Healthcare-associated infections

Healthcare-associated infections, sometimes termed nosocomial infections, are identified by the National Institute for Health and Care Excellence (NICE, 2016) as a serious risk to the health and wellbeing of patients, visitors and staff.

Healthcare-associated infections develop in a variety of settings and for a number of reasons, including:

• following a healthcare intervention (eg a surgical procedure, such as an operation)
• being in contact with an infectious agent in a healthcare setting
• as a result of healthcare delivered in the community
• as a result of an infection being brought into a care setting by visitors (NICE, 2011)

The most widely known infections associated with healthcare settings include:

• Methicillin-resistant Staphylococcus aureus (MRSA)
• Methicillin-sensitive Staphylococcus aureus (MSSA)
• Clostridium difficile 
• Escherichia coli 
• COVID-19

People who have a higher risk of contracting healthcare-associated infections include: 

• people who have had surgery which breaches the skin
• very young and older people
• people living with diabetes and similar diseases
• people living with diseases which affect their immune system or those taking immunosuppression agents
• people undergoing long hospital stays
• people in intensive care settings (Stiller et al, 2017; Peate and Nair, 2022)

COVID-19 is known to be highly infectious, and can spread at high rates in healthcare settings. Some risk factors for the infection and severity of COVID-19 include:

• older age
• male sex
• pre-existing comorbidities (Zhang et al, 2023)

Healthcare-associated infections are associated with high levels of morbidity and mortality among those affected. Healthcare-associated infections also affect several tens of thousands of healthcare workers annually (Guest et al, 2020).  

The Nursing and Midwifery Council (2018) requires all nurses to both practice infection prevention and control techniques, including

The signs and symptoms of a healthcare-associated infection will vary according to the type of infection and affected body system(s). For example, a healthcare-associated infection presenting as a surgical site infection may show tenderness, inflammation and, perhaps, pus at the operation site, while a respiratory infection may present as a productive cough and breathless. 

Most infections may share a range of similar signs and symptoms, where common general examples include:

• pain
• swelling
• heat
  • at the site of infection
  • general pyrexia
• altered blood tests
  • raised white cell count
  • raised c-reactive protein
  • altered blood gases
• lethargy
• confusion
• oliguria (Cattini and Kiernan, 2020)

More specific examples of signs and symptoms include:

• surgical site infection
  • tenderness
  • inflammation
  • pus
  • poor wound healing
• gastrointestinal infections
  • diarrhoea and/or vomiting
• pneumonia
  • cough
  • breathlessness
• urinary tract infection
  • dysuria
  • malodorous urine

Healthcare-associated infections occur when an infectious microorganism, such as a bacteria, virus or fungus, enter the body in quantities which overwhelm or bypass the body's natural defences. 

There are a number of ways in which microorganisms enter the body, these include through:

• contact with the skin (eg from a hard surface or handshake)
• inhalation of airborne droplets (eg from someone coughing nearby)
• bodily fluids (eg contact with blood)
• ingestion (eg from contaminated food)
• medically placed devices (eg central lines and urinary catheters)

Inadequate hand hygiene of healthcare professionals is the leading cause of healthcare-associated infections, and effective hand hygiene practices will help to reduce the prevalence of healthcare-associated infections in all settings (World Health Organization, 2009). However, the risk factors identified earlier additionally contribute to the proliferation of infection in healthcare settings (McLaws, 2015). 

Once inside the body, microorganisms act in a number of ways to cause the signs

Diagnosing an infection requires the nurse to observe and analyse the presenting signs and symptoms of the patient. Some infections will be more obvious to diagnose because of the presenting history, for example a surgical site infection which is inflamed and producing pus. The nature of the symptoms also aids diagnosis, for example breathlessness and a productive cough might point to a respiratory infection, such as pneumonia. 

More detailed diagnosis entails identifying the causative microorganism so that effective antimicrobial therapy might be started. This will usually require a specimen to be taken and sent for microscopy, culture and sensitivity testing. The types of specimen required will depend on the nature of the infection, but common specimens include cultures of:

• blood
• urine
• pus
• throat swabs
• faeces

The identification of the sensitivity of a bacterium and severity of infection is important in limiting the use of broad-spectrum antibiotics to combat antibiotic resistance

The fundamental key to the management of an infection in a healthcare setting is prevention. This relies on consistent and careful adherence to good infection prevention and control practices such as:

• effective hand hygiene 
• the use of personal protective equipment 
• Aseptic Non Touch Techniques 
• effective source isolation

When a healthcare-associated infection is identified, the management of the infecting microorganism will depend on the type of microorganism involved, the site of the infection and the availability of an antibiotic, antiviral or antifungal to treat the bacterial, viral or fungal infection, respectively. 

Medication management of an infection will rely, in part, on the nature of the infection, but has to be approached carefully in order to avoid increasing the risks of antibiotic resistance. Other management of infection strategies will depend on the severity of the infection. For example, severe infection may give rise to sepsis, which may require additional support for the

Cattini P and Kiernan M. Infection prevention and control. In: Lister S, Hofland J, Grafton H and Wilson C (eds). The Royal Marsden Manual of Clinical Nursing Procedures. 10th edn. Chichester: Wiley Blackwell; 2020: 69-129

Ellis P, Standing M. Patient assessment and care planning in nursing. 4th edn. London: Sage; 2023

Guest JF, Keating T, Gould D, Wigglesworth N. Modelling the annual NHS costs and outcomes attributable to healthcare-associated infections in England. BMJ Open. 2020;10:e033367. https://doi.org/10.1136/bmjopen-2019-033367

McLaws ML. The relationship between hand hygiene and health care-associated infection: it's complicated. Infect Drug Resist. 2015;8:7-18. https://doi.org/10.2147/IDR.S62704 

National Institute for Health and Care Excellence (NICE). Healthcare-associated infections: prevention and control. 2011. https://www.nice.org.uk/guidance/ph36/chapter/introduction (accessed 14 November 2023)

National Institute for Health and Care Excellence (NICE). Healthcare-associated infections. 2016. https://www.nice.org.uk/guidance/qs113/resources/healthcareassociated-infections-pdf-75545296430533 (accessed 14 November 2023)

National Institute for Health and Clinical Excellence (NICE). Sepsis: recognition, diagnosis and early management. 2017. https://www.nice.org.uk/guidance/NG51/chapter/Recommendations#risk-factors-for-sepsis (accessed 14 November 2023)

Nursing and Midwifery Council. Future nurse: standards of proficiency for registered nurses. 2018.