Download 9 March 2005 - written by BUPA`s Health information team

9 March 2005 - written by BUPA's Health information team
What is MRSA?
MRSA is the name given to a group of bacteria that belong to the
Staphylococcus aureus (SA) family of bacteria.
Most Staphylococcus aureus bacteria can be treated with medicines called
methicillin-type antibiotics.
However, certain types of Staphylococcus aureus bacteria cannot be treated
with methicillin-type antibiotics - the bacteria are resistant to these drugs.
These are called MRSA bacteria:
M - methicillin
R - resistant
S - Staphylococcus
A - aureus1
How did MRSA become resistant to methicillin-type
antibiotics?
Whenever bacteria encounter an antibiotic (such as methicillin) some of the
bacteria may be able to survive it. The surviving, methicillin-resistant bacteria
can then multiply, potentially producing bacteria with even better resistance.
The chances of resistant bacteria developing have been increased by: 1,4
failure to finish full courses of antibiotics, allowing bacteria with some
resistance to survive and multiply
overuse of antibiotics, meaning that bacteria encounter and survive a wide
range of antibiotics
For information on MRSA outside of Alaska,
please visit:
MRSA-Information for the Public
Campaign
to Prevent Antimicrobial Resistance in Healthcare Settings NonHospital Healthcare Settings Frequently Asked Questions
What is Staphylococcus aureus?
Staphylococcus aureus, often referred to simply as "staph," is a
bacteria commonly found on the skin and in the nose of healthy
people. Occasionally, staphylococci can get into the body and
cause an infection. This infection can be minor (such as pimples,
boils, and other skin conditions) or serious and sometimes fatal
(such as blood infections or pneumonia). Staph. aureus is a
common organism and can be found in the nostrils of up to 30% of
persons. Person-to-person transmission is the usual form of spread
and occurs through contact with secretions from infected skin
lesions, nasal discharge or spread via the hands.
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What is MRSA?
MRSA are staphylococci that are resistant to the antibiotic,
methicillin, and other commonly used antibiotics such as penicillin
and cephalosporins. These germs have a unique gene that causes
them to be unaffected by all but the highest concentrations of these
antibiotics. Therefore, alternate antibiotics must be used to treat
persons infected with MRSA. Vancomycin has been the most
effective and reliable drug in these cases, but is used intravenously
and is not effective for treatment of MRSA when taken by mouth.
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What is the concern about MRSA?
The increasing frequency of antimicrobial resistance among
infectious organisms is of great concern to both medical providers
and the general public. Of particular concern is the possibility of
spread of multi-drug resistant germs in the community. Since the
first reported episode of methicillin resistant Staphylococcus
aureus (MRSA) infection in the United States in 19681, the
proportion of S. aureus isolates resistant to methicillin causing
infections in hospitalized patients has risen significantly from 2%
in 19742 to about 40% 1997. Over the past 20 years, infections
with MRSA have been limited primarily to patients in hospitals or
long-term care facilities. However, recent reports of "communityacquired" MRSA infections raise concern.
These infections, reportedly occur in otherwise healthy, nonhospitalized persons without contact with healthcare personnel or
other colonized patients3. A report of MRSA infections leading to
four deaths in previously healthy children demonstrated that
MRSA infections can be community-acquired in persons with no
exposure to the hospital system.4 This raises serious concerns
about the possibility of transmission of MRSA outside the
healthcare system. If MRSA becomes the most common form of
Staphylococcus aureus in a community, it will make treatment of
common infections much more difficult.5
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Staph. aureus and MRSA in Alaska
Infections due to S. aureus have long been common among rural
Alaskans. In 1984, a large outbreak of Staph. aureus boils occurred
in the village of Kotlik. These were due to a methicillin-sensitive
strain. However, in 1996, an Alaska community reported an
outbreak of boils caused by S. aureus in healthy persons6. In some
of the patients cultures of revealed MRSA. Steam-bathing, a
common practice among some Alaska populations, was associated
with infection and especially the practices of bathing without
sitting on a towel or use of personal soap7. Recent anecdotal
reports from clinicians and laboratories in rural and urban Alaska
indicate that infections due to MRSA are becoming increasingly
common and present significant therapeutic challenges. These
reports raise concerns that MRSA infections are more common and
widespread that was previously realized.
In August 2000, health care providers in Southwestern Alaska
reported an increase in MRSA skin infections among Alaska
Natives, many of whom had no previous hospital exposure.8 The
Arctic Investigations Program was invited by the Yukon
Kuskokwim Health Corporation to conduct an investigation into
this outbreak. By evaluating laboratory and medical records we
found that large outbreak of community-onset MRSA infections
occurred in Southwestern Alaska during 1999 and 2000. Over 80%
of culture-confirmed S. aureus infections during this period were
MRSA, 84% of MRSA infections involved skin or soft tissue, but
more serious or invasive disease was rare.
Unlike a typical hospital-acquired MRSA, isolates from this
outbreak were unlikely to be resistant to multiple antimicrobial
classes. Patients with MRSA skin infections were more likely to
have received an antimicrobial prescription in the 180 days before
their infection than patients with methicillin-susceptible Staph.
aureus skin infections. Steam bathing was also a factor in this
outbreak. MRSA infections were more common among people
who used more common steam baths and among persons who used
steam baths that were found to be contaminated with MRSA.
These findings indicate a change in the epidemiology of MRSA in
rural Alaska and suggest that the emergence of MRSA in this
region was not related to spread of a hospital organism. Treatment
guidelines were developed that recommend a change in first-line
therapy for suspected S. aureus infections away from beta-lactam
antimicrobials and to encourage health care providers to consider
using treatments other than antibiotics for persons with mild skin
infections.