PREVENT INFECTION: Using Measurement
Most experts agree that a multifaceted approach is the best way to help stem the tide of Hospital Acquired Infections (HAIs). With the huge public health threat and cost drain that HAIs present, and the Association for Professionals in Infection Control & Epidemiology’s (APIC’s) commitment to ‘Target Zero’ HAIs (www.apic.org), bringing all available infection prevention and control weapons to bear on nosocomial illness in an integrated way makes sense.
Although the need for handwashing and behavior modification to encourage handwashing, aseptic surgical procedures, patient screening and other measures have been well-documented or advocated for, a major missing element – and one the cleaning industry directly impacts – has been integrating the effective cleaning of environmental surfaces with measurement of outcomes (known as ICM, or Integrated Cleaning and Measurement), then incorporating that data in a multi-pronged – and continuously improved – intervention plan.
This raises questions such as: What should we measure? What should we measure with? What do these measurements mean, and how can we use them to improve our operations and reduce infections in hospitals?
What should we be measuring?
It is universally agreed that touch points (places where skin, hands and fingers make contact) easily spread infectious agents, therefore, at a minimum we should be cleaning and measuring these areas (as well as other high risk locations such as restrooms, ORs, food service, etc.) frequently for elimination of pathogens.
What should we measure with?
There are three basic ways to assess or measure contamination on environmental surfaces: Visual examination, ATP (Adenosine TriPhosphate) and Bacterial Cultures.
According to the UK study titled ‘A modified ATP benchmark for evaluating the cleaning of some hospital environmental surfaces,’ by Lewis T, Griffith C, Gallo M, Weinbren M:
‘Visual inspection … can be misleading…[and] calls have therefore been made for a more objective approach to assessing surface cleanliness.’
‘ATP testing can be used to provide instant feedback on surface cleanliness, and was found to be a powerful way of demonstrating deficiencies in cleaning protocols and techniques to staff.’
‘ATP analysis measures both microbiological and non-microbiological sources of ATP, both of which should be removed by an effective cleaning protocol. Nevertheless, the validity of a cleaning assessment tool is enhanced if there is correlation between its performance and the degree of microbiological contamination on a surface.’
‘ATP measures residual surface organic soil, which may include micro-organisms, whereas microbiological assessments measure numbers of residual viable organisms.’
Translation? ATP is an excellent routine method of ensuring that microscopic organic soil that can support the growth of microbes is being removed, but ATP does not identify specific germs or count the total number of specific live germs (note – other studies indicate there is often a correlation between ATP measurements and general live bacterial counts). Still, for identifying specific microbes, you will need to use bacterial cultures.
In support of that contention:
A four-part study (‘An evaluation of hospital cleaning regimes and standards using ATP bioluminescence,’ by Griffith CJ, Cooper RA, Gilmore J, Davies C, Lewis M – School of Applied Sciences, University of Wales Institute, Cardiff, UK) ‘assessing cleanliness in up to 113 environmental surfaces in an operating theatre and a hospital ward [reported that]… visual assessment was a poor indicator of cleaning efficacy…[and that] an integrated cleaning monitoring program using ATP bioluminescence in conjunction with visual and microbiological assessments is recommended.’
ATP and Bacterial Cultures – What Do These Measurements Mean, and How Can We Integrate and Use Them to Improve?
Various studies help to show the value of ATP as a sound cleaning measurement method indicating removal of organic soil where microbes live. As discussed, however, ATP is not a substitute for bacterial cultures in healthcare. This latter point is very important in hospitals and nursing homes where there are immune-compromised people and extra potent and strong (resistant) bugs to contend with (a bad combination).
With some virulent bugs, even a ‘few’ infectious organisms can make people sick (these can be present even when a surface tests relatively ‘clean’ using ATP), thus hospitals such as a major medical center for children in Cincinnati and others, use a cross-section of bacterial sampling (cultures) rather than ATP alone since they are looking for certain pathogens that even in small numbers can infect weakened or immune-compromised people. These methods seem to be working in the Cincinnati facility, since their rate of HAIs is about half the national average.
Thus, the ultimate goal is to become proficient in bacterial sampling in addition to ATP sampling, since bacterial count methods are more sensitive and specific to target germs that can make people sick even in small numbers that ATP cannot detect. The Catch-22 with bacterial counts, is that they can vary widely from one place to another (even a few inches apart on a surface) so they can only be used as a general guide to the presence of a specific alarm bug; of course, that’s likely also true of ATP and cleaning measurements, reinforcing the need to take lots of samples and average the results.