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听 BRITISH BROADCASTING CORPORATION
RADIO SCIENCE UNIT
CASE NOTES Programme no. 6 - Superbugs
RADIO 4
TUESDAY 5TH FEBRUARY 2008
PRESENTER: MARK PORTER
CONTRIBUTORS: DAVID JENKINS HAJO GRUNDMANN ANDY POWELL CAROLINE TREVITHICK
PRODUCER: BETH EASTWOOD
NOT CHECKED AS BROADCAST
CLIP
Last summer me son went in for what should have been a fairly routine one day operation. He had this carried out - it was a gall bladder removal. He came out the same day. Two days later he started with very, very strong smelling loose stools. Little did we know then that this was C.diff.
PORTER
We will be hearing more about her son's plight later in the programme, but that mother's story has become depressingly common. Hospital acquired infections - like the so called "superbugs" MRSA and Clostridium difficile - are rarely out of the headlines these days. So how worried should we be? And what can you, and your hospital do, to reduce the risk?
Despite the recent publicity - and partly as a result of it - we seem to be winning the battle, if not the war. The latest set of quarterly figures from the Health Protection Agency show the number of cases of C.diff and MRSA are falling for the first time.
Hospitals in Leicester have had their fair share of problems with both bacteria, but are now at the forefront of the fight to contain them. Dr Jenkins is Director of Infection Prevention and Control at the University Hospitals of Leicester NHS Trust.
JENKINS
A lot of people don't understand that most of the MRSA in hospital is brought in by patients on their skin or up their nose and as I say they're totally asymptomatic - no signs or problems with that carriage. But consequently they may themselves get an infection with it or it may spread to other patients.
PORTER
You say they're carrying it on their skin or up their noses, so they can actually catch the MRSA off themselves once they're in?
JENKINS
Yes that's probably an under recognised problem. Most hospital acquired infections are from patients' own bacteria. We're covered in bacteria all over our skin and our intestines are full of millions and billions of bacteria and that's fine as long as they stay there, as long as they stay in the skin or in our intestines but if they get to places where they shouldn't - into the bloodstream or into wounds - they can then cause problems and infections. And that bacteria may well include MRSA.
GRUNDMANN
MRSA is only an acronym for a resistant type of Staphylococcus aureus. That is a bacterium which is actually quite prevalent in healthy individuals, about 30% of healthy people carry Staphylococcus aureus in the anterior nose.
PORTER
Professor Hajo Grundmann is from the National Institute of Public Health in the Netherlands which has one of the lowest rates of MRSA infection in Europe.
GRUNDMANN
Now some of these bacteria have acquired resistance down the line early in the '60s and increasingly become more prevalent. And they may not even cause any harm to most of the people. What usually happens, if you have a colonisation in the nose, what people do is they tend to put fingers in noses - that's quite a normal habit, it's a very normal habit - so you colonise your fingers and once you have it on your fingers you may spread it over your body. Which is not a problem unless you are in hospital and are exposed to, for example, devices that are indwelling - venous catheters or any other plastic devices - and then you could spread it on your skin and from the skin it colonises the plastic catheters, it may eventually end up in the bloodstream and then cause a severe infection.
PORTER
And it's not only you that could be at risk - once MRSA is established on the skin, it is easily spread from person to person - particularly if healthcare staff don't wash their hands and equipment as often as they should. So tackling the problem requires a multi-pronged attack - and making sure that patients don't unwittingly bring the infection in with them is a good a place to start.
JENKINS
One of the things that we've been doing is screening patients before they come in. Now clearly this is only appropriate if we know a patient is going to come in and the most obvious example here is a patient who's got an operation booked and they're coming in for surgery in three or four weeks time. There is a very common practice these days to have a pre-admission clinic and this is where a patient goes to a clinic has their bloods taken, has a chest x-ray and ECG done. And what we did was latch on an MRSA screen at the same time. So we started that off in cardiac surgery and spread it to orthopaedic surgery and lots of other specialities. So virtually all patients coming in for elective surgery in this trust now gets an MRSA screen.
PORTER
And that screen practically involves what?
JENKINS
It's basically just a swab up the nose and round the perineum, which is the area between the legs, and we look for MRSA carriage in that. It takes about 24, 48 hours to carry out that test. So if the specimen is taken two weeks before the admission we know well in advance whether or not the patient's an MRSA carrier or not.
We're in the laboratory now which carries out the MRSA screening for the trust and in front of me I've got a couple of small round dishes containing agar, which is a kind of seaweed jelly, and it allows the bacteria to grow on it. And we've also got some discs, which look a bit like the bits of paper that you get from a hole punch and they're arranged on the surface of the plate and each one of these discs has a specific antibiotic in it. And the antibiotic goes out from the disc into the agar and if the bacteria is sensitive to the antibiotic then you don't get any growth, if it's resistant then the bacteria will grow up to the disc.
PORTER
So we can see here that there are patches around at least - well three of the discs on this one here where there's big areas where the bacteria have not encroached upon them.
JENKINS
Yes, so this would indicate that the bacteria will be sensitive to those particular antibiotics. But you can see also there are a number of discs where the bacteria is growing straight up to the antibiotics - in this case it's MRSA.
PORTER
And the sort of carriage rates - what proportion of your booked in patients would be carrying the bug?
JENKINS
It varies from patient group to patient group. An average is about 1%.
PORTER
Are there some groups that are more likely to carry the bug, is it age related?
JENKINS
In this country you're more likely to have MRSA carriage if you've had multiple hospital admissions in the past. People who live in nursing or residential homes may have an increased risk as well because they're almost an extension of hospitals these days. But very young healthy adults, children, in this country are very unlikely to carry MRSA.
PORTER
So once you've identified those 1%, somebody's booked in for a routine hip let us say and they're found to carry MRSA, what do you do next?
JENKINS
If we detect MRSA on a patient we'd give them a course of treatment, it's a kind of antiseptic soap and also an antibiotic ointment that they put up their nose. So we try and get rid of the MRSA from their skin, from their nose.
PORTER
So even though MRSA is resistant to many antibiotics you still have an antibiotic that you can use to get rid of it in a nose cream?
JENKINS
Yes, the antibiotic in the nose cream is a unique antibiotic and it's only available as a cream.
PORTER
How do the patients react when they're told that they've got MRSA, it's a very emotive term, thanks to the coverage its had recently?
JENKINS
Well along with telling them they've got MRSA we also provide information about the bug and we also provide a service where they can contact infection control nurses and speak to them individually about what it means for them and what it means for their operation.
PORTER
And once the carriers have been treated do they need to be retested to check that the bug has been cleared?
JENKINS
Yes, yes we do that. Most of the times we remove the MRSA and the patient can come in and have the operation.
PORTER
So what proportion of your planned surgical patients would you screen at the moment?
JENKINS
At the moment we're looking towards a 100% of patients being admitted for surgery.
PORTER
But another big group of course that you can't screen are the patients that are coming in having broken their leg if they've fallen off the motorbike.
JENKINS
What we've been doing in trauma orthopaedics, which basically is the time, as you say, when a patient falls off a motorbike or an old lady, for example, slips and fractures her hip, we screen all those patients on admission. But we also assume that they're all positive until proven otherwise and for the last few years what we've been doing in that group of patients is treating them with the nasal ointment and the body wash until we get the negative result back. And we've also been keeping them separate from the elective patients. Now in this trust we're very lucky because we've got three different sites and we have elective operations on two sites and trauma operations on the third site. Consequently we've reduced infection rates both in trauma and in elective patients as well, in fact in elective patients we hardly ever get MRSA infections. And in trauma patients we've reduced the infection rate significantly.
PORTER
So step one, is to try and prevent patients bringing MRSA in with them when they come into hospital. Step two, presumably, is to stop the patients picking MRSA up once they get into the hospital and there's a widely held belief that, you know, it's something to do with the cleanliness of the hospital and that you're actually catching it from the environment, is that true?
JENKINS
Well to control infections we really need to understand how they're spread and as I said staph aureus sits on you skin and once every 30 days we replace our skin. So if you've got a 30 bedded ward flakes of skin with staph aureus can spread, which is why cleaning is very important.
PORTER
Something the Department of Health has taken to heart with its NHS wide deep cleaning programme. Practices vary from hospital to hospital but in Leicester wards are closed one at a time for up to a month for thorough cleaning and redecoration with antibacterial paint. Andy Powell is Head of Facilities at Leicester Royal Infirmary and I joined his team of cleaners to find out what's involved.
Well they're hard at it here, you can hear them in the background, I noticed that you've got one of your staff here with a face mask on wearing one of those sort of white suits that I've seen a forensic scene of crime officer in and steam cleaning a bedside cabinet, so everything gets a steam clean treatment does it?
POWELL
We take the opportunity to clean all the equipment that we can, yes. Some items can't be steam cleaned and they will be claw cleaned.
PORTER
And claw cleaning is what?
POWELL
That's using a disinfectant within water for actually washing and scrubbing. But the vast majority of stuff we will steam clean.
PORTER
The advantage of steam being what - that it kills things that it comes in contact with?
POWELL
Well it's an effective medium for actually removing the grime and the dust and any debris, so it actually lifts the - physically blows it away and then we actually wash it away. So it aids the process.
PORTER
So the first two stages are a sort of antiseptic wipe down, antibacterial wipe down, and then the steam cleaning. We'll leave them getting on with that here because I want to look at the next stage, which is the so-called hydrogen peroxide bombing. Explain to me how that works.
POWELL
Well in simple terms we have five little robots that we can pre-program and we insert a cartridge into each of them that has the hydrogen peroxide and then effectively we set them up and we will actually vacate the area and then they're timed to actually operate. It'll take about two hours to do half of a ward.
PORTER
The whole process takes how long to deep clean?
POWELL
What we allow is a very minimum of two weeks and possibly up to four weeks, depending on the amount of work and the maintenance and other initiatives that we want to put in place. And whilst we have a ward vacant that's quite unusual in a very busy and acute hospital, such as this, we maximise that opportunity. And we will actually look at installing things like additional wash hand basins. And also during the whole of the process at the end things like all the curtains will be replaced and obviously a lot of the equipment.
PORTER
So not only is the ward clean, microbiologically, but it also looks much better if it's been redecorated, new curtains.
POWELL
Yes indeed. I mean it's a very disruptive process in a very busy hospital but the benefits are that they returned back to a much better environment and that's very much supported by the staff.
PORTER
Presumably it's a rolling thing, so when you've done this ward you'll move on to another one, so there's always one ward out of commission is there?
POWELL
Oh indeed yes, I mean it's very much planned like a military operation. The logistics of completely moving a ward is very similar to that of moving house and so it can be a fraught experience at times but we've been undertaking this process almost 18 months now, so it's well developed.
PORTER
And when will you next be back in this ward would you think?
POWELL
We would aim to be back in this ward in approximately 12 months time, that would be our aim.
PORTER
Have you looked at the cost of doing this, because presumably it's an extra burden on the hospital having to do this, I'm just looking at these five robots here, they don't look cheap to me, how much does it cost to deep clean each ward do you think?
POWELL
We've had to invest in over a million pound a year extra, not only in the steam cleaning process but also in the introduction of minimum cleaning frequencies and also replacement of equipment. So it's a big commitment for the trust.
PORTER
But the deep clean initiative has attracted its fair share of criticism. Not least because patients are more likely to catch MRSA from themselves, a visitor or a doctor or nurse than they are from a dirty floor. So what is the microbiologist's view?
JENKINS
There are two important aspects to cleaning hospitals. One is day-to-day cleaning, you've got to get that right first and it means you've got to have the right resources, you've got to have the right number of cleaners and they've got to be doing the right thing with the right equipment. But number two, deep cleaning, I think does have a role, as long as it's done properly. What we're doing here in Leicester in terms of deep cleaning is closing a ward down completely - so all the patients are removed, all the nursing staff, they go to another ward and that's the decant ward. That leaves an empty ward which is very easy to clean for the cleaners.
PORTER
But it suggests that to do that you need to have some slack in the system presumably because you're effectively taking a ward - there's always a ward out of commission somewhere in the hospital.
JENKINS
Yeah, absolutely, you've got to have that spare ward capacity and I don't think it's a good idea to do the deep cleaning around patients, first of all it disturbs them - it's very noisy - and you can't do it properly. And there's also the danger then that you may stir up things and cause more of a problem in the short term.
PORTER
And have you done any research into what happens to that ward after it's been deep cleaned, I mean if you start swabbing and taking samples from the air and the floor and everything how quickly does it get recolonised by things that you're worried about?
JENKINS
That's a very critical question to ask. I'm not aware that we've got any information on that at the moment, in fact it's the subject of a research project that we've got planned looking at different bacteria and looking at the impact of different cleaning methods on bacterial bio-burden in effect on the ward and seeing what it does do. Once the ward is clean and you reopen it you bring patients back on and some of these patients will have infections or bacteria which then contaminate the ward again. Which is where the day-to-day cleaning comes in, I think if you've got very good day-to-day cleaning you can keep the number of bacteria down in the ward for much longer and it means that it's a safer environment for longer.
PORTER
Professor Grundmann used to work in the UK and remembers being surprised at the state of our hospitals. A cleaner hospital may not slash MRSA rates on its own but it's good for public morale - first impressions count.
GRUNDMANN
I believe that hospitals need to be clean places anyway, that's a condition of a hospital, what people would expect is that a hospital is at least as clean as a five star hotel. And therefore deep cleaning is not - is not a measure on its own, it's actually what you would expect from hospitals anyway. And it may not be the most cost effective way to handle MRSA but hospitals need to be clean in order to keep public confidence in the healthcare system.
PORTER
And some people have lost confidence in our healthcare system. This mother - who has asked to remain anonymous - saw her son's routine day case procedure turn into a nightmare that nearly cost him his life. He caught C.diff and the first sign of trouble was severe diarrhoea.
MOTHER
All he was doing was apologising to the nurses and meself because he was passing loose stools every 10-20 minutes, whenever he moved. It was terrible for him. His legs were so sore, it was as though they'd been burnt and he just could not even get to a commode, he was just lying in bed and passing these stools as - pooff - ah I find it hard to talk about it now actually at the moment.
PORTER
His condition deteriorated over a number of weeks culminating in a move to ITU.
MOTHER
The intensive care doctors were with him most of the night. He went for a scan the following morning and in the scan room I was told there was no - he had to go to theatre and he had to go now. His whole large intestine was full and bulging of C.diff and it needed to be removed immediately. They wheeled him straight from the scan room to the operating theatre. I went with him and explained the best I could what was happening to him. They made it perfectly clear that there was no choice but to have the operation or I would lose him.
PORTER
Her son survived and is now back at home - but because he had a large section of his bowel removed he now has an ileostomy empting through a hole in his abdominal wall into a bag.
Clostridium difficile is a bacterium found in small numbers in the colon of around 3% of the population. It is kept in check by the billions of other "friendly" bacteria that live in the bowel. But if they are killed by antibiotics, it can gain a foothold causing severe diarrhoea and potentially fatal inflammation of the colon or colitis.
Unlike MRSA, it is easily caught from a dirty environment like a contaminated loo, because the faeces of someone with C.diff is riddled with infectious spores that can survive for long periods on loo seats, wash basins and floors.
Just over a year ago an outbreak of a new strain of C.diff killed 49 patients in Leicester. Microbiologist David Jenkins.
JENKINS
It seems to have spread from the South East of England and going up the country. A bit like throwing a stone into a puddle and you get these ripples going out, in this case the stone has been thrown into London and the ripples are coming up across England and we've been hit with it in Leicester and other places have been hit with it as well. And it's caused a lot of problems for us and we've had to introduce an enormous amount of measures to fight it.
PORTER
Caroline Trevithick is Lead Infection Control Nurse at the hospital, and responsible for minimising the risks of infection on the wards.
Well Caroline we're here on the ward where some of the patients from the deep clean ward have been decanted to and we're starting by washing our hands. The alcohol rub, which every visitor and I presume every nurse and doctor has to do now.
TREVITHICK
Yeah, not necessarily at the entrance to the ward, we'd expect nurses and doctors to do it at the patient's bedside and that gives patients reassurance that staff are decontaminating their hands there in front of them.
PORTER
Now this is quite effective against MRSA but not so good against C.diff.
TREVITHICK
No C.diff likes to protect itself and alcohol is one of the things that's ineffective. So we've got a belt and braces approach in Leicester, we make sure that if we've got anybody with diarrhoea that it's hand washing plus alcohol gel. So they might have C.diff and another infection so we'll cover all bases really.
PORTER
So your staff are being encouraged to do what in between patients - if they're going round and the nurse is taking blood pressure for instance?
TREVITHICK
If they're in between patients then they'd be using the alcohol gel. If they're coming into contact with anybody that's got diarrhoea then it's hand washing followed by alcohol gel.
PORTER
Well let's wander down on to the ward. The ward's full, which I suspect is a perennial problem when you're dealing - you're always very busy, there's a high turnover in beds. What do you actually do other than the hand washing on the ward to reduce cross infection?
TREVITHICK
We look at making sure that patients with infections are moved to single rooms, so we can physically segregate them from other patients. And ..
PORTER
And that would apply to MRSA and C.diff?
TREVITHICK
Yes, chicken pox, flu, norovirus, anything.
PORTER
In terms of infection control on the ward do you differentiate between MRSA and C.diff, I mean we think of MRSA as principally a person-to-person problem possibly, C.diff does have more environmental connotations?
TREVITHICK
It does yes but the precautions that we take are the same for anything, because what we're saying is there's a potentially for environmental contamination with anything and if you have the same approach then people don't get confused. If you're taking one level of precaution for somebody with MRSA and something different for C.diff it's very easy not to know which is the right one to take.
PORTER
What about things that go inevitably from patient to patient, like blood pressure cuffs?
TREVITHICK
We're putting patient monitoring equipment in every bed space, so everybody will have their own blood pressure cuff, thermometer, stethoscope and tourniquet and that will get cleaned and disinfected when the patient goes home. So as part of the bed space cleaning protocol the next patient that comes in knows that the bed and all the equipment is clean and dedicated for that patient's use.
PORTER
Because historically that's not been the case, you often see, I mean particularly the doctors, I'm as bad as anybody, walking around going from patient to patient with your stethoscope. Are there measures in place in the meantime to get staff to clean equipment like that, is that something ..
TREVITHICK
Oh yes, yeah we've done a lot of training with medical staff and nursing staff to say it's really important that you clean your equipment and we've had to make sure that we've put lots of cleaning agents around for them, so on the blood pressure machine there is some chlorine available for them to decontaminant the cuff between patients. And the doctors know that they have to take responsibility for their own pieces of kit.
PORTER
And a more recent introduction has been bare below the elbows - how has that gone down?
TREVITHICK
That's been really good actually, it's caused a lot of debate with the medical staff about where's the evidence and infection control there's a lot of evidence that doesn't back up what we're saying. And we've been able to demonstrate that by having cuffs and watches it impedes your ability to hand wash properly. Some of the medical staff quite liked it because they can take their ties off, they can roll their sleeves up and they do feel that it's an easier way to work.
PORTER
So no more white coats ...
TREVITHICK
No we've got rid of white coats at ward level.
PORTER
Twenty years ago patients of mine who were coming into hospital for an operation, let's say, would have been worried about the anaesthetic, that would have been their principle concern, now a lot of them are worried about picking infections up. What can they do to protect themselves?
TREVITHICK
There's a lot that patients can do. In Leicester we've introduced the daily washes and patients that are self caring should really be making sure that they're using the special soaps to wash themselves in. Hand washing before mealtimes - big thing that you can do. And encouraging your visitors to be a good visitor. It's really difficult when you've got crowds of visitors around a bad space if it's the time that the domestic's coming to do the cleaning how do you get to that bed space to do the cleaning? But also we're starting to talk to patients about saying keep your bed space clean, if the domestic's got to clean the table and the locker and it's covered in flowers and magazines and that sort of thing it's very difficult for them to do because they don't like to touch people's personal belongings. And just be aware that there's a lot that goes on around them that isn't nursing care, it's about keeping the hospital clean and tidy.
PORTER
So patients and visitors can do their bit to help. But it's not just about observing good standards of cleanliness and basic hygiene.
JENKINS
The major risk factor for Clostridium difficile diarrhoea is use of antibiotics, so if you're a patient who's had antibiotics, whether your GP's prescribed them or if you've had them in hospital, then you may be at increased risk of Clostridium difficile infection.
PORTER
And that's because?
JENKINS
Certain classes of antibiotics disturb the bowel flora, you've all seen these adverts for friendly bacteria in the large bowel, and these are bacteria which fight pathogens such as Clostridium difficile. If you've got these friendly bacteria there then C.diff isn't a problem but if you get antibiotics which destroy those friendly bacteria any C.diff that's remained can multiple up, produce lots of toxin, produce disease. Now there are some classes of antibiotics which are considered to be high risk and we used to think that we knew what those were but the new strain of C.diff - the 027 strain of C.diff - has a novel antibiotic resistance pattern and antibiotics which were considered safe in the past are now considered high risk. And so we've restricted our antibiotics usage in the trust, so now no one can get more than five days of antibiotic without consulting the microbiology department. We've also restricted certain classes of antibiotics and changed the advice that we give to doctors on the wards as to which antibiotics to use for different conditions.
PORTER
And presumably it makes a difference what's going on in general practice. One of the things that we see as GPs quite often is people who are going into planned operations develop a little cough and cold that we normally wouldn't treat, they come in - can I have some antibiotics doctor because I'm going into hospital soon and I don't want to have my operation date put back - it's not a reason to prescribe but actually they could be making the situation worse for themselves?
JENKINS
They can be. A number of antibiotics which are commonly prescribed in general practice are now being seen as potentially high risk for C.diff.
PORTER
Antibiotics like?
JENKINS
Antibiotics like macrolides - Erythromycin, one that's commonly used for skin infections or chest infections; Quinolones, which have been commonly used for the treatment of urinary tract infections.
PORTER
So as regards C.diff it's a good thing to come into hospital with your natural bugs in a healthy state ...
JENKINS
Absolutely yeah, yes.
PORTER
One of the other things I read recently was that the effects of antacid medication could increase the chances of C.diff, what's happening there because these are extremely commonly prescribed groups of drug?
JENKINS
Over the last seven or eight years or so there's been a massive increase in the amount of drugs prescribed of a certain class called proton pump inhibitors or PPIs for short. And these are very super drugs for virtually eliminating acid production in the stomach and they're used in patients with indigestion of one sort or another and in fact in Leicester we've noticed a 700% increase in the prescription of these drugs. Now the relevance of this to C.diff is that there have been a number of studies looking at patients with C.diff and comparing them to patients without C.diff. And in fact in one study if you were on a PPI you were two and a half times more likely to get Clostridium difficile than a patient not on PPIs. Now this isn't clear cut and there have been some papers disputing this. But since there are many acceptable alternatives to PPIs we've developed a strategy within this trust and also with our GPs to look at alternatives to PPIs in patients who need that sort of medication.
PORTER
We don't fully understand the link but presumably it's something to do with stomach acid, is it that stomach acid forms the first line of defence against these spores if you were to swallow them, could that be a possibility?
JENKINS
It may be but these spores are extremely resistant, in fact bacterial spores are the most resistant form of life in the known universe. And gastric acid probably isn't much of a challenge for them to be honest. So it's not completely clear cut why PPIs increase the risk.
PORTER
And presumably being careful with our antibiotics is useful at preventing future emergent strains or even encouraging MRSA?
JENKINS
We've concentrated on antibiotic control to control C.diff but in fact there's increasing evidence that certain classes of antibiotics like Quinolones again promote MRSA.
PORTER
And that's presumably because they kill off the sensitive bacteria and allow MRSA to spread its wings effectively?
JENKINS
Absolutely, and this is just basically simple Darwinian evolution in motion. And it's not just MRSA of course, bacteria are extremely versatile organisms, they reproduce once every 30 minutes and their ability to respond to the use of antibiotics they use in disinfectants or use in cleaning or not really challenges them and they often find a way of striking back. So the important message I think is infection control is a continuing programme and we're always keeping an eye out for what's on the horizon.
PORTER
What's the situation here at Leicester in terms of battling C.diff and MRSA?
JENKINS
It's early days yet because we have had a problem with C.diff in Leicester. But so far this winter we've had very few cases and in fact this is normally regarded as a high risk time of year for C.diff - patients get chest infections, they get given antibiotics, they come in they get diarrhoea. But in fact our numbers now are the lowest for many years, in fact lower than they were before this new strain came along. Clearly this is something we do need to keep an eye and we're certainly not complacent about that.
PORTER
And MRSA?
JENKINS
MRSA - the government set a target for halving MRSA bloodstream infections by the end of March. At the moment we're on track for 70% reduction, so over performing from that point of view. And I calculated a couple of years ago that our MRSA rate then meant that you'd have to spend at least 20 years in hospital before you got a bloodstream infection with MRSA. And I think the figures now must be even better than that.
ENDS
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