The Dutch national policy for the prevention of
spread of methicillin resistant Staphylococcus aureus (MRSA) has
shown that it is possible to suppress and prevent MRSA from becoming
endemic in hospitals. Implementation of effective measures against MRSA
will also help prevent the spread of other infections in hospitals. The
problem of MRSA would benefit from a common European Union policy.
Staphylococcus aureus causes serious systemic infections such as
septicaemia, endocarditis, and wound infections as well as being a common
commensal. It is the commonest cause of bacteraemia and is one of the top
three causes of hospital acquired infections. Effective antibiotics exist,
but between 10% and 50% of patients with staphylococcal septicaemia still
die (1). The importance of methicillin resistant S. aureus (MRSA)
in comparison with methicillin sensitive strains (MSSA) lies not only in
their resistance to all beta-lactams but also in their resistance to
various other important antimicrobials. The major threat is that MRSA
strains seen in hospitals have epidemic potential and add to the
pre-existing hospital acquired MSSA infections instead of just replacing
them. In past two decades MRSA has spread worldwide, becoming an endemic
inhabitant of many hospitals (2). The pathogenicity of MRSA is similar to
that of MSSA, but the increasing number of infections in the hospital
setting, higher mortality, and additional costs also contribute to the
burden of human suffering (3).
MRSA is an important component in the risk profile of
the hospital inpatient. Vulnerability to MRSA colonisation and infection
increases with the duration of hospital stay, intensive care treatment,
previous antibiotic treatment, and previous stay in another hospital where
MRSA was present. Surgical wounds and catheters provide easy entry points
for staphylococci and local standards of hygiene also affect the risk.
How have Dutch hospitals brought MRSA under control?
Over ten years ago the Working Party for Infection Prevention produced
guidelines for the containment of MRSA (4), which have been endorsed by
the Health Inspectorate. The mainstay of the guidelines is a ‘search and
- All patients with MRSA are isolated in private rooms.
- Patients from foreign hospitals and suspected MRSA carriers are
screened and isolated.
- Contact patients and also health care workers are screened.
- MRSA positive contacts are treated with body washings with either 4%
chlorhexidine liquid soap or 7.5% polividone–iodine shampoo and
mupirocin nose ointment, which may lower the bacterial load and
therewith the degree of spread. (Healthy people who are usually MRSA
positive, presumably most health care workers, are usually
decontaminated with such treatment applied for five days.)
Small numbers of MRSA can be identified by taking
samples twice within 24 hours of nose, throat, sputum, perineum, urine,
skin lesions, and wounds, and culturing using enrichment broth (5). The
movement of MRSA carriers between hospitals generates a warning. The
policy is for such patients to be readmitted to the same hospital as far
as possible. The efforts of infection control practitioners and clinical
microbiologists are vital.
Results and discussion
A report on MRSA in Dutch hospitals since the MRSA
guidelines were implemented has shown that ‘only small outbreaks occur’
(6). How was this achieved? New MRSA patients registered by the National
Institute of Health and the Environment (RIVM) have increased from about
100 in 1988 to around 250 in 1997 (6). Further investigation using
questionnaires sent to hospital infection control nurses or infection
control committees of the hospitals showed that the number of MRSA
clusters rose from 18 to 39 between 1992 and 1997, but the number of cases
per cluster remained below ten for 90% of the clusters. Thus, events that
could have developed into large outbreaks were successfully quelled.
Investigation into the origin of the MRSA from the index patients of
clusters revealed that introduction from a foreign country could be
established in only a third of index cases. The origin of most index cases
was in the Netherlands or remained unknown. This could imply that a ‘national
source reservoir’ has developed (6). Around 50% of the MRSA strains
detected in the index patients belonged to the well known outbreak strain
of phage type III-29. Only 0.5% of S. aureus cultured and monitored
by a national surveillance network are MRSA (7).
Another backbone in the prevention of resistant
bacteria is the implementation of a strict antibiotic policy in Dutch
hospitals. This is steered by local committees and many hospitals produce
their own formularies with lists of ‘first choice’ compounds and their
indications for use. Rates of resistance of clinically important bacteria
are low (8) and older antibiotics continue to be first line drugs in the
treatment of serious infections, including those on intensive care units.
Resistance problems encountered on these units can spread quickly through
a hospital. In response to a MRSA threat, what is the management approach?
Containment measures should be ordered and the local ad-hoc MRSA team
should convene. The board of directors, medical specialists, nurses, and
other health care workers of the hospital are asked to cooperate with, if
necessary, additional measures including closure of wards. As many
clinicians think that the spread of MRSA in Europe and is inevitable and
that resistance is useless, this is no easy task. Reappearances of MRSA
are not unusual due to its sustained survival in the inanimate environment
(9) and (sometimes prolonged) colonisation of other patients (10). The
outcome of this management policy so far is that ‘MRSA is not stronger
than hospital hygiene’.
If MRSA becomes endemic, it is almost impossible to get
rid of it, even if wards are closed for weeks at a time. In such
situations revision of the counteracting measures and adaptation of a more
lenient approach to local preferences have been applied according to a
risk-assessment approach (11). The Danish example - close national
cooperation in preventive isolation, mutual warning system, and antibiotic
policy - has shown that it is not quite impossible to reverse a ‘lost
cause’ (2). If you can quell your MRSA problem, problems with other
resistant bacteria will be relatively easy to manage.
What are the future trends? The implications of MRSA
with intermediate resistance to vancomycin is a subject that generates
much discussion, as is community spread of MRSA with and without hospital
mediation (12). Could MRSA follow the pattern of spread of penicillin
resistant S. aureus in the 1950s, spreading in the general
population about a decade after its first appearance in hospital, whereby
hospital infections seeded the population with antibiotic resistant
staphylococci? Seven main reasons to continue the struggle against MRSA
are listed in the table. The threat of MRSA will remain a continuing
challenge for hospital management. Implementation of measures against MRSA
will improve the hygiene generally and lower the levels of bacterial
resistance in hospitals against other antimicrobials. The forthcoming
possibility created by European Union (EU) policy and European judges to
allow free choice of health care outside national borders (13) will
increase the potential for spread of MRSA, but the Dutch policy of MRSA
containment will continue to benefit patients (2,3). The problem of MRSA
needs more than national solutions, however, it requires effective
guidance, initiatives, and support by leading policy institutions of the
Seven reasons for continuing the struggle
against MRSA in the hospital