What is Infection Control?

Infection arises due to proliferation of microorganisms, typically bacteria, viruses or fungi in or on the body of a patient. Infection can be localised or disseminated. The measures that are routinely taken to reduce the risk of hospital-acquired (nosocomial) infection can be subdivided into general measures to reduce infection risk and specific measures for patients at specific risk. Broadly speaking every measure that is taken to ensure that patients in hospital are protected from contracting transmissible disease and all measures taken to avoid or minimise development of infection in association with surgical wounds or implants, such as urinary or peripheral venous catheters, constitute infection control.

Why Bother with Infection Control?

Infection arising in association with veterinary care can be troublesome for many reasons. In the most severe cases, nosocomial infection can result in systemic consequences or even death. For example, failure to prepare appropriately for abdominal surgery may result in the transfer of a significant bacterial burden into the abdominal cavity resulting in overwhelming peritonitis. This is hopefully an extreme example, but more regularly, patients are seen with postoperative seroma formation, delayed wound healing and a protracted recovery from surgery. Poor attention to infection control measures results in a greater reliance on pharmaceutical intervention, which further perpetuates antibiotic resistance. Medical management of persistent infections can be extremely costly; on occasion they cannot be managed medically resulting in death of a patient or the need for radical surgical measures such as amputation for localised infection problems.

Over and above the medical consequences of the in-house acquisition of infectious disease, repeated outbreaks of infectious disease within a practice can be very damaging. While a high incidence of nosocomial infection may simply be indicative of inadequate attention to infection control measures, it is likely to undermine confidence in all aspects of the veterinary care at that clinic.

Whose Responsibility is Infection Control?

As individuals committed to the care of our patients, it goes without saying that we all accept a degree of responsibility in the prevention and management of nosocomial infection. There are however different levels of responsibility that can be taken. A typical practice would probably have responsibility for infection control issues divided as follows. Personal responsibility would ensure that veterinary staff follow simple procedures like hand washing between patients and applying sterile technique in surgical procedures. General responsibility might fall to a head nurse or other senior practice figure and that individual might have the unenviable task of ensuring that colleagues apply appropriate measures in hygiene and infection control matters.

This model works to a degree but will always generate a them/us or a senior/junior or even a disciplinarian/naughty school child relationship and inevitably the quality of infection control matters and consequently the care provided suffer. Since we all accept responsibility for the welfare of our patients, we should all accept higher levels of responsibility in infection control. Ideally, all participants in the healthcare process are equal in the responsibility they take for ensuring not only that their own personal infection control measures are appropriate but that those of the people around them are also.

General Infection Control Measures

'Cleanliness is next to godliness', someone's grandparents will have said. The single most important measure that any individual can take to reduce the risk of nosocomial infection is to keep things clean. And while sparkly clean is good, we are really just talking about simply keeping things grossly clean. If dirt can be seen then the thing ain't clean. Cleaning should ideally be performed with... a cleaning product. Far too much emphasis is placed on the use of disinfectant. In fact disinfectant is denatured by organic material and therefore any macroscopic matter would limit its efficacy. Disinfectant will not work without prior application of a detergent, or cleaning agent, followed by a period of adequate drying (Figure 1).

Figure 1. Three steps to disinfection.

The principles of disinfection noted in Figure 1 apply equally to the cleaning of surfaces, to hand washing and to skin preparation for aseptic procedures.

All mammals have a level of innate immunity which protects them from the acquisition of infectious disease. For optimal function of their immune defences, these patients need to be as systemically well as they can be. Malnutrition is a significant risk factor for the development of nosocomial disease and as such every effort should be made to ensure that hospital patients achieve an adequate nutritional plane. Knowledge of energy requirement conversion factors is useful in this regard. Since many hospitalised patients are under our care because their clinical status results in them being unwilling or unable to eat adequately, attention must be given to providing nutritional support, potentially by means of feeding tubes, for example an oesophagostomy or gastrostomy tube.

Other general nursing principles must be adhered to. Patients need adequate warmth, to be able to toilet appropriately and to be cleaned in the event that the skin or coat become soiled by discharge or body waste.

Specific Infection Control Measures

There are specific circumstances where patients are known to be at increased risk of potential infection. A surgical patient is an obvious example. The surgical field is clipped and cleaned and then undergoes aseptic preparation prior to surgery. Other specific scenarios include patients with indwelling urinary catheters, peripheral venous cannulae and other implants. The site of the implant must be kept as clean as possible. Gloves should be worn to limit or prevent transfer of infectious elements from the veterinary staff member to the implant/tissue interface. Protocols are employed for regular disinfection of sites of cannula/skin contact. Patients with skin deficits following traumatic or burn injuries are at risk of nosocomial infection due both to the breach in normal cutaneous defences and the marked increase in energy and protein requirements that these patients exhibit. Immunosuppressed patients should be identified as being potential candidates for nosocomial infection. These patients can be barrier nursed to limit transfer of infectious elements from staff or other in-patients. Clinical situations known to induce immunosuppression include severe systemic illness, severe gastrointestinal disease, advanced cancer and chemotherapy administration.

Contagious disease is a specific infection control hazard and one that draws much attention. Typically, by the time an outbreak of a contagious disease has been identified in a practice, it is probable that all cases in that ward are exposed and therefore isolation of symptomatic patients is likely to be of limited benefit. Of greater importance is separation of those already 'exposed' cases from those definitely 'unexposed', i.e., new patients. Many practices do not have the facilities to hospitalise patients in multiple wards so this can be an impractical proposition.

How Can You Improve Infection Control in Your Practice?

Everybody in the practice takes part in infection control. On the simplest level, if everybody paid greater attention to hand washing technique and washed their hands between handling all patients, this in itself would significantly reduce the risk of nosocomial infection in all hospital institutes, not just veterinary ones. As the general public becomes more aware of infection-related issues, we have to take a more active role in evaluating our own infection control processes. Infection control is a subject of the highest importance and as such would benefit from being a regular fixture on the practice meeting agenda. In many institutions, infection control may be poor because of lack of education. Identification of a single individual within a practice who has a desire to learn and promote infection control would be a great advantage and this individual does not need to be veterinary-trained. Ultimately, infection control is the responsibility of all in the healthcare professions and it is up to us to police ourselves and to seek appropriate education to allow us to perform our job to the best of our abilities.

In essence, infection control is all about doing the simple things right. Wash hands. Clean surfaces. The rest will follow.

References

1.  National Audit Office. The management and control of hospital acquired infection in acute NHS trusts in England. London, The Stationery Office, 2000.

2.  Polton GA, Elwood CM. First wash your hands! Control of nosocomial infections in practice. In Practice 2006; 28: 548-550.