Infectious disease zebras Flashcards
nocardia characteristics on gram stain
partially acid fast, filamentous branching rods
nocardia affects what kind of pts?
how do you get it?
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
rapidly developing painful purulent ulcer with violacious and undermined border with fever
pyoderma gangrenosum = seen with IBS, arthropathies, hematological malignancies
tularemia presents with
ulceroglandular disease and fever or a single erythematous papulo ulcerative lesion with central eschar
who gets tularemia?
people who have been handling animals or exposed to ticks
Tularemia is caused by?
francisella tularensis which is a gram negative bacterium.
Fusarium species clinical facts
Fusarium is second most common pathogenic mold found in soil plant debris and invades tissue directly to cause destruction
Fusarium species presentation
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
diagnosis of Fusarium species mold
positive blood cultures (40%) growing mold, skin biopsy, tissue biopsy.
aspergillus fumigatus presentation
pneumonia and skin lesions but no positive blood culturs.
see this in immuncompromised pts who tend to have more presentations.
nocardia presentation
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
Treatment of fusariosis (mold) infections
treatment is with amphotericin B with or without voriconazole with varying efficacy
Tx of lung abscess
which antibiotics to use?
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
RF for lung abscess
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.
manifestations of lung abscess
weeks or months of cough with foul smelling sputum, night swats, weight loss.
diagnosis of lung abscess
CXR or CT scan with cavitary infiltrate with air fluid levels dependent portions of lung.
eschar, pustules, skin necrosis after a flea bite. Pt then has sudden onset of fevers, chills, weakness and headache.
Yersinia pestis
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
Yersinia pestis presentation as bubonic plague (80-95%) of cases.
septicemic plague presentation (10-20% of time)
sudden onset of fever, nausea, diarrhea, vomiting, and abdominal pain. No lymphadenopathy or bubo
progresses to hypotension, DIC, and multiorgan failure
when to suspect yersenia pestis
high clinical suspicion, with travel to endemic area (southwest US) or exposure to animals plus unexplained fever with regional lymphadenitis
diagnosis of yersenia pestis by labs:
blood cultures, peripheral smear (Wright Giemsa stain) fluid culture CSF, buboaspirate and serological titers
gram negative coccobacillus that causes in eschar or pustules and skin necrosis and bubos with swollen lymphadenopathy
bubonic plague
transmission of yersenia pestis is via:
infected fleas - rodents, cat bites or scratches, or rats
Yersinia entercolitica and Y. pseudotuberculosis cause
diarrheal illness. Not the same as Y. pestis which can cause bubonic plague or septicemic plague
Treatment of Yersinia pestis
tetracyclines or streptomycin
post exposure prophylaxis for Y. pestis exposure
doxycycline
coccidioides immitis presentation
nonspecific symptoms, dry cough, pneumonia, skin lesions in immunocompromised.
localized cellulitis within 24 hrs after being bitten or scratched by house pet. See sudden onset of fevers, chills,
pasteurella multocida
can have bacteremia with osteomyelitis, meningitis and endocarditis
rat bite fever
streptobacillus moniformis
see fever, severe myaglias, asymmetrical arthralgias and fine macular rash. NO LAD>
trypanosoma cruzi causes
Chagas disease with dilated cardiomyopathy
this is protozoan from Central and South America
Chagas disease has 3 phases
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.
how to diagnose Chagas disease
TTE and see varying degrees of right or left ventricular systolic dysfunction along with left ventricular apical aneurysm - pathognomonic for Chagas cardiomyopathy
what is seen on EKG with Chaga’s dx?
nonspecific EKG findings like RBBB and Left anterior fascicular block.
TTE will show left ventricular apical aneurysms
