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Reducing Stubborn HAI Rates: Evidence & Practice

Why do infection rates peak in some hospitals and not others? How can we best manage HAIs?

By: Ivan Obreza

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Surface Contamination

If environmental surfaces are contaminated and subsequently touched by healthcare workers, their hands become contaminated¹. Keeping environmental surfaces and patient care equipment free of pathogens is therefore an important part of infection prevention and patient safety.

However, cleaning compliance of surfaces in the patient zone is suboptimal. Carling studied patient room discharge cleaning on 14 high-touch surfaces across 23 acute care hospitals². Cleaning compliance was 49%, with individual surfaces ranging from 20% to 82% compliance across the study.

Daily cleaning of environmental surfaces and patient care equipment is not believed to be any more compliant than discharge cleaning. This emphasises that improving cleaning compliance for both daily and discharge cleaning should be an important infection prevention goal.

However, improving cleaning and disinfection by focusing solely on the cleaning performed by the environmental services (EVS) staff is unlikely to optimise the hygiene of environmental surface and patient care equipment because of the frequency with which these surfaces become contaminated.

 

Patient Room Traffic

Cohen et. al. studied the number of people entering a patient room, finding that the average number of room entries was 5.5 per hour³. Nursing staff accounted for only 45% of those entering the room. Of the staff entering the room, there were 3.5 different people entering the patient room per hour, so some of the people entered the room more than once per hour. The average nurse entered 4.5 patient rooms per hour.

This study was conducted across a 15 hour waking day for the patient, implying that 5.5 people per hour for 15 hours per day would equal 82.5 people entering a typical patient room in that timeframe.

The Cohen study also differentiated the surfaces that were touched in the patient room. 33% of room entrants touched the environment, but not the patient. 27% touched the patient’s intact skin, while 18% had contact with the patient’s blood or body fluids. 16% of people entering the room touched absolutely nothing. Surprisingly, visitors had a higher recorded contact with blood and body fluids (19%) than nurses did (15%).

Huslage et. al. investigated what surfaces staff touch while in the patient room for both an ICU and a general medical-surgical room⁴. In the general medical-surgical room, bedrails were the most commonly touched surface, averaging 3.1 touches per interaction. Over-bed tables (1.6x), IV pumps (1.4x) and bed surfaces (1.3x) were the next three most commonly touched surfaces.

Huslage also reported that in a medical-surgical unit, the staff touched on average 15 surfaces per interaction, while in an ICU, staff touched 44 surfaces per interaction. Across a 12 hour shift, the average nurse would be expected to touch 821 surfaces (4.5 patient rooms per hour x 15 surface touches per interaction x 12 hours = 821 surfaces) with a hand hygiene adherence of less than 40 percent.

Using the WHO’s five moments of hand hygiene model, staff would not be expected to perform hand hygiene after each surface contact, but they would minimally be expected to perform it at regular intervals based on entry and leaving the patient zone.

If hand hygiene compliance is less than perfect, then better cleaning of surfaces needs to occur in order to provide a safety net.

 

Surface Touch Frequency

Combining the Cohen data with the Huslage data suggests that the typical patient bedrail is touched 256 times per day on average:

• 5.5 people entering the room/hour x 3 bedrail touches/interaction = 17 touches/hour

• 17 bedrail touches/hour x 15 hours/day = 256 bedrail touches/day

Adams et. al. published an article providing similar data and attempting to connect frequency of hand contact with the level of aerobic bacteria and MRSA⁵. The right and left bedrails were touched 20 and 16 times per hour respectively, which reflects the Cohen data. They also found that higher touch frequency correlated with the number of bacteria on the surface for several surfaces, including the bedrail.

The primary cleaning intervention for patient room surfaces is to have the EVS worker clean and disinfect the bedrail and other surfaces once per day. This likely occurs with less than a 50% frequency.

While the clinical staff may have pre-wetted disinfectant wipes available to disinfect high-touch surfaces in the patient environment of care, there is little data available to demonstrate the frequency with which this occurs, and it is likely to occur rarely.

Since daily disinfection is unlikely to address all risks, and clinical staff perform hand hygiene less than 40% of the time, the probability of staff hands being contaminated at any given time is high.

The WHO hand hygiene guidelines for healthcare workers states that these employees “typically touch a continuous sequence of surfaces and substances including inanimate objects, patients’ intact or non-intact skin, mucous membranes, food, waste, body fluids, and the worker’s own body. With each hand-to-surface exposure, a bidirectional exchange of microorganisms between hands and the touched object occurs and the transient hand-carried flora is thus continually changing. In this manner, microorganisms can spread throughout a healthcare environment and between patients within a few hours.”

This highlights that the risk is bidirectional. Pathogens in the near-patient environment may represent little risk to the patient if they are part of the patient’s microbiome, but that’s only one part of the risk to the patient. As the WHO position makes clear, there is also a risk that healthcare workers are transferring organisms throughout the healthcare facility, increasing the risk of infection for patients.

 

Improving Cleanliness at the Point of Care

There are daily care procedures that may require surfaces at the point of care to be disinfected in case the healthcare worker’s technique was not perfect. While no studies have demonstrated the frequency with which surface disinfection needs to occur to protect the patient, once per day with a 50%   frequency is arguably too little. At the very least, surface disinfection should occur around these moments:

1. Before placing a food tray

2. After any procedure involving faeces within the patient bed space

3. After dressing/changing wounds

4. After assistance with productive coughing or vomiting

5. After bed baths and personal hygiene sessions

6. When surfaces are visibly soiled

Further investigation is needed to determine the impact on bacterial counts on high-touch surfaces in the near-patient environment and on healthcare associated infection rates. The CDC states “the methods, thoroughness, and frequency of cleaning and the products used are determined by healthcare policy”, and recognises that high-touch housekeeping surfaces (doorknobs, bedrails, etc.) should be cleaned and disinfected more frequently⁶.

In addition to improved environmental hygiene, a good patient hand hygiene program is also critical. The patient generally has the ‘portal of entry’ from the chain of infection, and in many cases the patient is the ‘mode of transmission’ (touching their mouth or other mucous membranes).

Landers describes moments for patient hand hygiene, but every patient should be assessed on admission for their capability to understand when to perform hand hygiene, and if they are physically and mentally able to manage their own hand hygiene⁷. Patients who require assistance with hand hygiene, either due to physical or cognitive issues, should be clearly identified to all staff. That allows the healthcare and ancillary teams to assist the patient with regular hand hygiene, using a product that is readily available.

 

Disinfectant Options

Sodium Hypochlorite

Sodium hypochlorite (chlorine bleach) appears in most state guideline documents. It is cheap and readily available. But its correct application is complex. Bleach needs to be dispensed at different doses for different applications, namely:

•  100 parts per million (ppm) for pools

•  1,000 ppm for micro-organisms except bacterial spores (e.g. C. difficile)

•  5,000 ppm as a sporicidal disinfectant for bacterial spores (e.g C. difficile)

•  10,000 ppm as a disinfectant for blood spills

The dose used by most hospitals is 1,000 ppm. Most dispenser systems have difficulty in delivering 5,000 ppm due to the high viscosity of the neat product. Thus to be sure you are using a sporicidal strength, the bleach needs to be diluted by hand, and that magnifies safety concerns.

Bleach is regarded with less affection these days because it is corrosive. It causes severe burns to skin and eyes, and destroys fabric (clothing, linen, curtains, toys and carpets). Bleach is linked with childhood asthma⁸ and adult onset respiratory disease in workers who have used it daily as a part of their working life⁹.

Notably, bleach biodegrades into minute quantities of various salts. These salts are a food source for bacteria in biofilm and further studies are needed to investigate whether intractable HAI rates in some hospitals are linked to the widespread use of chlorine bleach by cleaners¹ᴼ

Quaternary Ammonium (“Quat”)

To offset the adverse safety issues associated with bleach, many hospitals are buying pre-wetted disposable disinfectant wipes impregnated with quaternary ammonium (QAC or "quat"). The most common quats are benzalkonium chloride and didecyl dimethyl ammonium chloride. Quats have a retentive tendency because they don't break down readily. The resultant residue is marketed by some suppliers as having a residual antimicrobial effect.  On the contrary, quat binding occurs when quat molecules are attracted by and absorbed into fabrics, effectively reducing the active level of the disinfectant.

Quats have efficacy claims against most prevalent healthcare organisms except C. difficile as they are incapable of penetrating the outer shell of bacterial spores. If sporicidal activity is required, then a specific sporicidal product should be sought (high-dose bleach, peracetic acid, or high-dose AHP).

Accelerated Hydrogen Peroxide (AHP)

AHP is non-irritant, has no odour and is safe on most surfaces and fabrics. It breaks down into oxygen and water and has no retentive chemistry. As it is completely broken down it is also environmentally safe, with no adverse effects on ecology or aquaculture.

Boyce et. al. recently published the first ever prospective cluster-controlled crossover trial directly comparing two disinfectant classes in a real world setting (quat versus AHP in a major teaching hospital)¹¹.  Boyce showed that colony counts cultured after cleaning were significantly lower with AHP than with quat. Boyce’s data demonstrated that the proportion of surfaces that yielded no pathogenic growth after cleaning was significantly greater with AHP than with quat (p<0.0001).

AHP is available from Diversey Australia in liquid and disposable wipe variants (Oxivir Tb®) and as a high-dose variant for C. difficile spores (Sporicide Plus®).

 

Creating Safer Environments of Care

Surface disinfection must be considered alongside hand hygiene to adequately address the risk of infection for patients. While currently little data exists to support the frequency with which this must occur, current practices result in the patient bedrail being touched upwards of 256 times per day, while surface disinfection is done once per day with a 50 percent frequency.

All healthcare facilities need to address the other 255 contacts with a consistent, well described program for infection prevention in the patient zone. We can better manage HAI rates by enhancing staff hand hygiene compliance, by introducing patient hand hygiene protocols, and by routinely disinfecting high-touch surfaces at the point of care with an appropriate product.

Ivan Obreza is the senior clinical advisor at Diversey Australia and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it.