By Eugene Gordon
The rough statistics of hospital infection in the U.S. are well known, but they are reviewed here briefly to emphasize the claim that current approaches for infections control are not working and are unlikely to get better. In hospitals, of roughly 30 million in-patients annually, over 2 million acquire an infection in the hospital, spending on average an extra 21 days as a patient, and roughly 100,000 die as a result of hospital-acquired infection (HAI). This is about half the total deaths from infection in the U.S., the third highest cause of death behind cancer and heart disease. These infection statistics are currently stable despite valiant and expensive efforts to mitigate the situation. Moreover, the annual cost to the U.S. of HAI is estimated to be about $40 billion. Uncounted is the personal toll to family, friends and society. It is generally believed that these infections are transmitted to patients mostly as a result of healthcare worker (HCW) hand contact with the patient. No doubt a component of infection transmission is contamination of surfaces in the room, of HCW clothing, of instruments used by the HCW, and of visitors.
The current practices and attention to infection control are focused on sanitizing the hands of HCWs as they move from one patient to the next. Handwashing and alcohol handrub to achieve reduction of pathogen contamination of bare hands are the dominate means in use. Nothing is done about exam gloves other than sometime putting on a new pair after washing. Alcohol handrub is faster and more convenient but is ineffective on all endospores, C. diff being an example, and on many viruses. Handwashing can be more effective, but is not practical given the time required to sanitize. Moreover, it is difficult or impossible to achieve 100 percent compliance because of time required to implement or skin irritation, and as a result the typical rate of compliance is said to be 40 percent to 50 percent. Effort to improve that rate by electronic tracking would seem to be ineffective.(1) They are likely to remain ineffective for the reasons given. More to the point, it seems to this writer that the process necessarily fails even with 100 percent compliance because room surfaces are generally contaminated and are unavoidably contacted by hands; hence bare or gloved hands are quickly re-contaminated following between patient hand sanitation leaving the patient unprotected.
One potential solution to hand recontamination in the patient room is by means of room sanitizers based on UV-C band illumination of room surfaces. A number of companies have developed, and some hospitals have acquired systems that are used during a patient vacancy, and the room is empty and can be closed off. UV-C in a band roughly in the range 230 nm to 300 nm centered at a wavelength of 265 nanometers is effective in inactivation of every type of pathogens. Inactivation means eliminating the ability to reproduce, which nominally eliminates the ability of pathogens to cause an infection. That is not exactly true and I will return to the assertion. In any case, the UVC irradiates and nominally sanitizes the room surfaces. That is also not true because of shadowing, oblique incidence of UV-C, distance and inordinate amount of time required. So it is unlikely that UV-C can be fully effective at room decontamination to the required level of at least -4 log10 (reduction by a factor of 10-4) inactivation. In any case, during the elapsed time between uses of such equipment the room surfaces unavoidably become contaminated again. A dominant part of the problem is the fact that room surfaces are invariably contaminated by virtue of air motion and settling of dust, touching by HCWs, by other staff, by visitors; and of course from clothing and uniforms that are seldom sterile. Furthermore the applied dose is not fully effective on all pathogens since some can reactivate under the influence of normal room light in the range of 350 nm to 450 nanometers. Photo reactivation following UV-C inactivation is a well-known phenomenon when the UV-C dose is low as is the case for current UV-C room sanitizers. It is important in UV-C water sanitation.(2) Fortunately most of the pathogens involved in HAI do not photo reactivate. However, it apparently has been totally ignored, at least in public, by the hospital room infection control industry making UV-C devices for room sanitation.
UV-C room sanitization was developed as an alternative to sanitation of room surfaces by hospital workers while the patient is present. It is not possible for me to comment since it is so variable and dependent on the particular hospital worker, how often it is done, what germicidal solutions are used and how long they are effective, etc. It is possibly less effective on average than UV-C room sanitization. Hence, hands of healthcare workers, even if they have been sanitized between patient visits, are quickly recontaminated by contact with surfaces in the room. Moreover, they probably add to the bioburden when they have not been sanitized following the previous patient visit. As a result, even 100 percent adherence to between patient hand sanitation would be quickly undermined by hand contact with room surfaces. The logic is unassailable. Hence, both CDC and WHO, recognizing the indisputable deficiencies of current practice, take the view that hand sanitation must be practiced at bedside each and every time the patient, the patient clothing and the patient surround are about to be touched. This indisputably avoids hand recontamination by touching surfaces. WHO describes this concept as the Five Special Moments, (WHO-FSM).(3) The WHO-FSM strategy typically requires a substantial number of brief hand sanitation events at bedside. The currently available technology used only in the between patient mode, already poses substantial compliance issues relating to available time of HCWs and hand irritation, hence are totally incompatible with use in the WHO-FSM mode.
In what follows I describe the UV-C technology Germgard Lighting has developed and tested that conveniently allows an unlimited number of hand sterilizations at patient bedside because the UV-C hand sanitation step takes only seconds, and is non-irritating and not damaging to the skin. It is used safely on both gloved and lotion protected bare hands. The gloved hand receives the full UV-C dose and reduces the UV-C dose transmitted to the bare skin by a factor of 100,000. The protective lotion, resembling alcohol handrub with an additional ingredient to provide high UV-C absorption, reduces the UV-C dose incident on the bare skin by a factor of 10,000.
This is quite adequate to protect the skin from UV-C induced erythema and allows an integrated eight-hour dose that is less than the OSHA recommended maximum. Moreover, there is no danger of skin cancer at the wavelength used. The lotion need be used only a few times per day and it totally protects the skin from UV-C in the hand sanitizer.
The sanitizing radiation used is at a wavelength of 253.7 nanometers produced by low pressure argon-mercury lamps with UV-C transparent quartz envelopes. It uniformly radiates the space within the sanitizing unit with a UV-C intensity of over 500 watts/meter2 and totally illuminates the full, spread-fingered hand beyond the wrists including the space between fingers and the finger crotch, and the tips of the nails. The exposure time is 3 seconds, providing a dose of over 1,500 Joules/meter2. This is adequate to inactivate pathogens of all kinds by a factor ranging from 1.5-million to 15 billion, referred to in the science as an inactivation level exceeding 10 log10. The C. difficile endospore is sturdier and is inactivated by 6 log10. This is far greater inactivation than handwashing or alcohol handrubs, which achieve less than 3 log10, by more than a factor of 1,000. Moreover such a high level of inactivation totally eliminates the potential for photo reactivation. All pathogens are essentially mortally wounded; not just inactivated.
The hand sanitation unit we have developed is used also for instrument sterilization. At this point we will comment only that instruments placed in a sealed pouch and subject to UV-C exposure are available for use or storage in 10 seconds. Moreover, UV-C is not damaging to the instruments. This is an enormous advance over autoclaves.
A video of the brassboard unit for hand sanitation can be found on the website in the references(4) below. The total cycle including turning from the patient to the hand sanitation unit at bedside and back to the patient takes about eight seconds. It is fully automatic including sensing that the HCW intends to use the hand sanitizer. No UVC leaves the unit and the process is totally safe. It has been fully tested independently for a number of pathogens including C. difficile. Although it has not been tested for operating lifetime we expect that at the rate of 200 hand sanitations per day it should last a good part of a year without tube maintenance. It totally meets or exceeds the WHO-FSM requirement. The estimated cost of use of the UV-C hand sanitizer is less than that of current hand wash/alcohol handrub practice, hence will be economically attractive to hospitals.
The production unit will be much smaller and lighter, not need a stand, can be mounted at bedside, will be highly reliable and durable, and will be faster and less expensive than current practice. It will serve the WHO-FSM objective perfectly allowing hundreds of daily hand sanitations at bedside for HCW and visitors in minimal time and without irritation. It is worth emphasizing that this bypasses the entire issue of hospital room contamination.
Dr. Eugene Gordon is CEO/CTO of Germgard Lighting LLC.
1. Strategies to Boost Hand Hygiene Compliance. Infection Control Today. June 9, 2011.
2. Inactivation of pathogens with innovative UV technologies, By James P. Malley, AWWA Research Foundation, United States, Environmental Protection Agency, Water Environment Research Foundation