Clostridium difficile (C. diff)

Clostridium Difficile (C. diff) has rapidly become one of the most common, dangerous, and costly HAI’s in the U.S. health care system. C. diff accounts for 30.3% of total HAI’s according to The Journal of the American Medical Association (JAMA) Internal Medicine (Zimlichman 2013). C. diff is a bacteria that releases toxins that attack the lining of the intestines causing severe dehydration and deadly diarrhea that can quickly lead to death.  A study by the University of Houston College of Pharmacy presented at the American Society of Microbiology Meeting, showed 45% of shoe soles of health care professionals in a large hospital tested positive for toxigenic C. diff (ALAM 2015).

Nearly half of a million C. diff infections occur annually in the U.S. and as many as 30,000 deaths are related to the deadly organism. Although C. diff can infect people of all ages, the most vulnerable patients are 65 and older. One in nine patients in this age range who acquire C. diff dies within the first 30 days of diagnosis. Furthermore, C. diff infections reoccur in 20-30% of properly treated patients and are even more difficult to retreat.

C. diff is a bacterial spore that can be found in 2-4% of healthy adults (Kowalski 2012). This nosocomial pathogen is unique in that it primarily, and almost exclusively, transmits in hospital environments (Johnson 1999). It causes periodic outbreaks in health care facilities and spreads among patients and hospital personnel, among whom it may be asymptomatic. The most common contamination sites are floors and bathrooms, with contaminated equipment often being the source. C. diff, as a spore, can resist disinfection and can be spread along floors by shoe migration or air currents, thereby spreading far beyond an index patient’s immediate environment. Although fomites and direct contact are considered to be the primary mode of transmission, airborne transmission has also been demonstrated (Fekety 1981, Best 2010, Snelling 2011, Nielsen 2008). Environmental disinfection has been shown to be effective at interrupting outbreaks (Kaatz 1988). Results from 3rd party laboratory live C. diff testing, showed HealthySole® to have an 85.3% (0.83 log) kill rate in just 8 seconds.

Staphylococcus aureus

Staphylococcus aureus is generally a commensal microorganism. It can cause opportunistic infections when host resistance is compromised. Together with C. diff, these two organisms are two of the most common nosocomial infections in the U.S. Methicillin-resistant Staphylococcus aureus (MRSA) has been an increasing problem in both health care environments and the community. Once a patient is colonized, the particular strain of S. aureus may disseminate from physical contact, environmental surface contact, and air borne pathways. MRSA can spread quickly and displace nasal flora in patients and health care workers. 13% of males and 5% of females carry a heavy nasal inoculum and disperse, or shed, large numbers of microbes from their lower extremities and perineum into the air around them (Hare 1956). Infected health care workers and “heavy shedders” can continuously contaminate air and surfaces in their vicinity (Sherertz 2001). MRSA related infections could easily add additional healthcare cost of over $150,000 per patient (Zimlichman 2013).

One early study showed that healthcare workers who were shedders were associated with outbreaks in the operating room (Walter 1963). Skin squames fall to the floor in still air within seconds, but may be carried on air currents or lifted off the floor to become airborne again. MRSA can be isolated from the immediate environment of colonized patients and has been recovered from a plethora of hospital surfaces including floors, linens, air vents, furniture, and equipment. Findings from studies addressing operating rooms also prove the presence of pathogenic bacterial species responsible for postoperative wound infections such as staphylococci on all shoe types (Amirfeyz 2007).  Airborne transmission is a consideration whenever a patient acquires staphylococcal pneumonia and may be an important factor in infections occurring in burn trauma units as well (Thompson 1982, Rutala 1983). ICU’s, surgical ICU’s, and neonatal care units have often been the site of outbreaks of MRSA. In burn trauma centers, environmental reservoirs and the airborne spread of MRSA appear to be of the utmost importance (Hartstein 1999). Results from 3rd party laboratory live MRSA testing proved that in 8 seconds, HealthySole® has a 99.98% (3.66 log) kill rate.

HealthySole tested 6 of the most common organisms that lead to HAI’s or nosocomial infections. Live organism kill rate testing results of these 6 organisms below can be viewed here (click to download report).

  • Clostridium difficile ATCC 43598 (Endospores)
  • Staphylococcus aureus ATCC 33592 (MRSA)
  • Streptococcus pyogenes A ATCC 19615
  • Enterococcus faecalis ATCC 51575 (VRE)
  • Escherichia coli ATCC BAA-2469 (CRE)
  • Pseudomonas aeruginosa ATCC 15442

Eyal Zimlichman, MD, MSc; Daniel Henderson, MD, MPH; Orly Tamir, PhD, MSc, MHA; Calvin Franz, PhD; Peter Song, BSE; Cyrus K. Yamin, MD; Carol Keohane, BSN, RN; Charles R. Denham, MD; David W. Bates, MD, MSc Health Care–Associated Infections A Meta-analysis of Costs and Financial Impact on the US Health Care System JAMA Internal Medicine December 9/23, 2013 Volume 173, Number 22 2039-2046

M Jahangir Alam, Jacob K McPherson, Julie Miranda, Sangeetha S Fernando, Lynn Le, Jonathan Amadio, Kevin W Garey (2015)  Prevalence and characteristics of toxigenic Clostridium difficile, C. perfringens and Enterococcus on shoe-bottoms from a hospital system In: American Society for Microbiology (ASM) Texas Branch Fall Meeting, (poster presentation) Oct 29-31, 2015 (SAM HOUSTON STATE UNIVERSITY, HUNTSVILLE, TX)

Kowalski, W. J. (2012) Hospital Airborne Infection Control, Taylor & Francis/CRC Press, Boca Raton.

Johnson, S., and Gerding, D. N. (1999). Clostridium Difficile Hospital Epidemiology and Infection Control C. G. Mayhall, ed., Lippincott Williams & Wilkins, Philadelphia, 477-503.

Fekety, R., Kim, K.-H., Brown, D., Batts, D. H., Cudmore, M., and Jr., J. S. (1981). "Epidemiology of antibiotic-associated colitis. Isolation of Clostridium difficile from the hospital environment." AmJ Med 70, 906-908.

Best, E. L., Fawley, W. N., Parnell, P., and Wilcox, M. H. (2010). "The potential for airborne dispersal of Clostridium difficile from symptomatic patients." Clin Inf Dis 50, 1450-1457.

Snelling, A. M., Beggs, C. B., Kerr, K. G., and Sheperd, S. J. (2011). "Spores of Clostridium difficile in hospital air." Clin Infect Dis 51, 1104-1105.

Nielsen, P. (2008). "Clostridium difficile aerobiology and nosocomial transmission." , Northwick Park Hospital Harrow, Middelsex, UK.

Kaatz, G. W., Gitlin, S. D., Schaberg, D. R., Wilson, K. H., Kaufman, C. A., Seo, S. M., and Fekety, R. (1988). "Acquisition of Clostridium difficile from the hospital environment." Am J Epidemiol 127, 1289-1294.

Sherertz, R. J., Bassetti, S., and Bassetti-Wyss, B. (2001). ""Cloud" Health Care Workers." Emerg Inf Dis 7(2), 241-244.

Thompson, R. L., Cabezudo, I., and Wenzel, R. P. (1982). "Epidemiology of nosocomial infections caused by methicillin-resistant Staphylococcus aureus." Ann Intern Med 97, 309-317.

Rutala, W. A., Katz, E. B. S., Sherertz, R. J., and F. A. Sarubbi (1983). "Environmental study of a methicillin-resistant Staphylococcus aureus epidemic in a burn unit." J Clin Microbiol 18, 683-688.

Hartstein, A. I., and Mulligan, M. E. (1999). Methicillin-Resistant Staphylococcus Aureus Hospital Epidemiology and Infection Control C. G. Mayhall, ed., Lippincott Williams & Wilkins, Philadelphia, 477-503.

Amirfeyz R.; Tasker A.; Ali S.; Bowker K. Blom A. :Theatre shoes – a link in the common pathway of postoperative wound infection?” The Royal College of Surgeons of England 2007; 89: 605-608