Appendix 1
METICILLIN RESISTANT STAPHYLOCOCCUS AUREUS
(MRSA) INFORMATION SHEET
Staphylococcus aureus
What is Staphylococcus aureus?
Staphylococcus aureus is a bacterium that is commonly found on human skin
and mucosa (lining of mouth, nose etc). The bacterium lives completely
harmlessly on the skin and in the nose of about one third of normal healthy
people. This is called colonisation or carriage. Staphylococcus aureus can
cause actual infection and disease, particularly if there is an opportunity for the
bacteria to enter the body e.g. via a cut or an abrasion.
What illnesses are caused by Staphylococcus aureus?
Staphylococcus aureus causes abscesses, boils, and it can infect wounds –-
both accidental wounds such as grazes and deliberate wounds such as those
made when inserting an intravenous drip or during surgery. These are called
local infections. It may then spread further into the body and cause serious
infections such as bacteraemia (blood poisoning). Staphylococcus aureus can
also cause food poisoning.
How is Staphylococcus aureus infection treated?
Infections caused by many antibiotic-sensitive varieties of Staphylococcus
aureus are usually successfully treated with antibiotics such as some types of
penicillin and erythromycin. Some S. aureus bacteria are resistant to the
antibiotic methicillin, and they are termed methicillin-resistant Staphylococcus
aureus (MRSA). They tend to be more complicated to treat and require the use
of other antibiotics. We are lucky in the UK that the MRSA that infect patients
are usually more sensitive to antibiotics than in some other parts of the world.
MRSA
What is MRSA?
MRSA stands for methicillin-resistant Staphylococcus aureus. They are
varieties of Staphylococcus aureus that are resistant to methicillin (a type of
penicillin) and usually to some of the other antibiotics that are normally used to
treat Staphylococcus aureus infections. There are different types of MRSA and
the Health Protection Agency is able to carry out laboratory testing to
distinguish between them.
Is MRSA treatable?
It is not generally necessary to treat MRSA colonisation or carriage. MRSA
infection is no more dangerous or virulent than infection with other varieties of
Staphylococcus aureus, but it is more difficult to treat depending on whether it
is resistant to any other antibiotics. Some of the antibiotics used to treat MRSA
however can on occasion be more difficult to use or may cause side effects.
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Who is at risk of MRSA infection
MRSA infections usually occur in hospitals and in particular to vulnerable or
debilitated patients, such as patients in intensive care units, and on surgical
wards. Some nursing homes have experienced problems with MRSA. MRSA
does not normally affect hospital staff or family members (unless they are
suffering from a severe skin condition or debilitating disease). In general,
healthy people are at a low risk of infection with MRSA.
What is the prevalence of MRSA in the UK?
MRSA are one of the most prevalent micro-organisms involved with
healthcare-associated infections worldwide. Most patients who are colonized
with MRSA do not go on to develop an infection. The surveillance of MRSA in
the UK is a mandatory scheme run by the Department of Health and measures
the number of blood-stream infections reported by Acute NHS Trusts. The
latest data are available under Mandatory Surveillance.
MRSA strains were first seen in many countries in the 1960s, but new strains
appeared in the 1980s, which have caused outbreaks of infection in hospitals
throughout the world including the UK. Further new strains also emerged
during the 1990s.
What is the cause of the rise in MRSA infections in the UK?
The rise in MRSA infections in the UK is likely to be multi-factorial. The new
strains that emerged in the 1990s may be more virulent (i.e. more likely to
cause infections) than some of their predecessors, or more easily spread on
the hands of healthcare workers, equipment, and perhaps via the environment.
There are also a number of factors that aid in the spread of MRSA in hospitals
such as: patient transfers within and between hospitals, the increasing number
of very ill patients seen in hospital and the difficulty in isolating some patients
with MRSA. The increasing complexity of healthcare and medical intervention
also add to the risk of acquiring MRSA.
Several studies have shown that workloads are also an important factor: the
more the required number of hand hygiene measures needed per hour the less
the compliance. This is why rapid acting alcohol and other hand hygiene
solutions are now advocated in healthcare: they are easier and faster to use.
How is MRSA spread?
MRSA is most commonly spread via hands, equipment, and sometimes the
environment. It is important that healthcare workers and visitors wash their
hands before and after visiting a patient. Provided hands are not soiled (when
they should be washed with soap and water), rapid acting alcohol and other
hand hygiene solutions are now advocated in healthcare: they are easier and
faster to use than hand washing. Equipment should also be cleaned after use.
What happens if I get an MRSA infection?
There will be precautions put into place to prevent the spread of the organism
from patient to patient. Ways of limiting the spread include hand washing,
cleaning equipment after use and keeping the environment clean. The hospital
may need to move the patient into a single room, or in with other affected
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patients, to reduce the risk of spread to another patient. E
ach hospital will have a policy on how to best manage MRSA within their local
environment.
Can a patient with MRSA have visitors?
Hospital strains of MRSA do not normally cause harm to healthy people,
including pregnant women, children and babies. Visitors should ensure they
wash their hands before and after visiting the patient.
How do you measure MRSA bacteraemia rates?
Some people carry MRSA most commonly in the nose and occasionally on the
skin without it causing harm to themselves or others. This is known as
colonisation or carriage. When a person has an MRSA bacteraemia
(bloodstream infection) this means that MRSA has gained access to tissues
and bloodstream and is multiplying and causing harm. MRSA rates are
measured by dividing the number of patients with MRSA isolated from blood
specimens in a hospital by the activity level within the hospital which provides a
'rate'. This enables one hospital to gauge itself against other similar hospitals
and investigate possible causes for differences.
Is there any value in screening new patients to ensure they are not
bringing MRSA into the hospital with them?
Carriage of MRSA should not be a reason for stopping admission to hospitals,
nursing or residential homes or for discharge to their home. However
sometimes hospitals screen upon admission e.g. for planned elective surgery.
This enables treatment e.g. special washes or ointments to be given to reduce
or clear MRSA before surgery.
Can MRSA be passed on by cleaning teams?
If equipment and wards are not cleaned properly there is a possibility of a
contaminated environment contributing to the spread of infection. However
dirty areas of hospitals do not necessarily have high MRSA rates or, clean
ones low MRSA rates.
Can it be carried on cutlery, plates, clothing, curtains, sheets, cushions
etc?
Good hygiene particularly in the form of simple everyday precautions such as
hand washing is an effective method in the prevention of MRSA spread. If
cutlery and plates are washed using soap and water (preferably hot) this will
remove MRSA. The risk of acquiring MRSA through contact with curtains,
sheets and cushions etc is very low.
What decontamination methods can be used on people, wards, clothing
etc?
Thorough hand washing and drying between caring for people, and whenever
necessary, has been shown to be the single most important measure in
reducing cross-infection. Healthcare workers use antiseptic solutions, including
alcohol hand rubs. More recently, many hospitals have alcohol gels for hand
cleaning at the end of patients' beds. The environment must be kept clean and
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dry. Whilst in hospital, patients may have to be nursed in a special ward and
visitors may be asked to wear gloves and aprons. Before going home visitors
may be advised to wash their hands.
What research is being done to find better ways of protecting against the
spread of MRSA?
Various research initiatives are underway from the design of hospital wards,
the use of isolation rooms, to the effectiveness of interventions like Clean Your
Hands Campaign and investigation of the causes of multi-drug resistance. The
Department of Health has also set aside £3 million for research as part of
implementing Winning Ways, the Chief Medical Officer's action plan to reduce
healthcare associated infections.
Community-acquired MRSA
What is community-acquired MRSA?
Community-acquired MRSA infection (C-MRSA) is when an MRSA infection
occurs in a previously healthy individual who has no recognised risk factors
associated with MRSA - for example, no previous hospitalisation, surgical
procedures or prolonged antibiotic treatment. In the UK, the term community-
acquired MRSA may refer to infections in residential homes caused by hospital
strains of MRSA However, some other countries (e.g. United States) are
describing strains of MRSA that have arisen in the community ('true'
community MRSA) and are very different from hospital MRSA strains. Some of
these strains carry a toxin called Panton-Valentine Leukocidin (PVL). These
usually affect otherwise healthy people and are unusual in the UK.
Is C-MRSA a different infection than Hospital acquired MRSA?
Yes, 'true' C-MRSA infections are different from the hospital acquired MRSA,
notably C-MRSA is more sensitive to antibiotic treatment than hospital acquired
MRSA, and therefore a wider range of antibiotics can be used to treat them.
How common is C-MRSA in the UK?
There have been no systematic studies to establish how common C-MRSA
infection is in the UK, but S. aureus isolates referred to the HPA's reference
laboratory are routinely tested to identify whether they are C-MRSA. Through
this surveillance of MRSA isolates, the Health Protection Agency has identified
approximately 100 cases over the last three years.
Who is more at risk of contracting C-MRSA?
It is believed that personal contact is the principal risk factor, particularly where
the skin is likely to be broken. Investigations in countries that have seen this
type of MRSA describe infections in for example in prison inmates, those
involved in close contact sporting activities, the gay community, and injecting
drug users.
How is C-MRSA treated?
Treatment of C-MRSA infection is easier than for hospital acquired MRSA as
C-MRSA are more susceptible to antibiotic treatment. C-MRSA is universally
sensitive to the antibiotics vancomycin, rifampicin, gentamicin, and linezolid.
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MRSA Mortality
How many people die from methicillin-resistant Staphylococcus aureus
(MRSA) infection each year?
The Office for National Statistics (ONS) provides national statistics on causes
of deaths. ONS statistics show that in 2004 in England and Wales, 1168 death
certificates mentioned MRSA as a factor contributing to the death of those
individuals. In 360 of these individuals MRSA recorded as the main cause of
death, in other words a death due to MRSA infection.
Where does the figure of 5000 deaths due to MRSA each year come
from?
This figure is incorrect. It comes from a very rough estimate of the number of
deaths which may be attributed to all hospital acquired infections (HAI), not just
MRSA. The estimate was made in 1995 by a working group of the Public
Health Laboratory Health Service. It used an estimate of the percentage of
deaths associated with all HAIs made in the USA in the 1980s (1% of all
deaths in the USA). This percentage was applied to the total number of deaths
occurring in the UK, yielding a crude estimate of 5,000 deaths from HAI.
What factors increase the risk of death in patients with MRSA infection?
Patients in hospital are more vulnerable to many infections, including those
caused by MRSA, because devices such as intravenous catheters, or
procedures such as surgery, provide an entry point for germs to enter the body.
The most common types of infection caused by MRSA are local infections of the
skin that can be treated successfully with proper skin care and antibiotics. Some
MRSA infections can become life-threatening. Patients who are at particular risk
are those who are seriously ill with another medical condition or whose immune
system is weakened by diseases such as diabetes or kidney disease, or by
treatments for conditions such as cancer.
Mandatory Surveillance
Mandatory Staphylococcus aureus bacteraemia surveillance scheme
The mandatory Staphylococcus aureus bacteraemia surveillance scheme
began in April 2001.
This scheme is operated by the Health Protection Agency on behalf of the
Department of Health. Data are requested quarterly from each of the 173 acute
NHS trusts in England by Health Protection Agency Local and Regional
Services Division (LARS), and collated and analysed by the Centre for
Infections.
The following are collected as part of the surveillance scheme:
• Total blood culture sets examined (a sample arising from a single
venepuncture, irrespective of the number of bottles tested)
• Total number of positive blood cultures (all positive results for bacterial
growth, including repeat specimens and contaminants)
• Total S. aureus bacteraemias
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• Total methicillin-resistant S. aureus (MRSA) bacteraemias
Positive blood cultures from the same patient within 14 days of the initial
culture are considered to be part of the original episode and should not be
reported. Duplicate reports, more than 14 days apart should be reported as
these are considered to be a separate episode.
Results of the Department of Health's mandatory methicillin resistant
Staphylococcus aureus (MRSA) surveillance system
Mandatory MRSA bacteraemia enhanced surveillance scheme
The Methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia Enhanced
Surveillance Scheme (MESS) has been mandatory for all NHS acute trusts in
England since 1 October 2005. This scheme has been developed by the HPA at
the request of the Department of Health.
Trusts have access to a website that they can use to enter details about each
MRSA bacteraemia episode that is detected in their Trust. The existing CoSurv
surveillance system is also currently undergoing developments which will enable it
to accept MRSA bacteraemia enhanced surveillance data.
Enhanced surveillance involves collecting patient details for each MRSA
bacteraemia episode such as NHS number, hospital number, date of birth, and sex,
as well as information concerning the patient’s location, date of admission,
consultant specialty, and care details at the time the blood sample was taken.
It is hoped that this scheme will provide trusts with a more accurate picture, with
respect to MRSA bacteraemia rates, than current mandatory surveillance allows,
and will contribute to building a better evidence base regarding risk factors for
infection.
Guidelines
Surveillance of MRSA Bacteraemia in patients with Renal Disease. Guidance notes.
R.Fluck, April 2007
Screening for Methicillin-resistant Staphylococcus aureus (MRSA) colonisation: a
strategy for NHS trusts - a summary of best practice. Department of Health,
November 2006
Interim guidance on diagnosis and management of PVL-associated Staphylococcal
infections in the UK. Health Protection Agency PVL Working Group, April 2006.
Guidelines for the control and prevention of methicillin-resistant Staphylococcus
aureus (MRSA) in healthcare facilities. E. Coia, G.J. Duckworth, D.I. Edwards, et al.
J Hosp Infect 2006; 66 (S1):1-44
Guidelines for the prophylaxis and treatment of methicillin-resistant Staphylococcus
aureus (MRSA) infections in the UK. Curtis G. Gemmell, David I. Edwards, Adam P.
Fraise et al. J Antimicrob Chemother 2006 57(4):589-608
Guidelines for the laboratory diagnosis and susceptibility testing of methicillin-
resistant Staphylococcus aureus (MRSA). Derek F. J. Brown, David I. Edwards, et
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al. J Antimicrob Chemother 2005 56 (6):1000-1018
Guidelines on the control of methicillin-resistant Staphylococcus aureus in the
community. Report of a combined working party of the British Society for
Antimicrobial Chemotherapy and the Hospital Infection Society. Prepared by G.
Duckworth and R. Heathcock. J Hosp Infect 1995; 31:1-12
SHEA guidelines for preventing nosocomial transmission of multidrug-resistant strains
of Staphylococcus aureus and Enterococcus. Muto CA, Jernigan JA, Ostrowsky BE,
Richet HM, Jarvis WR, Boyce JM, et al. Infect Control Hosp Epidemiol 2003; 24:362-
386.
Taken from www.hpa.org.uk
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