Section 6 Flashcards
(22 cards)
where do flea associated ID cases seem to be concentrated
coastal & temperate zones
Yersinosis genus
pestis
enterocolitica
pseudotuberculosis
Bubonic plague spread
flea feeds on bacteremic host
Y pestis colonizes flea midgut and creates blockage
flea starves & becomes aggressive
flea feeds rapidly and regurgitates into subsequent host
Y pestis travels through lymphatics & blood stream
Plague transmission in US
naturally occurs in western US grasslands & scrub woodlands. Transmitted by fleas and cycles naturally among rodents; occasional outbreak
Yersinosis Microbiology
gram - bipolar staining bacillus
grows aerobically
Y pestis virulence factors
plasminogen
pesticin
lipopolysaccaride endotoxin
plasminogen
bacterial surface protein promoter; important for flea survival & responsible for blood bolus
pesticin
promotes iron uptake for pathogen
lipoplysaccaride endotoxin
promotes cytokine cascade
Yersinosis transmission
flea bites
inhaled respiratory specimens of infected humans or cats
Types of clinical plague
Bubonic
Primary septicemic
pneumonic
Bubonic plague clinical features
Incubation period of 1-7 days. Sudden onset; fevers >38, malaise, myalgia, dizziness, painful lymphadenopathy near the site of the bite.
○ Bubo = tender, swollen lymph node with boggy consistency & hard core upon palpation
○ Exquisitely tender without fluctuance
If untreated it can progress to septicemia
Primary septicemic plague clinical features
○ Sepsis: clinical syndrome of life threatening organ dysfunction due to dysregulated immune response to infection
a. Calculated using SOFA (sequential organ failure assessment) score paired with unstable vital signs
Patients appear extraordinarily ill and febrile localizing symptoms
Pneumonic plague clinical features
Short incubation period after exposure, averaging a few hours to 3 days; Sudden onset of fever, nonspecific signs: headache, myalgia, vomiting
○ Respiratory manifestations: cough, chest pain, sputum production with hemoptysis
○ Untreated has 100% mortality; treated has 50%
○ Associated with sick domestic cats transmitting vial aerosol droplets to their owners. Only form of plague that can be transmitted from person to person
Picture of CXR showing extensive infiltrates in R upper and middle lobes
Secondary complications for plague
pneumonic plague - infections reaches lungs, highly contagious, patchy infiltrates on CXR, sputum can be purulent with high bacilli counts
meningitis - rare complication, occurs more than 1 week after partially treated bubonic; high disease involvement
Plague diagnosis
high clinical suspicion; presence of fever and known contact with dead rodents or living/visited endemic area; hypotension, unexplained regional lymphadenitis;
smear stain and culture
Test for F1 antigen
Wayson’s stain
light blue bacilli, dark blue polar bodies
Reasons for plague spread in madagascar
political instability
flooding
keep pets inside
Famadihana
madagascar seasonal upsurge of plague
yearly between september and april; usually bubonic; pneumonic is non endemic
WHO Emergency Grading
ungraded: assessed event no response needed
grade 1: single or multiple event with minimal response
grade 2: single or multiple event with moderate response (recent plague in madagascar)
grade 3: single or multiple event with substantial response (ebola a few years ago)
Team based response
Support from MOH, WHO various committees CMs and CHWs Assess local education Resources & supplies field test public awareness social media & texting training leaders radio, TV traditional consideration with hygiene WASH program
WASH program
500 liter water tanks installed
soap and disposal supplies
teach how to wash
