08.22 - Exotic and Biohazard Pneumonias (Miller) - Questions Flashcards
3 important properties of B Anthracis
Gram-positive rod; Capsule of d-glutamate; Spore former
D-Glutamate capsule
B Anthracis
Transmission of B Anthracis
Cutaneous contact with animals; Aerosolized spores
Woolsorter’s Disease
B Anthracis
Why does capsule of B Anthracis serve as virulence factor
Prevents direct recognition of bacterium via phagocytes
Mortality rate in untreated pulmonary anthrax
90-100 %
Timecourse of B Anthracis pnuemonic disease
Typically 4-6 days to onset, but can be up to 6 weeks
Symptoms of Pneumonic Anthrax
Short prodromal period of cough, fever, aches; Then high fever, dyspnea, hypoxia, tachycardia
Radiology of Pnuemonic Anthrax
Widened mediastinum with infiltrates and pleural effusions
Widened mediastinum with infiltrates and pleural effusions
Radiology of Pnuemonic Anthrax
Two causes of death in Anthrax
Block of pneumonic lymph vessels; Cytokine storm - Septic Shock
Dx of Pneumonic Anthrax
Test sample or measure titers
Tx of Pneumonic Anthrax
Cipro for up to 60 days
3 important properties of Brucella spp
Gram-negative coccobacillus w/out capsule; Intracellular; Livestock resoivoirs
Epidemiology of B Anthracis
Worldwide, Cattle and Sheep
Epidemiology of Brucella
Everywhere but NA; Contaminated dairy products or animal secretions
Imported dairy from goats in Mexico or Mediterranean
Brucella melitensis
Pathogenesis of Brucellosis
Localize to reticuloendothelial system; Intracellular; Granuloma formation in lungs, Abscesses
Radiology of Brucellosis
Pretty big granulomas in lungs
Symptoms, Signs of Brucellosis
Fatigue, Weight Loss, Lymphadenopathy, Organomegaly, Pancytopenia
Fatigue, Weight Loss, Lymphadenopathy, Organomegaly, Pancytopenia
Brucellosis
Most frequent complication of Brucellosis
Osteomyelitis
Osteomyelitis
Most frequent complication of Brucellosis
Timecourse of Brucellosis
1-3 week incubation period with acute or gradual onset
Dx of Brucellosis
Rarely cultured; Slide Agglutination Test; Titers
Tx of Brucellosis
Tetracycline or Doxy + Rifampin
Whitmore’s Disease
Burkholderia pseudomallei
3 important properties of B pseudmallei
Small, motile gram neg rod; Facultative intracellular; Environmental
Epidemiology of B pseudomallei
Southest Asia; Environmental Bac
Transmission of B pseudomallei
Inhalation of aerosolized bac from soil; Contaminated water or body fluids
Cases of meliodosis spike following
Rains –> Raindrops aerosolize the bac from soil
Virulence factors of B pseudomallei
Capusle; Intracellular; Lysis; Actin network; Dormancy
Capusle; Intracellular; Lysis; Actin network; Dormancy
Virulence factors of B pseudomallei
Timecourse of Meliodosis
Varies, 2-3 days to many years
Symptoms and Signs of Meliodosis
Flu-like + Cough; Can mimic TB on CXR
CXR of Meliodosis
Can mimic TB: Small nodule and consolidations of upper lobe; Abscesses and cavitations
Px of Meliodosis
20-50% mortality even if treated
Dx of Meliodosis
Isolation of bac; Titers
Tx of Meliodosis
Ceftazidime for 8 weeks - 6 months; Intrinsically resistant to many abx
3 important properties of Coxiella Burnetti
Gram neg bacillus; Obligate intracellular parasite; Enzootic (livestock)
Epidemiology of Coxiella Burnetti
Almost every country with low incidence
Transmission of Coxiella Burnetti
Contaminated viscera of livestock or raw milk; Ticks; Aerosolized spore-like form
Q-fever
Coxiella Burnetti
Pathogenesis of Q Fever
C burnetti well adapted for survival within macrophages; One of the most infectious human pathogens
Timecourse of Q Fever
Acute febrile illness; Atypical pneumonia for 2-4 weeks
Signs and Symptoms of Q Fever
Typcially not severe, often resolves w/out tx; Sometimes liver and heart involvement
Dx of Q Fever
Titers
Tx of Q Fever
Most spontaneously resolve; Doxycycline
3 important properties of Francisella tularensis
Pleomorphic Gram neg rod; Obligate intracellular; Two biotypes
Transmission of F tularensis
Typically tick or blood-to-blood; Can be aerosol
Virulence factors of F tularensis
Atypical LPS not recognized by TLR-4; May produce a capsule; Long period survival in water
Pathogenesis of F tularensis
Extremely pathogenic; High mortality if inhaled; Can also disseminate to lungs
Signs and Symptoms of F tularensis
Sudden onset flu-like symptoms; Prolonged low-grade fever and adenopathy; Ulceroglandular; CXR - Spotted infiltrates, lobar pneumonia, pleural exudation
CXR of F tularensis
Spotted infiltrates in lungs, lobular pneumona, Pleura exudation
Dx of F tularensis
No culture; Agglutination tests
Tx of F tularensis
Streptomycin
3 important properties of Hantavirus
Bunyaviridae; Enveloped, trisegmented, SS, neg-sense RNA virus
Epidemiology of HPS
Healthy young adults; Rural areas
Symptoms of HPS
Prodrome of flu-like symptoms; Rapid pulmonary edema, severe hypotension, respiratory failure
Transmission of Hantavirus (HPS)
Breathing air containing aerosolized rodent excrement
CXR of HPS
Distinctive bilateral pulmonary edema; Bilateral intersitial infiltrates
Tx of HPS
Early, aggressive intensive support care
3 important properties of Yersinia pestis
Gram neg rod; Encapsulated, intracellular; Bipolar (Safety pin) staining
Bipolar (safety pin) staining
Yersinia Pestis
Epidemiology of Y pestis
Endemic worldwide, but 99% of cases occur in SE Asia
Transmission of Y pestis
Rodents via fleas; Strikingly low ID50; Can be person-to-person via aerosol
CXR of Y pestis
Lower lung zone airspace disease with bilateral pleural effusions
Pathogenesis of Y pestis
Spreads to regional lymph nodes; Disseminates and form abscesses
Reasons for the term black death
DIC and Cutaneous hemorrhage
Primary life-threatening consequences Y pestis
Septic Shock and Pneumonia
Symptoms of plaque
Fever, Headache, Hemoptysis, Dyspnea, Muscle weakness
Dx of Y pestis
Smear and culture of blood or pus is best
Tx of Y pestis
Streptomycin and Tetracycline
