Abstract
Infection is different from other aspects of medical care and clinical practice because it spreads. That is the defining characteristic of infection and it means that for every infected patient who needs treatment for their illness, there are two further questions – where has the infection come from, and where (to whom) may it have spread? The study of infection is a fascinating biological interaction between microbial populations and human populations with a variety of influencing factors linked to human behaviour. This includes the behaviour of patients, their relatives and, importantly, their healthcare attendants, particularly doctors and nurses. These factors have critical importance in relation to healthcare-associated infections. These infections are complications of a patient's underlying, primary illness or of the treatment they have received for that illness. They used to be called ‘hospital infections’ but they know no boundaries across health and social care because the bacteria move with people (both patients and staff) and these infections affect all health and social care settings. Therefore, responsibility for infection prevention and control lies across the whole health and social care community.
The scale of healthcare-associated infections (HCAI) challenge in England became starkly apparent after the introduction of mandatory surveillance of bacteraemia (bloodstream) infections caused by meticillin-resistant Staphylococcus aureus (MRSA) in 2001 and intestinal infection with Clostridium difficile (C. difficile), initially in patients older than 65 years in 2004, and extended to all patients over 2 years old in 2007. MRSA bacteraemia was chosen as the headline infection for surveillance because of concerns about this particular organism that can cause such a range of infections (wound and soft tissue infections, ventilator-associated pneumonia, urinary tract infection, etc.) of which those resulting in bacteraemia represented the most severe end of the spectrum with patients having the greatest risk of serious illness or death as a result.
Three years later, in 2005, C. difficile infection (CDI) became widely recognized as a serious and potentially life-threatening infection after several high-profile outbreaks in hospitals across the country. These two infections became issues of public and political priority in the early part of the decade. Mandatory surveillance showed a peak in MRSA bacteraemia cases of 7700 in 2003–2004, while CDI numbers reached 55,681 in patients aged over 65 years in 2006 (as these represent 75% of cases, the total number was around 70,000 cases).
These were unacceptable levels, but why had this happened? For the last quarter of the 20th century, infection had been considered to be a relatively minor nuisance in the broad picture of modern medical care. Medical advances had yielded much increased life expectancy, successful cancer treatments, increasingly complex surgery and better management of chronic illnesses. However, all of this creates a much more vulnerable population in terms of infection. Many more patients are frail, have various implants and many are immuno-compromised, i.e. very susceptible to infection. The period had been challenging for microbiologists and infection control specialists; there had been at least one new infection discovered each year during the period, including C. difficile in 1978; but dealing with infections generally, including HCAI, had been left as the province of these infection specialists. The lesson had to be re-learnt, by clinicians (doctors and nurses) in all specialties and NHS managers alike, that infection prevention and control is everyone's responsibility. In order to reduce HCAI, the mindset within the NHS had to change from one that had created a system to deliver specialist clinical care, with little thought towards some measures to prevent infection, to one that creates a safe environment for patient care and within that environment delivers the specialist clinical care that is needed.
Infection strategies
The Chief Medical Officer's strategy for infectious diseases, Getting Ahead of the Curve (2002), 1 emphasized health protection and recognized infections as being among the most significant emerging threats. Priorities were identified, the Health Protection Agency was created and the public health responsibilities of the NHS highlighted. The strategy also created the post of Inspector of Microbiology (soon to include infection control). Declared priorities were HCAI, antimicrobial resistance, tuberculosis and blood-borne and sexually-transmitted infections. At that point, media headlines and politicians suddenly focused on HCAI with outcries about dirty hospitals, superbugs, ‘new plagues’, and ‘MRSA massacres’. It was clear that measures had to be taken and that prevention and control of HCAI had to be made a top priority within the NHS.
MRSA
MRSA was the initial focus. S. aureus had been recognized for over a century as the major cause of infected surgical wounds and a range of other infections including bacteraemia. The habitat of S. aureus is the human body where carriage and colonization are normal – about one-third of people being colonized at any one time. The antibiotic meticillin (originally termed methicillin) was introduced into clinical practice in 1960 to treat penicillinase-producing S. aureus and the first MRSA was isolated within a year. It was a rarity until the 1980s when epidemic (EMRSA) strains emerged in hospitals. Localized outbreaks were controlled initially, but in the early 1990s two EMRSA strains, 15 and 16, emerged that spread readily. In December 2003, the CMO's strategy for HCAI, Winning Ways, 2 was published and six months later the second National Audit report on HCAI was critical of slow progress by the Department of Health and the NHS. 3 The response was the action plan Towards Cleaner Hospitals and Lower Rates of Infection, 4 which also announced the MRSA target of a 50% reduction in MRSA bacteraemias by 2008.
C. difficile
The outbreaks of CDI in June 2005 created more headlines. Again, this was not a new disease. C. difficile had been recognized as the cause of antibiotic-associated diarrhoea, pseudomembranous colitis and toxic megacolon for 20 years. It is an intestinal infection that affects predominantly vulnerable and elderly patients, and follows the use of antibiotics, particularly broad spectrum agents that disturb the normal gut flora thereby allowing the development of CDI. The spores of this clostridium are shed in large numbers in the faeces of affected patients and they can survive for long periods in the ward environment, especially in toilet areas and around the beds of those infected. When ingested by someone whose normal flora has been disturbed by antibiotics, the spores develop into vegetative bacteria that produce two very active toxins (A and B) that cause the characteristic disease. With the increasing numbers of cases of CDI in 2006–2007, and following two highly critical investigations by the Healthcare Commission of CDI outbreaks at Stoke Mandeville Hospital 5 and Maidstone and Tunbridge Wells NHS Trust, 6 a national target was set for a 30% reduction in CDI cases by 2010–2011. Unlike the MRSA bacteraemia target that was focused entirely upon the secondary care sector (i.e. hospitals), this target was based on populations across the whole healthcare community. There was shared responsibility between Primary Care Trusts (PCTs) and the Acute Trusts. All were charged with reducing the number of cases.
Controlling infections
The prevention and control of HCAI requires a tri-partite partnership between: clinicians who are responsible for the safe care of their patients through diagnosis, treatment, prevention and control of infections; the boards, chief executives and managers at all levels of the health service, who must provide the corporate environment to make infection prevention and control effective; and the government/DH which has to set standards, ensure that HCAI remains a priority area, set targets, monitor outcomes and use the performance management structures of the NHS to keep up the pressure for improvement. The government has also acted through legislation with the Health Act 2006 introducing a statutory Code of Practice 7 (CoP) for infection prevention and control that applied to all NHS bodies. Under the Health and Social Care Act 2008, a revised CoP was published in January 2010, 8 which extended the requirements to all health and care settings in the independent sector as well as the NHS. All are required to be registered with the Care Quality Commission and this registration requires compliance with the CoP.
Where are we now? The MRSA bacteraemia target has been achieved. By 2008–2009, the number of MRSA bacteraemias in the NHS in England had fallen by 62%, and by the July–September quarter of 2009–2010, the 465 cases reported represented a 57% decrease from the 2007–2008 numbers. For the CDI target, a 35% reduction was achieved in the first year (2008–2009) and the 6423 cases reported in the July–September quarter of 2009–2010 represented a 52% decrease from 2007–2008. Reductions have also been seen in the number of deaths attributed to MRSA (in 2006 there were 1652 mentions of which 519 were as the underlying cause; in 2008 there were 1230 mentions of which 228 were as underlying cause) and CDI (in 2007, 8324 mentions with 4056 as underlying cause; in 2008, 5931 mentions with 2502 as underlying cause).
How has this been achieved and how have we changed practice? There is no single ‘silver bullet’ for effective prevention and control. The reductions have been achieved by a raft of measures. Key elements were the targets. They were blunt instruments and were not universally popular but they focused the attention of managers on HCAI prevention and control. From the chief executive and chairman of the board to the most junior member of staff, all had to take responsibility and there was strong performance management from DH and the Strategic Health Authorities to keep up the pressure on NHS Trusts, Foundation Trusts and PCTs. This was supported by enhanced surveillance of the infections. You have to be able to measure what is happening if you are going to manage it. The Health Protection Agency established a web-based national surveillance programme with consistent definitions; this gave prompt monthly figures signed off by the chief executive of Acute Trusts for national monitoring and to drive local actions. DH also established a programme of improvement team visits to Trusts that needed help and support in improving their infection prevention and control activities and in reducing their HCAI numbers. As well as management support, these teams focused particularly upon the implementation of clinical practice protocols based upon the care bundle approach of the High Impact Interventions set out in the Saving Lives
9
and Essential Steps
10
packages for secondary and primary care, respectively. The aim was to improve performance in the invasive clinical activities that put patients at risk of developing infection. Many of the procedures that are part of normal medical and surgical practice involve invasion of normally sterile sites and the use of a variety of implanted artificial devices. Procedures such as intravenous catheterization and cannulation and the use of renal dialysis catheters place plastic tubes within the normally sterile blood stream. Urinary catheterization, artificial ventilation via an endotrachael tube, and surgical wounds all bypass the body's defence mechanisms and put patients at risk of HCAI. Effective clinical management of these invasive procedures is key to preventing the complications of infections and this was the focus of the care bundles. There was also a major emphasis on cleanliness and hygiene, particularly the promotion of hand hygiene for clinical staff and environmental cleaning in patient areas. Inadequate hand hygiene had been shown to be a major risk factor for the transmission of HCAI and this was addressed through the introduction of regular and repeated use of alcohol hand rub before and after each patient contact and within each clinical procedure. This was implemented through the NPSA
The future
Where do we go from here? Achievement of the target reductions is not the end of the road; there is still much more to be done to achieve zero tolerance of avoidable infections and inadequate practice. Zero tolerance does not mean that there will be no infections – that is biologically implausible – but there should be no tolerance of preventable or avoidable infections nor of poor clinical practice such as poor compliance with hand hygiene or aseptic procedure protocols, imprudent antibiotic prescribing or failure of coordinated actions across health and social care sectors. These things must be done right on every occasion.
MRSA infections will remain an issue. From April 2009, all elective admissions to NHS hospitals have been screened for MRSA colonization and this will extend to all emergency admissions by the end of 2010. The principle behind the screening programme is that colonization generally precedes infection and colonized patients are at risk of developing an MRSA infection themselves and a potential source of transmission to others. Identifying the colonized patients, isolating them where possible, and instituting a decolonization/suppressive regimen of nasal antiseptic cream, body wash and shampoo immediately reduces the MRSA bioburden and this reduces both risks for the individual and of transmission to others. The aim is not only to further reduce the MRSA bacteraemia numbers but also to reduce the other HCAIs (wound infections, skin and soft tissue infections, ventilator-associated pneumonia, urinary trace infection, etc.) caused by MRSA. The MRSA target has been transformed into an objective (or benchmark) to maintain the downward pressure on reducing the risk of MRSA infection. The objective will require NHS Trusts, Foundation Trusts and PCTs to reduce their MRSA bacteraemia rates to the median rate or by 20%, whichever is greater. Those with figures already better than the median will need to reduce to the best performing quartile or by 20%, whichever is less, and those in the best performing quartile will have local improvement plans in place. The median will be re-calculated each year. It is expected that a similar approach will be developed for CDI.
The programme will also need to address a range of infections beyond MRSA and CDI. Antibiotic-resistant bacteria such as Escherichia coli producing extended spectrum beta lactamases which make them resistant to all cephalosporin and penicillin antibiotics are increasingly prevalent. Rigorous attention to good antimicrobial stewardship will be essential in addressing these threats to our ability to treat infections. The National Audit Office report in June 2009 12 and the subsequent report of the Committee of Public Accounts 13 has recommended that surveillance of HCAI should be extended to other causes of bacteraemia and should also include wider surveillance of surgical site infections and some other HCAIs. Protocols for the extension of surveillance in this way will be developed on the basis of expert advice on the most clinically and cost-effective approaches.
Making infection prevention and control happen effectively requires management responsibility and personal responsibility. Management at all levels needs compliance assurance based upon surveillance data (cases, outbreaks, deaths) combined with audit results for hand hygiene, clinical protocols, antibiotic prescribing, etc. Personal responsibility needs to be embedded in the job descriptions and job plans of all clinicians, coupled with mandatory training for all staff and inclusion of infection prevention and control in CPD for all clinical staff. Maintenance of these standards should be part of appraisal and individual performance reviews for staff and backed up, where necessary, by disciplinary measures.
Role of commissioners
Finally, in an NHS delivered through a commissioner and provider partnership arrangement, the commissioners (primarily PCTs) have a clear responsibility to ensure that those providing services deliver reliable infection prevention and control. Commissioners should ensure that all their commissioned services have appropriate systems and protocols in place and their contract monitoring should include review of infection prevention and control provision and outcomes in terms of infection rates and compliance with required protocols. The ‘epidemic’ of HCAI has been a wake-up call to all delivering health and social care. We can no longer accept these infections as ‘normal’. Affected patients can be very ill, some may die, many will stay in hospital longer and they may need additional major surgery. For the NHS as a whole, significant resources devoted to treating the infected patients could be used for improved initial care. Zero tolerance is a professional obligation for all concerned.