The Importance of Infection Prevention and Control in High Risk Groups

In this step we will focus on the value of infection prevention and control (IPC) in high-risk groups, using cystic fibrosis patients as a key example. Content for this step was provided by Professor Jane Davies, Imperial College London.

Cystic fibrosis (CF) is a condition that affects multiple systems of the body, but the most taxing and life-limiting areas are the airways of the lung. CF can cause reduced lung function, frequent lung infections, inflammation, and progressive lung disease. Bacterial infections and the resulting inflammation are the main cause of detriment to lung health in CF.

Graph of common bacterial infections throughout an average CF patient’s lifetime. Click here for a closer look at the graph. Taken from the British Society of Immunology.

There are many organisms that can cause infection in CF patients, but the non-fermenter Pseudomonas aeruginosa is the most common and will be the focus of this step.

How do People with Cystic Fibrosis Acquire P. aeruginosa?

The majority of cases are found to be unique strains that have not been acquired through cross-infection. However, cross-infection is a possibility and can be serious when it happens. Epidemic strains of P. aeruginosa have been identified, such as the Liverpool Epidemic Strain; these strains have been found to be:

• Highly transmissible – more so than other strains of Pseudomonas
• Difficult to treat
• Associated with poor prognosis

The above factors highlight the importance of avoiding infections in CF patients, and as a result ‘basic tenets of CF infection control’ have been developed:

No patient mixing: Very strict segregation measures have been implemented as the current clinical standard worldwide. This includes no mixing of CF patients in outpatient clinics, pharmacies, and radiology departments. Inpatient wards for CF patients have been redesigned to be self-contained, and ideally have en suite facilities. Negative pressure cubicles have also been utilised – particularly for highly transmissible strains. For paediatric patients, the ‘no mixing’ extends to schools and leisure activities.

Hand hygiene, use of appropriate PPE, and cleaning hard surfaces between CF clinic attendees are essential infection prevention and control practices that must be adhered to.

Finally, sufficient air exchange between patients when they arrive and leave cubicles/consulting rooms is important. This is especially the case for Aerosol Generating Procedures (AGPs).

Current Challenges of Pseudomonas in Cystic Fibrosis

Infections must be detected before they can be eradicated. Current detection methods are based on culture and standard susceptibility testing. The limitation of these methods lies in the use of sputum as the substrate, as children and those with milder CF do not produce sputum. The development of non-invasive detection methods would likely improve this.

Antimicrobial resistance in P. aeruginosa is a concern as it has the ability to mutate quite rapidly to become resistant to antimicrobial agents. New approaches to treatment are being considered and developed, including optimising the efficacy of existing antibiotics and the use of new drugs.

IPC is vital to ensure CF patients avoid bacterial infection, particularly from P. aeruginosa. These considerations should be made for high-risk patients, although the specific needs may differ between groups.

We will now examine the current best practice IPC guidelines.