Hsiao_edit.qxp 30/1/09 3:41 pm Page 78
Bacterial Infections
Figure 1: Algorithm for Staphylococcus aureus Skin and Figure 2: Algorithm for Staphylococcus aureus Bacteraemia
Skin-structure Infections
SA abscesses SAB
1. Community acquisition
Repeat
2. Skin examination findings suggesting
Figure 2
blood cultures
acute systemic infection
Repeat blood
every 48 hours until
Complicated:
SAB
3. Persistent fever at 72 hours
cultures every
culture turns to
4. Positive follow-up blood culture
with cellulitis with
Blood cultures
48 hours until
a negative result
results at 48–96 hours
at least one of SIRS culture turns to
a negative result
8 days
No SAB
None of Remove all
Negative TTE,
2
Negative
IV antibiotics
4 factors infected catheters
negative deep-
TEE
tissue involvement
Starting empiric IV antibiotics:
I&D, cultures,
Positive
Right-sided
- vancomycin ± gentamicin
Any of 4 factors
endocarditis
wound care, hygiene
Starting oral antibiotics:
instructions
- trimethoprim-sulfamethoxazole
- minocycline or doxycycline
Myocardial
Involving deep tissues
- clindamycin (D-test)
Skin abscesses TTE
Left-sided
abscess
Streamline antibiotics:
with cellulitis
endocarditis
Haemodynamic
(stable)
No deep-tissue involvement
MSSA-β-lactams
PCN-susceptible: PCN
Deep-tissue
PCN-non-susceptible: nafcillin I&D
involvement
Haemodynamic
MRSA
Uncomplicated Hardware removed - vancomycin, teicoplanin
(unstable)
- linezolid
SAB >96 hours
No hardware
(caution, if with gentamicin)
Surgical
- daptomycin If MRSA
management
Remove
Surrounding
Retained infected
(no, if penumonia)
Vacomycin plate
hardware or
erythema
sources i.e. hardware
- quinupristin-dalfopristin
(6mg/ml) screen or
- tigecycline (no, if SAB)
Alternative
prostheses
vancomycin E-test
28–42 days
or prostheses
IV or oral
- trimethoprim-sulfamethoxazole anti-SA antibiotic or
IV antibiotics
No surrounding
antibiotics for at
- minocycline or doxycycline higher vancomycin Retained
erythema
- clindamycin (D-test)
least 10–14 days
dose
infected sources
i.e. hardware or
after the last I&D. PCN: penicillin
If osteomyelitis, SAB: S. aureus bactermia
Non-susc
prostheses Synthetic β-lactams
14 days IV antibiotics
eptible
Oral antibiotics 28–42 days
IV antibiotics for
or MIC >1
± gentamicin
7–14 days or longer
14–28 days, then oral
Prolonged IV
if MSSA
antibiotic suppression
antibiotics therapy (>42 days)
indefinitely
or 28 days IV antibiotics, then
oral antibiotic suppression
Clinical follow-up
Clinical follow-up
indefinitely
(up to 3 months after the end of treatment)
(up to 3 months after the end of treatment)
treatment course can be longer if the infection involves deep tissues, such previously been exposed to vancomycin, vancomycin may become less
as fascia or muscle, or if bacteraemia occurs. effective. Thus, laboratories that routinely use disc diffusion or an
automated system for staphylococcal susceptibility testing should consider
Invasive Staphylococcus aureus Infections using a commercially prepared brain–heart infusion agar plate with 6mg/ml
of vancomycin to screen SA isolates for reduced susceptibility to
Uncomplicated or Complicated vancomycin.
22
A vancomycin E-test of the SA can be requested to see
Staphylococcus aureus Bacteraemia whether vancomycin is an effective agent for treating SAB. Persistent SAB
Any infection with an SA-positive blood culture should be treated seriously. indicates a high probability of infection involving heart valves, endothelium,
Careful follow-up is required for at least three months after the last dose of deep tissue or artificial devices. Removal of infected sources is crucial to
antibiotic therapy. All SA bacteraemia (SAB) events should be treated with reach a successful treatment outcome.
23
Alternative antibiotic choices to
effective antibiotics with bactericidal capability for at least 14 days.
16–18
All treat SA would be daptomycin, quinupristin–dalfopristin and linezolid.
potentially complicated episodes of SAB require a longer duration of High-dose intravenous trimethoprim–sulfamethoxazole or long-acting
antibiotic therapy with every effort made to remove any infected source. tetracyclines such as minocycline or doxycycline are other potential agents,
despite the fact that there are no well-controlled clinical trial studies to
Complicated SAB is often difficult to identify; however, the strongest support their use in this setting. Tigecycline is not indicated in the setting
predictor of complicated SAB is a positive follow-up blood culture result at of bacteraemia despite its excellent activity against SA in vitro and its
48–96 hours, as described by Flower et al. A scoring system to predict the indication to treat complicated skin and skin-structure infections.
probability of complications of SAB based on the presence or absence of Daptomycin, which can be deactivated by surfactant,
24
is not
the following four risk factors has been developed: community acquisition; recommended if the lung is the primary source of the SA infection.
skin examination findings suggesting acute systemic infection; persistent
fever at 72 hours; and positive follow-up blood culture results at 48–96 There has been no clear guidance for the duration of antibiotic therapy for
hours. This scoring system has been able to predict complicated SAB.
19
SAB. We do know that a high relapse or complication rate occurs if the
Thus, sending follow-up blood cultures at 48–96 hours after the SAB event treatment course is shorter than 14 days.
16–18
Right-sided methicillin-
should be a standard of care for managing SA bloodstream infections.
19
sensitive SA (MSSA) endocarditis can be treated with synthetic
Since initial appropriate antibiotic therapy influences patient treatment antistaphylococcal β-lactams such as nafcillin with or without gentamicin for
outcomes,
20,21
antibiotics with bactericidal activity to MRSA should be used 14 days.
25
A simple, uncomplicated catheter-related SAB can be treated with
as an empirical therapeutic choice. catheter removal and, if there is no trans-oesophageal cardiographic
abnormality, with 14 days of parenteral antistaphylococcal therapy.
26
Worldwide, vancomycin is the most commonly used antibiotic to treat SAB. Basically, the decision for length of antibiotic therapy for all invasive SA
In some rare circumstances, especially in patients with SAB who have infections should be individualised. Generally, any potentially complicated
78 EUROPEAN INFECTIOUS DISEASE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116