Epidemiology andPrevention Of PLAGUE                     Prepared by:           Stacy Arvinna Jamarun                     ...
History & Significance14th Century: “Black Death” responsible for >20 million deaths in EuropeUsed as a BW agent by Japa...
Epidemiology Caused by Yersinia pestis Gram negative, non-motile, non-spore-forming bacillus Resistant to freezing temp...
Epidemiology Transmission   Historically, rat-borne urban epidemics   Now mostly endemic sylvatic plague with sporadic ...
Epidemiology   Risk Factors     Close contact with case     Contact with infected animal     Living or recent travel i...
History of Plague Plague recorded more than 2000 years ago Three pandemics     1st 542AD; 100million dead in 60 years; f...
Epidemiology cycles Sylvatic (wild) Cycle of Plague      Reservoir (foci) = wild rodents (prairie      dogs, rabbits, mic...
EpidemiologicalCycles of Plague
PlagueCase Definition   Characterized by    fever, chills, headache, malaise, prostration,    & leukocytosis that manifes...
PlagueCase Definition, cont.Laboratory criteria for diagnosis:  Presumptive     Elevated serum antibody titers to Y. pe...
Plague: Case ClassificationSuspected: Clinically compatible case w/o presumptive or confirmatory lab resultsProbable: Cl...
PlagueClinical Forms   Bubonic plague    Most common naturally-occurring form    Mortality 60% untreated, <5% treated ...
Bubonic Plague   Incubation: 2-8 days   Sudden onset nonspecific symptoms:    fever, chills, malaise, muscle aches, head...
Septicemic & Bubonic Plague                    Source: CDC NVBID
Pneumonic Plague    Clinical PresentationIncubation: 1-6 days (usually 2-4 days)Acute onset of fever with cough, dyspnea...
Surveillance Any clinical or laboratory suspicion of plague cases should be immediately reported to the local health depa...
Prevention Vaccination - Bubonic only  Killed virulent strain – used in U.S.    Formalin-fixed, no longer commercially ...
Prevention Vaccination   Indications     Lab workers with fully virulent strains     Military personnel stationed in e...
Prevention   Vaccination     Indications        Lab workers with fully virulent strains        Military personnel stat...
Infection Control   Mechanism for person-person spread     Not completely understood     Respiratory droplets most like...
Infection Control Respiratory Droplet Precautions  Mask during transport  Can cohort if not enough room Contacts – con...
Infection Control Standard Precautions  Successfully treated cases after 48hr    of abx Laboratory safety   Alert lab ...
Infection Control   Corpses    Standard strict precautions by     trained personnel    Transport same as live patient  ...
Infection Control   National control programs     Surveillance     Early diagnosis, treatment &      isolation of cases...
Decontamination Environment  Aerosol dispersed within an hour –   fragile  No evidence residual bacteria are a   threat...
Decontamination Patient rooms  Usual cleaning  Use standard precautions  Disinfect contaminated linens  Standard disi...
Post-exposure Prophylaxis Also for mass causalities For all asymptomatic contacts of suspected untreated pneumonic cases...
Post-exposure Prophylaxis Antibiotics   1st choices     Tetracyclines        Doxycycline          o 100 po bid adults ...
Post-exposure Prophylaxis   Alternatives     Chloramphenical 25 mg/kg po qid       Not in kids <2yo   For pregnant & b...
Epidemiology and prevention of plague
Upcoming SlideShare
Loading in …5
×

Epidemiology and prevention of plague

4,588 views

Published on

Published in: Health & Medicine
2 Comments
2 Likes
Statistics
Notes
No Downloads
Views
Total views
4,588
On SlideShare
0
From Embeds
0
Number of Embeds
9
Actions
Shares
0
Downloads
336
Comments
2
Likes
2
Embeds 0
No embeds

No notes for slide

Epidemiology and prevention of plague

  1. 1. Epidemiology andPrevention Of PLAGUE Prepared by: Stacy Arvinna Jamarun Group 3, 6th Year 2nd Semester 2013
  2. 2. History & Significance14th Century: “Black Death” responsible for >20 million deaths in EuropeUsed as a BW agent by Japan in WW IIStudied by Soviet and, to a smaller extent, U.S. BW programs1995: Larry Wayne Harris arrested for illicit procurement of culture via mail
  3. 3. Epidemiology Caused by Yersinia pestis Gram negative, non-motile, non-spore-forming bacillus Resistant to freezing temperature and drying, killed by heat and sunlight  Zoonotic infection; Humans are accidental hosts Human plague occurs from bite of an infected flea (bubonic) Outbreaks are cyclical corresponding to rodent reservoir and arthropod vector populations Only pneumonic form of plague is spread person-to- person Last case of person-to-person transmission in U.S. occurred in 1924
  4. 4. Epidemiology Transmission  Historically, rat-borne urban epidemics  Now mostly endemic sylvatic plague with sporadic outbreaks  Pneumonic is only form capable of person to person spread  Higher risk in overcrowding, indoor contacts, cold/wet weather
  5. 5. Epidemiology  Risk Factors  Close contact with case  Contact with infected animal  Living or recent travel in endemic area  Peridomestic animals running loose  Residing in crowded conditions  Cool, wet weather  Exposure to a known intentional release
  6. 6. History of Plague Plague recorded more than 2000 years ago Three pandemics 1st 542AD; 100million dead in 60 years; from N.Africa 2nd 14th century; Black Death; 25million dead in Europe alone (>1/4 of entire population); from central Asia; disease became endemic in urban rat population and smaller epidemics occurred through 17th century 3rd ended in 1990s; Burma to China (1894) & Hong Kong to other continents including N. America via rat-infected ships; 20million dead in India alone; foci of infection firmly established in wild rodents in rural areas About 10-15 cases/year U.S.
  7. 7. Epidemiology cycles Sylvatic (wild) Cycle of Plague Reservoir (foci) = wild rodents (prairie dogs, rabbits, mice, dogs) Vector = wild rodent flea Urban (domestic) Cycle of Plague Reservoir = domestic (urban) black rat Over 8 million in NYC = human population Vector = oriental rat flea (Xenopsylla cheopis) Human Cycle of Plague Bubonic plague acquired from contact with either sylvatic or urban reservoirs or arthropod vector bite and further transmitted in human population by spread of pneumonic plague
  8. 8. EpidemiologicalCycles of Plague
  9. 9. PlagueCase Definition  Characterized by fever, chills, headache, malaise, prostration, & leukocytosis that manifests in one or more of the following clinical forms:  Regional lymphadenitis (bubonic)  Septicemia w/o evident bubo (septicemic)  Plague pneumonia  Pharyngitis & cervical lymphadenitis (pharyngeal)
  10. 10. PlagueCase Definition, cont.Laboratory criteria for diagnosis: Presumptive  Elevated serum antibody titers to Y. pestis F1 antigen (w/o documented 4-fold 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  4-fold or greater change in serum antibody titer to Y. pestis F1 antigen
  11. 11. Plague: Case ClassificationSuspected: Clinically compatible case w/o presumptive or confirmatory lab resultsProbable: Clinically compatible case with presumptive lab resultsConfirmed: Clinically compatible case with confirmatory lab results
  12. 12. PlagueClinical Forms Bubonic plague Most common naturally-occurring form Mortality 60% untreated, <5% treated Primary or secondary septicemic plague Pneumonic plague Most likely BT presentation From aerosol or septicemic spread to lungs Survival unlikely if treatment not initiated w/in 24 hours of the onset of symptoms
  13. 13. Bubonic Plague Incubation: 2-8 days Sudden onset nonspecific symptoms: fever, chills, malaise, muscle aches, headache Regional lymphadenitis (buboes)  Swollen, very painful lymph nodes  Typically inguinal, femoral, axillary, or cervical  Erythema overlying skin  May have surrounding edema  Concurrent with or shortly after onset of other symptoms
  14. 14. Septicemic & Bubonic Plague Source: CDC NVBID
  15. 15. Pneumonic Plague Clinical PresentationIncubation: 1-6 days (usually 2-4 days)Acute onset of fever with cough, dyspnea, and chest painHemoptysis characteristic; watery or purulent sputum also possibleProminent GI symptoms may be present, including nausea, vomiting, diarrhea, and abdominal painOther symptoms include headache, chills, malaise, myalgias
  16. 16. Surveillance Any clinical or laboratory suspicion of plague cases should be immediately reported to the local health department and laboratory and if applicable the hospital epidemiologist or infection control practitioner
  17. 17. Prevention Vaccination - Bubonic only  Killed virulent strain – used in U.S.  Formalin-fixed, no longer commercially available  Future production and licensure unknown  Series  3 primary (1.0cc, 0.2 cc at 1-3 mo and 5-6 mo later)  2 boosters 0.2cc at 6 mo intervals then q1- 2yrs
  18. 18. Prevention Vaccination  Indications  Lab workers with fully virulent strains  Military personnel stationed in endemic areas  Efficacy  Based on WWII (0 cases) and Vietnam (3 cases) troops  Protects vs. bubonic only, not pneumonic  Adverse effects  Significant number have mild reactions
  19. 19. Prevention  Vaccination  Indications  Lab workers with fully virulent strains  Military personnel stationed in endemic areas  Efficacy  Based on WWII (0 cases) and Vietnam (3 cases) troops  Protects vs. bubonic only, not pneumonic  Adverse effects  Significant number have mild reactions  May be severe
  20. 20. Infection Control  Mechanism for person-person spread  Not completely understood  Respiratory droplets most likely, not droplet nuclei  Historically prevented by masks  Respiratory Droplet Precautions  Wear mask, gown, gloves, eye protection  Suspected cases - isolate  Immediately respiratory (even for bubonic)  Avoid unnecessary close contact 1st 48 hrs of abx  Duration  2 days after initiating antibiotics and clinically improved  After sputum cultures negative
  21. 21. Infection Control Respiratory Droplet Precautions  Mask during transport  Can cohort if not enough room Contacts – consider isolation  Recommended for those receiving PEP  during1st 48 hrs of Rx  Not recommended for those refusing PEP Image: National Library of Medicine
  22. 22. Infection Control Standard Precautions  Successfully treated cases after 48hr of abx Laboratory safety  Alert lab if suspected  BSL-2 for normal procedures  BSL-3 if hi risk aerosolizing or large volumes or resistant strains
  23. 23. Infection Control  Corpses  Standard strict precautions by trained personnel  Transport same as live patient  Avoid aerosolizing procedures or use HEPA filters and negative pressure room
  24. 24. Infection Control  National control programs  Surveillance  Early diagnosis, treatment & isolation of cases  Environmental sanitation & exposure avoidance  Public education  Non-eradicable
  25. 25. Decontamination Environment  Aerosol dispersed within an hour – fragile  No evidence residual bacteria are a threat  No environmental decon indicated  May need surveillance measures for rodents/fleas in area
  26. 26. Decontamination Patient rooms  Usual cleaning  Use standard precautions  Disinfect contaminated linens  Standard disinfectants
  27. 27. Post-exposure Prophylaxis Also for mass causalities For all asymptomatic contacts of suspected untreated pneumonic cases  Contact within last 6 days  Untreated pneumonic = <48hr approp treatment  Those within 2 meters of case  Household, hospital contacts  Those who might have been exposed to initial aerosol  Seek out homeless, mental handicaps, homebound
  28. 28. Post-exposure Prophylaxis Antibiotics  1st choices  Tetracyclines  Doxycycline o 100 po bid adults and kids >45 kg o 2.2 mg/kg po bid for kids <45 kg  Tetracycline – equivalent dosages  Fluoroquinolones  Ciprofloxacin o 500 mg po bid for adults o 20 mg/kg po bid (max 1g/day) for kids  Others at equivalent dosages
  29. 29. Post-exposure Prophylaxis  Alternatives  Chloramphenical 25 mg/kg po qid  Not in kids <2yo  For pregnant & breastfeeding women  Same as adults above but no tetracycline  Doxycycline may be used  Duration  7 days since last exposure PEP  10 days for mass casualties

×