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What is MRSA?
MRSA is one example of the Staphylococcus family of common bacteria. Many people naturally carry it on their throat, nose and skin and it can cause a mild infection such as pimples and impetigo in a healthy patient. Occasionally staphylococcus can get through the skin and cause serious infection elsewhere in the body such as septicaemia (a blood infection), pneumonia and endocarditis.
MRSA stands for methicillin-resistant Staphylococcus aureus, of which there are many strains but is shorthand for any strain of Staphylococcus aureus bacteria which is resistant to one or more conventional antibiotics. Experts have so far uncovered 17 strains of MRSA, with differing degrees of immunity to the effects of various antibiotics.
Two particular strains, EMRSA15 and EMRSA16, are thought to be more transmissible than the others, and account for 96% of MRSA bloodstream infections in the UK. At present, these strains are thought to be rare in other countries, but are spreading. MRSA is no more aggressive than other infections, simply more resistant to treatment.
Top
MRSA - causes and risk factors
It's all about survival of the fittest - the basic principle of evolution, and bacteria have been around a lot longer than us, so they're pretty good at it.
There are countless different strains of a single type of bacteria, and each has subtle natural genetic mutations which make it different from the other. In addition, bacterial genes are constantly mutating.
Some strains' genetic makeup will give them a slight advantage when it comes to fighting off antibiotic attack. So when susceptible strains encounter antibiotics, they die, while these naturally resistant strains may prove harder to kill. This means that next time you encounter Staph. aureus, it is more likely to be one which has survived an antibiotic encounter, i.e. a resistant one. Eventually the strain becomes resistant to different antibiotics, even though they work in slightly different ways
The advice from doctors who give you antibiotics is always to finish the entire course - advice which many of us ignore. When you don't finish the course, there's a chance that you'll kill most of the bugs, but not all of them - and the ones that survive are of course likely to be those that have adapted to bemore resistant to antibiotics. Over time, the bulk of the Staph.aureus strains will carry resistance genes, and further mutations may only add to their survival ability. Strains that manage to carry two or three resistance genes will have extraordinary powers of resistance to a range of different antibiotics.
The reason that hospitals seem to be hotbeds for resistant MRSA is because so many different strains are being thrown together with so many doses of antibiotics, vastly accelerating this natural selection process.
Top
Why is MRSA so dangerous?
It is a fact of life in the NHS that patients are at higher than normal risk of picking up a Staph infection on the wards.
This is for two reasons - firstly, that the population in hospitals tends to be older, sicker and weaker than the general population, making them more vulnerable to the infection. Secondly, conditions in hospitals, without very strict hygiene measures, involve a great many people living cheek by jowl, examined by doctors and nurses who have just touched other patients, are the perfect environment for the transmission of all manner of infections. This is why strict hand-washing and hygiene when entering and leaving wards and between seeing different patients is essential in preventing the spread of such bugs.
Staph infections can be dangerous in weakened patients, particularly if they can't be cleared up quickly with antibiotic treatments. MRSA infections can prove tough to treat because they are resistant to treatment, making them more dangerous than a simple case of Staph.
Top
Symptoms of MRSA
MRSA infections can cause a broad range of symptoms depending on the part of the body that is infected. These may include surgical wounds, burns, catheter sites, eye, skin and blood. Infection often results in redness, swelling and tenderness at the site of infection. Sometimes, people may carry MRSA without having any symptoms.
Top
MRSA - treatment and prevention
Antibiotics are not completely powerless against MRSA, but patients may require a much higher dose over a much longer period, or the use of an alternative antibiotic, often needing intravenous administration or with less tolerable side-effects, to which the bug has less resistance.
Doctors are very worried about what the future holds for MRSA. The number of reports of MRSA infections rises year by year - and the latest evidence suggests that deaths due to MRSA are increasing at a similar rate.
Top
What about new superbugs?
Already, the spectre of a bug resistant to all antibiotics is approaching. VRSA, or vancomycin resistant Staphylococcus Aureus, has acquired resistance to a drug considered the "last line of defence" when all other antibiotics have failed. The UK has already seen several cases of GISA, or glycopeptide intermediate Staphylococcus aureus, a kind of "halfway house" between MRSA and VRSA, which has developed a resistance to antibiotics of the vancomycin family.
Experts are also concerned a new killer 'superbug' is emerging in the UK called Panton-Valentine leukocidin (PVL) MRSA. PVL is a toxin which kills white blood cella and causes extensive tissue death. Not all types of Staph that make the PVL toxin are dangerous or so difficult to treat as some are sensitive to methicillin, but PVL MRSA appears to be particularly virulent.
Cases of another bug, Clostridium difficile, are also cropping up in UK hospitals. It is not a "superbug", living harmlessly in many peoples intestines, and can be treated relatively easily. However, the bug forms very hardy spores which means it can survive for long periods in the environment, such as on floors and around toilets, and spreads in the air.
C. difficile can cause illness when certain antibiotics disturb the balance of 'normal' bacteria in the gut. Rigorous cleaning with warm water and detergent is the most effective means of removing spores from the contaminated environment and the hands of staff, say experts. Worryingly, infections are cropping up in healthy people in the community, rather than among sick people in hospital. Although there are some new antibiotics being developed , pessimistic experts believe it is only a matter of time at current rates until virtually every weapon in the pharmaceutical arsenal is nullified. Nihilists suggest that there could come a point at which constantly mutating bacteria retake the upper hand, and doctors, as in previous centuries, have no answer to some bacterial infections.
It should be noted, they say, that humans have only had the upper hand over bacteria for a handful of decades - we have no right to expect that situation to last forever.
Top
What can we do about it now?
The government is already trying to at least slow down the apparently relentless march of the bacteria. One of the main reasons behind their swift evolution into "superbugs" is the overuse of antibiotics, both in human and veterinary medicine. Until recently, patients visiting their doctor with a viral infection might demand, and be given an antibiotic prescription - despite the fact that antibiotics have no effect on viral infections. All those patients were doing was strengthening the communities of bacteria in their bodies. Doctors have now been told to cut antibiotic prescribing and take more time advising patients about the nature of infections.
Hygiene is another tried and tested way of at least protecting the most vulnerable patients from the most dangerous strains. Hand washing by staff between examining patients should be a must, and all staff and visitors entering wards and potentially contacting contaminated surfaces and transferring infection must adopt similar hygiene measures. All additional staff (maintenance, cleaning, administrative) are also in the same position and must adopt equal hygiene rules.
Ministers are trying to improve overall standards of hygiene, perhaps by reintroducing the concept of the ward matron, with responsibility for cleanliness. New patient bedside phones are being introduced that include speed dial buttons to alert staff to the need to deal with a hygiene problem.
Whether a dirty ward rather than a dirty hand is a reservoir for Staphylococcus is a matter of debate. But MRSA patients are also increasingly being treated in isolation where possible. In the long run, many experts suggest it may take a breakthrough akin to the discovery of penicillin before humans can regain a temporary upper hand over
MRSA is one example of the Staphylococcus family of common bacteria. Many people naturally carry it on their throat, nose and skin and it can cause a mild infection such as pimples and impetigo in a healthy patient. Occasionally staphylococcus can get through the skin and cause serious infection elsewhere in the body such as septicaemia (a blood infection), pneumonia and endocarditis.
MRSA stands for methicillin-resistant Staphylococcus aureus, of which there are many strains but is shorthand for any strain of Staphylococcus aureus bacteria which is resistant to one or more conventional antibiotics. Experts have so far uncovered 17 strains of MRSA, with differing degrees of immunity to the effects of various antibiotics.
Two particular strains, EMRSA15 and EMRSA16, are thought to be more transmissible than the others, and account for 96% of MRSA bloodstream infections in the UK. At present, these strains are thought to be rare in other countries, but are spreading. MRSA is no more aggressive than other infections, simply more resistant to treatment.
Top
MRSA - causes and risk factors
It's all about survival of the fittest - the basic principle of evolution, and bacteria have been around a lot longer than us, so they're pretty good at it.
There are countless different strains of a single type of bacteria, and each has subtle natural genetic mutations which make it different from the other. In addition, bacterial genes are constantly mutating.
Some strains' genetic makeup will give them a slight advantage when it comes to fighting off antibiotic attack. So when susceptible strains encounter antibiotics, they die, while these naturally resistant strains may prove harder to kill. This means that next time you encounter Staph. aureus, it is more likely to be one which has survived an antibiotic encounter, i.e. a resistant one. Eventually the strain becomes resistant to different antibiotics, even though they work in slightly different ways
The advice from doctors who give you antibiotics is always to finish the entire course - advice which many of us ignore. When you don't finish the course, there's a chance that you'll kill most of the bugs, but not all of them - and the ones that survive are of course likely to be those that have adapted to bemore resistant to antibiotics. Over time, the bulk of the Staph.aureus strains will carry resistance genes, and further mutations may only add to their survival ability. Strains that manage to carry two or three resistance genes will have extraordinary powers of resistance to a range of different antibiotics.
The reason that hospitals seem to be hotbeds for resistant MRSA is because so many different strains are being thrown together with so many doses of antibiotics, vastly accelerating this natural selection process.
Top
Why is MRSA so dangerous?
It is a fact of life in the NHS that patients are at higher than normal risk of picking up a Staph infection on the wards.
This is for two reasons - firstly, that the population in hospitals tends to be older, sicker and weaker than the general population, making them more vulnerable to the infection. Secondly, conditions in hospitals, without very strict hygiene measures, involve a great many people living cheek by jowl, examined by doctors and nurses who have just touched other patients, are the perfect environment for the transmission of all manner of infections. This is why strict hand-washing and hygiene when entering and leaving wards and between seeing different patients is essential in preventing the spread of such bugs.
Staph infections can be dangerous in weakened patients, particularly if they can't be cleared up quickly with antibiotic treatments. MRSA infections can prove tough to treat because they are resistant to treatment, making them more dangerous than a simple case of Staph.
Top
Symptoms of MRSA
MRSA infections can cause a broad range of symptoms depending on the part of the body that is infected. These may include surgical wounds, burns, catheter sites, eye, skin and blood. Infection often results in redness, swelling and tenderness at the site of infection. Sometimes, people may carry MRSA without having any symptoms.
Top
MRSA - treatment and prevention
Antibiotics are not completely powerless against MRSA, but patients may require a much higher dose over a much longer period, or the use of an alternative antibiotic, often needing intravenous administration or with less tolerable side-effects, to which the bug has less resistance.
Doctors are very worried about what the future holds for MRSA. The number of reports of MRSA infections rises year by year - and the latest evidence suggests that deaths due to MRSA are increasing at a similar rate.
Top
What about new superbugs?
Already, the spectre of a bug resistant to all antibiotics is approaching. VRSA, or vancomycin resistant Staphylococcus Aureus, has acquired resistance to a drug considered the "last line of defence" when all other antibiotics have failed. The UK has already seen several cases of GISA, or glycopeptide intermediate Staphylococcus aureus, a kind of "halfway house" between MRSA and VRSA, which has developed a resistance to antibiotics of the vancomycin family.
Experts are also concerned a new killer 'superbug' is emerging in the UK called Panton-Valentine leukocidin (PVL) MRSA. PVL is a toxin which kills white blood cella and causes extensive tissue death. Not all types of Staph that make the PVL toxin are dangerous or so difficult to treat as some are sensitive to methicillin, but PVL MRSA appears to be particularly virulent.
Cases of another bug, Clostridium difficile, are also cropping up in UK hospitals. It is not a "superbug", living harmlessly in many peoples intestines, and can be treated relatively easily. However, the bug forms very hardy spores which means it can survive for long periods in the environment, such as on floors and around toilets, and spreads in the air.
C. difficile can cause illness when certain antibiotics disturb the balance of 'normal' bacteria in the gut. Rigorous cleaning with warm water and detergent is the most effective means of removing spores from the contaminated environment and the hands of staff, say experts. Worryingly, infections are cropping up in healthy people in the community, rather than among sick people in hospital. Although there are some new antibiotics being developed , pessimistic experts believe it is only a matter of time at current rates until virtually every weapon in the pharmaceutical arsenal is nullified. Nihilists suggest that there could come a point at which constantly mutating bacteria retake the upper hand, and doctors, as in previous centuries, have no answer to some bacterial infections.
It should be noted, they say, that humans have only had the upper hand over bacteria for a handful of decades - we have no right to expect that situation to last forever.
Top
What can we do about it now?
The government is already trying to at least slow down the apparently relentless march of the bacteria. One of the main reasons behind their swift evolution into "superbugs" is the overuse of antibiotics, both in human and veterinary medicine. Until recently, patients visiting their doctor with a viral infection might demand, and be given an antibiotic prescription - despite the fact that antibiotics have no effect on viral infections. All those patients were doing was strengthening the communities of bacteria in their bodies. Doctors have now been told to cut antibiotic prescribing and take more time advising patients about the nature of infections.
Hygiene is another tried and tested way of at least protecting the most vulnerable patients from the most dangerous strains. Hand washing by staff between examining patients should be a must, and all staff and visitors entering wards and potentially contacting contaminated surfaces and transferring infection must adopt similar hygiene measures. All additional staff (maintenance, cleaning, administrative) are also in the same position and must adopt equal hygiene rules.
Ministers are trying to improve overall standards of hygiene, perhaps by reintroducing the concept of the ward matron, with responsibility for cleanliness. New patient bedside phones are being introduced that include speed dial buttons to alert staff to the need to deal with a hygiene problem.
Whether a dirty ward rather than a dirty hand is a reservoir for Staphylococcus is a matter of debate. But MRSA patients are also increasingly being treated in isolation where possible. In the long run, many experts suggest it may take a breakthrough akin to the discovery of penicillin before humans can regain a temporary upper hand over