This winter seemed to see more people suffering from influenza – even among those who had a flu vaccination – due to an apparent genetic ‘drift’ in the A(H3N2) virus. Add to this the usual rounds of sickness bugs and we have another timely reminder of the need for good hygiene practices in all walks of life, and especially in optometric practice where a great deal of time is spent with patients/customers in relatively confined spaces. The opportunity for cross contamination is a common danger that all practitioners, and patients, need to be aware of and develop strategies to avoid.
Infection control
In optometric practice, infection may be transmitted from patient to staff, staff to patient, patient to patient and staff to staff by direct contact, aerosol formation or contamination of equipment or instruments in the practice.1 Interestingly, there is currently a lack of evidence-based studies directly linked with optometry to support the recommended guidelines set out by the College of Optometrists and the Association of British Dispensing Opticians. For that matter, there is little anecdotal evidence supporting the risk of cross infection as a result of patient’s visiting high street optometric practice. Instead these guidelines are based on expert opinion rather than conclusive evidence of efficacy in primary care.
Regardless, all optical professionals delivering ophthalmic services need to be aware of infection control procedures designed to minimise cross infection and, of course, all optical employers should be mindful that the Health and Safety at Work Act (1974) ‘requires employers to ensure, so far as is reasonably practical, the health, safety and welfare at work of all employees’.
It is also worth bearing in mind that the scope of optometric practice has expanded in recent years, so that optometrists may now be involved in the therapeutic management of patients, some of whom may have infectious conditions such as conjunctivitis. Some of the procedures that are used for these patients require more rigorous attention to infection control than was previously necessary.
Hand washing
Hand washing is considered to be the most important measure in preventing the spread of infection in the healthcare setting.1,2 The prevalence of infection decreases as hand hygiene is improved.3,4
The aim of hand washing is to remove transient flora that colonise the superficial layers of the skin, which are most frequently linked with healthcare associated infections. Hand washing must be performed before and after significant contact with any patient and after activities likely to cause contamination, for example, handling food, handling cash, emptying waste paper baskets, going to the toilet, blowing one’s nose.1 When seeing patients, optometrists must avoid touching their own face, nose, mouth and eyes. It is also good practice for the staff/optician to wash hands after handling patients’ frames or having carried out a spectacle frame adjustment. It is particularly important to do this before eating.
Hand basins should be fitted in all consulting rooms and locations where contact lenses may be inserted or removed and must be kept clean. In an ideal world, elbow or foot controls are recommended to regulate the flow of water. If not, it is often recommended to operate the taps after handwashing using a paper towel to act as a protective barrier. Recommended hand washing procedures are given in Table 1.
Table 1
Recommended procedures for hand washing:
- Remove jewellery
- Wet hands with water (to decrease the risk of dermatitis avoid using hot water)
- Apply recommended amount of product to hands (use liquid hand-wash dispensers with disposable cartridges and disposable dispensing nozzles)
- Rub hands together vigorously for at least 15 seconds, covering all surfaces of the hands and fingers
- Rinse hands with warm running water
- Dry thoroughly with a disposable paper towel, patting hands dry to minimise chapping (do not use multiple-use cloth towels or hand-dryers)
- Use disposable towel to turn off tap, if elbow or foot controls not available
One important part of using hand wash is that staff remember to wash their hands thoroughly. Too many people wash their palms and fingers only, completely forgetting that they need to cover their thumbs and the gaps in between their fingers. If these areas are not covered then the hand wash will have had no effect, with micro-organisms still being carried on the hands.
The World Health Organization (2006) has extended the recommendations on hand hygiene technique and produced a visual publication poster detailing the hand hygiene technique for use with hand sanitisers and the hand washing technique for use with soap and water (Figure 1).
It is highly recommended that optical businesses provide paper towels and avoid using reusable hand towels, which can easily spread germs and highly contagious infections like conjunctivitis. Placing reminder signs over the sink in the washing area, as a constant reminder to both patients and staff, is particularly useful. It is important for patients to witness their optometrist washing his or her hands before dealing with them. In addition to washing their hands, opticians and optometrists should also cover any cuts or abrasions on their skin with waterproof plasters, to reduce the risk of infection.1,2
Water versus waterless hand cleaning
In areas of the practice with no ready access to water, or where constantly popping out to wash hands is impractical, then the use of a hand sanitiser can be appropriate. Hand sanitiser rubs/gels, often alcohol-based,5 have been shown to be more effective at encouraging healthcare workers to clean their hands between patients. This is despite alcohol-based formulations being poorer antimicrobials.6 However, care must be taken to remove visible soil before use and dry skin and irritation are common with alcohol-based formulations.1
Products for hand hygiene
It is difficult to compare the suitability of products for hand hygiene due to differences in study methodology and design. Hand hygiene products include plain and antibacterial (liquid) soap, as well as alcohol, chlorhexidine, benzalkonium chloride formulations. However, it should be borne in mind that other factors also influence the suitability of products; for example, some active ingredients strip away the skin’s own natural, protective oils, causing drying, which can lead to dermitis and/or broken areas of skin if used too frequently. Cracked and damaged skin can then act to harbour harmful bacteria and create reluctance to wash/sanitise hands as often as necessary.
Plain soap
Plain (non-antimicrobial) soap has minimal antimicrobial activity and is not recommended for use by healthcare workers. It can remove loosely adherent transient bacteria but may become contaminated with gram-negative bacteria.5
Antibacterial soap
Antibacterial soap is widely available over the counter (OTC) for domestic use. These formulations often contain Triclosan and are often only bacteriostatic, with no activity against gram-negative bacteria and viruses.5
Alcohol-based antiseptics
Alcohol-based hand antiseptics contain isopropanol, ethanol, n-propanol or a combination of two agents; they are effective against gram-positive and gram-negative bacteria, fungi and viruses (HSV, HIV, influenza). They are more effective for hand washing than soap or antimicrobial soaps but are not effective when hands are visibly dirty.5
Chlorhexidine
Preparations that use 4 per cent chlorhexidine are most effective. Chlorhexidine has residual activity on the skin7 but allergic reactions are uncommon. Infection rates have been reported as being lower after antiseptic hand-washing using chlorhexidine than after hand washing with plain soap or alcohol-based hand rinse.8 Four per cent w/v chlorhexidine is widely used as a bacterial skin cleaner for hygienic and surgical hand washing.
Benzalkonium chloride
Benzalkonium chloride (BAK) is a detergent and quaternary ammonium compound with a broad range of antimicrobial activity, including against norovirus. It is used in a relatively low concentration of 0.1 per cent, decreasing the possibility of skin irritation and, like chlorhexidine, it has residual activity on the skin.
The National Institute for Health and Clinical Excellence (NICE) guidelines for hand hygiene recommend that hand creams should be used to protect hands from the drying effects of regular hand decontamination. However, those involved in contact lens fitting need to be cautious of the emollients used contaminating the surface of lenses they are inserting, creating the potential for poor wetting causing blurred vision and/or discomfort.
Use of gloves
When discussing hand hygiene in the prevention of cross infection, it is reasonable to question whether it would just be better to simply wear protective gloves. However, assuming the use of gloves was appropriate in optometry and not a hindrance to certain aspects of practice (such as contact lens fitting), gloves must be disposed of after every patient and best practice dictates that hand hygiene measures must still take place before wearing and after their removal.2 Prolonged use of gloves may also cause skin sensitivity.2
What products to use?
There are a number of considerations when selecting a product for cleaning and/or disinfection. Table 2 shows a range of product options for hand sanitisation.
Consideration should also be given to micro-organism kill rates. It is the author’s experience that most practices simply use liquid soap products purchased at a local retailer. These normally have a claimed bactericidal activity of 99.9 per cent. These products are designed for ‘social’ or ‘domestic’ use and therefore it is reasonable to question whether something more effective should be being used in a clinical care environment. To put the efficacy of these products into perspective practitioners, need to consider microbial kill rates in the same way that they do for contact lens disinfectants.
Table 3 shows the effect of a gradual log reduction of microorganisms on survival rates. It can be seen that, assuming 1 million colony forming units (CFUs) are present, a simple reduction of 99.9 per cent is equivalent to a 3 log unit reduction leaving 1,000 CFUs remaining. Using a product with a 99.9999 per cent efficacy is equivalent to 6 log reduction, leaving virtually no survivors. Thus while the extra 0.0999 might, at first glance, seem relatively insignificant, put into context a hand wash killing up to 99.9999 per cent of germs is at least a thousand times more effective than one killing 99.9 per cent.
Discussion
With hand hygiene identified as the most effective way of preventing the transmission of infection (either directly or indirectly) and practices having adopted a strategy of enhanced hand washing in order to minimise cross contamination, the next question is: what to use? Having recognised that OTC liquid soaps are inappropriate in a clinical setting, what other products should be considered?
There are a number of considerations when selecting a product and, like all other areas of cleaning and disinfecting, the two key drivers are efficacy and toxicity. Ideally a balance needs to be struck between the two. It is all very well having a highly effective, broad spectrum anti-microbial that rapidly kills organisms, but if at the same time it is damaging the epithelial cells of the skin and causing irritation, it will not be used as frequently as is required, severely limiting its efficacy.
Again, readers can draw on experience of contact lens disinfectants for an analogy. Alcohol-based solutions might be compared to hydrogen peroxide, in that it is a powerful antimicrobial but toxic to body tissue (if it is not neutralised). Similarly, frequent use of alcohol-based products dries the skin, leading to irritation.1 In the end disinfectants more gentle on body tissue might be more effective because regular use will be encouraged.
Modern hand hygiene products might be viewed similarly to multipurpose contact lens solutions (MPS) in that they are effective, with a prolonged action, but are gentler on body tissue. They may also have additional agents to enhance performance such as emollients to maintain and protect the skin condition.
How do optical professionals know which products are most effective? Some assurance can be gained when the product is compliant with all international hand wash protocols and, in the European Union, the EU Biocidal Products Directive 98/8 EC. Additional confidence comes if it is compliant with the 2013 EU Biocidal Products regulations and, in the UK, if it has been approved by the NHS for use in hospitals.
New types of preparation
Alongside traditional products, new formats of hand washing preparation are now becoming available. EcoHydra antimicrobial handwash, for example, is a liquid soap substitute for the wet method of washing and disinfecting. This product is designed to remove dirt and kill germs on the hands and arms, without damaging the skin’s natural integrity or pH level. It is also available as a foam sanitiser for use in practice areas without water.
Its key active ingredient is 0.1 per cent benzalkonium chloride, killing up to 99.9999 per cent of most commonly occurring bacteria and norovirus within 15-30 seconds.9 Additionally, surfactants complement the BAK by penetrating the skin to deliver the BAK to attack the pathogens. Aloe vera and emollients help condition and sooth the skin to maintain its integrity with repeated use.
This handwash also remains active and effective against microorganisms for four hours after drying. It is alcohol free, non-flammable and safe for use with children and people of all religious beliefs. It is compliant with international hand hygiene protocols, the 2013 EU Biocidal Products regulations and has been approved by the NHS for use in hospitals.
Conclusions
All members of the practice team should adopt thorough measures to decrease the risk of infection. This can be difficult since the nature of the job demands that practitioners are in close proximity to their patients, with a high potential for transmission of infection.
Adopting thorough hand hygiene protocols has been shown to be the most effective strategy for avoiding the spread of infection. The use of an effective broad spectrum antimicrobial hand wash or sanitiser, with efficacy greater than the standard domestic product kill rate of 99.9 per cent of bacteria, is most appropriate in a clinical consulting room setting. Similarly the use of an effective hand sanitiser should be considered in retail areas where there is no water, to encourage more regular hand disinfection between dispensing/adjustments or where constant popping ‘out the back’ is impractical.
Practices need a clear, documented strategy to prevent cross contamination in optometric practice. All members of the practice team need to strictly follow these basic hygiene rules, in order to help prevent cross contamination leading to infection. As well as making sense from a ‘good practice’ perspective, by helping reduce unnecessary infection among patients and staff, effective hand hygiene also makes good business sense, by saving unnecessary time off work for staff and potential negligence claims from patients.
Model answers
Correct answers are in bold italic
1 What is the WHO recommended time to allow hands to air dry after using an alcohol-based hand rub?
A 10 to 20 seconds
B 20 to 30 seconds
C 40 to 60 seconds
D Air drying is not recommended
2 Which of the following has the greatest risk of cross-infection?
A Viral conjunctivitis
B Blepharitis
C Allergic conjunctivitis
D Infected external hordeolum
3 Which of the following statements regarding soaps is true?
A Non-medicated soap can act as a medium for Gram-postivie bacteria
B Bacteriostatic soaps are effective against Gram-negative bacteria
C Alcohol-based soaps have anti-fungal action
D Chlorhexidine is most effective in soaps when present at 0.4% concentration
4 Skin irritation due to benzalkonium chloride is minimised by using what concentration?
A 0.10%
B 1%
C 10%
D 4%
5 A log reduction of a million colony forming units of 4 represents what percentage of micro-organisms killed?
A 90
B 99
C 99.9
D 99.99
6 Which of the following statements about the pH of human skin is true?
A It is a constant value of 5
B It is usually acidic
C An effective cleanser should alter the pH
D It should be maintained at a neutral 7
References
1 Lakkis C, Lian KY, Napper G et al. Infection control guidelines for optometrists. Clin Exp Optom, 2007;90:6 434-444.
2 Blakeney S. Infection control in optometric practice. Optom in Practice, 2009;10 1-12.
3 Cantrill HL, Henry K, Jackson B et al. Recovery of human immunodeficiency virus from ocular tissues in patients with acquired immune deficiency syndrome. Ophthalmol, 1988;95 1458-1462.
4 Tillman T, Klotz SA and Maino JH. Preventing transmission of infectious diseases including the human immunodeficiency virus in the practice of optometry. J Am Optom Assoc, 1992;63 18-20.
5 Centers for Disease Control and Prevention (CDC) Guideline for Hand Hygiene in Health-Care Settings 2002. www.cdc.gov
6 Voss A and Widmer AF. No time for hand washing!? Hand washing versus alcoholic rub: Can we afford 100 per cent compliance? Infect Control Hosp Epidemiol, 1997;18 205-208.
7 Lowbury EJ and Lilly HA. Use of 4 per cent chlorhexidine detergent solution (Hibiscrub) and other methods of skin disinfection. Br Med J, 1973;1 510-515.
8 Doebbeling BN, Stanley GL, Sheetz CT et al. Comparative efficacy of alternative hand-washing agents in reducing noso-comial infections in intensive care units. N Engl J Med, 1992;327 88-93.
9 Data on file, EcoHydra Technologies 2012. prEN 12054: Chemical disinfectants and antiseptics – Hygienic handwash test for the evaluation of bacterial activity (in vitro).
Nick Atkins is joint managing director of Positive Impact, the distributor for EcoHydra in UK optometry