal mucosaoropharyngeal mucosa

Begins on face, hands, forearmsBegins on face, hands, forearms Spread to lower extremities then Spread to lower extremities then

trunk over ~ 7 daystrunk over ~ 7 days Synchronous progression: flat Synchronous progression: flat

lesions lesions vesicles vesicles pustules pustules scabsscabs

Prodrome (Prodrome (incubation 7-19 daysincubation 7-19 days)) Acute onset of fever, malaise, Acute onset of fever, malaise,

headache, backache, vomiting, headache, backache, vomiting, occasional deliriumoccasional delirium

Transient red rashTransient red rash ExanthemExanthem (2-3 days later)(2-3 days later)

Preceded by enanthem on Preceded by enanthem on oropharyngeal mucosaoropharyngeal mucosa

Begins on face, hands, forearmsBegins on face, hands, forearms Spread to lower extremities then Spread to lower extremities then

trunk over ~ 7 daystrunk over ~ 7 days Synchronous progression: flat Synchronous progression: flat

lesions lesions vesicles vesicles pustules pustules scabsscabs

CDC

Lesions most abundant on Lesions most abundant on face and extremities, face and extremities, including palms/solesincluding palms/soles 13


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SmallpoxSmallpoxClinical CourseClinical Course

SmallpoxSmallpoxClinical CourseClinical Course

WHO

SmallpoxSmallpox Clinical ProgressionClinical Progression


WHO 15

http://www.who.int/emc/diseases/smallpox


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Thomas, D.

Day 14Day 10 Day 21

SmallpoxSmallpoxClinical TypesClinical TypesSmallpoxSmallpox

Clinical TypesClinical Types

Ordinary smallpox: 90% of casesOrdinary smallpox: 90% of cases Case-fatality average 30%Case-fatality average 30% Occurs in non-immunized persons Occurs in non-immunized persons

Modified smallpoxModified smallpox Milder, rarely fatalMilder, rarely fatal Occurs in 25% of previously immunized Occurs in 25% of previously immunized

persons and 2% of non-immunized persons and 2% of non-immunized personspersons

Fewer, smaller,more superficial lesions that Fewer, smaller,more superficial lesions that evolve more rapidlyevolve more rapidly

Ordinary smallpox: 90% of casesOrdinary smallpox: 90% of cases Case-fatality average 30%Case-fatality average 30% Occurs in non-immunized persons Occurs in non-immunized persons

Modified smallpoxModified smallpox Milder, rarely fatalMilder, rarely fatal Occurs in 25% of previously immunized Occurs in 25% of previously immunized

persons and 2% of non-immunized persons and 2% of non-immunized personspersons

Fewer, smaller,more superficial lesions that Fewer, smaller,more superficial lesions that evolve more rapidlyevolve more rapidly

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Hemorrhagic smallpox: <3% of casesHemorrhagic smallpox: <3% of cases Immunocompromised persons and Immunocompromised persons and

pregnant women at riskpregnant women at risk Shortened incubation period, severe Shortened incubation period, severe

prodromeprodrome Dusky erythema followed by petechiae & Dusky erythema followed by petechiae &

hemorrhages into skin and mucous hemorrhages into skin and mucous membranes membranes

Almost uniformly fatal within 7 daysAlmost uniformly fatal within 7 days

Hemorrhagic smallpox: <3% of casesHemorrhagic smallpox: <3% of cases Immunocompromised persons and Immunocompromised persons and

pregnant women at riskpregnant women at risk Shortened incubation period, severe Shortened incubation period, severe

prodromeprodrome Dusky erythema followed by petechiae & Dusky erythema followed by petechiae &

hemorrhages into skin and mucous hemorrhages into skin and mucous membranes membranes

Almost uniformly fatal within 7 daysAlmost uniformly fatal within 7 days

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Malignant or flat-type smallpox: 7% of casesMalignant or flat-type smallpox: 7% of cases Slowly evolving lesions that coalesce Slowly evolving lesions that coalesce

without forming pustuleswithout forming pustules Associated with cell-mediated immune Associated with cell-mediated immune

deficiencydeficiency Usually fatal Usually fatal

Variola sine eruptioneVariola sine eruptione Occurs in previously vaccinated persons or Occurs in previously vaccinated persons or

infants with maternal antibodiesinfants with maternal antibodies Asymptomatic or mild illnessAsymptomatic or mild illness Transmission from these cases has not Transmission from these cases has not

been documentedbeen documented

Malignant or flat-type smallpox: 7% of casesMalignant or flat-type smallpox: 7% of cases Slowly evolving lesions that coalesce Slowly evolving lesions that coalesce

without forming pustuleswithout forming pustules Associated with cell-mediated immune Associated with cell-mediated immune

deficiencydeficiency Usually fatal Usually fatal

Variola sine eruptioneVariola sine eruptione Occurs in previously vaccinated persons or Occurs in previously vaccinated persons or

infants with maternal antibodiesinfants with maternal antibodies Asymptomatic or mild illnessAsymptomatic or mild illness Transmission from these cases has not Transmission from these cases has not

been documentedbeen documented 19


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Malignant Smallpox Malignant Smallpox Malignant Smallpox Malignant Smallpox

Thomas, D.

SmallpoxSmallpoxComplicationsComplicationsSmallpoxSmallpox

ComplicationsComplications

Encephalitis Encephalitis

1 in 500 cases Variola major1 in 500 cases Variola major

1 in 2,000 cases Variola minor1 in 2,000 cases Variola minor

Corneal ulceration Corneal ulceration

Blindness in 1% of casesBlindness in 1% of cases

Infection in pregnancyInfection in pregnancy

High perinatal fatality rate High perinatal fatality rate

Congenital infectionCongenital infection

Encephalitis Encephalitis

1 in 500 cases Variola major1 in 500 cases Variola major

1 in 2,000 cases Variola minor1 in 2,000 cases Variola minor

Corneal ulceration Corneal ulceration

Blindness in 1% of casesBlindness in 1% of cases

Infection in pregnancyInfection in pregnancy

High perinatal fatality rate High perinatal fatality rate

Congenital infectionCongenital infection 21

SmallpoxSmallpoxMedical ManagementMedical Management


Respiratory and contact isolation for hospitalized Respiratory and contact isolation for hospitalized casescases Negative pressure room; HEPA-filtered exhaust Negative pressure room; HEPA-filtered exhaust All health care workers employ aerosol and contact All health care workers employ aerosol and contact

precautions regardless of immunization statusprecautions regardless of immunization status No specific therapy availableNo specific therapy available Supportive care: fluid and electrolyte, skin Supportive care: fluid and electrolyte, skin

nutritionalnutritional

Respiratory and contact isolation for hospitalized Respiratory and contact isolation for hospitalized casescases Negative pressure room; HEPA-filtered exhaust Negative pressure room; HEPA-filtered exhaust All health care workers employ aerosol and contact All health care workers employ aerosol and contact

precautions regardless of immunization statusprecautions regardless of immunization status No specific therapy availableNo specific therapy available Supportive care: fluid and electrolyte, skin Supportive care: fluid and electrolyte, skin

nutritionalnutritional

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Antibiotics for secondary infectionAntibiotics for secondary infection

Antiviral drugs under evaluationAntiviral drugs under evaluation

Notify Public Health and hospital epidemiology Notify Public Health and hospital epidemiology immediatelyimmediately for for suspectedsuspected case case

Antibiotics for secondary infectionAntibiotics for secondary infection

Antiviral drugs under evaluationAntiviral drugs under evaluation

Notify Public Health and hospital epidemiology Notify Public Health and hospital epidemiology immediatelyimmediately for for suspectedsuspected case case

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SmallpoxSmallpox OutbreakOutbreak ManagementManagement


Case identification, isolation, and immunizationCase identification, isolation, and immunization Rapid identification of contacts Rapid identification of contacts Immediate vaccination or boosting of Immediate vaccination or boosting of ALLALL potential potential

contacts including health care workers (ring contacts including health care workers (ring vaccination)vaccination) Vaccination within 4 days of exposure may Vaccination within 4 days of exposure may

prevent or lessen disease prevent or lessen disease Isolation with monitoring for fever or rashIsolation with monitoring for fever or rash

18 days from last contact with case18 days from last contact with case Respiratory isolation if possible for febrile contactsRespiratory isolation if possible for febrile contacts

Case identification, isolation, and immunizationCase identification, isolation, and immunization Rapid identification of contacts Rapid identification of contacts Immediate vaccination or boosting of Immediate vaccination or boosting of ALLALL potential potential

contacts including health care workers (ring contacts including health care workers (ring vaccination)vaccination) Vaccination within 4 days of exposure may Vaccination within 4 days of exposure may

prevent or lessen disease prevent or lessen disease Isolation with monitoring for fever or rashIsolation with monitoring for fever or rash

18 days from last contact with case18 days from last contact with case Respiratory isolation if possible for febrile contactsRespiratory isolation if possible for febrile contacts

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Priority groups for vaccination in a smallpox Priority groups for vaccination in a smallpox outbreak include persons involved in the direct outbreak include persons involved in the direct medical or public health evaluation of confirmed, medical or public health evaluation of confirmed, probable, or suspected smallpox patients probable, or suspected smallpox patients

Passive immunization (VIG)Passive immunization (VIG)

Potential use for contacts at high risk for Potential use for contacts at high risk for vaccine complications vaccine complications Pregnancy, skin disorders, Pregnancy, skin disorders,

immunosuppressionimmunosuppressionVIG not readily available VIG not readily available

Priority groups for vaccination in a smallpox Priority groups for vaccination in a smallpox outbreak include persons involved in the direct outbreak include persons involved in the direct medical or public health evaluation of confirmed, medical or public health evaluation of confirmed, probable, or suspected smallpox patients probable, or suspected smallpox patients

Passive immunization (VIG)Passive immunization (VIG)

Potential use for contacts at high risk for Potential use for contacts at high risk for vaccine complications vaccine complications Pregnancy, skin disorders, Pregnancy, skin disorders,

immunosuppressionimmunosuppressionVIG not readily available VIG not readily available

More on CDC's response plan...


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SmallpoxSmallpoxDefinition of a ContactDefinition of a Contact

SmallpoxSmallpoxDefinition of a ContactDefinition of a Contact

Contact: A person who has had contact with a Contact: A person who has had contact with a suspected, probable or confirmed case of suspected, probable or confirmed case of smallpoxsmallpox Cases should be considered infectious from the Cases should be considered infectious from the

onset of fever, until all scabs have separatedonset of fever, until all scabs have separated

Close contact: Face-to-face contact (Close contact: Face-to-face contact (6ft) with 6ft) with a smallpox casea smallpox case

Contact: A person who has had contact with a Contact: A person who has had contact with a suspected, probable or confirmed case of suspected, probable or confirmed case of smallpoxsmallpox Cases should be considered infectious from the Cases should be considered infectious from the

onset of fever, until all scabs have separatedonset of fever, until all scabs have separated

Close contact: Face-to-face contact (Close contact: Face-to-face contact (6ft) with 6ft) with a smallpox casea smallpox case


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Smallpox Outbreak ManagementSmallpox Outbreak ManagementPre-release VaccinationPre-release Vaccination

Smallpox Outbreak ManagementSmallpox Outbreak ManagementPre-release VaccinationPre-release Vaccination

Select individuals vaccinated to enhance Select individuals vaccinated to enhance smallpox response capacitysmallpox response capacity

Smallpox Response TeamsSmallpox Response Teams Designated public health, law enforcement, Designated public health, law enforcement,

and medical personnel in each state/territoryand medical personnel in each state/territory Investigate, evaluate, and diagnose initial Investigate, evaluate, and diagnose initial

suspect cases of smallpoxsuspect cases of smallpox Select personnel at acute care health care Select personnel at acute care health care

facilities (Smallpox Health Care Teams)facilities (Smallpox Health Care Teams)

Select individuals vaccinated to enhance Select individuals vaccinated to enhance smallpox response capacitysmallpox response capacity

Smallpox Response TeamsSmallpox Response Teams Designated public health, law enforcement, Designated public health, law enforcement,

and medical personnel in each state/territoryand medical personnel in each state/territory Investigate, evaluate, and diagnose initial Investigate, evaluate, and diagnose initial

suspect cases of smallpoxsuspect cases of smallpox Select personnel at acute care health care Select personnel at acute care health care

facilities (Smallpox Health Care Teams)facilities (Smallpox Health Care Teams)ACIP, June 2002

Smallpox VaccineSmallpox VaccineSmallpox VaccineSmallpox Vaccine

Made from live Made from live VacciniaVaccinia virus virus ~ 200 million doses in U.S. stores~ 200 million doses in U.S. stores

Intradermal inoculation with bifurcated needle Intradermal inoculation with bifurcated needle (scarification)(scarification) Pustular lesion or induration surrounding Pustular lesion or induration surrounding

central lesion (scab or ulcer) 6-8 days post-central lesion (scab or ulcer) 6-8 days post-vaccinationvaccination

Low grade fever, axillary lymphadenopathyLow grade fever, axillary lymphadenopathy Scar (permanent) demonstrates successful Scar (permanent) demonstrates successful

vaccination (“take”) vaccination (“take”) Immunity not life-longImmunity not life-long

Made from live Made from live VacciniaVaccinia virus virus ~ 200 million doses in U.S. stores~ 200 million doses in U.S. stores

Intradermal inoculation with bifurcated needle Intradermal inoculation with bifurcated needle (scarification)(scarification) Pustular lesion or induration surrounding Pustular lesion or induration surrounding

central lesion (scab or ulcer) 6-8 days post-central lesion (scab or ulcer) 6-8 days post-vaccinationvaccination

Low grade fever, axillary lymphadenopathyLow grade fever, axillary lymphadenopathy Scar (permanent) demonstrates successful Scar (permanent) demonstrates successful

vaccination (“take”) vaccination (“take”) Immunity not life-longImmunity not life-long

WHO

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Smallpox VaccineSmallpox Vaccine AdministrationAdministration

Smallpox VaccineSmallpox Vaccine AdministrationAdministration

WHOJAMA 1999;281:1735-45 Vaccine admin instructions

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http://www.who.int/emc/diseases/smallpox/factsheet.html

Smallpox Smallpox VaccineVaccine “Take” “Take”

Smallpox Smallpox VaccineVaccine “Take” “Take”

WHO

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http://www.who.int/emc/diseases/smallpox


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Smallpox Vaccine ComplicationsSmallpox Vaccine ComplicationsSmallpox Vaccine ComplicationsSmallpox Vaccine Complications

More common in children and primary More common in children and primary vaccinees vaccinees

Most common: secondary inoculation Most common: secondary inoculation Skin, eye, nose, genitaliaSkin, eye, nose, genitalia 50% of all complications50% of all complications 529/million (30% in one study were contacts)529/million (30% in one study were contacts)

Severe reactions less common Severe reactions less common Primary vaccination ~ 1 death/millionPrimary vaccination ~ 1 death/million Revaccination ~ 0.2 deaths/millionRevaccination ~ 0.2 deaths/million

More common in children and primary More common in children and primary vaccinees vaccinees

Most common: secondary inoculation Most common: secondary inoculation Skin, eye, nose, genitaliaSkin, eye, nose, genitalia 50% of all complications50% of all complications 529/million (30% in one study were contacts)529/million (30% in one study were contacts)

Severe reactions less common Severe reactions less common Primary vaccination ~ 1 death/millionPrimary vaccination ~ 1 death/million Revaccination ~ 0.2 deaths/millionRevaccination ~ 0.2 deaths/million

Smallpox Smallpox Complication Rates for Primary VaccinationComplication Rates for Primary Vaccination

Smallpox Smallpox Complication Rates for Primary VaccinationComplication Rates for Primary Vaccination

Less commonLess common Post-vaccination encephalopathy (7-42.3/million)Post-vaccination encephalopathy (7-42.3/million)** Post-vaccination encephalitis (12.3/million) Post-vaccination encephalitis (12.3/million)

25% fatal; 23% neurological sequelae25% fatal; 23% neurological sequelae Progressive vaccinia/vaccinia necrosum (1.5/million)Progressive vaccinia/vaccinia necrosum (1.5/million) Generalized vaccinia (241.5/million): severe in 10%Generalized vaccinia (241.5/million): severe in 10% Eczema vaccinatum (38.5/million)Eczema vaccinatum (38.5/million) Fetal vaccinia - rareFetal vaccinia - rare

Less commonLess common Post-vaccination encephalopathy (7-42.3/million)Post-vaccination encephalopathy (7-42.3/million)** Post-vaccination encephalitis (12.3/million) Post-vaccination encephalitis (12.3/million)

25% fatal; 23% neurological sequelae25% fatal; 23% neurological sequelae Progressive vaccinia/vaccinia necrosum (1.5/million)Progressive vaccinia/vaccinia necrosum (1.5/million) Generalized vaccinia (241.5/million): severe in 10%Generalized vaccinia (241.5/million): severe in 10% Eczema vaccinatum (38.5/million)Eczema vaccinatum (38.5/million) Fetal vaccinia - rareFetal vaccinia - rare

Sourced: MMWR June 22, 2001 / 50(RR10);1-25. Vaccinia (Smallpox) Vaccine Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2001 *Vaccines 3rd Ed. Plotkin SA, Orenstein WA. W.B. Saunders, Phila. 1999 32

Smallpox Vaccine Smallpox Vaccine Pre-exposure ContraindicationsPre-exposure Contraindications

Smallpox Vaccine Smallpox Vaccine Pre-exposure ContraindicationsPre-exposure Contraindications

ImmunosuppressionImmunosuppression AgammaglobulinemiaAgammaglobulinemia Leukemia, lymphoma, generalized malignancyLeukemia, lymphoma, generalized malignancy Chemo- or other immunosuppressive therapyChemo- or other immunosuppressive therapy HIV infectionHIV infection

History or evidence of eczemaHistory or evidence of eczema Household, sexual, or other close contact with Household, sexual, or other close contact with

person with one of the above conditionsperson with one of the above conditions Life-threatening allergy to polymixin B, Life-threatening allergy to polymixin B,

streptomycin, tetracycline, or neomycinstreptomycin, tetracycline, or neomycin PregnancyPregnancy

ImmunosuppressionImmunosuppression AgammaglobulinemiaAgammaglobulinemia Leukemia, lymphoma, generalized malignancyLeukemia, lymphoma, generalized malignancy Chemo- or other immunosuppressive therapyChemo- or other immunosuppressive therapy HIV infectionHIV infection

History or evidence of eczemaHistory or evidence of eczema Household, sexual, or other close contact with Household, sexual, or other close contact with

person with one of the above conditionsperson with one of the above conditions Life-threatening allergy to polymixin B, Life-threatening allergy to polymixin B,

streptomycin, tetracycline, or neomycinstreptomycin, tetracycline, or neomycin PregnancyPregnancy 33


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Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: SimilarSimilar Epidemiologic FeaturesEpidemiologic Features

Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: SimilarSimilar Epidemiologic FeaturesEpidemiologic Features

Incubation period 14 (10-21) daysIncubation period 14 (10-21) days


Seasonal transmission of disease highest Seasonal transmission of disease highest during winter and early spring during winter and early spring

Incubation period 14 (10-21) daysIncubation period 14 (10-21) days


Seasonal transmission of disease highest Seasonal transmission of disease highest during winter and early spring during winter and early spring


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Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: Epi FeaturesEpi Features that Differthat Differ

Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: Epi FeaturesEpi Features that Differthat Differ

Chickenpox (varicella)Chickenpox (varicella)

Most cases occur in Most cases occur in childrenchildren

Expected case fatality Expected case fatality rate 2-3/100,000rate 2-3/100,000

Secondary attack rate Secondary attack rate of 80% among of 80% among susceptible household susceptible household contactscontacts

Chickenpox (varicella)Chickenpox (varicella)

Most cases occur in Most cases occur in childrenchildren

Expected case fatality Expected case fatality rate 2-3/100,000rate 2-3/100,000

Secondary attack rate Secondary attack rate of 80% among of 80% among susceptible household susceptible household contactscontacts

Smallpox (variola)Smallpox (variola)

Most of the population Most of the population expected to be expected to be susceptiblesusceptible

Expected case fatality Expected case fatality rate averages 30%rate averages 30%

Secondary attack rate Secondary attack rate ~60% in unvaccinated ~60% in unvaccinated family contacts family contacts

Smallpox (variola)Smallpox (variola)

Most of the population Most of the population expected to be expected to be susceptiblesusceptible

Expected case fatality Expected case fatality rate averages 30%rate averages 30%

Secondary attack rate Secondary attack rate ~60% in unvaccinated ~60% in unvaccinated family contacts family contacts


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Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: Clinical FeaturesClinical Features that Differthat Differ

Distinguishing Smallpox from Chickenpox: Distinguishing Smallpox from Chickenpox: Clinical FeaturesClinical Features that Differthat Differ

Chickenpox (varicella)Chickenpox (varicella) Lesions superficialLesions superficial Rash concentrated Rash concentrated

on trunk on trunk Lesions rarely on Lesions rarely on

palms or soles palms or soles Lesions in different Lesions in different

stages of stages of developmentdevelopment

Rash progresses Rash progresses more quickly more quickly

Chickenpox (varicella)Chickenpox (varicella) Lesions superficialLesions superficial Rash concentrated Rash concentrated

on trunk on trunk Lesions rarely on Lesions rarely on

palms or soles palms or soles Lesions in different Lesions in different

stages of stages of developmentdevelopment

Rash progresses Rash progresses more quickly more quickly

Smallpox (variola)Smallpox (variola) Lesions deep Lesions deep Rash concentrated Rash concentrated

on face & on face & extremitiesextremities

Lesions on palms & Lesions on palms & solessoles

Lesions in same Lesions in same stage of evolution on stage of evolution on any one area of any one area of bodybody

Rash progresses Rash progresses slowlyslowly

Smallpox (variola)Smallpox (variola) Lesions deep Lesions deep Rash concentrated Rash concentrated

on face & on face & extremitiesextremities

Lesions on palms & Lesions on palms & solessoles

Lesions in same Lesions in same stage of evolution on stage of evolution on any one area of any one area of bodybody

Rash progresses Rash progresses slowlyslowly

CDC


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Smallpox Surveillance Smallpox Surveillance Smallpox Surveillance Smallpox Surveillance

Pre-eventPre-event Development of a listing of surveillance partners, Development of a listing of surveillance partners,

points of contact, and mechanisms for reportingpoints of contact, and mechanisms for reporting Establishing sentinel surveillance for generalized Establishing sentinel surveillance for generalized

febrile vesicular-pustular rash in health care febrile vesicular-pustular rash in health care settingssettings

Post-event: Post-event: Once a confirmed case of smallpox is identified Once a confirmed case of smallpox is identified

in your jurisdiction, active surveillance for in your jurisdiction, active surveillance for suspected, probable, and confirmed cases suspected, probable, and confirmed cases should be initiatedshould be initiated

Pre-eventPre-event Development of a listing of surveillance partners, Development of a listing of surveillance partners,

points of contact, and mechanisms for reportingpoints of contact, and mechanisms for reporting Establishing sentinel surveillance for generalized Establishing sentinel surveillance for generalized

febrile vesicular-pustular rash in health care febrile vesicular-pustular rash in health care settingssettings

Post-event: Post-event: Once a confirmed case of smallpox is identified Once a confirmed case of smallpox is identified

in your jurisdiction, active surveillance for in your jurisdiction, active surveillance for suspected, probable, and confirmed cases suspected, probable, and confirmed cases should be initiatedshould be initiated


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Smallpox Surveillance, cont. Smallpox Surveillance, cont. Smallpox Surveillance, cont. Smallpox Surveillance, cont.

Contact tracing, interviewing, and vaccination Contact tracing, interviewing, and vaccination Monitored for vaccine “take” Monitored for vaccine “take” Non-symptomatic contacts monitored for Non-symptomatic contacts monitored for

fever or rash fever or rash 18 days beyond last contact 18 days beyond last contact OROR 14 days beyond successful vaccination 14 days beyond successful vaccination

Followup Followup Laboratory results & epi links Laboratory results & epi links Case outcomes/complicationsCase outcomes/complications Vaccine adverse events (for VAERS)Vaccine adverse events (for VAERS)

Contact tracing, interviewing, and vaccination Contact tracing, interviewing, and vaccination Monitored for vaccine “take” Monitored for vaccine “take” Non-symptomatic contacts monitored for Non-symptomatic contacts monitored for

fever or rash fever or rash 18 days beyond last contact 18 days beyond last contact OROR 14 days beyond successful vaccination 14 days beyond successful vaccination

Followup Followup Laboratory results & epi links Laboratory results & epi links Case outcomes/complicationsCase outcomes/complications Vaccine adverse events (for VAERS)Vaccine adverse events (for VAERS)


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Smallpox Smallpox Summary of Key PointsSummary of Key Points


Smallpox is transmitted person to person; standard and airborne precautions should be initiated in all suspected cases until smallpox is ruled out.

Smallpox cases should be considered infectious from the onset of fever until all scabs have separated.

Smallpox is transmitted person to person; standard and airborne precautions should be initiated in all suspected cases until smallpox is ruled out.

Smallpox cases should be considered infectious from the onset of fever until all scabs have separated.


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Vaccine-induced immunity wanes with time; therefore most people today are considered susceptible to smallpox infection.

In a smallpox outbreak, vaccination is indicated In a smallpox outbreak, vaccination is indicated for all case contacts, including health care for all case contacts, including health care workers and case investigators. workers and case investigators.

Smallpox surveillance includes pre-event rash Smallpox surveillance includes pre-event rash surveillance, post-event surveillance for active surveillance, post-event surveillance for active cases, and follow-up of cases, contacts, and cases, and follow-up of cases, contacts, and vaccine recipients.vaccine recipients.

Vaccine-induced immunity wanes with time; therefore most people today are considered susceptible to smallpox infection.

In a smallpox outbreak, vaccination is indicated In a smallpox outbreak, vaccination is indicated for all case contacts, including health care for all case contacts, including health care workers and case investigators. workers and case investigators.

Smallpox surveillance includes pre-event rash Smallpox surveillance includes pre-event rash surveillance, post-event surveillance for active surveillance, post-event surveillance for active cases, and follow-up of cases, contacts, and cases, and follow-up of cases, contacts, and vaccine recipients.vaccine recipients.


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Epidemiologic features that differentiate Epidemiologic features that differentiate smallpox from chickenpox include a higher case smallpox from chickenpox include a higher case fatality and a lower attack rate. fatality and a lower attack rate.

Clinical features differentiating smallpox from varicella include differences in lesion progression and distribution, illness course and presence of a febrile prodrome.

Epidemiologic features that differentiate Epidemiologic features that differentiate smallpox from chickenpox include a higher case smallpox from chickenpox include a higher case fatality and a lower attack rate. fatality and a lower attack rate.

Clinical features differentiating smallpox from varicella include differences in lesion progression and distribution, illness course and presence of a febrile prodrome.


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Resources Resources Resources Resources

Centers for Disease Control & Prevention Centers for Disease Control & Prevention Bioterrorism Web page: Bioterrorism Web page: CDC Office of Health and Safety Information System CDC Office of Health and Safety Information System

(personal protective equipment)(personal protective equipment)

USAMRIID -- USAMRIID -- includes link to on-line version of includes link to on-line version of Medical Management of Biological Casualties HandbookMedical Management of Biological Casualties Handbook

Johns Hopkins Center for Civilian Biodefense Johns Hopkins Center for Civilian Biodefense StudiesStudies

Centers for Disease Control & Prevention Centers for Disease Control & Prevention Bioterrorism Web page: Bioterrorism Web page: CDC Office of Health and Safety Information System CDC Office of Health and Safety Information System

(personal protective equipment)(personal protective equipment)

USAMRIID -- USAMRIID -- includes link to on-line version of includes link to on-line version of Medical Management of Biological Casualties HandbookMedical Management of Biological Casualties Handbook

Johns Hopkins Center for Civilian Biodefense Johns Hopkins Center for Civilian Biodefense StudiesStudies

http://www.hopkins-biodefense.org

http://www.usamriid.army.mil/

http://www.bt.cdc.gov/

http://www.cdc.gov/od/ohs/


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Office of the Surgeon General: Medical Office of the Surgeon General: Medical Nuclear, Biological and Chemical InformationNuclear, Biological and Chemical Information

St. Louis University Center for the Study of St. Louis University Center for the Study of Bioterrorism and Emerging Infections Bioterrorism and Emerging Infections

Public Health - Seattle & King CountyPublic Health - Seattle & King County

Office of the Surgeon General: Medical Office of the Surgeon General: Medical Nuclear, Biological and Chemical InformationNuclear, Biological and Chemical Information

St. Louis University Center for the Study of St. Louis University Center for the Study of Bioterrorism and Emerging Infections Bioterrorism and Emerging Infections

Public Health - Seattle & King CountyPublic Health - Seattle & King County

http://www.nbc-med.org

http://www.metrokc.gov/health

http://bioterrorism.slu.edu


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Washington State Department of Health Washington State Department of Health

Communicable Disease EpidemiologyCommunicable Disease Epidemiology (206) 361-2914 (206) 361-2914 OROR (877) 539-4344 (24 hour emergency)(877) 539-4344 (24 hour emergency)

Association for Professionals in Infection Association for Professionals in Infection Control Control

MMWR Rec & Rep. Case definitions under MMWR Rec & Rep. Case definitions under public health surveillance.public health surveillance.

Washington State Department of Health Washington State Department of Health

Communicable Disease EpidemiologyCommunicable Disease Epidemiology (206) 361-2914 (206) 361-2914 OROR (877) 539-4344 (24 hour emergency)(877) 539-4344 (24 hour emergency)

Association for Professionals in Infection Association for Professionals in Infection Control Control

MMWR Rec & Rep. Case definitions under MMWR Rec & Rep. Case definitions under public health surveillance.public health surveillance. 1997;46(RR-10):1-55

http://www.apic.org/bioterror

http://www.doh.wa.gov

Documents

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