Stethoscopes and otoscopes--a potential vector of infection?

Disinfection of Stethoscope and Non-Infrared Thermometer: Practices of Physicians in Ethiopia in the Era of COVID-19

Background

Stethoscopes and non-infrared thermometers are the customary medical equipment used by the physicians on a daily basis, among various patients. With the rise of potential infections in the healthcare facilities and the transmission nature of the current COVID-19 pandemic, consistent and correct disinfections of these devices after each use should not be pardoned. This study, therefore, aimed to assess the level of stethoscope and non-infrared thermometer disinfection practices among physicians involved in direct patient contact during the COVID-19 pandemic.

Methods

A web-based cross-sectional survey was conducted among physicians working in Ethiopia to assess their practice of stethoscope and non-infrared thermometer disinfection. The online survey was circulated using an anonymous and self-reporting questionnaire via Google form with a consent form appended to it. The developed Google form link was shared with physicians through their email addresses and social media pages. A descriptive summary was computed and presented by tables and figures. Multivariable logistic regression model was used to identify factors associated stethoscope and non-infrared thermometer after every use.

Results

The proportion of stethoscope and non-infrared thermometer disinfections after every use was 13.9% (95% CI: 10.9–17.6) and 20.4% (95% CI: 16.7–24.5), respectively. Taking COVID-19 training (AOR: 2.52; 95% CI: 1.29–4.92) and the availability of stethoscope disinfection materials at the workplace (AOR: 3.03; 95% CI: 1.29–7.10) were significantly increased the odds of stethoscope disinfection after every use. The odds of stethoscope disinfection after every use was significantly decreased for those who reported the use of shared stethoscope (AOR: 0.34; 95% CI: 0.12–0.92).

Conclusion

Only a wee share of the respondents reported that they have disinfected their stethoscopes and non-infrared thermometers after every use – possibly jeopardizing both patients and clinicians safety, particularly during the COVID-19 pandemic.

Comparison of Effectiveness of 70%-isopropanol, 65%-ethanol and 1%-chlorhexidine for Stethoscope Decontamination

Stethoscopes are potential vector for health care associated infections worldwide. Ethyl alcohol (EA), isopropyl alcohol (IPA) and chlorhexidine (CH) are widely used for disinfecting stethoscope, however, comparative analysis of these disinfectants are scarce. Hence this paper aims to compare the reduction in bioburden with respect to stethoscope decontamination. A randomized, double-blind study was undertaken from various categories of health care workers (HCW) working in various departments. Each participant was asked to fill a questionnaire and diaphragms of their stethoscopes were imprinted on blood agar and sabourauds dextrose agar before and after disinfection with either 65%-EA, 70%-IPA or 1%-CH. The culture plates were incubated aerobically and the growth was further identified. 384 HCW participated in the study. 168 participants never cleaned their stethoscope, out of which 147 respondents (91.6%) comprised of students. EA (47%) and IPA (23%) were the two major types of alcohols used as disinfecting agents. 280 samples showed growth among which 51.8% were potent pathogens. Before disinfection, Staphylococcus aureus (27%) was the predominant pathogen, followed by Klebsiella (6.8%), Enterococcus and Candida respectively. Among the disinfectants used, maximum antimicrobial activity was exhibited by IPA (92.5%) compared to EA (82.5%) and CH (77.8%). Huge lacunae regarding knowledge, attitude and practice of stethoscope maintenance was found among student community. The microbial growth varies at various department. Disinfecting stethoscope with 70%-IPA for just 30 seconds is equally efficient compared to 1 minute and IPA was superior to EA and CH for decontaminating stethoscope. Stethoscopes are potential vector for health care associated infections worldwide. Ethyl alcohol (EA), isopropyl alcohol (IPA) and chlorhexidine (CH) are widely used for disinfecting stethoscope, however, comparative analysis of these disinfectants are scarce. Hence this paper aims to compare the reduction in bioburden with respect to stethoscope decontamination. A randomized, double-blind study was undertaken from various categories of health care workers (HCW) working in various departments. Each participant was asked to fill a questionnaire and diaphragms of their stethoscopes were imprinted on blood agar and sabourauds dextrose agar before and after disinfection with either 65%-EA, 70%-IPA or 1%-CH. The culture plates were incubated aerobically and the growth was further identified. 384 HCW participated in the study. 168 participants never cleaned their stethoscope, out of which 147 respondents (91.6%) comprised of students. EA (47%) and IPA (23%) were the two major types of alcohols used as disinfecting agents. 280 samples showed growth among which 51.8% were potent pathogens. Before disinfection, Staphylococcus aureus (27%) was the predominant pathogen, followed by Klebsiella (6.8%), Enterococcus and Candida respectively. Among the disinfectants used, maximum antimicrobial activity was exhibited by IPA (92.5%) compared to EA (82.5%) and CH (77.8%). Huge lacunae regarding knowledge, attitude and practice of stethoscope maintenance was found among student community. The microbial growth varies at various department. Disinfecting stethoscope with 70%-IPA for just 30 seconds is equally efficient compared to 1 minute and IPA was superior to EA and CH for decontaminating stethoscope.

Stethoscope disinfection is rarely done in Ethiopia: What are the associated factors?

Introduction

The stethoscope, which is non-critical medical devices and a symbol of healthcare, is likely to be contaminated by pathogenic microorganisms and can play a contributory role in the transmission of hospital-acquired infection. And regular cleaning of the diaphragm of the stethoscope with a suitable disinfectant is decisive. However, in the resource-constrained setting like many healthcare facilities in Ethiopia healthcare provider’s stethoscope disinfection practice and its associated factors have not been well studied so far. Therefore, this study sought to determine stethoscope disinfection practice and associated factors among the healthcare providers in Addis Ababa, Ethiopia.

Methods

A facility-based cross-sectional study was carried out between April and May 2016. For this study, 576 healthcare providers (physicians, health officers, nurses, midwives, and anesthesiologist) were included from 21 healthcare facilities in Addis Ababa. A pre-tested structured questionnaire was used for data collection. Descriptive statistics were computed. Bivariate and multivariable logistic regression analyses were used to identify factors that were significantly associated with stethoscope disinfection after every use.

Results

A total of 546 healthcare providers participated in this study, for a response rate of 94.7%. Two-fifths, 39.7% (95%CI: 35.9, 44.0%) of healthcare providers disinfecting their stethoscope after every use. And a significant number of participants 34.6% (95%CI: 30.8, 38.5%) never disinfect their stethoscope. Three out of four (76.0%) healthcare providers believe that stethoscope contamination can contribute to the transmission of infections. Safe infection prevention practice (AOR = 3.79, 95%CI: 2.45–5.84), awareness on infection prevention guideline (AOR = 1.93; 95%CI: 1.31, 2.82), and favorable attitude towards infection prevention (AOR = 1.73, 95%CI: 1.02, 2.93) were significantly associated with stethoscope disinfection after every use. The study also found that the odds of stethoscope disinfection were likely to be reduced by 79% among physicians than nurses (AOR = 0.21; 95%CI: 0.09, 0.49).

Conclusions

Only a small proportion of healthcare providers disinfect their stethoscopes after every use. Factors such as safe infection prevention practice, awareness on infection prevention guidelines, and favorable attitude towards infection prevention were the independent predictors of stethoscopes disinfection after every use. Hence, promotion of stethoscope hygiene along with an educational program to enhance disinfection compliance in healthcare facilities may have a positive effect.

Non-critical healthcare tools as a potential source of healthcare-acquired bacterial infections in eastern Ethiopia: A hospital-based cross-sectional study

Background:

Outbreaks of healthcare-acquired infections have been linked to contaminated medical devices such as electronic thermometers, sphygmomanometers, stethoscopes, latex gloves, masks, neckties, white coats and other.

Objective:

The aim of this study was to assess non-critical healthcare tools as a potential source of healthcare-acquired bacterial infections and associated factors in public health hospitals of Harar, eastern Ethiopia from March 2016 to February 2017.

Methods:

A hospital-based cross-sectional study was conducted on 212 non-critical healthcare tools owned by different health professionals. The data were collected from each owner using self-administered questionnaire. Swab specimens were collected from 187 stethoscopes and 25 sphygmomanometers using sterile cotton tips. Bacterial investigation and antimicrobial susceptibility tests were performed using standard culture tests. The data were double entered into EPI-Data version 3.1 and exported into the Statistical Package for Social Sciences version 16 for analysis.

Result:

The overall prevalence of non-critical healthcare tool contamination was 53.8%. A total of 137 bacterial strains were isolated. Staphylococcus aureus was the most frequent isolate (35%). Resistance to two or more different classes of antimicrobial was found to be 19.3%. The proportion of stethoscopes or sphygmomanometers contamination owned by the health professionals who were not cleaned regularly before and after examining each patient was found to be high (77%). The majority of non-critical healthcare tools used by health professionals working in the intensive care unit were contaminated (75%) followed by medical wards (73.5%).

Conclusion:

This study confirmed that the majority of the stethoscopes and sphygmomanometers were contaminated with pathogenic bacteria known to be associated with healthcare-acquired infections. Most of the healthcare workers did not practice stethoscope and sphygmomanometers disinfection. Strict and careful decontamination of stethoscopes and sphygmomanometers need to be in place before use.

Photobactericidal Activity of Dual Dyes Encapsulated in Silicone Enhanced by Silver Nanoparticles

Crystal violet (CV) and methylene blue (MB) dyes with silver (Ag) nanoparticles (NPs) were encapsulated into silicone to produce light-activated antimicrobial surfaces. Optical microscopy and X-ray photoelectron spectroscopy showed that CV and MB were diffused throughout the silicone samples and that Ag NPs were successfully encapsulated by the swell-encapsulation-shrink process. Antimicrobial tests on Staphylococcus aureus and Escherichia coli showed that CV/MB-encapsulated silicone samples have stronger photobactericidal activity than CV or MB samples and the addition of Ag NPs significantly enhanced the antimicrobial activity under white light. The number of viable bacteria decreased below the detection limit (below <103 CFU) on the silicone-incorporating CV/MB/Ag NPs within 3 h for S. aureus and within 5 h for E. coli. In leaching tests over 216 h, the amount of dye leaching from the samples was barely detectable (<0.02 ppm). These surfaces have a potential for use in healthcare settings to decrease hospital-associated infections.

The bacterial contamination rate of glucose meter test strips in the hospital setting

Objectives:

To assess the rate of bacterial contamination of the multi-use vial and single-use packed glucose meter strips, and to identify the type and frequency of various bacterial contamination in different hospital wards.

Methods:

This prospective observational study was conducted by a team from the Strategic Center for Diabetes Research in 7 general hospitals in the Central region of Saudi Arabia during the period from August to September 2014 to assess the bacterial contamination rate of the unused strips. A total of 10,447 strips were cultured using proper agar media and incubated both aerobically and anaerobically.

Results:

The total bacterial contamination rate for the multi-use vials glucose strips was 31.7%, while single-use packed strips were not contaminated at all. Ministry of Health hospitals had the highest contamination rates compared with other hospitals. Critical, obstetric, and surgical wards had the highest bacterial isolates number, where most were in the risk group 3 according to the National Institute of Health guidelines. Staphylococcus species were the most common bacteria found.

Conclusion:

Glucose meter strips should be recognized as a source of bacterial contamination that could be behind serious hospital acquired infections. The hospital infection control team should adopt proper measures to implement protocols for glucose meter cleaning and glucose strips handling.

Building conditions and the risk of nosocomial infection from microbial contamination of hospital appliances in a health care facility

Nosocomial infections (NIs) remain a global health burden with higher incidence in Africa. We assessed building conditions and risk of NIs from microbial contamination of appliances and surfaces in a Specialist hospital in Southwest Nigeria. The study sampled 120 surfaces in 12 wards during normal occupational activities. Moulds on ceilings and dusty surfaces were observed in the wards. Microbial burden (1038.0 × 10⁵ cfu) peaked in the ICU but was lowest (446.9 × 10⁵ cfu) in the male ward. Bacteria counts ( × 10⁵ cfu) of 234.7, 199.7 and 67.0 were measured on ICU tap, doorknob and ECG, respectively. Theatre diatomy machine, anaesthetic machine and operating lamp had bacteria counts ( × 10⁵ cfu) of 40.0, 85.0 and 109.0, respectively. Highest total fungal count (58.2 × 10⁵ cfu) was recorded on ICU trolley handle, switch and suturing tube. Our study established surfaces as major environmental routes for NI transmission in this health care facility.

Disinfection of the Radiologist Workstation and Radiologist Hand Hygiene: A Single Institution Practice Quality Improvement Project

Purpose

The purpose of this study was to evaluate the workstation disinfection rates and hand hygiene of radiologists and trainees at shared departmental workstations and assess the impact of education and reminder placards on daily habits.

Methods

A 10-question survey was administered to all staff radiologists, fellows, and residents at our institution. The questions pertained to workstation disinfection, hand hygiene habits, and accessibility to disinfectant wipes and hand sanitizer stations. Subsequently, a short educational PowerPoint presentation was emailed to the department and small reminder placards were placed at each workstation. A follow-up survey was administered. Chi-square and Wilcoxon signed-rank tests were used to analyse the results.

Results

The percentage of participants who disinfect their workstations 1-2 times/week, 3-4 times/week or everyday increased from 53.4% (45 of 84 participants) to 74.3% (55 of 74 participants; P = .01), while the number who disinfect their workstation <1 time/week or never decreased from 46.4% (39 of 84 participants) to 25.7% (19 of 74 participants; P = .01). Hand washing before working at the workstation increased from 41.6% (35 of 84 participants) to 48.7% (36 of 74 participants; P = .76) and hand washing after working at the workstation increased from 50.0% (42 of 84 participants) to 56.8% (42 of 74 participants; P = .49).

Conclusions

At our institution, the implementation of daily reminder placards at each workstation and the administration of an educational PowerPoint presentation improved the rate of radiologist workstation disinfection.

Self-Sterilizing Sputtered Films for Applications in Hospital Facilities

This review addresses the preparation of antibacterial 2D textile and thin polymer films and 3D surfaces like catheters for applications in hospital and health care facilities. The sputtering of films applying different levels of energy led to the deposition of metal/oxide/composite/films showing differentiated antibacterial kinetics and surface microstructure. The optimization of the film composition in regards to the antibacterial active component was carried out in each case to attain the fastest antibacterial kinetics, since this is essential when designing films avoiding biofilm formation (under light and in the dark). The antimicrobial performance of these sputtered films on Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) were tested. A protecting effect of TiO₂ was found for the release of Cu by the TiO₂-Cu films compared to films sputtered by Cu only. The Cu-released during bacterial inactivation by TiO₂-Cu was observed to be much lower compared to the films sputtered only by Cu. The FeOx-TiO₂-PE films induced E. coli inactivation under solar or under visible light with a similar inactivation kinetics, confirming the predominant role of FeOx in these composite films. By up-to-date surface science techniques were used to characterize the surface properties of the sputtered films. A mechanism of bacteria inactivation is suggested for each particular film consistent with the experimental results found and compared with the literature.

Sphygmomanometers and thermometers as potential fomites of Staphylococcus haemolyticus: biofilm formation in the presence of antibiotics

BACKGROUND

The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown.

OBJECTIVES

In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated.

METHODS

The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces.

FINDINGS

ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene.

MAIN CONCLUSIONS

Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.

Decontamination of stethoscope membranes with chlorhexidine: Should it be recommended?

OBJECTIVE

To determine differences in the recontamination of stethoscope membranes after cleaning with chlorhexidine, triclosan, or alcohol.

METHODS

Experimental, controlled, blinded trial to determine differences in the bacterial load on stethoscope membranes. Membranes were cultured by direct imprint after disinfection with 70% isopropyl alcohol, 1% triclosan, or 1% chlorhexidine and normal use for 4 hours. As a baseline and an immediate effect control, bacterial load of membranes without disinfection and after 1 minute of disinfection with isopropyl alcohol was determined as well.

RESULTS

Three hundred seventy cultures of in-use stethoscopes were taken, 74 from each arm. In the baseline arm the median growth was 10 CFU (interquartile range [IQR], 32-42 CFU); meanwhile, in the isopropyl alcohol immediate-effect arm it was 0 CFU (IQR, 0-0 CFU). In the arms cultured after 4 hours, a median growth of 8 CFU (IQR, 1-28 CFU) in the isopropyl alcohol arm, 4 CFU (IQR, 0-17 CFU) in the triclosan arm, and 0 CFU (IQR, 0-1 CFU) in the chlorhexidine arm were seen. No significant differences were observed between the bacterial load of the chlorhexidine arm (after 4 hours of use) and that of the isopropyl alcohol arm (after 1 minute without use) (Z= 2.41; P > .05).

CONCLUSIONS

Chlorhexidine can inhibit recontamination of stethoscope membranes and its use could help avoid cross-infection.

Time Effectiveness of Ultraviolet C Light (UVC) Emitted by Light Emitting Diodes (LEDs) in Reducing Stethoscope Contamination

Today it is well demonstrated that stethoscopes can be as contaminated as hands, which are a recognized source of Health-Care Associated Infections (HCAIs). Ultraviolet C (UVC) light has proven disinfection capacity and the innovative UVC technology of Light Emitting Diode (LED) shows several potential benefits. To verify whether the use of UVC LEDs is effective and reliable in stethoscope membrane disinfection after prolonged use, a pre-post intervention study was conducted. A total of 1668 five-minute cycles were performed on two UVC LEDs to simulate their use; thereafter, their disinfection capacity was tested on stethoscope membranes used on a previously auscultated volunteer. Then, a further 1249 cycles were run and finally the LEDs were tested to assess performance in reducing experimental contamination by Staphylococcusaureus, Pseudomonasaeruginosa and Escherichia coli on the stethoscope membrane. Baseline volunteer contamination identified 104 Colony Forming Units (CFUs) while treated Petri dishes had 12 and 15 CFUs (p < 0.001). Statistically significant differences (p < 0.001) were also found relating to the reduction of specific bacteria: in particular, after treatment no CFU were observed for S. aureus and E. coli. UVC LEDs demonstrated the capacity to maintain high levels of disinfection after more than 240 h of use and they were effective against common microorganisms that are causative agents of HCAIs.

Healthcare Personnel Attire and Devices as Fomites: A Systematic Review

BACKGROUND Transmission of pathogens within the hospital environment remains a hazard for hospitalized patients. Healthcare personnel clothing and devices carried by them may harbor pathogens and contribute to the risk of pathogen transmission. OBJECTIVE To examine bacterial contamination of healthcare personnel attire and commonly used devices. METHODS Systematic review. RESULTS Of 1,175 studies screened, 72 individual studies assessed contamination of a variety of items, including white coats, neckties, stethoscopes, and mobile electronic devices, with varied pathogens including Staphylococcus aureus, including methicillin-resistant S. aureus, gram-negative rods, and enterococci. Contamination rates varied significantly across studies and by device but in general ranged from 0 to 32% for methicillin-resistant S. aureus and gram-negative rods. Enterococcus was a less common contaminant. Few studies explicitly evaluated for the presence of Clostridium difficile. Sampling and microbiologic techniques varied significantly across studies. Four studies evaluated for possible connection between healthcare personnel contaminants and clinical isolates with no unequivocally direct link identified. CONCLUSIONS Further studies to explore the relationship between healthcare personnel attire and devices and clinical infection are needed. Infect Control Hosp Epidemiol 2016;1-7.

Knowledge, Attitude, and Practices of Healthcare Personnel Regarding the Transmission of Pathogens via Fomites at a Tertiary Care Hospital in Karachi, Pakistan

Background.  Fomites are objects that can become colonized and serve as vectors in the transmission of pathogenic microorganisms. Literature examining the knowledge of healthcare personnel about this method of spread of infection is lacking. We conducted a study to assess the knowledge, attitude, and practices of healthcare personnel across different areas of patient care regarding the spread of infections at a tertiary care hospital in Karachi, Pakistan. Methods.  A descriptive, cross-sectional study was conducted among healthcare personnel using a self-administered questionnaire. The questionnaire contained sections pertaining to demographic details and knowledge, attitude, and practices regarding fomites and their role in the transmission of pathogens. Results.  Three hundred and fifty-three participants completed the questionnaire: 168 were male and 185 were female. Laboratory coats, stethoscopes, and bedside curtains were most frequently identified as fomites by the participants. Medical students had significantly lower mean scores in the knowledge and attitude sections than consultant physicians, resident physicians, and nurses. Nurses scored higher than consultant physicians, resident physicians, and medical students regarding practices that minimize fomite-borne spread of infections. 95% of the participants scored above 50% on the knowledge component of the questionnaire, but only 32.3% scored above 50% in the practices section. Conclusions.  Our results show a large gap between the knowledge about fomites acting as vectors in the spread of pathogens and practices done to minimize this spread. Possessing adequate knowledge is ineffectual until and unless it is translated into the proper application of infection control practices. Incorporating awareness sessions and exercises into curricula are a reasonable way to raise awareness regarding this subject.

Examination of staphylococcal stethoscope contamination in the emergency department (pilot) study (EXSSCITED pilot study)

Introduction:

The objective of this study was to determine the prevalence of Staphylococcus-contaminated stethoscopes belonging to emergency department (ED) staff and to identify the proportion of these that were Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA).

Methods:

We conducted a prospective observational cohort study of bacterial cultures from 100 ED staff members' stethoscopes at three EDs. Study participants were asked to complete a questionnaire.

Results:

Fifty-four specimens grew coagulase-negative staphylococci and one grew methicillin-susceptible S. aureus. No MRSA was cultured. Only 8% of participants, all of whom were nurses, reported cleaning their stethoscope before or after each patient assessment. Alcohol-based wipes were most commonly used to clean stethoscopes. A lack of time, being too busy, and forgetfulness were the most frequently reported reasons for not cleaning the stethoscope in the ED.

Conclusions:

This study indicates that although stethoscope contamination rates in these EDs are high, the prevalence of S. aureus or MRSA on stethoscopes is low.

Comparing the auscultatory accuracy of health care professionals using three different brands of stethoscopes on a simulator

Background

It is considered standard practice to use disposable or patient-dedicated stethoscopes to prevent cross-contamination between patients in contact precautions and others in their vicinity. The literature offers very little information regarding the quality of currently used stethoscopes. This study assessed the fidelity with which acoustics were perceived by a broad range of health care professionals using three brands of stethoscopes.

Methods

This prospective study used a simulation center and volunteer health care professionals to test the sound quality offered by three brands of commonly used stethoscopes. The volunteer’s proficiency in identifying five basic ausculatory sounds (wheezing, stridor, crackles, holosystolic murmur, and hyperdynamic bowel sounds) was tested, as well.

Results

A total of 84 health care professionals (ten attending physicians, 35 resident physicians, and 39 intensive care unit [ICU] nurses) participated in the study. The higher-end stethoscope was more reliable than lower-end stethoscopes in facilitating the diagnosis of the auscultatory sounds, especially stridor and crackles. Our volunteers detected all tested sounds correctly in about 69% of cases. As expected, attending physicians performed the best, followed by resident physicians and subsequently ICU nurses. Neither years of experience nor background noise seemed to affect performance. Postgraduate training continues to offer very little to improve our trainees’ auscultation skills.

Conclusion

The results of this study indicate that using low-end stethoscopes to care for patients in contact precautions could compromise identifying important auscultatory findings. Furthermore, there continues to be an opportunity to improve our physicians and ICU nurses’ auscultation skills.

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.

Light-activated antimicrobial surfaces with enhanced efficacy induced by a dark-activated mechanism

We report a potent antimicrobial polymer demonstrating an enhanced bactericidal activity upon white light illumination.

Bacterial contamination, bacterial profile and antimicrobial susceptibility pattern of isolates from stethoscopes at Jimma University Specialized Hospital

INTRODUCTION

Hospital acquired infections are recognized as critical public health problems. Infections are frequently caused by organisms residing in healthcare environment, including contaminated medical equipment like Stethoscopes.

OBJECTIVE

To determine bacterial contamination, bacterial profile and anti-microbial susceptibility pattern of the isolates from stethoscopes at Jimma University Specialized Hospital.

METHODOLOGY

Cross-sectional study conducted from May to September 2011 at Jimma University Specialized Hospital. One hundred seventy-six stethoscopes owned by Health Care Workers (HCWs) and Medical students were randomly selected and studied. Self-administered structured questionnaire was used to collect socio-demographic data. Specimen was collected using moisten sterile cotton swab and 1 ml normal saline was used to transport the specimen, all laboratory investigations were done following standard microbiological techniques, at Microbiology Laboratory, Jimma University. SPSS windows version 16 used for data analysis and P <0.05 was considered statistically significant.

RESULT

A total, of 151 (85.8%) stethoscopes were contaminated. A total of 256 bacterial strains and a mean of 1.44×104 CFUs/diaphragm of stethoscopes was isolated. Of the 256 isolates, 133 (52%) were potential pathogens like S. aureus, Klebsiella spp., Citrobacter spp., Salmonella spp., Proteus spp., Enterobacter spp., P. aeruginosa and E. coli. All strains were resistant to multiple classes of antibiotics (two to eight classes of antibiotics). Disinfection practice was poor. Disinfection practice was found to be associated with bacterial contamination of stethoscopes (P < 0.05). High contamination rate 100 (90.9%) was observed among stethoscopes that had never been disinfected; while the least contamination 29 (72.2%) was found on those disinfected a week or less before the survey.

CONCLUSION

Bacterial contamination of the stethoscope was significant. The isolates were potential pathogens and resistant to multiple classes of antibiotics. Stethoscope is potential vehicle in the transmission of infections between patients and Healthcare Workers. Stethoscope diaphragm should be disinfected before and after each patient contact.

Improving stethoscope disinfection at a children's hospital

OBJECTIVE

Stethoscopes are contaminated with pathogenic bacteria and pose a risk for transmission of infections, but few clinicians disinfect their stethoscope after every use. We sought to improve stethoscope disinfection rates among pediatric healthcare providers by providing access to disinfection materials and visual reminders to disinfect stethoscopes.

DESIGN

Prospective intervention study.

SETTING

Inpatient units and emergency department of a major pediatric hospital.

PARTICIPANTS

Physicians and nurses with high anticipated stethoscope use.

METHODS

Baskets filled with alcohol prep pads and a sticker reminding providers to regularly disinfect stethoscopes were installed outside of patient rooms. Healthcare providers' stethoscope disinfection behaviors were directly observed before and after the intervention. Multivariable logistic regression models were created to identify independent predictors of stethoscope disinfection.

RESULTS

Two hundred twenty-six observations were made in the preintervention period and 261 in the postintervention period (83% were of physicians). Stethoscope disinfection compliance increased significantly from a baseline of 34% to 59% postintervention (P < .001). In adjusted analyses, the postintervention period was associated with improved disinfection among both physicians (odds ratio [OR], 2.3 [95% confidence interval (CI), 1.4-3.5]) and nurses (OR, 14.3 [95% CI, 4.6-44.6]). Additional factors independently associated with disinfection included subspecialty unit (vs general pediatrics; OR, 0.5 [95% CI, 0.3-0.8]) and contact precautions (OR, 2.3 [95% CI, 1.2-4.1]).

CONCLUSIONS

Providing stethoscope disinfection supplies and visible reminders outside of patient rooms significantly increased stethoscope disinfection rates among physicians and nurses at a children's hospital. This simple intervention could be replicated at other healthcare facilities. Future research should assess the impact on patient infections.

Otitis externa following aural irrigation linked to instruments contaminated with Pseudomonas aeruginosa

BACKGROUND

The incidence of acute otitis externa, an infection of the external auditory canal, in general practitioners' (GP) practices in The Netherlands is about 14 per 1000 patients per year. In early 2010, one of the authors noted that some of the otitis externa patients in his GP practice had undergone cerumen removal by ear syringing a few weeks earlier. Bacterial cultures of samples taken from the instruments used showed contamination of an ear syringe by Pseudomonas aeruginosa. From then on, P. aeruginosa isolates from patients' ears were stored in the laboratory.

AIM

It was assessed whether cross-contamination with P. aeruginosa between patients in the same GP practice could occur through the use of contaminated ear lavage instruments.

METHODS

From 17 GP practices, the otolaryngology Outpatient Department and the Out-of-Hours GP Service, instruments used for examining and cleaning the outer ear were swabbed. Strains of P. aeruginosa cultured from the instruments were genotyped together with isolates of patients registered in the same practice.

FINDINGS

In four practices where contaminated instruments were found, genotyping showed similarity between P. aeruginosa strains isolated from a patient and the ear syringe, and/or between strains of different patients in the same practice.

CONCLUSIONS

Transmission of P. aeruginosa from ear lavage instruments to patients appears to occur with otitis externa as a result. Together with the Infection Control Unit of our hospital we have formulated recommendations for the appropriate cleaning, disinfection and storage of re-usable ear lavage instruments for the GP practices to implement.

Predictors of stethoscope disinfection among pediatric health care providers

BACKGROUND

Stethoscopes are contaminated with bacteria, but predictors of stethoscope disinfection frequency are unknown. We sought to describe health care provider stethoscope disinfection attitudes and practices and determine predictors of frequent disinfection.

METHODS

We used an anonymous online survey of nurses, nurse practitioners, and physicians at a pediatric hospital. We assessed frequency and methods of disinfection, perceptions of contamination, and barriers to disinfection. Multivariate logistic regression models were used to identify independent predictors of disinfecting after every use.

RESULTS

One thousand four hundred one respondents completed the survey: 76% believed that infection transmission occurs via stethoscopes, but only 24% reported disinfecting after every use. In multivariate analyses, belief that infection transmission occurs via stethoscopes significantly increased the odds of disinfection after every use (odds ratio [OR], 2.06 [95% confidence interval (CI): 1.38-3.06]). The odds of disinfection after every use were significantly decreased in those who perceived the following barriers: lack of time (OR, 0.31 [95% CI: 0.18-0.54]), lack of access to disinfection material (OR, 0.41 [95% CI: 0.29-0.57]), or lack of visual reminders to disinfect (OR, 0.22 [95% CI: 0.14-0.34]).

CONCLUSION

Only a minority of pediatric health care providers reported disinfecting their stethoscopes after every use. Increasing access to disinfection materials and visual reminders in health care facilities may improve stethoscope disinfection practices.

Pattern of bacterial colonization in a new neonatal intensive care unit and its association with infections in infants

BACKGROUND

There is paucity of information on the pattern of bacterial colonization of a new neonatal intensive care unit.

OBJECTIVE

To study the pattern of bacterial colonization on the environmental surfaces in a new neonatal intensive care unit (NICU) and correlate it with infections in the infants.

METHODS

Environmental cultures from the faucets and computer keyboards in the NICU were obtained prospectively every 2 weeks for 1 year. Positive blood, cerebrospinal fluid, and respiratory cultures from the infants in the NICU were also obtained.

RESULTS

A total of 175 swab cultures was collected, which were sterile for initial 6-week period. Subsequently, 31 cultures grew microbes: 26 (83.8%) from the faucets and 5 (16.2%) from the computers keyboard (P < .001). Of the 48 positive blood cultures in NICU patients, 6 (12.5%) matched the organism growing from the surveillance sites, but the correlation was not significant (P = .076). None of the 31 positive respiratory cultures and 1 positive cerebrospinal fluid culture correlated to the organisms grown from the NICU environment.

CONCLUSION

The environment was colonized after an initial period of sterile cultures in a new NICU. Once colonized, they can persist, increasing the risk of developing resistance to antibiotics. They did not correlate with the positive cultures from the infants admitted to the NICU during the study period.

Filmcards Used in Radiation Therapy: Are They a Potential Source of Cross-infection?

INTRODUCTION

Industrial radiographic film (exposed to light and then cut into a filmcard) is a tool used by radiation therapists (RTs) in the setup of patients before delivering external beam radiation therapy. At the Tom Baker Cancer Center (TBCC), filmcards are reused throughout the day on multiple patients and multiple body sites; thus the risk of cross-contamination exists. The primary objective of this study was to assess the risk of cross-contamination by determining the potential for bacteria to survive on filmcards, in an effort to reduce the risk of cross-infection.

METHODS AND MATERIALS

This control study evaluated the potential of the following to survive on filmcards: coliforms, Pseudomonas, Staphylococcus spp. (specifically S. aureus and methicillin-resistant S. aureus [MRSA]), Enterococcus, and hemolytic streptococcus species. Thirty filmcards used by RTs throughout the day were collected and voluntarily placed in individual collection bags. Thirty control cards (unused filmcards) were also collected. Collection bags were stored at 4°C until cultured. A reference strain of MRSA (38591) was used in the MRSA survival assay, along with methicillin-sensitive S. aureus (MSSA) isolate (pure form). The MRSA survival experiment required eight larger, unused filmcards (four designated as negative controls and four positive control cards) to be cut into 28.5 × 6.5 cm. Microbiological plates were used to identify and select for bacteria. The various selective and differential plates contain growth factors, antimicrobials, and color indicators that can selectively allow some groups of bacteria to grow on the plate while inhibiting other types of bacteria.

RESULTS

This study provides evidence to support that filmcards are a source of cross-contamination. 58% (17/29) of the used filmcards tested positive for pathogenic bacteria, compared to only 20% (6/30) of the control cards (P = 0.003). Staphylococcus aureus bacteria were present on 11/29 (38%) of the used filmcards, compared to 2/30 (6.7%) on the control filmcards (P = 0.005). Other colonies found on the used filmcards included strep bacteria (P = 0.24), entero bacteria (P = 0.24), and skin flora (P = 0.36); and although reported as statistically insignificant, these bacteria were viable and thus hold a level of clinical significance. In addition, this experiment provides evidence that certain bacteria (including MRSA found to survive on filmcards for at least 21 days) were viable on filmcards, but an incidental finding reports that fungi is also able to survive on filmcards.

CONCLUSION

Filmcards used by RTs can harbor a number of pathogenic bacteria, including MRSA, and are therefore a source of cross-contamination. We recommend that the TBCC external beam radiation treatment program-and any other facilities providing external beam radiation therapy-adopt infection control policies that support discarding filmcards after each use (one-time per patient use) or adopt policies that endorse the elimination of filmcards entirely.

Evaluation of serological tests for diagnosis of brucellosis

The aim of the present study was to compare serological tests (Rose Bengal [RB]; standard agglutination test [SAT]; enzyme immunoassay [EIA] for detection of IgM, IgA, and IgG; and 2-mercaptoethanol [2-ME] test) that are routinely used in patients prediagnosed with different clinical types of brucellosis (acute, subacute, or chronic), and to evaluate the results of the IgG avidity test. Ninety-two patients having titers≥1/160 as measured by SAT were included in the study. The IgG avidity test was performed in 78 patients who had positive EIA-IgG results. RB test results were positive in 88 (95.7%) patients. A statistically significant correlation was found between a positive EIA-IgM result and the diagnosis of acute brucellosis. When compared to the results of the SAT, the 2-ME test showed a lower titer in 55 (59.8%) patients, and the agreement between the 2-ME test and EIA-IgG was calculated as 84.8%. No statistical difference was found between the 40% avidity index used in the IgG avidity test and avidity maturation time (6 months). From our study, we concluded that (i) the RB and SAT tests are appropriate and reliable tests for the serological diagnosis of brucellosis; (ii) IgM can be used as a marker of acute brucellosis; (iii) the 2-ME test, similar to EIA, can be used to determine IgM levels; and (iv) the IgG avidity test should be standardized.

The microbial contamination of pressurised metered-dose inhalers anonymously sourced from the South-East Queensland Australia community population

OBJECTIVES

To provide preliminary evidence regarding the presence, identity and level of microbial contamination of metered-dose inhalers sourced from the community. To correlate the level of microbial colonisation to the visible presence of debris on the interior and exterior surface of the device mouthpiece.

METHODS

In this exploratory study, 45 post-use de-identified pressurised metered-dose inhalers were collected from the South-East Queensland Australian community. Prior to swabbing, the presence of visible debris on the internal and external surfaces of the mouthpiece was recorded for each device. Swabs taken from external and inner surfaces of the mouthpiece of each device were streaked onto standard growth media for colony counts. Individual colonies were selected and enriched then streaked onto a range of differential and chromogenic media for differential identification.

KEY FINDINGS

A total of 36 post-use pressurised metered dose inhalers (80%) were shown to be colonised by microbes relative to unused devices (P=0.01). Devices were primarily colonised by common respiratory flora, including Staphylococcus, Streptococcus and Haemophilus species. Of greatest concern was the positive identification of methicillin-resistant Staphylococcus aureus (18%) and extended-spectrum β-lactamase-producing Enterobacteriaceae (7%), Pseudomonas aerugonisa (2%) and Candida species (9%). The level of internal microbial contamination appeared to correlate to the presence of visible debris on the inside of the inhaler mouthpiece (P=0.06) but not external debris (P=0.59) while external contamination was not associated with internal (P=0.99) or external debris (P=0.63).

CONCLUSIONS

These preliminary data suggest that pressurised metered dose inhalers are potential reservoirs for bacteria. While this study was not aimed at determining the impact that contaminated pressurised metered-dose inhalers may have on the user, future research is being conducted to address the implications of these findings and the consequences they may have for the population of users.

A prospective study of the case-notes of MRSA-positive patients: a vehicle of MRSA spread

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) has received much publicity and remains a major problem for the health service. The aim of this study was to determine whether case-notes of MRSA-positive patients can act as a vehicle for MRSA transmission.

PATIENTS AND METHODS

A prospective study was performed of patients with active MRSA infection identified from a microbiology department database. Two swabs were taken from the cover of the case-notes and the page with the most recent entry for identification of MRSA using MRSA ID (Chromogenic agar medium), Pastorex and DNase tests. Positive case-notes were re-swabbed 96 h later.

RESULTS

A total of 50 MRSA-positive patients were identified from medical, surgical, high dependency and intensive care wards. Three sets of notes were MRSA positive (3/50; 6%). None of the positive case-notes was positive on re-swabbing at 96 h.

CONCLUSIONS

Case-notes of MRSA-positive patients can act as carriers of MRSA with the potential to spread MRSA to both healthcare and non-healthcare workers without direct contact with infected patients. We recommend extending the universal precautions to the handling of case-notes belonging to MRSA-infected patients.

Testing wound dressings using an in vitro wound model

OBJECTIVE

To determine whether or not there are any significant differences in the effects of wound dressings on bacterial bioburden.

METHOD

A selection of non-occlusive, non-adhesive dressings was tested for their effect on bacterial bioburden. The dressings selected included two dressings with antimicrobial properties (one containing silver and one containing PHMB), a cotton-based dressing enclosed in a perforated sleeve of poly(ethylene terephthalate), a carboxymethyl cellulose-based dressing, a fibre-free alginate dressing, and a 12-ply 100% cotton gauze. Using the colony-drip flow reactor (DFR) model, a meticillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa biofilm was grown underneath a dressing sample. Biofilm growth was examined via plate counts, fluorescent microscopy and scanning electron microscopy.

RESULTS

The dressings containing antimicrobial agents had the greatest effect on bacterial load. In the MRSA experiments, both antimicrobial dressings produced lower bacteria counts than the other dressings (p<0.001), while in the P. aeruginosa experiments, only the silver-containing sample had fewer bacteria (p<0.0001). However, neither antimicrobial dressing was able to completely eradicate the bacteria when testing with either microorganism.

CONCLUSION

The results presented herein illustrate that bacteria can grow unchallenged within the dressing environment and that an antimicrobial dressing can limit this bacterial growth.

DECLARATION OF INTEREST

None.

The microbial colonisation of mobile phone used by healthcare staffs

Mobile phones are dispensable accessories in social life and normally they are not cleaned properly. Therefore, they serve as a reservoir of bacteria and may cause nosocomial infections in hospitals. The purpose of this study was to investigate microbiological colonization of mobile phones used by healthcare staffs. The study was carried out collecting swab samples with Cary-Blair transport medium from mobile phones of attending healthcare staffs from different departments of three hospitals in March, 2008. All collected samples were inoculated in 5% sheep blood agar, eosin-methylene blue agar and Sabouraud Dextrose agar. Isolated bacteria were identified using by classic technique and Vitec2 (Biomerieux, France) full automated bacteria identification system. Growth was observed in 65 of collected 106 samples, corresponding to 61.3%. The most frequent bacteria were Staphylococcus epidermidis followed by Staphylococcus aureus, Bacillus sp., Corynebacterium sp. and Escherichia coli, respectively. In conclusion, bacteria were colonized on mobile phones frequently and mobile phones may become reservoir of microorganism for nosocomial infections.

"Can religious icons be vectors of infectious diseases in hospital settings?"

According to Jewish tradition, Mezuzahs should be affixed on all doorposts leading to communal places. We evaluated the bacterial pathogenic load on the Mezuzah covers in our hospital. Mezuzahs were sampled in all hospital departments, and cultures were carried out. Serving as a control group, door handles belonging to the same departments were tested as well. Most samples harbored potential pathogens. Few cultures were positive in the control group, demonstrating that regular disinfection is carried out, but apparently religious artifacts are overlooked.

Ethanol-based cleanser versus isopropyl alcohol to decontaminate stethoscopes

Approximately 1 in 20 hospital admissions is complicated by a health care-associated infection. Stethoscopes may play a role in spreading nosocomial infections. The objective of this study was to determine the effectiveness of an ethanol-based cleanser (EBC) compared with isopropyl alcohol pads in reducing bacterial contamination of stethoscope diaphragms. Stethoscopes were cultured from medical professionals on 4 medical floors before and after cleaning with either EBC or isopropyl alcohol pads. The numbers of colony-forming units (cfu) grown were compared between the 2 cleaners and to baseline values. A total of 99 stethoscopes were cultured (49 EBC; 50 isopropyl alcohol), and all were positive for growth. After cleaning, 28.28% of the stethoscopes were growth-free (12 EBC; 16 isopropyl alcohol). Cleaning with EBC and isopropyl alcohol pads significantly reduced the cfu counts (by 92.8% and 92.5%, respectively), but neither was found to be statistically superior (F = 1.22; P = .2721). Cleaning a stethoscope diaphragm using either EBC or isopropyl alcohol led to a significant reduction in bacterial growth in culture. As an extension of the hand, a stethoscope should be cleaned with the same frequency as the hands. The simultaneous cleaning of hands and stethoscope may further increase compliance with current standards.

The stethoscope as a vector of infectious diseases in the paediatric division

AIM

Nosocomial infections are of great concern in hospital settings, and even more so in the paediatric ward. Health professionals and their medical equipment have long been known to act as vectors of infectious diseases. This study aimed at evaluating the presence of bacterial pathogens on the stethoscopes of medical personnel in the paediatric division.

METHODS

Forty-three stethoscopes belonging to senior physicians, residents, interns and medical students at the paediatric ward were sampled. Bacterial cultures and antibiotic sensitivity testing were carried out.

RESULTS

All but six bacterial cultures were positive (85.7%). Staphylococcal species were the most common contaminants (47.5%). One case of methicillin-resistant Staphylococcus aureus was encountered. Gram-negative organisms were isolated in nine different samples (21%) including one case of Acinetobacter baumannii in the neonatal intensive care unit.

CONCLUSION

Most stethoscopes harbour potential pathogens. The isolation of Gram-negative organisms pose a real risk of spreading potentially serious infections, especially in the setting of intensive care departments. Apparently, the current recommendations of regular disinfection of stethoscopes are not carried out by health personnel that participated in the study.

MRSA and the environment: implications for comprehensive control measures

Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) is established soon after colonized or infected patients become resident. There are many studies that detail the mechanisms of spread and environmental survival of methicillin-susceptible Staphylococcus aureus (MSSA); this knowledge translates directly into the same findings for MRSA. The potential ubiquity of MRSA in a health-care setting poses challenges for decontamination. Whereas patients and medical staff are important sources for MRSA spread, the environmental burden may contribute significantly in various contexts. Effective control measures must therefore include consideration for MRSA in the environment.

Using marker pens on patients: a potential source of cross infection with MRSA

INTRODUCTION

Marker pens are widely used in surgery but pre-operative marking of patients may be a cause of bacterial cross-infection.

PATIENTS AND METHODS

Two experiments were performed to assess whether marking pens can be cause of cross-infection: (i) 26 indelible marker pens were collected from surgical wards for analysis; and (ii) 'fresh' as well as 'dry' (artificially dried by removing cap and exposing tip for 2 h) new permanent marker pens, and whiteboard marker pens were inoculated by dipping the tips into various concentrations of methicillin-resistant Staphylococcus aureus (MRSA). Each pen was inoculated onto 2 blood agar plates at 0 (immediately after inoculation) to 30 min at various intervals, 4 h and 24 h. The plates were incubated for 18 h at 35 degrees C in an incubator.

RESULTS

Of 26 pens collected from the wards, 2 cultured Micrococci spp. (skin commensals). The constituents of new 'fresh' pen tips rapidly kill MRSA - in all cases by 4 h, but usually within minutes. At high inoculum concentrations, MRSA is not killed immediately. Dry marker pens harbour MRSA for at least 30 min and probably longer.

CONCLUSIONS

Marker pens can act as fomites for nosocomial infection. The ethanol-based ink in permanent marker pens has a bactericidal action against MRSA that starts within seconds, and they are likely to be safe to use with a gap of at least 2 min between patients. Usually, harmless skin commensals are not pathogenic except in immunocompromised patients. Old or dried-out marker pens can harbour pathogens and should be discarded before attempted use on patients. We recommend disposable markers for the immunocompromised and patients with a known positive MRSA status.

Microbial contamination of nebulizers in the home treatment of cystic fibrosis

BACKGROUND

Home nebulizers are in widespread use in cystic fibrosis (CF) and other chronic pulmonary diseases. Bacterial contamination may be a source of respiratory tract colonization.

OBJECTIVES

To investigate microbial contamination of home nebulizers in CF patients, compare with sputum cultures and relate to cleaning practices.

METHODS

A total of 29 home nebulizers of CF patients were cultured. Families were interviewed regarding cleaning routines and patients had sputum cultures for bacteria and fungi.

RESULTS

In total, 19/29 (65%) nebulizers were contaminated: 18 reservoir cups, 14 mouthpieces and five filters. Pseudomonas spp. were isolated from 10 nebulizers (35%) and all 10 had Pseudomonas aeruginosa airway infection although without genetic typing we could not be sure this was the same bacteria as that from their nebulizer unit. An additional 7/29 had Pseudomonas aeruginosa airway infection without a contaminated nebulizer (P=0.001). No nebulizers were contaminated with Aspergillus. Only 4/19 contaminated nebulizers (22%) had been cleaned after every use, compared with seven of the 10 (70%) uncontaminated nebulizers (P=0.017). Only 7/19 patients with contaminated nebulizers (37%) and 5/10 with clean nebulizers (50%) recalled receiving cleaning instructions (not significant).

CONCLUSIONS

Home nebulizers are frequently contaminated, particularly when cleaning instructions are inadequate, and may be a source of airway infection or reinfection especially following contamination from a patient chronically colonized with P. aeruginosa. Simple oral and written cleaning instructions should be offered.

Bacterial contamination of stethoscopes with antimicrobial diaphragm covers

Antimicrobial stethoscope covers impregnated with silver ions have been developed to prevent surface contamination and potential transmission of bacterial pathogens to patients. To test their practical utility, covers were distributed with the manufacturers' recommendations to a mixed group of health care professionals in a medical/surgical intensive care unit and an emergency department. Seventy-four clinicians were selected from a convenience sample for surface cultures and standard questioning regarding cleaning and cover use. Surface colony counts were significantly lower for uncovered stethoscope diaphragms (mean, 71.4 colonies) compared with covers used <or=1 week (mean, 246.5 colonies) and those >1 week old (mean, 335.6 colonies). After controlling for type of clinician, frequency of stethoscope cleaning, and method of stethoscope cleaning, only the presence of a stethoscope cover was associated with higher colony counts (P<.0001). We question the practical utility of the antimicrobial diaphragm covers evaluated in this study for reducing the surface colonization of potentially harmful microorganisms.

The risk of cross-infection when marking surgical patients prior to surgery - review of two types of marking pens

INTRODUCTION

Two types of marker pens were compared to find whether they produced different risks of infection transmission over different time intervals.

PATIENTS AND METHODS

Twenty-four patients were marked according to the type of surgery: each had a set of new dry white-board marker (DWM) and a permanent marker (PM) pen. Once used, their tips were used to inoculate blood agar plates at different time intervals.

RESULTS

At 0 min, 96% of the DWM pens and 29% of the PM pens were positive of growth. At 3 and 10 min, all of the DWM pens remained positive. The rate dropped to 16.67% in 3 min down to none at 10 min for the PM pens.

CONCLUSIONS

DWM pens carry a significant risk of transmitting infection between patients. It is recommended that they are not used in marking. PM pens should not be used between patients in less than a 10-min interval.