Case

1
Case2 75 y/o female with h/o MRSA bacteremia
presented with fever

• The Pt with h/o ESRD, on HD, was admitted in the
  hospital 6-weeks ago with fever (102), anorexia,
  nausea.
• Blood cxs drawn through Perm Catheter and
  peripheral vein grew MRSA.
• TTE was negative for vegetation.
• The Pt was treated with vancomycin and rifampin
  for 4-weeks. Subsequent cxs were negative.
• 2-weeks after Atbx were D/Cd, pt presented with
  low grade fever, nausea, and anorexia.

2
Case2 HP (contd)

• Tm 100.4, P 98, R 24, BP 142/91, Pox 96
• Exam- unremarkable.
• PC site- no erythema, nontender, no purulence.
• Wbc 4.9 (no diff), plt 165, cr 3.0
• Blood cx was drawn (site not labeled).
• ID was consulted.

3
Risk of MRSA infection after previous infection
or colonization (CID 2003 36281)

• A retrospective study in hospitalized pts who had
  MRSA-positive cultures including only new
  infection and colonization.
• Frequency of subsequent MRSA infection was
  observed in these pts over 18-months after the
  initial detection.
• All isolates from normally sterile sites were
  considered to indicate infection.
• A total of 209 pts were identified as newly
  infected or colonized with MRSA over 6-months in
  2000.

4
Risk of subsequent MRSA infection (contd)

• 112 pts (54) had MRSA-positive cultures
  representing infection, and 97 (46) had cultures
  representing colonization.
• The respiratory tract was the most common source
  of newly identified MRSA isolates for cases of
  both infection and colonization.

5
Risk of subsequent MRSA infection (contd)

• Of the 209 MRSA positive pts, 60 (29) developed
  90 subsequent infections due to MRSA.
• 19 pts (9) had 1 episode of MRSA infection.
• On average, infections occurred 102 days after
  (median, 29 days) the initial MRSA-positive
  culture.

6
Risk of subsequent MRSA infection (contd)

• Risk of subsequent MRSA infection was higher in
  pts (40-50) who had initial MRSA from bone,
  joint fluid, or the nares than those (20-30)
  who had initial MRSA from respiratory and soft
  tissues.
• Of the 60 pts with subsequent MRSA infection, 48
  (80) had infections localized to a different
  site.
• Those episodes were commonly bacteremia (33) or
  soft tissue infection (24).
• The majority of same site infections were
  pneumonia.

7
Risk of subsequent MRSA infection (contd)

• Bone and joint infections were more likely to
  result in recurrent infections at the same site.
• 3 bone infections (2 sternal and 1 foot
  infection) recurred despite surgical debridement.
• A prosthetic hip infection was followed by
  infection of the cement spacer after prosthesis
  removal and by subsequent infection of the femur
  and pelvis despite radical surgery.

8
Risk of subsequent MRSA infection (contd)

• Risk did not differ significantly according to
  age, sex, infection vs colonization, h/o
  hemodialysis or discharge disposition.
• There were no significant predictors for
  development of predischarge versus postdischarge
  MRSA infections.
• Predischarge infections were more likely to be
  related to the presence of a vascular catheter or
  involve the bloodstream.
• 52 of the pts developed subsequent infection
  that became manifest after discharge from the
  index hospitalization.