Question 5. Which is the most common focus of MRSA
bloodstream infections in your practice?
Background. Most MRSA bacteraemia in Europe is healthcare-associated.
Several studies [21,22] have demonstrated
that the most common foci for MRSA bacteraemia are intravascular
catheters—those sited in peripheral vessels, as well
as those sited centrally. Even if the patient presents to hospital
with an MRSA bacteraemia, the focus is often related to a
vascular catheter sited at a recent hospital visit. Other common
foci are skin and soft tissue sites—especially ulcers,
chronic wounds, or surgical wounds—and the urinary tract
in association with urinary catheters.
Data from the MRSA bacteraemia Enhanced Surveillance
Scheme provide an important means of identifying risk factors
and sources of bacteraemia in British patients [22].
SSTIs (the most common sources of bacteraemia in the
admission-diagnosed group) may result from the use of
peripheral intravascular devices, the most common risk factor
in this group. It is hypothesized that a large proportion
of those patients presenting to the acute hospital with an
MRSA bacteraemia developed this condition as a result of a
prior healthcare contact. Identification of key risk factors
and sources of bacteraemia will allow effective targeting of
infection control interventions and help guide selection of
initial empirical antibacterial therapy.
Responses. In the survey, 48% of ECCMID delegates listed
intravascular lines as the most common foci of bloodstream
infections (Fig. 3). These sources therefore represent a
major target for healthcare intervention in the reduction of
serious MRSA infection across Europe. Careful management
of intravascular lines is an effective intervention in reducing
bloodstream infections. Skin and soft tissue was reported by
31% of respondents as the most common focus of bacteraemia
(Fig. 3). As the great majority of MRSA bloodstream
infections in Europe are healthcare-related, the sources of
many of these infections are likely to be surgical wounds.
Preventing these also represents a target for reducing the
number of MRSA bloodstream infections, and the obvious
method for this is the screening of surgical patients for
MRSA and, if necessary, subsequent decolonization therapy
[23,24].
The fact that 13% of ECCMID delegates and one faculty
member reported respiratory tract infection as the most
common focus for MRSA bacteraemia is surprising. Staphylococcal
pneumonia is relatively rare. Even in ventilated patients
in high-dependency units, the finding of staphylococci,
especially MRSA, in respiratory secretions usually represents
colonization rather than infection.
Conclusions. Healthcare organizations should optimize the
care of intravascular catheters by ensuring insertion under
aseptic conditions, documentation in the patient records,
daily inspection of the catheter site, and removal as soon as
possible. Decreasing the frequency of catheter use is also
important. Surgical wound infection with MRSA can be
reduced by preoperative screening for MRSA and, if necessary,
decolonization therapy