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EPI Response Team Training: Plague

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Title: EPI Response Team Training: Plague


1
EPI Response TeamTraining Plague
  • Paige Jordan RN, BSN
  • Region II Epidemiologist

2
The Organism
3
Yersinia pestis
  • Family Enterobacteriaceae
  • Gram negative coccobacillus (pleomorphic)
  • Aerobic, Facultatively anaerobic
  • Facultative intracellular pathogen
  • Survival
  • Briefly in soil
  • Soft tissue 1 week
  • Frozen - years

4
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5
History
6
History
  • Outbreaks
  • Justinians pandemic 540-590
  • Black Death pandemic 13461400
  • Great Plague of London 1665
  • Hawaii, 1899
  • San Francisco, 1900
  • Last U.S. outbreak, 1924, Los Angeles
  • 32 pneumonic cases/31 deaths

7
Black Death Pandemic
  • Sudden appearance in Europe 1347
  • Rattus rattus and Xenopsylla cheopis
  • Quarantine
  • Impact on England greatest of all countries
  • Sporadic outbreaks throughout 14th century
  • 17-55 million perished (1/3 of population)

8
Great Plague of London
  • Began 1664
  • Foundations of public health laid
  • Reporting of sick persons, shutting up homes
  • Lord have mercy upon us
  • Killed dogs and cats
  • Peak mortality of 7,000/week
  • Total mortality 1/5th of pop.

9
United States
  • Hawaii 1899
  • San Francisco 1900
  • 1924 Epidemic Los Angeles
  • 32 pneumonic cases/31 deaths
  • Spread throughout the western U.S.
  • From Rattus norvegicus and Rattus rattus to
    sylvatic rodents
  • Primarily ground squirrels

10
U.S. - First Human Cases
  • California 1900
  • Oregon 1934
  • Utah 1936
  • Nevada 1937
  • Idaho 1940
  • New Mexico 1949
  • Montana 1987
  • Arizona 1950
  • Colorado 1957
  • Wyoming 1978
  • Oklahoma 1980s
  • Texas 1920
  • Washington 1907
  • New York 2002

11
Plague as a Disease
  • Class 1 quarantinable disease (WHO)
  • CDC Division of Quarantine
  • Reportable disease

12
Transmission
13
Transmission to Humans
  • Flea bite 78
  • Especially those associated with ground squirrels
  • Direct animal contact 20
  • Tissues, body fluids, scratches, bites
  • Y. pestis enters through break in skin
  • Aerosol (ie, cough) 2
  • Cats
  • Human cases, April-November

14
Flea Vectors
  • Can live off host for months
  • Many species can transmit
  • Oropsylla montana
  • Rock and California ground squirrels, prairie
    dogs
  • Excellent vector
  • Most important flea vector in United States

15
Flea Transmission
  • ?27C (80.6F) blood clots in flea gut and
    transmission occurs more readily
  • ?27C blood clot in flea gut dissolves and
    transmission less likely

16
Epidemiology
17
Where Are Cases Found?
  • Southwest
  • Northern New Mexico
  • Northern Arizona
  • Southern Colorado
  • California
  • Accounts for 90 of all human cases

18
Human Plague U.S. 1970-1991(295 cases)
19
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20
Human Cases
  • United States
  • 1925-1964 41 cases, avg. 2 cases/year
  • Since 1970 avg. 13 cases/year
  • Worldwide
  • 1,000-3,000 cases/yr
  • 18,739 cases from 19801994
  • 2,603 cases in 1999 from 14 countries
  • 181 deaths
  • Africa (76 of all cases)

21
Plague, reported human cases, U.S. 1970-2000
Prairie dog and rock squirrel epizootic
0 5 10 15 20 25
30 35 40 45
Reported Cases
1970 1975 1980
1985 1990 1995
2000 Year
22
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23
Public Health Significance
  • 10-15 fifteen people each year are diagnosed with
    plague in the United States
  • Approx 14 (1 out of 7) of the cases of plague
    are fatal
  • associated with delays in diagnosis and treatment
  • Scattered in rural areas
  • Associated with rats and rat fleas

24
Public Health Significance
  • Seventeen cases of pneumonic plague from 1972 to
    1994 were acquired from household cats.
  • There has never been a case of plague reported in
    West Virginia.

25
Public Health Significance
  • 390 cases reported in US from 1947-1996
  • 84 of which were bubonic
  • 13 septicemic
  • 2 pneumonic
  • Concomitant case fatality rates were 14, 22,
    and 57 respectively (JAMA, 283(10), May 3, 2000)

26
Public Health Significance
  • Because of the terrorist events of 2001
    associated with anthrax, and because large
    quantities of plague may have been weaponized, a
    bioterrorist event in which Y. Pestis is
    aerosolized cannot be ruled out. In 1970, the
    World Health Organization reported that in a
    worst-case scenario, if 50 mg of Y. Pestis was
    released as an aerosol over a city of 5 million
    people, pneumonic plague could occur in as many
    as 150,000 persons, 36,000 of whom would be
    expected to die

27
Plague Epidemiology in Nature
  • Sylvatic (wild)
  • Urban (domestic)
  • Reservoirs
  • Rock squirrels
  • Ground squirrels
  • Prairie dogs
  • Mice
  • Voles
  • Others

28
Sylvatic Plague
  • Enzootic
  • Plague maintained at steady level in rodent
    populations
  • Low death rates
  • Mice, voles

29
Sylvatic Plague
  • Epizootic
  • Large die-offs, fleas change hosts
  • Amplifying hosts prairie dogs, ground squirrels,
    rock squirrels, woodrats, chipmunks
  • Expansion into human occupied areas
  • Greatest threat to humans

30
Robert B. Crave. Plague. Infectious Diseases, 5th
ed. J.B. Lippincott Co. 1994.
31
Urban Plague
  • Infected fleas or rodents move to urban area
  • Interface areas around homes
  • Western U.S. cities suburban-wilderness zone
  • Commensal (domestic) rodents
  • Roof rat, Norway rat
  • Rat fleas may feed on humans
  • Poverty, filth, homelessness

32
West Virginia
  • No natural reservoir of infection in West
    Virginia
  • Implications for case investigations
  • Urgent investigation
  • Identify potential natural exposure (travel to
    endemic area, importation/exposure to sick
    animal)
  • BT

33
Plague as a Biological Weapon
  • 1970 WHO estimate
  • 50 kg agent
  • City of 5 million
  • 150,000 pneumonic cases
  • 36,000 deaths
  • 80,000-100,000 hospitalized
  • 500,000 secondary cases
  • Up to 100,000 deaths total

34
Disease in Humans
35
Human Disease
  • Bubonic
  • Cutaneous infection
  • Swollen, tender lymph glands (buboes)
  • Fever, chills, headache, exhaustion

36
Human Disease
  • Septicemic
  • Multiplication in bloodstream
  • Fever, chills, prostration,
  • abdominal pain, shock,
  • bleeding into skin

37
Human Disease
  • Pneumonic
  • 1 4 day incubation period
  • Infection of the lungs
  • High fever, chills, cough, difficulty breathing,
    bloody sputum
  • Most likely for BT (may also see gastrointestinal
    manifestations)
  • 100 fatal if not treated early

38
Laboratory Confirmation
  • Acceptable specimens
  • Material from infected bubo
  • Blood specimen (Series taken 10-30 minutes apart)
  • Bronchial or Tracheal Wash
  • Sputum (Not the best)
  • Office of Laboratory Services

39
Laboratory Diagnostic TestsPLAGUE
Colonial Morphology on SBA at 72 hrs
Gram Stain
40
Plague Treatment and Prophylaxis
  • Without treatment Death 2-6 days after exposure
  • Treatment is effective if begun early
  • Symptomatic Exposed (cough or fever)
  • Streptomycin or Gentamicin
  • Doxycycline or Tetracycline
  • Ciprofloxacin
  • Post-exposure Prophylaxis
  • Doxycycline or Ciprofloxacin (7 days)
  • Fever/Cough watch

41
Health Workers
  • Droplet precautions
  • Gown, gloves, eye protection, mask
  • Post-exposure antibiotic prophylaxis

42
Response to BT Plague(Life-saving interventions)
  • Early recognition and reporting
  • Case-finding
  • Fever or cough in known outbreak
  • Early initiation of treatment
  • Isolation of cases
  • Contact tracing and case investigation
  • Initiate post-exposure prophylaxis
  • Monitor exposed for symptoms
  • Antibiotic susceptibility testing

43
Training/Preparation Considerations
  • Physicians and Hospitals
  • Recognition, reporting, treatment, and infection
    control
  • Labs
  • Confirmation of clinical diagnosis
  • Local Health Departments
  • Investigation and pharmaceutical supply
    assessment
  • State Health Departments
  • Investigation, communication, support LHD, etc
  • Increasing overall surveillance and reporting

44
Additional Information
  • CDC, Division of Vector-borne Infectious Diseases
    http//www.cdc.gov/ncidod/dvbid/index.htm
  • CDC, plague information http//www.bt.cdc.gov/agen
    t/plague/index.asp

45
Plague Surveillance Protocol
46
  • Plague may occur from an unintentional exposure
    to infected rodents and their fleas or through an
    intentional exposure such as a bioterrorism (BT)
    event. When necessary this protocol addresses
    unintentional and intentional exposures
    separately otherwise the protocol applies to
    both situations. This protocol applies if a case
    of plague is highly suspected and does not apply
    to non-specific pulmonary, gastrointestinal, or
    rash illnesses.

47
Public Health Action
  • Prior to the occurrence of a case of plague
  • Protect employee health
  • Identify high risk employees
  • Educate high risk employees
  • Personal Protective Equipment (PPE)
  • Assemble and train BT response teams
  • Assemble BT response teams
  • Responsibilities of BT response teams
  • Surge capacity for BT response teams
  • Train BT response teams

48
Protect employee health
  • Identify high risk employees
  • Identify high risk employees who will be involved
    in the response to a bioterrorism (BT) event or
    may have direct contact to plague cases
  • laboratory workers who test specimens and
    environmental samples
  • state and local epidemiologic response teams,
    healthcare workers and support workers in
    hospitals, and EMS staff who may come into
    contact with plague cases
  • hazmat teams, industrial hygienists, health
    department sanitarians, and other personnel that
    may collect environmental samples
  • first responders such as law enforcement, EMS,
    and fire department personnel that respond to a
    BT event.

49
Protect employee health
  • Educate high risk employees
  • Educate high risk employees about plague from a
    BT event
  • respiratory droplet precautions and isolation of
    cases
  • Personal Protective Equipment (PPE)
  • Educate employees on the use of proper PPE
  • Provide appropriate PPE to employees for use
    during an outbreak
  • Ensure fit testing for employees for respirator
    use
  • (see Preventive interventions)

50
Assemble and train BT response teams
  • Assemble BT response teams
  • Identify staff for two BT response teams (an
    epidemiology response and a vaccination /
    medication team) that can adequately respond to a
    large outbreak by conducting surveillance and
    epidemiologic response and by providing
    prophylaxis or treatment after a BT event
  • Responsibilities of BT response teams
  • Specific team responsibilities are described in
    WV Public Health Preparedness Plan for
    Surveillance and Epidemiologic Response

51
Assemble and train BT response teams
  • Surge capacity for BT response teams
  • Identify pools of individuals for surge capacity
    for the response teams during large outbreaks.
    A detailed plan for surge capacity is described
    in the WV Public Health Preparedness Plan for
    Surveillance and Epidemiologic Response
  • Train BT response teams
  • Periodically train and pre-drill individuals on
    the teams in their respective responsibilities
    during an outbreak

52
Public Health Action
  • Educate health care providers and the public in
    the recognition and diagnosis of plague
  • Educate providers and laboratories to report
    plague to the local health department in the
    patients county of residence immediately
  • Educate veterinarians to report confirmed or
    suspected cases of plague in animals to the West
    Virginia Department of Agriculture

53
Public Health Action
  • When a plague case is reported
  • Confirm cases
  • Confirmation of an intentional or unintentional
    exposure and Notification Procedure
  • Activate the BT response teams
  • Protect employee health

54
Case Finding
  • Develop a working case definition
  • Begin enhanced passive surveillance
  • Prepare for active surveillance
  • Confirm new cases
  • Develop line list of cases

55
Contact tracing
  • Identify contacts
  • Direct contacts
  • Direct contacts are defined as any person who has
    had face-to-face contact (within 2 meters) with a
    suspected, probable, or confirmed case of plague
    during the infectious period (See Infectious
    Period section)

56
Contact tracing
  • Interview all suspected, probable, and confirmed
    cases and identify all persons who had direct
    contact with the case since the cases onset of
    symptoms (henceforth referred to as a
    case-contact). Continue interviews daily and
    record contacts until case is no longer
    infectious (See Infectious Period section). For
    each case develop a line list of all
    case-contacts including all household members of
    case-contacts using plague contact tracing forms

57
Contact tracing
  • Locate case contacts
  • Find locating information for each case-contact.
    Use work and school telephone numbers, telephone
    directories, voting lists, neighborhood
    interviews, site visits, hangouts, etc., to
    trace case-contacts when locating information is
    unknown or incomplete. If case-contacts cannot
    be found through these mechanisms, other sources
    for notification, such as media announcements,
    may have to be considered

58
Contact tracing
  • Interview case-contacts
  • Interview all case-contacts and all household
    members of case-contacts including those who work
    full time in the household. Assure that all
    case-contacts are contacted within 24 hours and
    record all information on plague contact tracing
    forms

59
Maintain line listing of cases, develop risk
factor/exposure data base
  • Track cases on case line list and ensure that
    clinical and laboratory information are collected
    from health providers and laboratories, if not
    done

60
continued
  • Develop and maintain a data base of pertinent
    clinical and exposure data for hypothesis testing
  • Compile clinical, laboratory, and exposure
    assessment data as they are collected or
    submitted by health care providers and labs.
  • Review data for completeness and complete pending
    case investigations and incomplete exposure
    assessments.
  • Develop and maintain electronic database for
    hypothesis testing.

61
Hypothesis testing
  • Exposure assessment Conduct an assessment of
    the source and characteristics of exposure
    immediately after a case is suspected as follows
  • Interview a representative sample of cases and
    obtain a complete risk factor and exposure
    history including travel/activity information
    using the Risk Factor and Exposure Form plague
    forms for travel and activities during the cases
    exposure period (1-7 days before symptom onset)
  • If a possible BT event or intentional exposure
    location/source is suspected, continue the
    interview with the same sample of cases. Using
    the Suspicious Exposure Form, determine more
    detailed information, including the type,
    location and specific areas, duration, relative
    amount, and method of dissemination of exposure
    for the possible BT event

62
Hypothesis testing
  • Analyze the clinical, laboratory, risk factor,
    and exposure assessment data to test plausible
    hypotheses for the source and location of exposure

63
Identify exposed population
  • After the source of the exposure is confirmed,
    identify the exposed population.
  • Definition of an exposed individual An exposed
    individual will be a person who shared or
    possibly shared airspace that was contaminated by
    Y. pestis, had direct contact with or inhaled
    contaminated material such as powder or other
    environmental exposures as part of a BT event, or
    shared airspace with an infected animal, or was
    bitten by infected fleas from an infected animal.

64
Identify exposed population
  • Develop a line listing of all persons possibly
    exposed using the Exposed Individual Line Listing
    Form. Record each persons exposure risk based
    upon proximity to exposure.

65
Surveillance of case-contacts and exposed
population
  • Interview case-contacts and exposed individuals
    Assure that all case-contacts and exposed
    individuals are interviewed within 24 hours and
    refer them to a clinical center for post exposure
    prophylaxis (PEP), as necessary (See Treatment
    Section). For large populations, alert the
    public about the location of clinical centers for
    treatment or PEP through media announcements.

66
Surveillance of exposed
  • Conduct surveillance of all exposed individuals
    for
  • 7 days
  • If an exposed individual does not have
    signs/symptoms of plague by end of 7 days, then
    discontinue surveillance. Interview all exposed
    individuals to verify they have no symptoms, and
    if so, indicate status of exposed individual as
    closed on Exposed Individual Line Listing Form

67
Surveillance of exposed
  • If exposed individual develops fever (gt38.5 C) or
    cough then assure referral for parenteral therapy
    (See Treatment Section) after cultures are
    obtained, and assure implementation of
    appropriate infection control and preventive
    interventions (See Preventive Intervention
    Section). Enter status of exposed individual as
    a case and move to Case Line List. Begin contact
    tracing for this new case

68
Surveillance of case-contacts
  • Place all case-contacts under surveillance for 7
    days from day of suspected or known direct
    contact with a confirmed case
  • If case-contact does not have signs/symptoms of
    plague by end of 7 days, then discontinue
    surveillance. Interview all case-contacts daily
    to verify they have no symptoms, and if so, after
    seven days, indicate status of case as closed
    on Contact Line List Form

69
Surveillance of case-contacts
  • If case-contact develops fever (gt38.5C) or cough,
    then assure referral for parenteral therapy (See
    Treatment Section), and assure implementation of
    appropriate infection control and preventive
    interventions (See Preventive Intervention
    Section). Enter status of case-contact as case
    on Case Line List. Begin contact tracing for
    this new case (See B, 6)

70
Prevention and Control
  • After the source has been identified, remove
    people from the environment,(e.g., contaminated
    by a BT event) until decontamination is achieved.
  • Post exposure prophylaxis
  • Because of the short incubation period, and the
    high mortality, PEP must begin before the
    investigation is complete. See Treatment Section
    for PEP guidelines. Recommend to the State
    Health Commissioner that PEP should be offered to
    all exposed and all case-contacts
  • Groups of persons in which 2 or more persons have
    culture-confirmed plague (and therefore
    common-source exposure is likely or plausible).
    PEP should be offered for up to 7 days (See
    Treatment Section.)

71
Prevention and Control
  • Groups of persons in which 1 person has
    culture-confirmed plague and there is a common
    environmental exposure which was confirmed
    positive for Y. pestis. PEP should be offered
    for up to 7 days
  • Groups of persons in which multiple persons meet
    the suspect case definition and have onset of
    illness within 3 days. PEP should be offered for
    up to 7 days pending culture results and a final
    recommendation.

72
Prevention and Control
  • Recommend to the State Health Commissioner that
    all cases should be immediately referred for
    treatment according to current guidelines (See
    Treatment Section)
  • Recommend to the State Health Commissioner the
    amount of antibiotics that are needed for PEP or
    treatment.

73
Disease Prevention Objectives
  • Prevent unnecessary illness and death through
  • rapid identification of populations exposed to
    plague so appropriate treatment or post exposure
    prophylaxis can quickly be administered and
  • adherence to infection control isolation and
    barrier guidelines via standard and droplet
    precautions

74
Disease Control Objectives
  • Educate health care workers regarding the use of
    droplet precautions when dealing with pneumonic
    plague up to 72 hours following institution of
    appropriate antibiotic therapy
  • Educate public to contact the West Virginia
    Department of Agriculture for the proper disposal
    of infected animals

75
Disease Control Objectives
  • Educate workers that may be exposed to infected
    animals in proper hygiene and personnel
    protective measures

76
Surveillance Objectives
  • To rapidly detect and confirm a case of plague
    when it occurs in WV

77
Clinical Description
  • Five individual forms of plague
  • Common systemic symptoms include
  • headache, fever, cough, chills and progressive
    weakness.
  • Accurate diagnosis of plague may be delayed by
    the presence of gastrointestinal symptoms
  • nausea, vomiting, diarrhea and abdominal pain
  • or absence of the classic bubo.

78
Pneumonic Plague
  • The clinical symptoms involving the lungs
  • cough, fever, difficulty breathing and hemoptysis
    (bloody sputum).
  • Patients with pneumonic plague will require
    substantial advanced medical supportive care in
    addition to antimicrobial therapy.
  • Complications of sepsis include
  • adult respiratory distress syndrome, disseminated
    intravascular coagulation, shock, and multiorgan
    failure.
  • Pneumonic plague is the most likely form of
    plague following a bioterrorist event

79
Plague following a BT attack
  • The pathogenesis and clinical manifestations of
    plague following a BT attack would be notably
    different than naturally occurring plague
  • Inhaled aerosolized Y. Pestis would cause primary
    pneumonic plague
  • The time from exposure to aerosolized plague
    bacilli until development of first symptoms in
    humans and nonhuman primates has been found to be
    1 to 6 days and most often, 2 to 4 days

80
Plague following a BT attack
  • The first sign of illness would be expected to be
    fever with cough and dyspnea, sometimes with the
    production of bloody, watery, or less commonly,
    purulent sputum
  • Prominent gastrointestinal symptoms, including
    nausea, vomiting, abdominal pain, and diarrhea,
    might be present

81
Plague following a BT attack
  • The ensuing clinical findings of primary
    pneumonic plague are similar to those of any
    severe rapidly progressive pneumonia and are
    quite similar to those of secondary pneumonic
    plague (which may develop following onset of
    bubonic or primary septicemic plague).

82
Plague following a BT attack
  • Clinicopathological features may help to
    distinguish primary from secondary pneumonic
    plague
  • In contrast to secondary pneumonic plague,
    primary pneumonic plague would include absence of
    buboes (except, rarely, cervical buboes), and
  • On pathological examination, pulmonary disease
    with areas of profound lobular exudation and
    bacillary aggregation
  • Chest radiographs are variable, but bilateral
    infiltrates or consolidation are common

83
Plague following a BT attack
  • Laboratory studies may reveal
  • Leukocytosis (incr. WBCs) with toxic
    granulations
  • Coagulation abnormalities
  • Aminotransferase elevations
  • Azotemia (incr. blood urea level)
  • Evidence of multiorgan failure
  • All are nonspecific findings associated with
    sepsis and systemic inflammatory response
    syndrome

84
Plague following a BT attack
  • The time from respiratory failure to death in
    humans is reported to have been between 2 to 6
    days in epidemics during the preantibiotic era,
    with a mean of 2 to 4 days

85
Bubonic Plague
  • Most common form of naturally occurring plague
  • Acute onset of fever and painful swollen lymph
    nodes (also known as buboes)
  • inguinal lymph nodes are most commonly involved
  • axillary or cervical lymph nodes may also be
    affected

86
Septicemic Plague
  • Clinical symptoms include
  • Low blood pressure
  • Acute respiratory problems
  • Bleeding into the skin and other organs
  • usually results from a complication of bubonic or
    pneumonic plague
  • When septicemic plague occurs alone, buboes do
    not develop

87
Pharyngeal Plague
  • Clinically this would appear to be a viral or
    streptococcal pharyngitis, but the cervical
    lymphadenopathy associated with this would be
    much more painful and severe

88
Meningeal Plague
  • Most rare form of plague
  • Follows the hematogenous seeding of bacilli into
    the meninges
  • Associated with symptoms of
  • Fever
  • Headache
  • Meningismus

89
Plague
  • Etiologic Agent
  • Yersinia pestis is a non-motile, gram-negative
    bacillus sometimes coccobacillus
  • Reservoir
  • Plague is a zoonotic disease associated with
    rodents (mainly ground squirrels) and fleas.
    Rabbits, hares, wild carnivores, prairie dogs and
    domestic cats may also serve as a source of
    infection

90
Modes of Transmission
  • Primary pneumonic plague is transmitted through
    airborne droplets from an infected human or
    animal (especially household cats) with
    respiratory plague or from aerosol exposure in
    the laboratory setting

91
Modes of Transmission
  • The most common source of human bubonic plague is
    through the bite of an infected flea. This form
    of plague may also be transmitted less commonly
    through the direct contact or handling of
    infected tissues and fluids from animals (i.e. a
    bite or scratch from a household cat)

92
Mode of Transmission
  • Septicemic plague may by transmitted by
  • handling infectious materials
  • the bite of an infected flea
  • more commonly as a complication of bubonic or
    pneumonic plague
  • Neither bubonic plague nor septicemic plague
    spreads directly from person to person

93
Mode of Transmission
  • Small percentage of patients with bubonic or
    septicemic plague develop secondary pneumonic
    plague
  • can then spread the disease by respiratory
    droplets
  • persons contracting the disease by this route
    develop primary pneumonic plague????

94
Mode of Transmission
  • Pharyngeal plague is a rare form of plague that
    may follow inhalation or ingestion of the plague
    bacilli
  • Meningeal plague usually occurs as a complication
    of inadequately treated bubonic plague, but may
    occur as a primary infection. A high mortality
    is associated with this form of plague

95
Mode of Transmission
  • A bioterrorist event or an intentional exposure
    would most likely occur through aerosolization of
    the plague bacillus

96
Epidemiology continued
  • Incubation Period
  • Signs and symptoms may develop from 2-8 days
    after- being bitten by a flea, but can be a few
    days more in individuals that have been
    previously immunized. The incubation period for
    primary plague pneumonia is 1-4 days. An
    airborne exposure (i.e., from a BT event) would
    likely cause symptoms in 1-6 days. Contacts are
    considered to be at risk for development of
    pneumonic plague for up to 7 days after exposure
    to a case with pneumonic plague

97
Epidemiology continued
  • Infectious Period
  • A person is infectious from onset of cough until
    48 hours after treatment with antibiotics and
    signs of clinical improvement.

98
Outbreak Recognition
  • Outbreak recognition and investigation requires
    timely and complete epidemiological investigation
    paired with a timely and thorough laboratory
    investigation. As West Virginia has never
    reported a case of plague, one case is defined as
    an outbreak

99
Case Definition
  • Clinical Description
  • Plague is transmitted by humans, fleas, or direct
    exposure to infected tissues via respiratory
    droplets the disease is characterized by fever,
    cough, chills, headache, malaise, prostration,
    and leukocytosis that manifests in one or more of
    the following principal clinical forms
  • Regional lymphadenitis (bubonic plague)
  • Septicemia without an evident bubo (septicemic
    plague)

100
Case Definition
  • Plague pneumonia, resulting from hematogenous
    spread in bubonic or septicemic cases (secondary
    pneumonic plague) or inhalation of infectious
    droplets (primary pneumonic plague)
  • Pharyngitis and cervical lymphadenitis resulting
    from exposure to larger infectious droplets or
    ingestion of infected tissues (pharyngeal plague)

101
Laboratory criteria for diagnosis
  • Presumptive
  • Elevated serum antibody titer(s) to Yersinia
    pestis fraction 1 (F1) antigen (without
    documented fourfold or greater change) in a
    patient with no history of plague vaccination or
  • Detection of F1 antigen in a clinical specimen by
    fluorescent assay
  • Confirmatory
  • Isolation of Y. pestis from a clinical specimen
    or
  • Fourfold or greater change in serum antibody
    titer to Y. pestis F1 antigen

102
Case classification
  • Suspected
  • Clinically compatible case without presumptive or
    confirmatory laboratory results
  • Probable
  • Clinically compatible case with presumptive
    laboratory results
  • Confirmed
  • Clinically compatible case with confirmatory
    laboratory results

103
Laboratory Notes
  • Specimens
  • Sputum
  • lymph node biopsy
  • Blood
  • Environmental samples should be sent to OLS for
    testing (Level B lab)

104
Laboratory Notes
  • Clinical specimens should be sent to hospitals or
    level A labs for rule-out or presumptive testing
    for Y. Pestis. If Level A tests indicate
    suspicious findings consistent with Y. pestis
    isolates should be sent to OLS, a Level B lab for
    confirmation.

105
Preventive Interventions
  • Person-to-person transmission of pneumonic plague
    occurs via respiratory droplets
  • transmission by droplet nuclei has not been
    demonstrated
  • Droplet transmission-occurs when droplets
    containing microorganisms generated from the
    infected person, primarily during coughing,
    sneezing, and talking and during the performance
    of certain procedures, such as suctioning and
    bronchoscopy, are propelled a short distance and
    deposited on the hosts conjunctivae, nasal
    mucosa, and/or mouth

106
Preventive Interventions
  • Because these relatively large droplets do not
    remain suspended in the air, special air handling
    and ventilation are not required to prevent
    droplet transmission
  • droplet transmission should not be confused with
    airborne transmission via droplet nuclei, which
    are much smaller

107
Recommended prevention measures
  • Environmental exposure precautions
  • For persons going into an environment where there
    has been an environmental contamination by
    plague, personnel should use a NIOSH approved
    self contained breathing apparatus (SCBA) in
    conjunction with a level A protective suit. Other
    guidelines see CDC, Interim Recommendations for
    the Selection and Use of Protective Clothing and
    Respirators Against Biological Agents, October
    24, 2001

108
Recommended prevention measures
  • Infection control procedures
  • Standard and respiratory droplet precautions are
    recommended for caring for all suspected,
    probable, or confirmed cases of plague, for close
    contacts of patients, and for handling bodies of
    deceased patients. Recommendations for infection
    control against transmission of Y. Pestis are as
    follows (JAMA, May 8, 2002, 2872391-2405)

109
Infection control procedures
  • Close contacts
  • Staff who have close contact with cases should
    practice standard and respiratory droplet
    precautions (surgical mask, gown, gloves, and eye
    protection). Employees and individuals coming
    into close contact with suspected or confirmed
    plague patients who have had less than 48 hours
    of antimicrobial therapy should wear surgical
    masks. Unnecessary close contact within the
    first 48 hours of therapy should be avoided

110
Infection control procedures
  • Isolation of patients and close contacts
  • Patients
  • Patients should remain isolated during the first
    48 hours of antibiotic therapy and until clinical
    improvement occurs. If isolation is impossible
    due to a large number of patients, patients may
    be cohorted while undergoing antibiotic therapy.
    Patients being transported should also wear
    surgical masks.

111
Infection control procedures
  • Close contacts
  • Previous public health guidelines have advised
    strict isolation for all close contacts of plague
    patients who refuse prophylaxis. In modern
    times, pneumonic plague has not spread widely or
    rapidly within a community, and thus, isolation
    of close contacts refusing prophylaxis is not
    recommended. Instead close contacts should be
    put under surveillance for development of fever
    or cough during 7 days post exposure and treated
    immediately

112
Recommended prevention measures
  • Housekeeping
  • Hospital rooms of patients should receive
    terminal cleaning in a manner consistent with
    standard precautions and clothing and linens
    contaminated with body fluids should be
    disinfected.
  • Laboratories
  • Laboratories should observe biosafety level 2
    conditions. Activities with a high potential for
    aerosol or droplet production (centrifuging,
    grinding, vigorous shaking, animal studies)
    require biosafety level 3 conditions

113
Recommended prevention measures
  • Deceased patients
  • Bodies of deceased patients should be handled
    with standard and droplet precautions
  • Contact with remains should be limited to trained
    personnel
  • Safety precautions for transporting corpses for
    burial should be the same as those for
    transporting ill patients

114
Recommended prevention measures continued
  • Aerosol-generating procedures such as bone saws
    associated with surgery or postmortem examination
    which are associated with special risks of
    transmission are not recommended. If such
    procedures are necessary, then high efficiency
    particulate air filtered masks and negative
    pressure rooms should be used

115
Preventive Interventions
  • Prophylaxis
  • Prophylaxis of all exposed individuals and
    contacts, and treatment of cases is recommended
    (See Treatment Section). In the U.S., there is
    no vaccine currently available for primary
    pneumonic plague. A U.S. licensed
    formaldehyde-killed whole bacilli vaccine was
    discontinued by manufacturers in 1999 and was
    effective in preventing bubonic plague

116
Preventive Interventions
  • Environmental exposures
  • Remove people from the environment (e.g.,
    contaminated by a BT event) until environment is
    deemed safe
  • no evidence that residual Y. pestis bacilli pose
    an environmental threat to the population
    following dissemination of a primary aerosol such
    as in a BT event
  • no spore forming life cycle similar to Bacillus
    anthracis.
  • Y. pestis is very sensitive to sunlight and
    heating and does not survive long outside the
    host

117
Preventive Interventions
  • some evidence that the bacterium may survive in
    the soil for some time, but there is no evidence
    to suggest an environmental risk to humans and
    thus no need for environmental decontamination
  • WHO estimate plague aerosol was infectious for
    only 1 hour

118
Preventive Interventions
  • For naturally occurring incidents, remove people
    from the source of infected cats, rodents, or
    their fleas

119
Treatment
  • Recommendations based on JAMA, 283(17), May
    3,2000
  • Recommendations for use of antimicrobials
    following a deliberate release of plague are made
    on the basis of limited knowledge
  • A further complication is the possibility that a
    large number of people will need treatment

120
Treatment
  • Contained casualty setting, where a modest number
    of people require treatment, parenteral
    antibiotic therapy is recommended
  • streptomycin or gentamicin
  • Mass casualty setting, intravenous or
    intramuscular therapy may not be possible, so
    oral therapy
  • doxycycline (or tetracycline) or ciprofloxacin

121
Treatment
  • Patients with pneumonic plague will require
    substantial advanced medical supportive care.
    Complications of gram-negative sepsis would be
    expected, including adult respiratory distress
    syndrome, disseminated intravascular coagulation,
    shock, and multiorgan failure

122
Treatment Postexposure prophylaxis (PEP)
  • Tables found on page 17 18
  • Management of special groups
  • Breastfeeding woman Treat the mother and infant
    with the same antibiotic based on what is safe
    and effective for the baby. In the contained
    casualty setting, gentamicin is recommended. In
    the mass casualty setting, doxycycline is
    recommended. Fluoroquinolones are the
    recommended alternative

123
Treatment Postexposure prophylaxis (PEP)
  • Once plague is confirmed or strongly suspected in
    a particular area, anyone in that area with fever
    (of 38.5C or higher) or cough should immediately
    be treated with antimicrobials for presumptive
    pneumonic plague. Delaying therapy until tests
    confirm plague will greatly decrease the person's
    chance of survival

124
Treatment Postexposure prophylaxis (PEP)
  • Doxycycline is the first-choice antibiotic for
    PEP other recommended antibiotics are included
    in the Table.
  • Asymptomatic persons who have had household,
    hospital, or other close contact (2 meters or
    less) with persons with untreated pneumonic
    plague should receive PEP for 7 days and be
    monitored for fever and cough

125
Treatment Postexposure prophylaxis (PEP)
  • Tetracycline, doxycycline, sulfonamides, and
    chloramphenicol have been recommended for these
    individuals
  • On the basis of mice studies, fluoroquinolones
    might also be protective

126
Treatment PEP
  • Persons refusing prophylaxis should be closely
    monitored for the development of fever or cough
    for the first 7 days after exposure and should be
    treated immediately if either occurs.
  • Clinical deterioration of patients despite early
    presumptive therapy could indicate antimicrobial
    resistance and should be promptly evaluated.

127
Treatment PEP
  • Special measures should be taken for treatment or
    prophylaxis of those unaware of the outbreak or
    those requiring special assistance, such as
    persons who are homeless or who have cognitive
    disorders
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