L 79 Tularemia, Brucellosis, Bartonellosis

Question 1

Causative agent for tularemia

Answer 1

Also called Rabbit Fever
Caused by Franciscella tularensis
Facultative intracellular pathogen–prefers macrophages
Gram (-) bacteria
Has extended survival times in environment including animal carcasses, mud, water

Question 2

Geographic distribution of tularemia

Answer 2

northern hemisphere

Question 3

Epidemiology for tularemia

Answer 3

Few cases/year in US
From ticks and rabbits, but also squirrels and deer flies
Only requires 1 bacillus
Usually involves contact with an animal somehow but can be inhaled or ingestion of infected meat
No person-person contact

Question 4

Clinical presentations of Tularemia and route of infection

Answer 4

Ulceroglandular: skin abrasion or bite
Pneumonic: inhalation
Oropharyngeal: ingestion of meat
Oculoglandular: autoinoculation
Typhoidal: systemic spread

Question 5

Ulceroglandular tularemia

Answer 5

Most common form, rarely fatal
Bacteria pass through skin and infect macrophages
Painful papules develop after 3-5 days => ulceration
Lymphadenopathy in regional lymph nodes resembling bubonic plague
Abrupt onset of flu-like Sx

Question 6

Pneumonic tularemia

Answer 6

High mortality rate 30%+
Bacteria inhaled and form necrotizing granulomas
Bacteremia can occur

Question 7

Oropharyngeal tularemia

Answer 7

High mortality rate 30%+
Bacteria ingested, then cross mucosa and enter bloodstream
Endotoxemia from bacterial cell lysis
Fever, sore throat, abdominal pain, vomiting, diarrhea, splenomegaly

Question 8

Oculoglandular tularemia

Answer 8

Bacteria in eye, often from contaminated hands
Involvement of conjunctival sac and nearby lymph nodes
Pain, itching, photophobia, lacrimation, mucopurulent discharge

Question 9

Typhoid tularemia

Answer 9

High mortality rate 30%+
Systemic bloodstream involvement, sepsis, pneumonia
Flu-like
Often lack ulcers and LAD

Question 10

Diagnosis and treatment and prevention of tularemia

Answer 10

Patient Hx
Culture aspirate of lymph node or drainage or sputum

Streptomycin, gentamicin
Relapses can occur

Avoid animal contact live or dead, don’t mow over dead animals

Question 11

Causative agent of brucellosis

Answer 11

Four species:
B. abortus: from catle
B. canis: dogs
B. suis: pigs/boars
B. melitensis: goats & sheep

Gram (-) bacteria
Facultative intracellular–gets phagocytozed by macrophages and taken to lymph nodes
Obligate aerobe
Can survive for long periods in milk or animals or soil

Question 12

Brucella routes of transmission

Answer 12

Unpasteurized milk
Direct contact with animals, and lab techs dealing with samples
Spreads via lymphatics and multiplies in macrophages

Question 13

Brucella fever pattern

Answer 13

Undulating fever is common

Question 14

Brucella presentation

Answer 14

Incubation from days to months
Huge variation in presentation
Insidious onset with non-specific symptoms that vary by person and case
Persistent infection can => abscesses and granulomas in any tissue

Question 15

Brucella diagnosis

Answer 15

Culture

Serological tests–lots of false negatives

Question 16

Brucella treatment

Answer 16

doxycycline with rifampin or gentamicin for 6+ weeks

Question 17

Brucella prevention

Answer 17

Vaccinate animals, avoid unpasteurized dairy

Question 18

Bartonella spp that cause disease

Answer 18

B. bacilliformis: bartonellosis, Oroya fever, verruga, isolated to South America, sandfly vector
B. quintana: trench fever, bacillary angiomatosis, SBE, body louse vector
B. henselae: cat scratch, cat flea vector?
B. elizabethae and B. clarridgeiae: endocarditis

Question 19

Bartonella charactersitics

Answer 19

Gram (-) aerobic bacilli

Facultative intracellular of blood and RES

Question 20

Bartonella tansmission

Answer 20

Bite from arthropod
Scratch or bite from cat
Also, highest risks for immunocompromised and poor hygiene/sanitation

Question 21

Bartonella from B. bacilliformis

Answer 21

Oroya Fever (acute)
Verruga (chronic)
Transmitted by sandfly bite
Multiplication in blood stream with penetration of RBC’s and RBC fragility, clearance of these cells by RES => Oroya fever

Oroya: incubation 3 weeks, fever, malaise, headache, anemia, found in western South America

Verruga: Red-purple skin lesions appear in crops and are wart-like, recurrence for months-years

Question 22

Bartonella from B. quintana

Answer 22

Trench fever from WWI
Transmission from body louse feces
Bacteria survive in RES cells
Severe headache, sudden onset fever, weakness, rash, pain in long bones
5 day fever recurrence

Question 23

Bartonella from B. henselae

Answer 23

Cat scratch disease (bite or scratch)
Bacteria infect RES cells and lymph nodes
Often benign, but can be significant in immunocompromised–bacillary angiomatosis
Within 3-50 days chronic regional lymphadenopathy, can last for months

Question 24

Bacillary angiomatosis

Answer 24

From either B. henselae or B. quintana
Seen in immunocompromised patients
Ulcerating lesions in the skin, can also involve the liver, lymph nodes, spleen in henselae or the sub-q, and bone in quintana

Question 25

Bartonella diagnosis

Answer 25

History
Serology: DFA or IFA
Rarely cultured

Question 26

Bartonella treatment

Answer 26

Cat scratch: azithromycin
Bartonellosis: doxy or chloramphenicol
Angiomatosis: macrolides or doxy
Trench Fever: doxy