L 79 Tularemia, Brucellosis, Bartonellosis Flashcards
Causative agent for tularemia
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
Geographic distribution of tularemia
northern hemisphere
Epidemiology for tularemia
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
Clinical presentations of Tularemia and route of infection
Ulceroglandular: skin abrasion or bite Pneumonic: inhalation Oropharyngeal: ingestion of meat Oculoglandular: autoinoculation Typhoidal: systemic spread
Ulceroglandular tularemia
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
Pneumonic tularemia
High mortality rate 30%+
Bacteria inhaled and form necrotizing granulomas
Bacteremia can occur
Oropharyngeal tularemia
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
Oculoglandular tularemia
Bacteria in eye, often from contaminated hands
Involvement of conjunctival sac and nearby lymph nodes
Pain, itching, photophobia, lacrimation, mucopurulent discharge
Typhoid tularemia
High mortality rate 30%+
Systemic bloodstream involvement, sepsis, pneumonia
Flu-like
Often lack ulcers and LAD
Diagnosis and treatment and prevention of tularemia
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
Causative agent of brucellosis
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
Brucella routes of transmission
Unpasteurized milk
Direct contact with animals, and lab techs dealing with samples
Spreads via lymphatics and multiplies in macrophages
Brucella fever pattern
Undulating fever is common
Brucella presentation
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
Brucella diagnosis
Culture
Serological tests–lots of false negatives
Brucella treatment
doxycycline with rifampin or gentamicin for 6+ weeks
Brucella prevention
Vaccinate animals, avoid unpasteurized dairy
Bartonella spp that cause disease
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
Bartonella charactersitics
Gram (-) aerobic bacilli
Facultative intracellular of blood and RES
Bartonella tansmission
Bite from arthropod
Scratch or bite from cat
Also, highest risks for immunocompromised and poor hygiene/sanitation
Bartonella from B. bacilliformis
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
Bartonella from B. quintana
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
Bartonella from B. henselae
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
Bacillary angiomatosis
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
Bartonella diagnosis
History
Serology: DFA or IFA
Rarely cultured
Bartonella treatment
Cat scratch: azithromycin
Bartonellosis: doxy or chloramphenicol
Angiomatosis: macrolides or doxy
Trench Fever: doxy
