View source for Staphylococcus aureus bacteremia

= ''Staphylococcus aureus'' bacteremia =

== Definition ==

* '''Community-onset:''' positive blood culture obtained within 48 hours of presentation
* '''Nosocomial:''' positive blood culture obtained after 48 hours of presentation

== Etiology ==

* IVDU
* Poor dentition
* Dental work

== Clinical Presentation ==

* Often non-specific fevers and chills, diagnosed on blood cultures
* May have back pain unrelated to spinal osteomyelitis
* May present with focus of metastatic disease

== Investigations ==

== Management ==

* Infectious diseases consultation
* Must rule out endocarditis! TTE, followed by TEE if suspicion remains high
* Low risk for endocarditis (no TEE) if all of the following:
** No intracardiac device
** Sterile follow-up blood cultures within 4 days from the initial set
** No hemodialysis
** Nosocomial acquisition of S. aureus
** Absence of secondary foci
** No clinical signs of endocarditis
* Uncomplicated if
** Endocarditis is excluded
** No implanted prostheses
** Blood cultures clear by 2-4 days
** Defervesces within 72 hours
** No evidence of metastases
** +/- identified source has been removed
* Two-week course acceptable if uncomplicated, otherwise 4-6 weeks
* MSSA: cloxacillin 2g IV q4h for 2 weeks (cefazolin as an alternative)
* MRSA: vancomycin 1g IV q12h for 2 weeks
** Adjust based on serum trough before every fourth dose
** Target trough 15-20

== Prognosis ==

* Mortality 20-50% at 30 days, 60% at 1 year
* Mortality halved by ID consult
* Prognosis worse with
** Increased age
** Female sex
** Pneumonia or source unknown
** Dementia
** Increasing comorbidities
** Shock at time of presentation
** Institutionalized patient

== Further Reading ==