Bacterial Zoonoses Flashcards
what is the vector for Bacillus anthracis?
NO VECTOR (usually)
What is the vector for Francisella tularensis?
ticks, mosquitos, deer flies
What is the vector for Brucella ?
NO vector
What is the vector for Yersinia pestis?
fleas
What is the vector for Bartonella henselae?
fleas, ticks
What is the pathogenesis of Bacillus anthracis?
infected mammals die and spores are released into soil which gets picked up by other live mammals or humans.
Three types of anthrax?
1- cutaneous (most common)
2- inhalation
3- GI
How does cutaneous anthrax present?
small sore–>blister–> skin ulcer with a black area in the center
Usually significant edema
Blister and ulcer do not hurt
How does GI anthrax present?
nausea, loss of appetite, bloody diarrhea, and fever, followed by bad stomach pain
How does Inhalation anthrax present?
cold or flu symptoms and can include a sore throat, mild fever and muscle aches. Later symptoms include cough, chest discomfort, shortness of breath, tiredness and muscle aches.
Association Card for anthrax
spore in dirt dying cattle no vector cutaneous, GI, inhaled painless black eschar with edema GPR on culture of lesion tx: cipro, doxy
Francisella Tularemia: gram ______, _____ shaped, how does it deal with oxygen?
gram negative
rod
aerobic
List the five forms of tularemia
- ulceroglandular (most common)
- glandular
- oculoglandular
- oropharyngeal
- pneumonic
What is the most serious form of tularemia?
pneumonic - from inhaling dusts of aerosols. sx= cough, chest pain, difficulty breathing
*can be fatal
what form(s) of tularemia are generally acquired via a tick or deer fly bite?
ulceroglandular, glandular
What are some of the other exposures that can lead to tularemia?
inhaling dust or aerosols from farming or landscaping, mowing over infected carcasses –> pneumonic type
T/F: brucella has only one species?
FALSE: many species of brucella that naturally infect a variety of animals
What signs in cattle might indicate a brucella infection?
third trimester abortions, retained placenta, endometritis, birth of dead or weak calves, low milk yield
Brucella transmission to humans
contact with conjunctiva or broken skin with infected tissues
ingestion (raw milk, undercooked meat)
inhalation of infectious materials
What is the incubation period for brucella?
5 days to 3 months
How does brucella present?
affects any and all organ systems
notable for cyclical fever!
Name that bug:
cyclic fever + orchitis + cow exposure
brucella
list the complications of brucella1
osteoarticular (sponylitis, osteomyelitis) hepatomegaly/splenomegaly GI complications GU (orchitis, epididymitis) neuro (depression, mental fatigue) cardio (endocarditis)
How do you diagnose brucella?
culture, serum agglutination test, immunofluorescence, PCR
How do you treat brucella?
doxy x 6 wks
recovery is common but a small amoutn will relapse
What is the incubation period for yersinia pestis?
1-6 days
What are three types of plague?
bubonic
pneumonic
septicemic
how does bubonic plague present?
rapid onset feverand painful swollen tender lymph nodes, usually inguinal, axillary, or cervical
how does pneumonic plague present?
high fever, overwhelming pneumonia, cough, bloody sputum, chills
how does septicemic plague present?
fever, prostration, hemorrhagic or thrombotic phenomena, acral gangrene (terminal digits)
yersinia pestis is gram ______. treated with:
gram negative
tx: parenteral abx with streptomycin (gentamycin, and doxy are backup)
cat scratch fever is caused by________
bartonella henselae
what is primary infection with bartonella caused?
croyo fever
What is the most common exposure that leads to bartonella infection?
people under 21 y.o. with kittens - scratches or bites or contact with fleas
What are the symptoms of cat scratch fever?
fever, enlarged tender lymph nodes 1-2 wks after exposure
papule or pustule at site of inoculation
granulomatous conjunctivitis, neuroretinitis, atypical pneumonia, endocarditis
how does bartonella present in immunocompromised people?
Bacillary angiomatosis (B. henselae or B. quintana)
HIV pts
sx: skin, subcutaneous or bone lesions
What are the common pathogens associated with dog bites?
capnocytophaga canimorsus
pasteurella multocida
What are the common pathogens associated with cat bites?
*pasteurella multocida
bartonella henselae
francisella tularensis
capnocytophaga canimorsus
how does pasteurella multocida present?
evidence of wound infection within a few hours of a bite injury, scratch or lick.
Cellulitis or abscesses +/- bacteremia
Occasional pneumonia and endocarditis
Other: metastatic seeding of internal organs from bacteremia.
CNS: meningitis (rare), most often in young children or the elderly
A cause of rapidly progressive infections similar to Group A Streptococcus or Vibrio
patient may present within a few hours of a cat bite with established severe infection
How do you treat pasteurella multocida?
Amoxicillin/clavulanate , Ampicillin/-sulbactam, Penicillin, Ciprofloxacin, levofloxacin, doxycycline
First generation cephalosporins, cloxacillin, erythromycin and clindamycin NOT effective
capnocytophaga canimorsus is _________ anaerobic, gram _______, _____ shaped.
facultative anaerobic
gram negative
rod
What is the natural habitat of capnocytophaga canimorsus?
normal flora of cat and dog
capnocytophaga canimorsus presentation:
history of dog bite or scratch, less commonly in cats
Cellulitis
Bacteremia/sepsis
Meningitis and endocarditis (rare)
Severe: shock, DIC, acral gangrene, disseminated purpura, renal failure, meningitis and pulmonary infiltrates
Fulminant sepsis following dog > cat bites, particularly in asplenic patients, alcoholics or immunosuppressed
capnocytophaga canimorsus treatment:
Mild Cellulitis /Dog or Cat Bites
Preferred : Amoxicillin/clavulanate
Alternative: Clindamycin, doxycycline
Severe Cellulitis /Sepsis
Penicillin G 2-4 mU q 4h IV or Clindamycin 600mg IV q 8h.
Alternative : Ceftriaxone 1-2q IV qd, ciprofloxacin 400mg IV q12h or meropenem 1g IV q8h.
Prevention
Asplenic patients - amoxicillin/clavulanate for 7-10d
