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21 Cards in this Set
- Front
- Back
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Briefly discuss cat scratch disease and its associated lymphadenopathy
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caused by bartonella henselae
- slow-growing fastidious gram (-) rod presents w/small abscesses at site of cat scratch/bite after 3-5 days. followed by fever & localized lymphadenopathy 1-2 weeks later |
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Describe the clinical presentation of cat scratch disease
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small abscesses at site of cat scratch/bite after 3-5 days followed by localized lymphadenopathy and fever for 1-2 weeks then resolution in an immunocompetent pt, if pt has AIDS then dissemination of bacteria causing sepsis, infection of skin, liver, organs, & production of erythematous papules.
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describe the sequelae of B. henselae infection (cat scratch fever) in a pt w/AIDS
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the bacteria can multiply greatly and disperse thru bloodstream causing:
sepsis localized infection of skin, liver, other organs bacillary angiomatosis (proliferation of small blood vessels due to cytokines causing red papules allover skin) |
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Explain the treatment and prevention of cat scratch disease
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azithromycin
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Describe the epidemiology and incidence of plague in the US
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< 10 cases/year, mostly in southwest US
2 types: a. sylvatic plague (reservoir is ground squirrels & praire dogs in SW, transmitted by fleas to humans) b. urban plague (rats are reservoir, transmitted by fleas to humans) |
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Discuss the pathogenesis of plague in relation to the virulence factors of the causative agent
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yersinia pestis [gram (-) rod] has:
- slime capsule (F-1 antigen) - endotoxin - exotoxin (bacteriocin & other enzymes) - smear from needle aspirate is stained w/Giemsa to show bipolar staining - grows well on BAP, Choc, Mac agar |
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Describe the clinical presentation of plague
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after 2-5 day incubation period pt will have sudden onset of high fever, painful enlarged regional lymph nodes in neck, axilla or groin. Vomiting or diarrhea may develop w/sepsis.
Rapid vascular collapse w/DIC causing blackening of skin. Hypotension, altered mental status, renal & cardiac failure, mortality rate is ~50% untreated. |
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Explain the treatment and prevention of plague
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gentamicin or streptomycin
- alt = doxycyline - vaccine for persons traveling to endemic area - destroy vector & infected animals |
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describe the following for yersinia enterocolitica:
1. clinical presentation 2. pathogenesis 3. lab findings |
1. diarrhea that is often bloody
-accompanied by severe pain in LRQ mimicking appendicitis -associated w/consumption of unpasteurized dairy products 2. obtained from unpasteurized dairy & invades gut mucosa 3. grows on routine lab media - stool culture no effective - biopsy & culture of swollen mesenteric lymph nodes may reveal bacteria |
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Discuss the pathogenesis of franciscella tularemia in relation to the virulence factors of the causative agent
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franciscella tularensis
- survives & multiplies w/in macrophages b/c of lipid capsule |
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Describe the laboratory diagnosis of Francisella tularemia
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*Serology for febrile agglutinins
ELISA for IgM & IgG (demonstrated rise in antibody response)* - culture req's choc agar w/cystein & glucose (slow growing gram (-) rod) |
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Describe the clinical presentation of fransiscella tularemia
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formation of ulcers from contact w/contaminated animal products
- lymphadenopathy - flu-like symptoms (fever, myalgia) |
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Explain the treatment and prevention of fransiscella tularemia
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streptomycin or gentamicin
-avoid sick/dead animals, insect repellent, promptly remove ticks, drink potable water & cook wild meat |
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Describe the epidemiology and incidence of fransiscella tularemia in the US
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carried by rodents, rabbits, beavers & muskrats; transmitted to humans by flies & mosquitos.
-100-200 cases/yr in US most often affects vets, hunters, & meat handlers |
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Describe the epidemiology and incidence of brucellosis in the US
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primarily found in farm animals
-requires direct contact w/infected animal or its byproducts (unpasteurized milk/dairy) < 100 cases/yr in US - look for history of travel to middle east, other endemic areas |
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Discuss the pathogenesis of brucellosis in relation to the virulence factors of the causative agent
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gram (-) coccobacilli
nonmotile urease & nitrate (+) strictly aerobic - localizes in reproductive organs; high #'s in milk, urine, placenta - resists killing by macrophages; enters lymphatics -> nodes -> blood stream -> organs - forms granulomatous nodules (NO skin lesions) |
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Describe the laboratory diagnosis of Brucella
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Febrile agglutinins standardized w/brucella O-antigens
- 4x increase in titer -LIA for brucella IgM & IgG Culture highly hazardous & only done by CDC |
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Explain the treatment and prevention of brucellosis
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doxycycline + streptomycin or gentamicin for prolonged period
- eradication/control of Dz in animals, avoid contact w/infected animals & byproducts (unpasteurized dairy) |
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describe the clinical presentation of Brucella:
1. acute 2. chronic |
1. onset of symptoms after 1-6 weeks. insidious onset: malaise, fever, weakness, aches & sweats
= fever rises in afternoon (ass'd sweats) & falls during the night 2. generalized weakness, aches & pains, low grade fever, & nervousness - lymphadenopathy or hepatosplenomegaly |
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8-year-old girl complained of a 2-wk history of severe sore throat, fever, abdominal pain, anorexia and a 5-pound weight loss
Recently immigrated with her parents from Syria, where she had been treated with a 4 wk course of trimeth/sulfa for food-borne illness Hx - remarkable only for rheumatic fever; immunization utd included BCG vaccine; born in Iraq, moved with her parents and sibling to Syria; lived on a farm - consumed raw milk Physical findings: fever (102oC, tachycardic (108 beats/min), slightly tachypneic (24/min), and normotensive (90/48 mm Hg) Appeared acutely ill but nontoxic, oral mucosa was dry TM normal, oropharynx erythmatous, tonsils swollen without exudate Diffuse cervical adenopathy Abdomen not distended but tender in right upper quadrant (liver) and left upper quadrant (spleen) Leukopenia Anemia Thrombocytopenia Hypoalbuminemia Echocardiogram: small pericardial effusion BM biopsy: granulomas |
1. Brucella
2. IV rifampin & gentamicin 5 days -> doxycycline + rifampin 45 days |
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A previously healthy 25-year-old man traveled to Nantucket Island, Massachusetts, and installed an outdoor speaker system, a job that involved digging in the ground and laying cable. Ten days later, he presented to another facility with fever, pain in the left arm and axilla, and a "pimple" on the left thumb base, which became necrotic and was accompanied by papules and nodules ascending the wrist and forearm. His condition improved after receipt of ceftriaxone, but he developed a drug-related rash. When subsequently treated with vancomycin, he developed recurrent fever, additional nodules on the upper arm, and necrosis of the nodules that were already present The necrotic lesions were debrided by a surgeon; cultures of samples obtained from the wound were performed at an outside laboratory and were reported to have grown Haemophilus influenzae. Treatment with doxycycline produced a modest improvement in the patient's condition, and he was referred to our facility. The appearance of th
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1. francisella tularensis
2. streptomycin |
