infectious Diseases p34-45 Flashcards
organism that can cause endocarditis on normal heart valves; risk factor
staph aureus; iv drug abuse
best initial tests for endocarditis
blood culture (95-99% sensitive) TEE (95% sensitive)
endocarditis causing organisms associated with colonic pathology
strep bovis,
clostridium septicum
best initial empiric therapy for endocarditis
vancomycin and gentamicin
Rx of endocarditis a)viridians strep B) staph aureus (sensitive) C)fungal D)Staph epidermidis and MRSA E) Enterococci
A) ceftriaxone *4 weeks B) oxacillin, nafcillin, or cefazolin C) amphotericin and valve replacement D) vancomycin E) ampicillin n gentamicin
strongest indications for surgery in patients with endocarditis
acute valve rupture;
CHF
most common cause of culture negative endocarditis
COXIELLA
Bartonella
other than coxiella, what are the causes of culture negative endocarditis
HACEK group(treat with ceftriaxone), Bartonella
procedures that need prophylaxis to prevent endocarditis
a) dental work,
B)respiratory tract surgery
C) prosthetic valve
D) cardiac transplant with valvulopathy
other indications: previous endocarditis, unrepaired cyanotic heart disease
Amoxicillin is given for prophylaxis
tick that transmits lyme disease
Ixodes scapularis
minimum time required for tick attachment leading to transmission of lyme
24 hours
most commonly involved joint in lyme disease
knee
most common neurological manifestation of lyme disease
bells palsy involving facial nerve
most common cardiac manifestation of lyme disease
transient AV block
do u need a confirmatory serology for lyme disease when patient presents with erythema migrans
no,
but is required for all other manifestations. Done using IgM, IgG, ELISA, Western blot and PCR testing
Rx for lyme disease
*rash= doxycycline
Amoxicillin or cefuroxime
*joint, seventh cranial nerve palsy= doxycycline,
amoxicillin and cefuroxime
*cardiac and neurological manifestations other than 7th CN palsy = IV ceftriaxone
management of asymptomatic tick bite
single dose of doxycycline if A) Ixodes scapularis identified as the tick B) tick attached longer than 24-48 hours C) engorged tick D) endemic area
CD4 levels for PCP prophylaxis
below 200/microL
infections that can still occur with HIV despite CD4>200
shingles, herpes simplex, TB oral and vaginal candidiasis bacterial pneumonia Kaposi sarcoma
Best initial test for HIV
ELISA
confirmatory test for HIV
Western blot
why is ELISA unreliable for HIV in infants
because maternal HIV antibodies may be present up to 6 months after delivery
Uses of viral load testing(PCR RNA level) in HIV
A) measure response to therapy
B) detect treatment failure
C) Diagnose HIV in babies
CD4 counts when HIV treatment is initiated
below 500/microL
