Key Questions - Infection Prevention and Control

Pauline MacDonald, MSc, BSc, ARRC, is nurse consultant in communicable disease, public health department, Dudley PCT, and managing director, Infection Matters Ltd.

What is the single most effective method of preventing and controlling healthcare-associated infection (HCAI)?

Hand hygiene (decontamination) is the most effective way to prevent the transmission of organisms between patients and objects in the care environment. Organisms can be transferred from patients, equipment or hand surfaces to other people, objects and equipment. Pathogenic organisms transferred directly or indirectly to vulnerable patients can cause subsequent infection.

How do I effectively decontaminate my hands?

Hands must always be washed when visibly soiled, after wearing gloves or after contact with contaminated surfaces. In these instances effective hand decontamination is achieved using warm running water, soap and disposable paper towels to dry thoroughly. The soap breaks down natural skin oils to which microorganisms adhere. Washing relies on the physical removal, and flushing away, of the microorganisms – 'drown a germ' theory. Antiseptic soap is not required for routine handwashing in general clinical areas. High-level hand decontamination with antiseptics is only necessary in areas where patients are at high risk or before invasive procedures.

What should I do if I cannot wash my hands?

The recognition that handwashing facilities are not always available, handwashing is time-consuming, and not all patient interventions require it, has led to the introduction of handrubs and wipes.

Wipes can work by physically removing microorganisms, and by leaving chemicals on the skin to kill or disable remaining microorganisms. Gels and rubs rely on killing or disabling the microorganisms in situ, so they cannot cause infection. Some microorganisms may be resistant to chemicals and antiseptics. Clostridium difficile and norovirus are resistant to alcohol, while Pseudomonas aeruginosa thrives in chlorhexidine; therefore these products may be of little use when trying to control infections caused by these organisms. Practitioners should be wary of products that claim to kill 99.9% of bacteria – they are unlikely to kill spores, fungi and viruses.

Are all HCAIs unavoidable?

About 30% of these infections will occur despite best efforts to prevent them. Resident microorganisms cause no harm if they remain on or in their normal resident area, but if relocated they can cause infection. Escherichia coli is necessary for a healthy gut but if transferred to the sterile urinary tract causes infection. Endogenous infections are caused by patients' own resident microorganisms. Surgical or invasive device infections are often endogenous. High standards of patient hygiene can reduce, but not eliminate, the risk of endogenous infection.
 
Which patients are most vulnerable to HCAI?

Patients on chemotherapy or steroids are often immunocompromised and vulnerable to infection. The very young and the elderly may not mount an effective immune response to infection; cases of MRSA and C. difficile are more common in patients over 65.
Each day spent in healthcare settings increases patients' risk of acquiring an HCAI. The high burden of microorganisms, inappropriate use of antibiotics and healthcare interventions which breach or bypass vital parts of the immune system, all increase risk. When considering average hospital or care home populations those most at risk are elderly long-stay patients, who are taking or recently had antibiotics, and who have invasive devices or breaks in their skin. 

Web links for more information:

Clean, Safe Care
clean-safe-care.nhs.uk

National Patient Safety Agency
npsa.nhs.uk/cleanyourhands

Health Protection Scotland
washyourhandsofthem.com