While surface disinfection may seem like a commonsense practice — how hard can it be to use a wipe on a tray or table? — there's more to it than meets the eye. Test your staff's knowledge of the basic rules and rationales surrounding proper cleaning protocols with this evidence-based quiz.

1. A patient has explosive diarrhea in the OR. You discover from the patient's record that an assay for Clostridium difficile is pending. What chemical disinfectant would you use to clean the room after the case?

a. quaternary ammonium compound
b. hospital-grade, EPA-approved disinfectant
c. 1:10 bleach-based product
d. 70% isopropyl alcohol

c. 1:10 bleach-based product

C. difficile is an anaerobic, gram-positive bacterium that can persist for extended periods on a variety of surfaces in the environment because it is spore-forming. According to the Association for Professionals in Infection Control and Epidemi-ology's "Guide to the Elimination of Clostridium difficile in Healthcare Settings," the term "hypersporulation" has been used "to denote the propensity of the bacterium to move from the vegetative form to the spore form with increased rapidity. The term has also been used to note that contact with some germicides stress the bacterium, so it more readily transitions to the spore form."¹ In other words, using the wrong disinfectant can actually make C. diff more difficult to eradicate.

The guide further states, "Although many EPA-registered germicides kill vegetative C. difficile, only chlorine-based disinfectants and high-concentration, vaporized hydrogen peroxide kill spores." With vaporized hydrogen peroxide still emerging as an option for outpatient facilities, this leaves the CDC-recommended regime: "meticulous cleaning followed by disinfection using hypochlorite-based germicides," that is, bleach-containing disinfectants.²

2. When cleaning the OR between cases or at the end of the day, it's important to start by cleaning the floor, because it's the dirtiest and most contaminated surface in the room.

a. true
b. false

b. false

Because floors receive minimal hand contact, they should be cleaned "on a regular basis, when soiling or spills occur, and when a patient is discharged" from the area.² Extraordinary cleaning and decontamination are not warranted, as "studies have demonstrated that disinfection of floors offers no advantage over regular detergent/water cleaning" and minimally affects incidence of healthcare-associated infections.²

Further, floors should be tackled last during any cleaning because "newly cleaned floors rapidly become recontaminated from airborne microorganisms and those transferred from shoes, equipment wheels and body substances," according to the CDC.²

So if you clean the OR table after the floor, you risk spreading any microorganisms from the table back to the floor — possibly negating the work you just did. Wet-mopping or -vacuuming using an EPA-registered detergent/disinfectant is recommended after a procedure that has resulted in a blood or body fluid spill, or "when a multi-drug-resistant organism is likely to be in the environment."²

3. What is the leading cause of surgical site infections?

a. methicillin-resistant Staphylococcus aureus
b. C. difficile
c. vancomycin-resistant Enterococcus
d. norovirus

a. methicillin-resistant S. aureus

S. aureus is the leading cause of surgical site infections in the United States.³ Antimicrobial prophylaxis is the main strategy to prevent methicillin-resistant S. aureus, but it's important to note that surface disinfection also plays a role. Evidence is accumulating that contaminated surfaces contribute to transmission of all the answer options as well as Acinetobacter baumannii and Pseudomonas aeruginosa, and that improved environmental decontamination helps to prevent and control outbreaks.⁴ MRSA, in fact, can live for months on surfaces.⁵

It's important to note that norovirus is the leading cause of outbreaks of infection in general in the United States. This winter, norovirus was frequently in the headlines for causing many outbreaks, giving it timely significance for surgical facilities.⁶ A recent survey found that medical/surgical units represented 25.7% of 386 outbreak investigations reported by 289 hospitals over 24 months.6 Unfortunately (although perhaps not surprisingly), norovirus is "relatively resistant to the most common surface disinfectants."⁷

4. The disinfectant you use to wipe down the Mayo stand between procedures lists a contact time of 10 minutes, but the solution dries much faster than that. Do regulatory agencies expect you to reapply the disinfectant product to meet the recommended contact time?

a. yes
b. no

a. yes

Non-critical items in the OR — those that come into contact only with intact skin — carry little risk of infecting patients, but regulatory agencies expect you to follow the disinfectant label instructions. However, William Rutala, MS, MPh, PhD, prominent infection prevention and control expert and co-author of the CDC's "Sterilization and Disinfection Guidelines," writes that the Environmental Protection Agency would clear the CDC's environmental disinfection guidelines only if it included a disclaimer about deviating from EPA-approved contact times.⁸ As such, there's a disconnect between label instructions and the evidence.

Dr. Rutala notes that adhering to a label's prescribed contact time can require 5 to 6 reapplications during each cleaning. He also says that multiple studies demonstrate efficacy with a contact time of 1 minute, and that thorough application of disinfectant is just as important as contact time.⁸

"There are no data that demonstrate improved infection prevention by a 10-minute contact time versus a 1-minute contact time," he writes, "and we are not aware of an enforcement action against healthcare facilities for 'off-label' use of a surface disinfectant."⁸

A 1-minute contact time is sufficient — but be sure to stress to your staff that they must be thorough when cleaning.

5. Studies show one of the following combinations is most efficacious for sanitizing floors. Which is it?

a. microfiber mop alone
b. cotton-loop mop alone
c. cotton-loop mop with disinfectant
d. microfiber mop with disinfectant

d. microfiber mop with disinfectant

The use of a disinfectant with a microfiber mop has demonstrated 95% microbial elimination.⁹ However, "a microfiber mop alone" is incredibly close behind at 94%.⁹ Either option is a significant improvement over a cotton-loop mop alone (68%), although adding disinfectant to the cotton-loop mop raises microbial removal to 95%.

Yes, this matches the efficacy of microfiber plus disinfectant, but there is further rationale for choosing the microfiber route. First, microfibers are thin yet densely constructed and positively charged, so they attract dust and can be wet with disinfectants while remaining absorbent. Second, the main advantage of using a microfiber system is that the pads are single-use, so you don't risk transferring microorganisms to other rooms.

If you do stick with traditional cotton-loop mops, it's important that you decontaminate them regularly "to prevent surface contamination during cleaning with subsequent transfer of organisms from these surfaces to patients or equipment by the hands of healthcare workers."⁹

6. Which of the following statements is correct about the use of disinfectant wipes?

a. use each wipe only once
b. use each side of the wipe only once
c. neither
d. both a and b

d. both a and b

Disinfectant wipes are a wonderful tool for surface cleaning, but if you don't use them properly, you may actually be doing harm. Researchers at the University of Cardiff (Wales) found that antimicrobial-impregnated wipes actually have the potential to spread microorganisms and cross-contaminate surfaces.¹⁰ They determined that microorganisms can live on wipes long enough to make it to the next surface and that, in order to minimize this possibility, you should use each wipe — and each side of each wipe — only once, then dispose.¹⁰ And don't forget to keep the container top closed during storage, so wipes don't dry out.

7. Quaternary ammonium compound impregnated wipes effectively decontaminate keyboards and other high-touch computer equipment.

a. true
b. false

a. true

According to the CDC, while quaternary ammonium compounds are considered to have poor mycobactericidal activity, they (along with 70% isopropyl alcohol, phenolics and chlorine-containing wipes) remove or inactivate more than 95% of contaminants (including MRSA, vancomycin-resistant Entercoccus and P. aeruginosa) from computer keyboards. Any chemical used must be allowed to air-dry, which usually takes less than a minute. Application doesn't cause functional or cosmetic change, even after 300 applications.⁹

8. Choose the microorganism set that correctly lists the organisms from most-resistant to disinfectants to least-resistant to disinfectants.

a. prions, bacterial spores, fungi, vegetative bacteria
b. vegetative bacteria, fungi, bacterial spores, prions
c. bacterial spores, prions, fungi, vegetative bacteria
d. prions, fungi, bacterial spores, vegetative bacteria

a. prions, bacterial spores, fungi, vegetative bacteria

The correct order is prions (such as Creutzfeldt-Jakob Disease), bacterial spores (such as C. difficile) fungi (such as Candida), vegetative bacteria (such as Staphylococcus and Pseudomonas).⁹ There are others on the resistance spectrum, but prions are the most difficult to kill. The good news? You can rest easy: Surfaces and the environment don't play a role in prion transmission.¹¹

9. Which of the following increases the risk of your disinfectants becoming contaminated?

a. diluting
b. using containers that haven't been properly disinfected
c. improper storage
d. all of the above

d. all of the above

The CDC has received reports of contaminated chlorhexidine, quaternary ammonium compounds, phenolics and pine oil.⁹ But these reports have occurred within healthcare facilities, not at the point of production. The CDC therefore recommends 3 control measures to ensure your EPA-registered germicides will function as they are meant to: Follow label instructions for dilution precisely — including instructions to not dilute; ensure that uncontaminated water is used for diluting, that containers used for mixing are properly disinfected and that the area used for preparation is clean; and store germicidal solutions according to label instructions (for example, at the proper temperature, or in a cool, dry place).⁹

10. When adding ultraviolet (UV) light for surface disinfection, you can skip the step of cleaning the room first because UV sterilizes all surfaces.

a. true
b. false

b. false

UV light as a method of surface disinfection originated in the food service industry, and the benefits of its application have become apparent to healthcare professionals in recent years. UV light offers "reliable biocidal activity against a wide range of pathogens," the ability to decontaminate surfaces and equipment, no need to disable the HVAC system or to seal the room, no potential for residue and low acquisition costs.¹²

One study found that 30 minutes was an adequate exposure time to inactivate gram-positive and gram-negative bacterial spores and fungi to the order of 4 logs when UV light was used from a distance of 8 feet.¹³ (In fact, even indirect UV light results in meaningful bacteria reduction.¹⁴) According to Dr. Rutala, UV light kills 99.9% of vegetative bacteria within 15 minutes and 99.84% of C. difficile spores within 50 minutes.¹²

The use of UV light on surfaces is best left to terminal cleaning, particularly given the quick turnover times necessary in surgical facilities. But don't discount the importance of terminal cleaning, nor the effect UV light can have on this task. Dr. Rutala has noted that the "mean proportion of surfaces disinfected at terminal cleaning is less than 50%" and that the lack of full effectiveness of products, combined with the ease of inserting human error in the process, mean that most "terminal cleaning methods [are] ineffective in eliminating epidemiologically important pathogens."¹⁴

I can attest from personal experience that for the 3 years we've used UV light for surface disinfection, we've seen what we believe is good evidence for its effectiveness as an additional tool for preventing healthcare-acquired infections. However, although it's true that UV light will reliably kill all organisms after the appropriate dosage is reached, the question remains regarding how adequately it disinfects shadowed areas. Because of this, thorough surface cleaning per your usual protocols must always be done first.