Bioterrorism Agents: Plague Lesson 1 Introduction and Overview

Objectives Identify plague bacteriumIdentify plague bacterium EpidemiologyEpidemiology Natural OccurrenceNatural Occurrence

Bio-Terror Threat Plague can cause large numbers of casesPlague can cause large numbers of cases Could create panicCould create panic Considered for use since 14 th centuryConsidered for use since 14 th century

Clinical Syndromes BubonicBubonic PneumonicPneumonic SepticemicSepticemic Plague MeningitisPlague Meningitis PharyngealPharyngeal “Safety Pin” Y. Pestis in blood

Bubonic Plague Infected flea biteInfected flea bite Exposure through break in skinExposure through break in skin No person-to-personNo person-to-person Untreated progresses to pneumonicUntreated progresses to pneumonic

Pneumonic Plague Inhalation of plague bacteriaInhalation of plague bacteria Disease progressionDisease progression –Respiratory failure –Shock –Rapid death Person-to-person transmissionPerson-to-person transmission

Septicemic Plague Primary FormPrimary Form –Direct inoculation in bloodstream Secondary FormSecondary Form –Development of untreated pneumonic or bubonic plague

Epidemiology Natural Reservoirs Bites of infected fleaBites of infected flea Most common – Oropsylla montanaMost common – Oropsylla montana Blood meal from bacteremic animalBlood meal from bacteremic animal Regurgitates into human/ animal hostRegurgitates into human/ animal host Common reservoirsCommon reservoirs –Deer mice –Ground squirrels

Epidemiology Transmission Bite of infected fleaBite of infected flea Respiratory dropletsRespiratory droplets Direct contact (6 feet)Direct contact (6 feet) Direct skin/mucous membrane less commonDirect skin/mucous membrane less common BT event – Respiratory droplets or aerosolsBT event – Respiratory droplets or aerosols

Plague Incidence United States, Endemic to USEndemic to US Bubonic Most CommonBubonic Most Common –83% Bubonic –2% Primary Pneumonic –15% Septicemic 5 to 15 cases per year5 to 15 cases per year Greatest ConcentrationsGreatest Concentrations –Arizona, Colorado, New Mexico, Utah

Plague Case Fatality Rates United States, In US, 14% diedIn US, 14% died Untreated – 50 to 90%Untreated – 50 to 90% Treated – 15%Treated – 15% Deaths mostly from delays in diagnosis and treatmentDeaths mostly from delays in diagnosis and treatment

Plague Incidence Worldwide, All inhabited continents, but AustraliaAll inhabited continents, but Australia 1,500 to 3,000 cases annually1,500 to 3,000 cases annually Greatest ConcentrationsGreatest Concentrations –Asia, South America

Plague Bioterrorism Scenario Most dangerous as aerosolMost dangerous as aerosol Outbreak of pneumonicOutbreak of pneumonic Possibly pharyngeal or ocularPossibly pharyngeal or ocular Report all suspect cases to public health immediatelyReport all suspect cases to public health immediately

Review Questions – Plague Lesson 1 Overview

Plague Review Questions Lesson 1, Question 1 Santa Fe, New Mexico hospitalSanta Fe, New Mexico hospital Treating suspect plague caseTreating suspect plague case Hearing of more cases in areaHearing of more cases in area When do you start to worry about bioterrorism?

When do you start worrying about bioterrorism? A.Unrelated clusters B.Unusual rise in cases C.Both of the above D.None of the above Plague Review Questions Lesson 1, Question 1

When do you start worrying about bioterrorism? Answer - C. Both of the above Unrelated clustersUnrelated clusters Unusual rise in casesUnusual rise in cases Plague Review Questions Lesson 1, Question 1

Abnormally large, tender lymph nodeAbnormally large, tender lymph node Right armRight arm Lab specimen for preliminary testingLab specimen for preliminary testing What organism causes plague? Plague Review Questions Lesson 1, Question 2

What organism causes plague? B. anthracisB. anthracis C. botulinumC. botulinum C. burnetiiC. burnetii Y. pestisY. pestis Plague Review Questions Lesson 1, Question 2

What organism causes plague? D. Y. pestis Plague Review Questions Lesson 1, Question 2

New Hampshire hospitalNew Hampshire hospital Labs – Unable to rule out plagueLabs – Unable to rule out plague Recent US travelRecent US travel Where in the US would you expect the patient to get plague? Plague Review Questions Lesson 1, Question 3

Where in the US would you expect the patient to get plague? A.Western US, Southwest B.Eastern US, Southeast C.Northern US, Northeast D.Southern US, Southwest Plague Review Questions Lesson 1, Question 3

Where in the US would you expect the patient to get plague? A. Western US, Southwest