Zoonoses Flashcards
Why is brucellosis an important medical condition?
Highly contagious
One of the most common zoonoses worldwide
What type of organism is brucella?
Intracellular
Gram negative
What are the 4 brucella spp associated with human disease?
B. melitensis
B. abortus
B. suis
B. canis
B. melitensis is associated with which animals?
Sheep
Goats
B. abortus is associated with which animals?
Bovine
B. suis is associated with which animals?
Pigs
B. canis is associated with which animals?
Dogs
Which brucella spp is most virulent, most severe and most acute?
B. melitensis
Does B. abortus cause complications?
Rarely
Most common cause of brucella in SA?
B. abortus
Which brucella causes prolonged illness with suppurative destructive lesions?
B. suis
Which 2 brucella species are very similar in clinical presentation?
Abortus
Canis
Transmission of brucella?
Unpasteurized dairy
Undercooked meat
Contact with animal fluids/tissue
Inhalation
Human-to-human rare (breastfeeding, sexual, transplant, transfusion)
What is the pathogenesis of brucellosis?
Endocytosed by macrophages -> replicate -> move into circulation -> deposited in multiple organs
Clinical presentation of brucellosis?
Undulant fever
Ocular
CNS
CVS
Pulmonary
Cutaneous
Genitourinary
Gastrointestinal
Skeletal
What conditions must suspected brucella specimens be processed with?
BSL2 conditions with BSL3 practices
Insidious brucella?
Abortus
Acute brucella?
Melitensis
What is the colony morphology of brucella?
Non-hemolytic
Non-pigmented
Slow growing, enhanced by CO2
When are isolation rates of brucella highest?
First 2 weeks of symptomatic disease
Can you culture brucella?
Yes! But takes longer
Lots of specimens allowed
What is mainstay of brucella diagnosis?
Serology, paired specimens
Rose Bengal test, Coombs, ELISA, direct agglutination
Can brucella serology have issues?
Yes, cross reaction with other gram negatives
Discuss treatment of brucellosis
6w doxy + rif + 2w genta
6w doxy + 2w strepto
Which treatment forms for brucellosis are not recommended?
Monotherapy
<30d treatment
Quinolones
Which leptospira serovar is associated with rats?
Icterhaemorrhagic
Which leptospira serovar is associated with dogs?
Canicola
Which leptospira serovar is associated with pigs?
Pomona
Which leptospira serovar is associated with cattle?
Hardjo
Where do chronic leptospira infection usually occur?
Brain
Eyes
Genital tract
How is leptospirosis transmitted to humans?
Direct contact with animal urine/tissues via skin lesions and mucous membranes
What is Weil’s disease?
Hepatorenal failure in leptospirosis infectoin
Which pathogenic leptospira serovars are important?
L. interrogans
L. borgpetersenii
Which saprophytic leptospira serovars are important?
L. biflexa
What kind of flagellum do leptospirae have?
Endoflagellum
What is the difference between rickettsia and coxiella?
Coxiella
- y proteobacteria
- legionellacaea order
Rickettsia
- alpha proteobacteria
- rickettsiales order
Why is it called ‘Q’ fever?
Named after “query fever”
How is Q fever transmitted?
Inhalation
Tissue handling
? tick bites
? milk
? human-to-human
What is the clinical presentation of Q fever?
60% are asymptomatic
Post-infection fatigue
Which Q fever antibody raises first?
Phase 2 antibody
Discuss treatment of Q fever
Doxycyline 7-10d
Chronic = combination
Phagolysosome alkalisation adjuvant
Is there a Q fever vaccine?
Yes, whole-cell vaccine for abattoir workers in Australia
