Evidence against transmission of Pseudomonas aeruginosa by hands and stethoscopes in a cystic fibrosis unit

Contemporary stethoscope cleaning practices: What we haven't learned in 150 years

BACKGROUND

Stethoscopes can be microorganism reservoirs. The US Centers for Disease Control and Prevention (CDC) has published medical equipment disinfection guidelines to minimize infection transmission risk, but studies of guideline adherence have been predominately survey based, with little direct observation of disinfection practices.

METHODS

We performed an observational, cross-sectional, anonymous study of patient-provider interactions, assessing practitioners' frequency and methods of stethoscope and hand disinfection practices.

RESULTS

Stethoscopes were disinfected in 18% of 400 observed interactions, with less than 4% verified as conforming to CDC guidelines. None was disinfected before patient examinations involving open chest or abdominal wounds, as recommended by the CDC. Hands were cleaned before and after encounters 27 times (6.8%) but were not cleaned at all in 231 (58%) encounters, although gloves were worn in 197 (85.3%) of these cases.

DISCUSSION

Stethoscope disinfection is grossly overlooked, possibly jeopardizing patient safety, particularly in acute care interactions. Periodic stethoscope disinfection, although inconvenient, helps reduce bacterial contamination and may reduce health care-associated infections.

CONCLUSIONS

Stethoscopes were disinfected per CDC guidelines in less than 4% of encounters and were not disinfected at all in 82% of encounters. Although hands were rarely cleaned (6.8%) per CDC guidelines, gloves were usually worn, but no convenient stethoscope equivalent exists. Stethoscope cleanliness must be addressed.

Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update

The 2013 Infection Prevention and Control (IP&C) Guideline for Cystic Fibrosis (CF) was commissioned by the CF Foundation as an update of the 2003 Infection Control Guideline for CF. During the past decade, new knowledge and new challenges provided the following rationale to develop updated IP&C strategies for this unique population:

1.The need to integrate relevant recommendations from evidence-based guidelines published since 2003 into IP&C practices for CF. These included guidelines from the Centers for Disease Control and Prevention (CDC)/Healthcare Infection Control Practices Advisory Committee (HICPAC), the World Health Organization (WHO), and key professional societies, including the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). During the past decade, new evidence has led to a renewed emphasis on source containment of potential pathogens and the role played by the contaminated healthcare environment in the transmission of infectious agents. Furthermore, an increased understanding of the importance of the application of implementation science, monitoring adherence, and feedback principles has been shown to increase the effectiveness of IP&C guideline recommendations.

2.Experience with emerging pathogens in the non-CF population has expanded our understanding of droplet transmission of respiratory pathogens and can inform IP&C strategies for CF. These pathogens include severe acute respiratory syndrome coronavirus and the 2009 influenza A H1N1. Lessons learned about preventing transmission of methicillin-resistantStaphylococcus aureus(MRSA) and multidrug-resistant gram-negative pathogens in non-CF patient populations also can inform IP&C strategies for CF.

The stethoscope and healthcare-associated infection: a snake in the grass or innocent bystander?

There is a concern that stethoscopes may transmit infectious agents which could result in healthcare-associated infection (HCAI). The aim of this review was to evaluate the available literature as to the role of the stethoscope in the development of HCAI. A literature search was conducted across several databases for relevant studies and reports. Stethoscopes were consistently shown to harbour bacteria. The mean rate of stethoscope contamination across 28 studies was 85% (range: 47-100%). The majority of bacteria isolated were deemed to be non-pathogenic. The most frequently isolated organisms were coagulase-negative staphylococci. The mean level of contamination was in excess of the French Normalization standard for cleanliness (which equates to <20 colony-forming units per membrane) in all six studies in which contamination levels were quantified. Potentially pathogenic organisms cultured from stethoscopes included: Staphylococcus aureus, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and Clostridium difficile. There was evidence that bacteria can transfer from the skin of the patient to the stethoscope and from the stethoscope to the skin. However, studies were not designed to detect a correlation between stethoscope contamination and subsequent HCAI. Surveys assessing cleaning practices revealed a suboptimal commitment to stethoscope disinfection among doctors and medical students. The optimum method for stethoscope cleaning has not been defined, although alcohol-based disinfectants are effective in reducing bacterial contamination. In conclusion, a link between contaminated stethoscopes and HCAI has not yet been confirmed, but transfer of bacteria between skin and stethoscope has been shown. The available information would suggest that stethoscopes should be decontaminated between patients.

Contamination of stethoscopes and physicians' hands after a physical examination

OBJECTIVES

To compare the contamination level of physicians' hands and stethoscopes and to explore the risk of cross-transmission of microorganisms through the use of stethoscopes.

PATIENTS AND METHODS

We conducted a structured prospective study between January 1, 2009, and May 31, 2009, involving 83 inpatients at a Swiss university teaching hospital. After a standardized physical examination, 4 regions of the physician's gloved or ungloved dominant hand and 2 sections of the stethoscopes were pressed onto selective and nonselective media; 489 surfaces were sampled. Total aerobic colony counts (ACCs) and total methicillin-resistant Staphylococcus aureus (MRSA) colony-forming unit (CFU) counts were assessed.

RESULTS

Median total ACCs (interquartile range) for fingertips, thenar eminence, hypothenar eminence, hand dorsum, stethoscope diaphragm, and tube were 467, 37, 34, 8, 89, and 18, respectively. The contamination level of the diaphragm was lower than the contamination level of the fingertips (P<.001) but higher than the contamination level of the thenar eminence (P=.004). The MRSA contamination level of the diaphragm was higher than the MRSA contamination level of the thenar eminence (7 CFUs/25 cm(2) vs 4 CFUs/25 cm(2); P=.004). The correlation analysis for both total ACCs and MRSA CFU counts revealed that the contamination level of the diaphragm was associated with the contamination level of the fingertips (Spearman's rank correlation coefficient, ρ=0.80; P<.001 and ρ=0.76; P<.001, respectively). Similarly, the contamination level of the stethoscope tube increased with the increase in the contamination level of the fingertips for both total ACCs and MRSA CFU counts (ρ=0.56; P<.001 and ρ=.59; P<.001, respectively).

CONCLUSION

These results suggest that the contamination level of the stethoscope is substantial after a single physical examination and comparable to the contamination of parts of the physician's dominant hand.

Infection Control Practice in Cystic Fibrosis Centers

In this article, the authors outline some of the major historical events that signaled the need to better understand mechanisms of infection in cystic fibrosis (CF). The authors discuss general principles of infection control, focusing on issues of particular importance to patients who have CF. The authors also describe the major pathogens associated with the CF airway, provide a review of findings from inpatient and outpatient studies of infection control, and provide an outline of future directions for investigation.