nosocomial infection

Clinical

Module 1835

Nosocomial infection From this CPD module you will learn: • The consequences of nosocomial infections • How infective organisms are spread • Who is susceptible to hospital-acquired infections • The role of antibiotic resistance, MRSA and Clostridium difficile in nosocomial infection Philip Crilly, Pharmacy teaching fellow As someone working in a community pharmacy, you won’t need to examine or treat patients suffering from nosocomial infection. You may, however, be asked – by patients or their carers – about the risks, treatments and aftercare. This module will prepare you for these questions, and provide you with answers that ensure you can have meaningful discussions about this subject.

make pre-existing medical conditions worse, prolong hospital stays, and affect a patient’s general wellbeing. Consequences of nosocomial infection also extend to the community where patients, patient visitors and hospital staff can

What is a nosocomial infection? Nosocomial is the term used to describe infections if they acquired while in hospital, specifically those that occur 48 hours or more after hospital admission. They are often referred to as hospital-acquired or healthcare-associated infections (HCAI). According to figures obtained from the National Institute for health and Care Excellence (Nice), 300,000 people a year acquire an infection while in an NHS hospital. The most common types of these are associated with the respiratory tract, urinary tract and surgical sites.

Consequences of a nosocomial infection Nosocomial infections can have a serious impact on a patient’s health and recovery. They can

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spread the infection. Nosocomial infections not only pose a health risk, they also have a financial consequence for the NHS. Additional treatment costs and extended hospital stays all have a negative impact on the NHS bank balance. With patients needing to stay in hospital for longer than intended, the number of working days lost is also an effect of these infections.

rooms are often overcrowded, allowing for the easy transfer of pathogens from one person to another. For this reason, a number of hospitals have started to invest in single-bed rooms. While the initial cost of building these rooms is high, the long-term savings – in terms of reduced infections and hospital stays – have been demonstrated to be significant.

Where do these infections usually occur?

What are the key organisms that cause nosocomial infections?

A study by Trubiano and Padiglione in 2015 identified that the most common types of nosocomial infections are those associated with urinary catheters, surgical sites, ventilators (typically pneumonia), and central lines. Urinary tract infections (UTIs) account for the majority of nosocomial infections, but are often associated with lower morbidity than other types of HCAI. Open-bay hospital rooms have been implicated in the spread of nosocomial infections. These

Bacteria, viruses and fungi can all cause nosocomial infections. However, bacteria are the most common nosocomial pathogens – with the most common bacterial pathogens including Staphylococcus aureus, Clostridium difficile (C. difficile) and Escherichia coli. Viral causes include hepatitis B and C, while fungal causes include Candida albicans. Fungal pathogens, in particular, commonly cause infections in patients on long-term antibiotic therapy and those who are immunocompromised.

How is the infective organism spread? Nosocomial infections can be broadly categorised as exogenous or endogenous. Exogenous infections develop as a result of pathogens being introduced from sources outside of the body. Sources of exogenous infection include: • surgical devices used in invasive surgery • medical devices, such as ventilators and catheters • patient visitors and hospital staff, who may not have properly followed hand hygiene recommendations • pathogens carried in the air • surfaces of a hospital ward (see Environmentassociated infections, below) Studies have also highlighted the use of mobile phones and devices such as pagers in hospitals as having the potential to cause nosocomial infections. A study by Ulger et al. in 2009 noted that while these devices allow hospital staff to

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“According to figures obtained from the National Institute for health and Care Excellence (Nice), 300,000 people a year acquire an infection while in an NHS hospital“

rapidly communicate and share information with each other, they are often not cleaned properly, meaning pathogens can be passed to the patient, causing infection. Environment-associated infections occur if proper ward-cleaning procedures have not been followed. Pathogens can remain on any surface that the carrier has been in contact with, and then spread to others who touch the same surface. Endogenous infections develop as a result of the body’s own flora. Normal floral bacteria – found naturally on the body – can be found on the skin of healthy patients. Should a patient develop a cut or have a wound from surgery, bacteria can gain access to other areas of the body, where they can cause infection. In addition, C. difficile is present in the gut of some healthy individuals. Following antibiotic therapy, the patient’s own protective bacteria may be reduced, allowing C. difficile to proliferate and cause the symptoms of infection.

Who is susceptible? Healthy patients can be susceptible to nosocomial infections if they have a wound – for example from invasive surgery – or if they undergo therapeutic procedures, such as catheterisation or ventilation. These latter procedures can present entry points for foreign pathogens to gain access to the body and cause infection. Other patients particularly at risk include: • the elderly • those who are immunocompromised • children, especially those under two years old • those with certain medical conditions – eg diabetes, kidney disease and cancer can all make patients more prone to infection • those taking certain medications, such as

steroids and drugs that weaken the body’s immune system.

The role of antibiotic resistance Antibiotic resistance is a major cause of concern in the treatment of nosocomial infections. Due to historical over-prescribing of antibiotics for both treatment and prophylaxis, multi-drug resistant strains of bacteria have emerged. Antibiotics that were once used to treat infections are no longer effective, with many staphylococcus and pneumococcal strains now resistant to the vast majority of, if not all, antibiotics. Community pharmacists can have an impact on antibiotic resistance. When patients present with coughs, colds and sore throats, they have an important role in educating them about the importance of rest and symptomatic relief, rather than the use of antibiotics. Evidence suggests that managing patients’ expectations about their illness, telling them how long it is likely to last and advising them on how to manage the symptoms, can help prevent them from seeking antibiotics from their GP. For those patients presenting with prescriptions for antibiotics, pharmacists must counsel them clearly on the importance of taking the medication at regular intervals and finishing the treatment course, regardless of symptom improvement. Patients should be advised on hand-hygiene measures, as well as the importance of disposing of any used tissues after first use. Furthermore, all patients should be encouraged to build up their own immunity by living a healthy lifestyle, such as eating a balanced diet and maintaining a regular exercise routine. You should also offer smoking cessation support and the annual flu jab, as this will help to ward off infection, particularly for vulnerable groups.

MRSA and C. difficile Two of the most commonly acquired and difficult-to-treat infections in a hospital setting are methicillin-resistant Staphylococcus aureus (MRSA) and C. difficile. Figures obtained from


Patients admitted to hospital may be swabbed to check for MRSA before any invasive procedures occur

the National Audit Office indicate that MRSA and C. difficile infections were responsible for 9,000 deaths in English hospitals and primary care in 2007 alone. Up to a third of the UK population carry MRSA on their skin and in their nostrils without any adverse effects. However, issues arise if the carrier has open cuts on their skin or if they go into hospital for an invasive surgical procedure. This increases the risk that MRSA will be able to enter the body. For this reason, many people admitted to hospital will be swabbed to check for MRSA before any invasive procedures occur. If MRSA is identified, then the patient may be treated with an antiseptic shampoo and body wash to remove it. If a patient exhibits signs of MRSA infection, they will initially be isolated to prevent the

spread of the infection, and will then often receive a combination of intravenous antibiotics – as directed by local hospital formularies. As MRSA has featured heavily in the news over the last decade, many of your patients may have deep concerns about going into hospital. A useful patient information guide (found at tinyurl.com/MRSAinfoCD) has been developed by the Health Protection Agency explaining MRSA infections, their prevention and treatment. This may help to alleviate some of your patients’ concerns. As with MRSA, it is possible to have C. difficile without any problems. The majority of the most serious cases of C. difficile are reported in elderly patients, patients who are immunocompromised, and children under two years old. C. difficile infection usually occurs after a patient has taken a course of antibiotics – these


reduce the body’s own natural gut bacteria, allowing C. difficile to flourish. Common symptoms of infection include diarrhoea, fever, nausea and abdominal pain. Diagnosis is initially based on a patient’s symptoms and knowledge that a patient has recently taken antibiotics. A faeces sample is also taken, but confirmation of C. difficile can take a few days. In the interim, patients are usually isolated to prevent the spread of the infection and started on antibiotic therapy – again dictated by local health formularies. As of 2005, Public Health England has closely monitored MRSA and C. difficile infection rates, requiring hospitals to report these on a monthly basis. In addition, as of 2013, hospitals must also complete a post-infection review

(tinyurl.com/postinfectionreview) to identify how infections occurred and how they could have been prevented. The Department of Health previously set itself a target to reduce MRSA infections by 50% by 2008 and C. difficile infections by 30% by 2010-11. While a large proportion of NHS trusts managed to achieve these targets, a number noted that their rates of MRSA and C. difficile infection actually rose.

Future mechanisms to prevent nosocomial infection The World Health Organisation has produced guidance to help hospital teams reduce rates of nosocomial infections. Hospitals are encouraged to have infection prevention and control

programmes in place that are adhered to by all staff members. In addition, staffing levels should be appropriate to allow for regular cleaning of hospital facilities and to ensure patients are treated in a hygienic environment. Hand-hygiene procedures are essential in reducing the spread of infection, while the prescribing of antibiotics only when needed is necessary in preventing antibiotic resistance. Any staff in contact with patients with active infections must wear gloves and wash their hands thoroughly with soap and water after contact, to prevent the spread of the infection. Patients and their carers also have an important role to play in the prevention of nosocomial infection. As with hospital staff, hand-hygiene practices should be followed,

particularly by those with active infections. Washing hands thoroughly with soap and water is the most commonly recommended method of preventing the spread of infection. Alcohol gels are sometimes used for hand cleaning, but these are not as effective as washing with soap and water, as spores can remain on the hands, allowing for further spread of the infection. As community pharmacists, your role is to educate patients on infection control measures and help them to understand the importance of reducing the frequency of their antibiotic use. Through a collaborative approach, the profession will be able to stem the tide of antibiotic resistance and improve the health outcomes for all patients suffering from nosocomial infections.

Nosocomial infection CPD

Take the 5-minute test online

Reflect

1. Nosocomial infections are acquired while in hospital, occurring 48 hours or more after admission. True or false

What organisms cause nosocomial infections? Which patient groups have a greater risk of nosocomial infections? How can the spread of infection be prevented? Plan This article contains information about what nosocomial infections are, the organisms that cause them and how they are spread. The role of antibiotic resistance and mechanisms to prevent the spread of infection are also discussed. Act

• Find out more about MRSA on the NHS Choices website at tinyurl.com/nosocomial1 • Read more about C. difficile on the Patient website at tinyurl.com/nosocomial2 • Learn more about the antibiotic awareness campaign on the NHS Choices website at tinyurl.com/nosocomial3 • Read the advice about keeping your home clean and how to prevent germs from spreading on the NHS Choices website at tinyurl.com/nosocomial4 and at tinyurl.com/nosocomial5 Evaluate Do you now have a good understanding of nosocomial infections and their causes? Could you give advice to patients and carers worried about MRSA and C. difficile?


2. According to Nice, over 500,000 people a year acquire an infection while in an NHS hospital. True or false 3. Surgical site infections account for the majority of nosocomial infections. True or false 4. The most common bacterial pathogens causing nosocomial infections include Staphylococcus aureus, C. difficile and Escherichia coli. True or false 5. Endogenous infections develop as a result of pathogens being introduced by external sources from outside of the body. True or false

6. Patients at increased risk of nosocomial infections include the elderly, immunocompromised patients and children aged under two years. True or false 7. Half of the UK population carries MRSA on their skin and in their nostrils without any adverse effects. True or false 8. C. difficile infection usually occurs after a patient has taken a course of antibiotics. True or false 9. Symptoms of C. difficile infection include diarrhoea, fever, nausea and abdominal pain. True or false 10. Hospitals must complete post-infection reviews to identify how infections occurred and how they could have been prevented. True or false
