Infectious disease zebras

Question 1

nocardia characteristics on gram stain

Answer 1

partially acid fast, filamentous branching rods

Question 2

nocardia affects what kind of pts?

how do you get it?

Answer 2

immunocompetent hosts

results from direct inoculation of hosts

has a skin dx with a presentation that looks like spirotrichosis but the culture will be different

Question 3

rapidly developing painful purulent ulcer with violacious and undermined border with fever

Answer 3

pyoderma gangrenosum = seen with IBS, arthropathies, hematological malignancies

Question 4

tularemia presents with

Answer 4

ulceroglandular disease and fever or a single erythematous papulo ulcerative lesion with central eschar

Question 5

who gets tularemia?

Answer 5

people who have been handling animals or exposed to ticks

Question 6

Tularemia is caused by?

Answer 6

francisella tularensis which is a gram negative bacterium.

Question 7

Fusarium species clinical facts

Answer 7

Fusarium is second most common pathogenic mold found in soil plant debris and invades tissue directly to cause destruction

Question 8

Fusarium species presentation

Answer 8

Immunocompromised pts (neutropenic, lymphopenic, graft vs host dx and steroid incuded) or people with hematological malignancy and getting induction chemotherapy or bone marrow transplant, persistent fever, sinusitis, pneumonia (sometimes cavitary) skin infection (multiple painful erythematous papules or nodules with central necrosis sometimes

fungemia - disseminated dx seen in 70% of pts

Question 9

diagnosis of Fusarium species mold

Answer 9

positive blood cultures (40%) growing mold, skin biopsy, tissue biopsy.

Question 10

aspergillus fumigatus presentation

Answer 10

pneumonia and skin lesions but no positive blood culturs.

see this in immuncompromised pts who tend to have more presentations.

Question 11

nocardia presentation

Answer 11

presents as skin dx with ulcerations, pyoderma, cellulitis, or nodules and subcutaneous abscesses.

weakly gram positive staining and rod shaped bacteria that forms partially acid fast beaded branching filaments

Question 12

Treatment of fusariosis (mold) infections

Answer 12

treatment is with amphotericin B with or without voriconazole with varying efficacy

Question 13

Tx of lung abscess

which antibiotics to use?

Answer 13

Treat with ampicillin-sulbactam or carbapenem. DO not recommend clindamycin anymore due to risk for C diff

Doesn’t require drainage and treat until repeat CXR is clear without small stable residual lesions

Question 14

RF for lung abscess

Answer 14

necrosis of lung tissue due to microbial infection - seen usually of oral anaerobic and aerobic bacteria
- seen with ETOH or drug overdose or epilepsy

also seen with esophageal stricture diverticula or prior stroke.

Question 15

manifestations of lung abscess

Answer 15

weeks or months of cough with foul smelling sputum, night swats, weight loss.

Question 16

diagnosis of lung abscess

Answer 16

CXR or CT scan with cavitary infiltrate with air fluid levels dependent portions of lung.

Question 17

eschar, pustules, skin necrosis after a flea bite. Pt then has sudden onset of fevers, chills, weakness and headache.

Answer 17

Yersinia pestis

Question 18

pt with sudden onset of fevers, chills ,headache and found to have painful lymphadenopathy with swelling (bubo) and inguinal nodes and rapid progression of sepsis by pneumonia, meningitis and shock

Answer 18

Yersinia pestis presentation as bubonic plague (80-95%) of cases.

Question 19

septicemic plague presentation (10-20% of time)

Answer 19

sudden onset of fever, nausea, diarrhea, vomiting, and abdominal pain. No lymphadenopathy or bubo

progresses to hypotension, DIC, and multiorgan failure

Question 20

when to suspect yersenia pestis

Answer 20

high clinical suspicion, with travel to endemic area (southwest US) or exposure to animals plus unexplained fever with regional lymphadenitis

Question 21

diagnosis of yersenia pestis by labs:

Answer 21

blood cultures, peripheral smear (Wright Giemsa stain) fluid culture CSF, buboaspirate and serological titers

Question 22

gram negative coccobacillus that causes in eschar or pustules and skin necrosis and bubos with swollen lymphadenopathy

Answer 22

bubonic plague

Question 23

transmission of yersenia pestis is via:

Answer 23

infected fleas - rodents, cat bites or scratches, or rats

Question 24

Yersinia entercolitica and Y. pseudotuberculosis cause

Answer 24

diarrheal illness. Not the same as Y. pestis which can cause bubonic plague or septicemic plague

Question 25

Treatment of Yersinia pestis

Answer 25

tetracyclines or streptomycin

Question 26

post exposure prophylaxis for Y. pestis exposure

Answer 26

doxycycline

Question 27

coccidioides immitis presentation

Answer 27

nonspecific symptoms, dry cough, pneumonia, skin lesions in immunocompromised.

Question 28

localized cellulitis within 24 hrs after being bitten or scratched by house pet. See sudden onset of fevers, chills,

Answer 28

pasteurella multocida

can have bacteremia with osteomyelitis, meningitis and endocarditis

Question 29

rat bite fever

Answer 29

streptobacillus moniformis

see fever, severe myaglias, asymmetrical arthralgias and fine macular rash. NO LAD>

Question 30

trypanosoma cruzi causes

Answer 30

Chagas disease with dilated cardiomyopathy

this is protozoan from Central and South America

Question 31

Chagas disease has 3 phases

Answer 31

acute mild phase of nonspecific symptoms with fever and myalgias

2nd phase follows first phase with indeterminant phase of serologic or parasitic T cruzi infection in the absence of symptoms or infection. This can be asymptomatic for years.

Last phase is Chagas cardiomyopathy and seen with development of heart failure.

Question 32

how to diagnose Chagas disease

Answer 32

TTE and see varying degrees of right or left ventricular systolic dysfunction along with left ventricular apical aneurysm - pathognomonic for Chagas cardiomyopathy

Question 33

what is seen on EKG with Chaga’s dx?

Answer 33

nonspecific EKG findings like RBBB and Left anterior fascicular block.

TTE will show left ventricular apical aneurysms