An HCAI is acquired while receiving care in a hospital or other healthcare setting and must not have been present prior to that episode of healthcare; 6.6% of people who go into hospital in the UK will develop an HCAI. The figure for Europe is about 4 million people every year, with around 37,000 deaths occurring as a direct result (PHE [96]). The majority of these infections result from the procedures and interventions that patients undergo as treatment, such as insertion of invasive devices, surgery or the administration of antimicrobials that alter natural bacterial flora; all of these ultimately breach the body's natural defences and thereby increase vulnerability to infection. The greater the number of devices and the longer they are in situ, the more likely it is that an infection will occur. If the patient is also immunocompromised, the infection risk can be much higher. One report found that patients receiving treatment under oncology or haematology specialities were almost four times as likely to have an HCAI (a similar rate to those in intensive care units) compared to other patients in the same hospital and were twice as likely to be receiving an antibiotic (PHE [97]).

In addition, bringing many vulnerable people together in a healthcare setting increases the likelihood of exposure to infection and the risk of cross‐infection. Patients are often expected to share a room and bathroom facilities with those who may be carrying infection or different normal flora to them. This can lead to cross‐infection, for example a patient who has diarrhoea may contaminate a shared toilet, thereby passing the infection to others using the same facilities.

The greater the number of patients that staff are caring for and the greater their workload, the greater the risk of cross‐infection between patients. Overcrowding, lack of time and lack of facilities also contribute to non‐compliance with best practice (Borg [8], Eiamsitrakoon et al. [37], Harbarth et al. [51], Kampf et al. [67], WHO [124]).

Over the past century, there have been many changes in the types of organism that cause problems in healthcare, largely mirroring advances in medicine. The advent of penicillin and then other antibiotics in the 1940s allowed such advances in medicine and surgery. More complex surgery became possible, such as surgeries requiring implants (joint replacements) or organ transplants, and patients were able to tolerate treatments such as chemotherapy. More and more patients began to survive previously untreatable conditions, largely due to the ability to treat complications such as infection.

With the increasing use of antibiotics, new challenges began to emerge, including C. difficile infections (CDI) in the 1970s and epidemic strains of meticillin‐resistant S. aureus (MRSA) in the 1980s. During the 1990s and early 2000s there was a significant rise in both MRSA and CDI in the UK. Concerted effort engineered by the UK government saw impressive reductions in both these infections (DH [34]); however, the 2000s saw a rise in the prevalence of gram‐negative organisms with increasing resistance to antibiotics and an associated increase in untreatable infections. It is fair to argue that increasing antimicrobial resistance is the biggest challenge to healthcare across the world. As stated by the UK Chief Medical Officer Professor Dame Sally Davies, ‘We have reached a critical point and must act now on a global scale to slow down antimicrobial resistance’ (DH [29]) (see also Box 4.1).

Nurses, along with other healthcare workers, have a duty to reduce the burden of antimicrobial resistance though effective infection prevention in their everyday work and help to preserve antimicrobials for future generations. An infection prevented means an antibiotic not required.

The term ‘antimicrobial stewardship’ is widely used to describe efforts to improve and rationalize antimicrobial prescribing. Much of this effort is targeted at doctors, who are the main prescribers of antimicrobials. Examples include the Start Smart – Then Focus toolkit (PHE [95]) and Antimicrobial Stewardship: Systems and Processes for Effective Microbial Medicine Use (NICE [84]), which exist to improve antimicrobial prescribing and develop a wider understanding of antimicrobial stewardship. ‘Start smart’ means:

‘Then focus’ means:

Nurses also have an important role in antimicrobial stewardship even if they are not themselves prescribers. This should include not being afraid to question the use of antimicrobials and encouraging good documentation.

In the UK, E. coli has increasingly been implicated as a source of bloodstream infection, as can be seen in Figure 4.6. E. coli and other gram‐negative bloodstream infections caused by organisms such as Klebsiella spp. and P. aeruginosa are subject to mandatory reporting and reduction targets. A significant proportion of these isolates are showing increasing resistance to antimicrobials, which makes recognition and reduction of risk factors very important in controlling their spread. Such gram‐negative infections seem predominantly to originate in the community and are often associated with older age, dehydration and urinary tract problems. Examples include an elderly gentleman with an enlarged prostate that leads to repeated urinary tract infection and an elderly lady becoming dehydrated because she is not drinking due to anxiety about incontinence (PHE [98]).