Ambulances, Stethoscopes, Hospital Curtains: Beware of Fomites

On January 30, 2020 WHO declared a global health emergency because of the emerging COVID-19 virus. With multiple cities in China under quarantine, now seems like a good time to look at transmission routes. Though people around the world may sanitize hands and don face masks, there are avenues of transmission that are difficult to avoid. Healthcare providers, and healthcare facilities are among these.

So many points of contact exist in the healthcare system that I have to limit my discussion here to only three that may serve as fomites. A fomite is an inanimate object that transmits disease-causing microorganisms.

The three I will briefly consider are pretty basic for most people who use healthcare facilities: stethoscopes, ambulances (ground, not air) and hospital textiles (sheets/privacy curtains). Of the three,stethoscopes have been the subject of the most research. Despite the long-established fact that stethoscopes can transmit disease, there is an alarming lack of concern about this among many healthcare professionals. And, even when protocols are followed, cleaning is not 100% effective.

As the studies cited below reveal, however, protocols generally are not followed.

The European Journal of Public Health published the results of a meta analysis (2018) of stethoscopes as fomites. The conclusion: "Stethoscopes have an high contamination of microorganisms. Some of them are also involved in Hospital Acquired Infections." The authors of the study suggest that the absence of standardized protocols in healthcare facilities, across the world, leads to the transmission of disease.

Saudi Arabia

A study carried out in the King Fahd Hospital of the University in Saudi Arabia looked at cleaning protocols employed by healthcare workers. The "gold standard" of sanitizing a stethoscope is "swiping using alcohol pads", before and after each patient. How common is this practice? The chart below was derived from the Saudi study.

Chart constructed by me, using information published in the study

100 stethoscopes were collected and cultured. 70% were free of microorganisms. 30% were contaminated. Seven of the contaminated instruments tested positive for E. coli. Two had Klebsiella, nine had S. epidermis, and twelve had gram positive bacilli.

E. coli

GIF adapted (by me) from a video credited to Taute K, Gude S, Tans S, Shimizu T. Used under a CC 4.0 license

United States

In a study conducted at the U. of Pennsylvania Perelman School of Medicine, stethoscopes used in the ICU were cultured. The findings: multiple pathogens, including: "Staphylococcus (including S. aureus); Pseudomonas; Acinetobacter; Clostridium; Enterococcus; Stenotrophomonas; and Burkholderia."

A surprising finding (to me): even after cleaning not all stethoscopes tested as 'clean'.

Pseudomonas

Nigeria

1800 stethoscopes were cultured. The following pathogens were detected: "Escherichia coli (10.0%), Proteus Mirabilis (8.33%), Proteus vulgaris (6.70%), Pseudomonas aeruginosa (23.3%), Staphylococcus aureus (0.83%), Streptococcus spp. (18.3%), E. faecalis (3.33%), Coagulase negative staph (28.3%) and Salmonella choleraesius (0.83%)."

Canada

A 2011 study (published by Cambridge.org) came up with the following results: of 110 stethoscopes collected from 3 emergency room departments: "Fifty-four specimens grew coagulase-negative sta-phylococci and one grew methicillin-susceptible S.aureus. No MRSA was cultured." Questionnaires were handed out that inquired about cleaning practices. Findings: only 8% of the respondents ("all nurses") reported cleaning the stethoscope after each patient.

Multinational

An essential, often unavoidable link between healthcare consumers and healthcare providers is the ambulance. An article published in the Journal of the American Society for Microbiology (2017) looks at ambulances as fomites. The authors of the article explain that while disease transmission in hospitals (nosocomial transmission) has been studied extensively, this is not true for EMS--ambulance services. The authors state: "Our review provides evidence that EMS microbiomes are dynamic and important pathogen reservoirs." In other words, traveling in an ambulance can make you sick. EMS workers themselves are also at risk, and may be carriers of disease contracted in their vehicles.

The study cited in this article looked at data from eight countries: United States, Australia, Saudi Arabia, Germany, Denmark, Thailand, United Kingdom and South Korea. While a variety of pathogens were identified in ambulances (ground, not air) from different countries, only ambulances in the U. S. and Germany tested positive for MRSA. And in those tests, the U.S had a much higher occurrence.

The authors of the article are quick to point out that the U.S. has far less stringent protocols for handling MRSA patients than does Germany, or the other countries included in the study.

The article concludes with this assessment: EMS workers have to be better educated about pathogens and modes of transmission; decontamination procedures must be improved; and these enhanced procedures are essential to meet emerging challenges of "biological threats, bioterrorism and epidemics."

Egypt

A multi-center study looked at twenty-five vehicles. Sixteen "selection points" were swabbed in each vehicle. The results: "589 bacteria were isolated and 286 (48.6%) of the isolates were potentially pathogenic. The highest contamination rate with pathogenic bacteria was detected in suction devices (75.8%) and stethoscopes (67.7%)." The usual suspects, staphylococci, Klebsiella, E. Coli, Citrobacter spp. and Proteus spp. were detected. Several cultured pathogens were methicillin resistant. The authors of the study conclude that even before patients get to the hospital they may contract multidrug-resistant infections. Just from riding in an ambulance.

The United States (Specifically Oxygen Canisters)

The Journal of Emergency Medicine published the results of a study that looked at methicillin-resistant Staphylococcus aureus on oxygen canisters in ambulances. The results: nine out of nine canisters cultured tested positive for MRSA. Off-site, in a facility where the canisters were stored, 67 out of 70 cultured positive for MRSA. The study concludes: "Oxygen cylinders appear to act as a fomite for MRSA".

This one really got me. A lot of attention is paid to hard surfaces in healthcare facilities. But how about those curtains we casually pull aside for privacy. Or, how about the sheets we must sleep on?

One article I found in Infection Control Today considers "healthcare textiles and other soft surfaces" as fomites.

Privacy Curtains

With regard to privacy curtains:
The authors of the article state that even when cleaning does occur (which is not often the case) dangerous pathogens remain and may be passed on to patients and/or healthcare workers. The pathogens include: Clostridium difficile; vancomycin-resistant enterococci (VRE); methicillin-resistant Staphylococcus aureus (MRSA); Acinetobacter baumannii; and Pseudomonas aeruginosa.

The results of a survey about cleaning protocols for privacy curtains: out of fifty respondents, 37 percent (14/38) of the facilities surveyed cleaned ‘only when visibly soiled’; 13 percent (5/38) cleaned ‘every month’; 13 percent (5/38) ‘every 3 months’ and, remarkably, 13% cleaned them only once a year!

Sheets

A 2018 study out of the UK had some disturbing findings. Even after being commercially laundered according to healthcare industry standards, some sheets still carried C. difficile, which is a persistent and difficult to treat pathogen. The authors of this study suggest that endurance through cleaning might explain some C. difficile outbreaks among patients and healthcare workers.

Finally, another study suggests that pathogens from sheets in a laundry room could be aerosolized. Workers are infected with these air-borne pathogens. The workers then may transmit disease through a facility.

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In Conclusion

Whatever the outcome of the current coronavirus alarm, it is certain that transmission vulnerabilities exist in the healthcare system...in all healthcare systems. This is partly due to ineffective methodology, but mostly due, it seems, to human failure. Healthcare workers must be better educated and more diligent in applying established protocols.

Thank you for reading my blog

Steem on!

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Some Sources Used in Writing This Blog

1. TRINITY HOSPITALOwned and Operated byMountain Communities Healthcare District2012 Annual House-wide In-Service:Hand-washing, Infection Prevention, PPE Use, Seasonal and Novel Influenza, Respiratory Hygiene / Cough Etiquette, MRSA, C-dif
2. Ambulance vehicles as a source of multidrug-resistant infections: a multicenter study in Assiut City, Egypt
3. Emergency medical services oxygen equipment: a fomite for transmission of MRSA?
4. The Emergency Medical Service Microbiome
5. Bacteriological assessment of stethoscopes used by healthcare workers in a tertiary care centre of Nepal
6. A novel approach to stethoscope hygiene: A coat-pocket innovation
7. Pan African Medical Journal Isolation of pathogenic bacteria from fomites in the operating rooms of a specialist hospital in Kano, North-western Nigeria
8. SciELO Analytics Sphygmomanometers and thermometers as potential fomites of Staphylococcus haemolyticus: biofilm formation in the presence of antibiotics
9. Journal of the Society for Healthcare Epidemiology of America, Infection Control & Hospital Epidemiology
10. WHO WHO Declares Coronavirus Outbreak a Global Health Emergency
11. CDC About Coronavirus Disease 2019 (COVID-19)
12. Center for Food Security and Public Safety Fomite Exposure
13. European Journal of Public Health Contamination in Stethoscopes: A Retrospective Review
14. BMC Research Notes Bacteriological assessment of stethoscopes used by healthcare workers in a tertiary care centre of Nepal
15. Journal of Family and Community Medicine Bacterial Contamination of Stethoscopes
16. Medpage Today ICU Stethoscopes Harbor DNA from Nosocomial Bacteria
17. Cambridge.org Examination of staphylococcal stethoscopecontamination in the emergency department (pilot)study (EXSSCITED pilot study)
18. Journal of the American Society for Microbiology The Emergency Medical Service Microbiome
19. Infection and Drug Resistance Ambulance vehicles as a source of multidrug-resistant infections: a multicenter study in Assiut City, Egypt
20. Journal of Emergency Medicine Emergency medical services oxygen equipment: a fomite for transmission of MRSA?
21. Infection Control Today Hospital Privacy Curtains and Bed Sheets: Soft Surface Contamination and Transmission
22. Cambridge.org From ward to washer: The survival of Clostridium difficile spores on hospital bed sheets through a commercial UK NHS healthcare laundry process
23. Microbiome Microbial aerosol liberation from soiled textiles isolated during routine residuals handling in a modern health care setting
24. Modern Healthcare Hospital bed linens could be source of C. difficile outbreaks
25. CDC Klebsiella pneumoniae in Healthcare Settings
26. Infection Control and Hospital Epidemiology Contamination of Hospital Curtain with Healthcare-Associated Pathogens
27. ResearchGate The Impact Of Hospital Bed And Beddings On Patients: The Ghanaian Healthcare Consumer Perspectives
28. Florence Health Even “Clean” Hospital Sheets Carry Potentially Deadly Bacteria
29. Florence Health 6 Ways Healthcare Workers Unknowingly Spread Deadly Bacteria
30. Clinical Infectious Diseases The Role of Patient Care Items as a Fomite in Healthcare-Associated Outbreaks and Infection Prevention
31. Nature Reviews: Microbiology Staphylococcus epidermidis – the “accidental” pathogen