ABSTRACT.
The study was conducted to determine bacterial contamination of stethoscopes used by doctors before and after disinfecting with isopropyl alcohol and analyze their practices of disinfecting stethoscopes. Samples from stethoscopes were taken before and after disinfecting with 70% isopropyl alcohol swab with the help of a sterile swab. All swabs were inoculated on Blood and MacConkey agar plates and were examined for growth. Stethoscopes of 78 doctors were sampled which included 45 (58%) males and 33 (42%) females. Before decontamination of diaphragms with isopropyl alcohol, 27 (34.6%) diaphragms had “growth” while 51 (65.4%) had “no growth.” After decontamination with isopropyl alcohol, 5 (6.4%) had “growth” while 73 (93.6%) had “no growth.” The most common microorganism isolated from stethoscopes’ diaphragms was methicillin-resistant Staphylococcus epidermidis (MRSE), that is, 14 out of 78 (17.9%). The survey also evaluated factors associated with contamination of stethoscopes. Most doctors 71(91%) believe that stethoscopes can be a source of infection and 55.1% (N = 43) responded that both diaphragm and bell of stethoscopes can transmit infections. Many doctors (41%, N = 32) reported that “forgetfulness/laziness” was the barrier which they faced regarding stethoscope hygiene followed by “lack of time” (21.8%, N = 17). The contamination rate (66.6%) is highest in those doctors who are using their stethoscopes for 3–5 years. Of them, 30 doctors (38.5%) never decontaminated their stethoscopes among which 17 had growth in their stethoscopes before cleaning with isopropyl alcohol, while three had growth even after decontamination. Most doctors used sanitizer (29.5%) and isopropyl alcohol (25.6%) as cleaning agents.
INTRODUCTION
The development of nosocomial infection is a critical problem in a hospital setting.1–4 Healthcare-associated infections (HAIs) can be transmitted by medical devices routinely used by doctors such as stethoscopes, blood pressure cuffs, white coats, etc.1,2,4–6 Among these, stethoscopes used by doctors are a major threat to the transmission of HAIs in hospitals.1,3,7 The burden of healthcare costs has escalated because of HAIs and so is the morbidity and mortality of the patients.6,8 However, the disinfection compliance of physician’s equipment such as stethoscope is low.1,3,9
The stethoscope is considered as “Physician’s third hand,”10–12 but the importance of disinfecting stethoscope has been underrecognized as compared with hand hygiene.2 As stethoscopes can come in contact with patients many times, so microorganisms on contaminated stethoscopes (e.g., diaphragms) could spread the disease to other patients.4–6,8
Studies conducted globally have reported high contamination rates of stethoscopes, ranging from 66% to 100%.6 Cross-contamination can occur due to stethoscopes in the same way as environmental surfaces, transferring microorganisms from the membrane to the skin.7
There is a high risk of transmission of multidrug-resistant (MDR) and pan drug-resistant bacteria in the hospital setting with stethoscopes as a vector because their routine disinfection is not practiced by doctors. Among resistant bacteria, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus, and extended-spectrum beta-lactamase-producing species are potentially dangerous pathogens.3,6,7
To cope with increased contamination of stethoscope, different disinfectants have been investigated. The effectiveness of isopropyl alcohol as a good cleaning agent has been demonstrated.2,6,7,9 There is a dire need to evaluate the contamination rate of stethoscopes, sensitize the doctors about disinfection practices, and increase awareness of the magnitude of the problem.
MATERIALS AND METHODS
This was a descriptive cross-sectional study conducted in Lahore General Hospital, Pakistan, between May 2019 and December 2019 using convenient sampling technique for the sampling of stethoscopes. Permission was obtained from the institutional ethical committee with article number 0052-19 on May 14, 2019. The sample size (N = 78) was calculated by using a 95% confidence interval, prevalence as 72.1%,3 and precision as 10%.
Written and informed consent of each participant doctor was obtained on consent Proforma. After getting informed consent, a questionnaire Performa was given to the respective doctor to assess his or her stethoscope disinfecting practices and knowledge about infection prevention. The questionnaire was designed after an extensive literature review.2,3,6 It was composed in English language, and was validated by senior doctors and consultants. It was divided into two sections. First section was about demographic data, and second section was about stethoscope disinfecting practices and knowledge about infection prevention.
The study subjects were Doctors from the Medical wards, and samples were collected from doctors’ stethoscopes. The stethoscope diaphragm was divided into two halves. One-half was used to collect the sample (labeled as SB) using sterile swabs moistened with physiological saline (0.9%w/v), that is, before cleaning with isopropyl alcohol. The other half was used to collect the sample (labeled as SA) after cleaning with 70% isopropyl alcohol swab. The swab was rubbed for 10 seconds and then allowed to dry for 60 seconds before collecting the sample. This division of diaphragm was done to eliminate the effect of the physical removal of bacteria by the first swab.
Swabs were labeled with date and time. Each participant was assigned a unique identification number and anonymity was maintained. All samples were taken to the microbiology laboratory of the Pathology Department of Lahore General Hospital. All swabs were inoculated on Blood and MacConkey agar plates and incubated for 24 hours aerobically at 37°C. After 24 hours, all plates were examined for growth. If there was growth on plates, then the organisms were identified by Gram staining, oxidase test, catalase test, and biochemical tests according to standard microbiological procedures.
We included those stethoscopes which were in use for at least 1 month and were owned by Doctor of Medical units in hospitals. We excluded stethoscopes that were shared by more than one person in the common area and with damaged diaphragms or tubing.
All the data was entered and analyzed using IBM SPSS version 25.0 (Armonk, NY). In this study, we evaluated the frequency and response of doctors to questionnaires distributed and the contamination rate of stethoscopes before and after disinfecting with isopropyl alcohol.
RESULTS
Stethoscopes of 78 doctors were sampled in the study from medical unit “A” 40 (51%) doctors, medical unit “B” 16 (21%) doctors, and medical unit “C” 22 (28%) doctors, which included 45 (58%) males and 33 (42%) females. Out of 78 doctors, 36 (46%) were house officers, 33 (42%) were medical officers, and 9 (12%) were consultants. Before decontamination of diaphragms with isopropyl alcohol, 27 (34.6%) diaphragms had “growth” while 51 (65.4%) had “no growth.” After decontamination with isopropyl alcohol, 5 (6.4%) had “growth” while 73 (93.6%) had “no growth” (Figure 1). The most common microorganism isolated from stethoscopes’ diaphragms was methicillin-resistant Staphylococcus epidermidis (MRSE), that is, 14 out of 78 (17.9%). Other microorganisms isolated from diaphragms are shown in Figure 2.
Figure 1.
Contamination of diaphragms before and after decontamination with isopropyl alcohol. This figure appears in color at www.ajtmh.org.
Figure 2.
Frequency to microorganisms isolated from diaphragms before and after decontamination with isopropyl alcohol. MRSA = Methicillin resistant Staphylococcus aureus; MRSE = Methicillin resistant Staphylococcus epidermidis; MSSA = Methicillin sensitive Staphylococcus aureus; MSSE = Methicillin sensitive Staphylococcus epidermidis. This figure appears in color at www.ajtmh.org.
Questionnaires filled by doctors revealed that 71 (91%) doctors believe that stethoscopes can be a source of infection. Most doctors (55.1%, N = 43) responded that both diaphragm and bell of stethoscopes can transmit infections. The highest number of doctors (41%, N = 32) reported that “forgetfulness/laziness” was the barrier which they faced regarding stethoscope hygiene followed by “lack of time” (21.8%, N = 17) as shown in Table 1. Questionnaires filled by doctors also revealed that 30 doctors (38.5%) never decontaminated their stethoscopes. From 30 doctors who never decontaminated their stethoscopes, 17 had growth in their stethoscopes before cleaning with isopropyl alcohol, while three had growth even after decontamination. Most doctors used sanitizer (29.5%) and alcohol (25.6%) as a cleaning agent (Table 2).
Table 1.
Response to questionnaire from doctors
| Questions asked | No. (%) of doctors responded | |
|---|---|---|
| Stethoscopes as source of infection | ||
| Yes | 71 (91%) | |
| No | 1 (1.3%) | |
| Sometimes | 6 (7.7%) | |
| Habit of practicing hand hygiene in between patient examination | ||
| Yes | 57 (73.1%) | |
| No | 21 (26.9%) | |
| Part of stethoscope transmitting infection | ||
| Diaphragm | 24 (30.8%) | |
| Bell | 2 (2.6%) | |
| Both a and b | 43 (55.1%) | |
| Tubing | 1 (1.3%) | |
| Earpiece | 1 (1.3%) | |
| All of these | 7 (9%) | |
| Barrier in stethoscope hygiene | ||
| Lack of time | 17 (21.8%) | |
| Forgetfulness/Laziness | 32 (41%) | |
| Lack of knowledge regarding disinfection of stethoscope | 4 (5.1%) | |
| Lack of access to disinfectant | 14 (17.9%) | |
| Unspecified | 11 (14.1%) | |
| Participation in infection prevention program | ||
| Yes | 30 (38.5%) | |
| No | 48 (61.5%) | |
Table 2.
Decontamination practices of doctors and corresponding contamination rate of stethoscopes before and after decontamination with isopropyl alcohol
| Methods | No. (%) of doctors responded | No. (%) of stethoscopes contaminated | |
|---|---|---|---|
| Before decontamination | After decontamination | ||
| Duration of use of stethoscope | |||
| 1–6 months | 21 (26.9%) | 5/21 (23.8%) | 1/21 (4.7%) |
| 6–12 months | 18 (23.1%) | 8/18 (44.4%) | 1/18 (5.5%) |
| 1–3 years | 29 (37.2%) | 10/29 (34.4%) | 3/29 (10.3%) |
| > 3 years | 10 (7.7%) | 4/10 (40%) | 0/10 (0%) |
| Cleaning of stethoscope | |||
| Regularly | 4 (5.1%) | 1/4 (25%) | 1/4 (25%) |
| Occasionally | 44 (56.4%) | 9/44 (20.4%) | 1/44 (2.3%) |
| Never | 30 (38.4%) | 17/30 (56.7%) | 3/30 (10%) |
| Stethoscopes last time decontaminated | |||
| 1 week or less | 13 (16.7%) | 1/13 (7.7%) | 0/13 (0%) |
| 1–4 weeks | 21 (26.9%) | 3/21 (14.3%) | 2/21 (9.6%) |
| 4–8 weeks | 5 (6.4%) | 2/5 (40%) | 0/5 (0%) |
| More than 8 weeks | 9 (11.5%) | 4/9 (44.4%) | 0/9 (0%) |
| Never | 30 (38.5%) | 17/30 (56.7%) | 3/30 (10%) |
| Cleaning agent used to clean stethoscopes | |||
| Alcohol | 20 (25.6%) | 4/20 (20%) | 1/20 (5%) |
| Water only | 3 (3.8%) | 1/3 (33%) | 0/3 (0%) |
| Soap and water | 1 (1.3%) | 0 (0%) | 0/1 (0%) |
| Sanitizer | 23 (29.5%) | 7/23 (30.4%) | 1/23 (4.3%) |
| Others | 1 (1.3%) | 0 (0%) | 0/1 (0%) |
| Never used | 30 (38.5%) | 17/30 (56.7%) | 3/30 (10%) |
Table 3 demonstrated the factors that were found associated with the hygiene practices and growth of microorganism from the stethoscopes. Medical officers and those with job duration of more than 4 years were at a slightly higher risk of contaminated stethoscopes on multivariable analysis (P = 0.055), while practicing hand hygiene in between patient examination (P = 0.042) and performing both washing and rubbing reduces the risk of contaminating stethoscopes (P = 0.008) as compared with rubbing (OR: 0.3) and washing alone (OR: 0.5). However, none of the other factors like type of cleaning agent used for disinfection, place of keeping stethoscopes, duration of use of stethoscope, number of patients examined per day, number of persons using the same stethoscope, and placement of diaphragm while examination was found insignificant on regression analysis as shown in Table 3.
Table 3.
Factors of decontamination practices of doctors associated with contamination of stethoscopes
| Factors | Total N (%) | Regression analysis | |||
|---|---|---|---|---|---|
| Crude OR (95% CI) | P value | Adjusted OR (95% CI) | P value | ||
| Gender | |||||
| Male | 45 (57.7%) | 0.875 (0.341–2.244) | 0.781 | – | |
| Female | 33 (42.3%) | 1.000 | – | ||
| Designation | |||||
| House officer | 37 (47.4%) | 1.000 | 1.000 | ||
| Medical officer | 32 (41.0%) | 2.420 (0.868–6.748) | 0.091 | 2.874 (0.976–8.460) | 0.055 |
| Consultant | 9 (11.5%) | 2.489 (0.548–11.313) | 0.238 | 3.093 (0.652–14.670) | 0.155 |
| Job duration | |||||
| < 1 year | 37 (47.4%) | 1.000 | |||
| 1–4 years | 24 (30.8%) | 2.222 (0.736–6.714) | 0.157 | 2.600 (0.819–8.257) | 0.105 |
| More than 4 years | 17 (21.8%) | 2.765 (0.822–9.300) | 0.100 | 3.446 (0.972–12.219) | 0.055 |
| Working hours | |||||
| < 6 hours | 16 (20.5%) | 1.000 | – | ||
| 6–8 hours | 32 (41.0%) | 1.800 (0.472–6.867) | 0.390 | – | |
| 8–10 hours | 18 (23.1%) | 1.154 (0.250–5.335) | 0.855 | – | |
| > 10 hours | 12 (15.4%) | 3.000 (0.606–14.864 | 0.178 | – | |
| Hand hygiene habit | |||||
| Yes | 57 (73.1%) | 0.355 (0.126–0.997) | 0.049* | 0.337 (0.118–0.961) | 0.042* |
| No | 21 (26.9%) | 1.000 | 1.000 | ||
| Hand hygiene practices | |||||
| Hand rub | 16 (20.5%) | 0.318 (0.076–1.332) | 0.117 | 0.307 (0.072–1.312) | 0.111 |
| Hand washing | 12 (15.4%) | 0.500 (0.112–2.241) | 0.365 | 0.536 (0.119–2.417) | 0.417 |
| Both washing and rubbing | 33 (42.3%) | 0.188 (0.053–0.675) | 0.010* | 0.168 (0.045–0.628) | 0.008* |
| Not applicable | 17 (21.8%) | 1.000 | 1.000 | ||
| Number of patients auscultated per day | |||||
| < 10 patients | 39 (50.0%) | 1.000 | – | ||
| 10–30 patients | 30 (38.5%) | 1.125 (0.406–3.117) | 0.821 | – | |
| More than 30 patients | 9 (11.5%) | 2.812 (0.640–12.358) | 0.171 | – | |
| Sharing of stethoscope | |||||
| One doctor only | 47 (60.3%) | 1.000 | – | ||
| Two to three doctors | 25 (32.1%) | 0.912 (0.324–2.565) | 0.861 | – | |
| More than three doctors | 6 (7.7%) | 1.938 (0.350–10.715) | 0.448 | – | |
| Diaphragm placement on patient | |||||
| Directly on skin | 11 (14.1%) | 0.637 (0.151–2.683) | 0.539 | – | |
| Over clothes | 13 (16.7%) | 0.756 (0.206–2.775) | 0.673 | – | |
| Both | 54 (69.2%) | 1.000 | – | ||
| Duration of use of stethoscope | |||||
| 1–6 months | 21 (26.9%) | 0.469 (0.093–2.357) | 0.358 | – | |
| 6–12 months | 18 (23.1%) | 1.200 (0.250–5.768) | 0.820 | – | |
| 1–3 years | 29 (37.2%) | 0.789 (0.180–3.464) | 0.754 | – | |
| > 3 years | 10 (12.8%) | 1.000 | – | ||
| Place of keeping stethoscope | |||||
| In bag | 40 (51.3%) | 0.857 (0.261–2.819) | 0.800 | – | |
| In car | 20 (25.6%) | 1.636 (0.438–6.112) | 0.464 | – | |
| In locker or other places | 18 (23.1%) | 1.000 | – | ||
| Stethoscopes decontaminated (last time) | |||||
| 1 week or less | 13 (16.7%) | 0.889 (0.219–3.609) | 0.869 | – | |
| 1–4 weeks | 21 (26.9%) | 1.500 (0.475–4.739) | 0.490 | – | |
| More than 4 weeks | 14 (17.9%) | 0.800 (0.200–3.199) | 0.752 | – | |
| Never | 30 (38.5%) | 1.000 | – | ||
| Cleaning agent used to clean stethoscopes | |||||
| Alcohol | 21 (26.9%) | 0.950 (0.290–3.114) | 0.933 | – | |
| Soap/water | 5 (6.4%) | 0.475 (0.047–4.839) | 0.530 | – | |
| Sanitizer | 23 (29.5%) | 1.221 (0.393–3.799) | 0.730 | – | |
| Never used | 29 (37.2%) | 1.000 | – | ||
| Part of stethoscope transmitting infection | |||||
| Diaphragm | 24 (30.8%) | 1.200 (0.239–6.025) | 0.825 | – | |
| Both bell and diaphragm | 45 (57.7%) | 1.000 (0.219–4.564) | 1.000 | – | |
| Tubing/Earpiece/All of these | 9 (11.5%) | 1.000 | – | ||
| Barriers in stethoscope hygiene | |||||
| Lack of time | 17 (21.8%) | 2.567 (0.518–12.723) | 0.248 | – | |
| Forgetfulness/Laziness | 32 (41.0%) | 2.200 (0.509–9.507) | 0.291 | – | |
| Lack of access to disinfectant | 14 (17.9%) | 1.833 (0.346–9.719) | 0.476 | – | |
| Lack of knowledge/Unspecified reason | 15 (19.2%) | 1.000 | – | ||
| Participation in infection prevention program | |||||
| Yes | 30 (38.5%) | 0.912 (0.348–2.387) | 0.851 | – | |
| No | 48 (61.5%) | 1.000 | – | ||
DISCUSSION
In this study, 34.6% of stethoscopes were positive for bacterial growth before decontamination and 6.4% were found to have bacterial growth even after decontamination with isopropyl alcohol. In contrast to this study, other studies reported contamination rates as 56%, 72%, and 78% irrespective of the cleaning status of stethoscopes.3,6,13 The difference in contamination rates could be due to relatively cleaner hygiene practices in our hospital and more awareness among the doctors regarding disinfection practices.14 Other reasons could be personal errors in the sampling and small sample size.
Isopropyl alcohol is observed as an effective cleaning agent with a low cost.2 After cleaning diaphragms with isopropyl alcohol contamination rate decreased from 34.6% to 6.4% in our study. This finding is similar to the study done in India, which reported the decrease in contamination rate from 56% to 5% after cleaning with 70% isopropyl alcohol.6 On the other hand, 6.4% of stethoscopes remained contaminated after decontamination with isopropyl alcohol. It is comparable to the studies by Horiuchi et al.2 and Fenelon et al.15 which showed that few bacteria were resistant to isopropyl alcohol.
The results of the present study revealed contamination of stethoscopes with potentially pathogenic microorganisms such as MRSA, Acinetobacter spp., and Klebsiella spp. Other studies by Datta et al. and Lavanya et al. also reported similar findings.6,16 Therefore, stethoscopes can act as a vector of transmission of pathogenic MDR bacteria among hospitalized patients leading to potentially life-threatening infections.3 In Figure 2, MRSE and Methicillin sensitive Staphylococcus epidermidis (MSSE) ratio is greater than MRSA and MSSA ratio, which is consistent with the study of other authors.3,16 Staphylococcus epidermidis (Coagulase-negative Staphylococcus CoNS) causes prosthetic valve endocarditis, with a high rate of intracardiac abscesses and mortality.17
Our study showed that three (3.8%) diaphragms were contaminated with MRSA. Two stethoscopes (2.5%) were contaminated before the use of isopropyl alcohol, while one stethoscope (1.3%) was found to be contaminated even after decontamination with alcohol. Similar to our results, many other studies also isolated MRSA from contaminated stethoscopes in their setups.6,13 Methicillin-resistant Staphylococcus aureus is a multidrug resistant pathogen. Its isolation from stethoscopes is an alarming situation, as MRSA is both difficult to decontaminate and treat.18,19 In this study, we also isolated Acinetobacter spp. from stethoscope diaphragms. Various studies have also reported Acinetobacter spp. from stethoscopes.6,20,21 Acinetobacter spp. has emerged as a potentially dangerous hospital-acquired pathogen and is progressively acquiring resistance to multiple antimicrobial agents.6,22 A new development is the emergence of extremely drug-resistant Acinetobacter spp. with colistin as the last resort drug.23 Klebsiella spp. was also isolated from stethoscopes diaphragms in this study (1.3%). Multidrug-resistant Klebsiella spp. has been reported in various studies.9,24,25 Studies by Shiferaw et al. and Daoudi et al. have reported MDR strains of Klebsiella spp. isolated from the stethoscopes of the doctors.9,25
The results in Figures 1 and 2 clearly show that isopropyl alcohol is a good cleaning agent and reduces contamination but does not eliminate the pathogens from contaminated stethoscopes. Knecht et al. revealed that hydrogen peroxide is a better cleaning agent than others, for example, isopropyl alcohol and sodium hypochlorite but none of these cleaning agents were successful to eliminate the pathogens.21
On review of survey data in this study, 91% of doctors think that stethoscopes can transmit infections (Table 1). This response is like another study by Datta et al.6 which showed 100% and in contrast to this study, Rao et al.1 showed that 61% of doctors think that stethoscopes can transmit infections. For patients’ and doctors’ safety, hand hygiene habits are very important. In our survey, the response of questionnaires from doctors revealed that 73.1% practice hand hygiene in between patient examination. In contrast, the study of Thappa and Sapokta shows that only 21.3% of doctors practice hand hygiene in between patient examination.3
In this study, most doctors (55.1%) responded that both diaphragm and bell can transmit infection while a study conducted in India in 2015 showed that most doctors (83.7%) think that only diaphragm can transmit infection.6 This perception is due to more usage of the diaphragm of the stethoscope as in a study by Datta et al. but now as knowledge and awareness in doctors has been increased so any part of the stethoscope can transmit infection as in this study.6 Our findings revealed that the most common barrier in stethoscope hygiene was “forgetfulness/laziness” (41%) followed by “lack of time” (21.8%). In contrast, the study of Thappa and Sapkota reported a lack of time (35.2%) as the most common barrier in stethoscope hygiene.3 Hence by changing behavioral attitudes, getting knowledge, and setting protocols in hospitals regarding duty hours and hygiene practices, the transmission of infection can be prevented.1
Table 1 showed that only 38.5% of doctors had participated in the infection prevention program. So, there is a need for the arrangement of targeted infection prevention programs in our hospital settings, and health workers should be compelled to attend them. Table 2 showcased that the lowest contamination rate (23.8%) was observed in those stethoscopes which were comparatively newer and in use for only 1–6 months, but the pattern of contamination rate is not specific with the duration of stethoscope use. So important thing is how frequent doctors are decontaminating their stethoscopes and which cleaning agent is being used by them as we found out in this survey, that 38.5% of doctors never decontaminated their stethoscopes. Thappa and Sapokta reported 27.8% and Datta et al. reported 36.7% of doctors never decontaminated their stethoscopes, which is comparable with our study.3,6 About 38.5% of doctors who never cleaned their stethoscopes showed 56.7% bacterial growth before decontamination and 10% even after decontamination with isopropyl alcohol. Doctors who cleaned their stethoscopes more frequently showed a lesser contamination rate of only 7% as compared with those who did not clean, and stethoscopes’ contamination rate became 0% after cleaning with alcohol. A similar pattern was reported in other studies.3,26
It was observed in our study that despite the healthcare providers know the role of stethoscopes in the transmission of diseases, only a few doctors (5%) were indulged in cleaning practices to prevent such transmission. Similar results were depicted in other studies.6,27 According to the CDC recommendations, surfaces of stethoscopes should be decontaminated regularly and cleaning of stethoscopes with a disinfectant, after examining every patient, would minimize the spread of nosocomial infections.5,28 About 25.6% of doctors used alcohol as a cleaning agent for the stethoscopes and only 20% contamination rate was found on their stethoscopes while 30.4% contamination rate was found on the stethoscopes which were cleaned by sanitizers as reported by the doctors. The highest contamination rate (56.7%) was found on the doctors’ stethoscopes who never used any cleaning agent. When diaphragms of their stethoscopes were decontaminated with isopropyl alcohol, the contamination rate was reduced to only 10%. So isopropyl alcohol is an effective cleaning agent as reported by Horiuchi et al.2 and Martinez et al.2,13
A study with 18% contaminated stethoscopes also revealed that no stethoscopes were disinfected before use near open chest or abdominal wounds. Hands were cleaned before and after encounters only 27 times (6.8% of 400) and were not cleaned at all in 58% of encounters.29 A local study conducted in Karachi also depicted similar findings such as only 18% of participants cleaned their stethoscopes regularly.1 Data from departments such as medicine and orthopedics,30 intensive care unit,31 pediatrics32 have also suggested similar outcomes. Few studies have shown no MRSA growth in the contaminated stethoscopes,33 while majority of the studies shown staphylococcal species as most growing organism either sensitive or resistant to methicillin.34,35 Interventional studies focusing on stethoscopes contamination have also yield significant results specially when reporting quantification of colony forming units.35 Use of aseptic barriers have also shown promising results in reducing the transmission of pathogens via stethoscopes.36
Regarding study limitations, we only analyzed bacterial agents as a contamination source because they are easier to isolate. We did not analyze other contaminating organisms like fungi and viruses. The other was a lack of comparison of isopropyl alcohol with other cleaning agents, for example, hydrogen peroxide, sodium hypochlorite, chlorhexidine, ethyl alcohol. Lastly, our sample size was small because of limited resources. However, the strength of this study included that we imposed evidence-based practices and disseminated our findings in seminars and workshops related to infection prevention in our institution which would subsequently be fruitful in quality improvement of our healthcare system. Furthermore, there are observational and laboratory studies showing some organisms that do not get killed with isopropyl alcohol highlight the fact that it may be a temporizing measure, and further better measures need to be in place. Such as, use of barrier devices has recently been getting popularity for keeping stethoscopes aseptic and clean.11,12,37,38 Interventions at the hospital level will improve and makes things more consistent than at individual level.
CONCLUSION
Based on the results of this study, it is evident that stethoscopes can be a source of many pathogenic bacteria. Hence, nosocomial infections can be reduced by implementing simple disinfection practices. Healthcare workers (HCWs) need motivation and education regarding stethoscope hygiene. The availability of 70% isopropyl alcohol swabs by hospital management at the patient’s bedside in the wards can reduce the burden of nosocomial infections. As isopropyl alcohol swabs are easily available and very cost-effective, HCWs can buy themselves easily if not available in health settings. Now, new studies are required to find out such low-cost cleaning agents that could eliminate the pathogens from stethoscopes. Since HCWs need motivation and education regarding stethoscope hygiene, workshops and seminars were carried out subsequently in the hospital to disseminate these findings and to provide awareness regarding the curtailment of transmission if good hygiene practices and disinfection of stethoscopes by isopropyl alcohol is carried out regularly. Factors such as practicing hand hygiene between patient examination and both rubbing and washing hands simultaneously were found significant in our survey and were emphasized upon in those quality improvement seminar and workshops while promoting good hygiene practices in hospital environment.
ACKNOWLEDGMENTS
We thank the doctors who participated in this study and helped in data collection and analysis. We especially express gratitude to the Department of Pathology, Lahore General Hospital, Lahore, Pakistan. The American Society of Tropical Medicine and Hygiene (ASTMH) assisted with publication expenses.
REFERENCES
- 1. Rao DA, Aman A, Muhammad Mubeen S, Shah A, 2017. Bacterial contamination and stethoscope disinfection practices: a cross-sectional survey of healthcare workers in Karachi, Pakistan. Trop Doct 47: 226–230. [DOI] [PubMed] [Google Scholar]
- 2. Horiuchi Y, Wettersten N, Vasudevan RS, Barnett O, Maisel AS, 2018. Stethoscope as a vector for infectious disease. Curr Emerg Hosp Med Rep 6: 120–125. [Google Scholar]
- 3. Thapa S, Sapkota LB, 2017. Bacteriological assessment of stethoscopes used by healthcare workers in a tertiary care centre of Nepal. BMC Res Notes 10: 353. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Weldegebreal F, Admassu D, Meaza D, Asfaw M, 2019. Non-critical healthcare tools as a potential source of healthcare-acquired bacterial infections in eastern Ethiopia: a hospital-based cross-sectional study. SAGE Open Med 7: 2050312118822627. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Bansal A, Bhan BD, Gupta K, Purwar S, 2019. To assess the stethoscope cleaning practices, microbial load and efficacy of cleaning stethoscopes with alcohol-based disinfectant in a tertiary care hospital. J Infect Prev 20: 46–50. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Datta P, Kaur M, Rawat S, Gupta V, Chander J, 2018. Stethoscope, “the friendly foe”—a study to evaluate bacterial contamination of stethoscopes and disinfection practices. J Infect Dev Ctries 12: 887–893. [DOI] [PubMed] [Google Scholar]
- 7. Álvarez JA, Ruíz SR, Mosqueda JL, León X, Arreguín V, Macías AE, Macias JH, 2016. Decontamination of stethoscope membranes with chlorhexidine: should it be recommended? Am J Infect Control 44: e205–e209. [DOI] [PubMed] [Google Scholar]
- 8. O’Flaherty N, Fenelon L, 2015. The stethoscope and healthcare-associated infection: a snake in the grass or innocent bystander? J Hosp Infect 91: 1–7. [DOI] [PubMed] [Google Scholar]
- 9. Shiferaw T, Beyene G, Kassa T, Sewunet T, 2013. Bacterial contamination, bacterial profile and antimicrobial susceptibility pattern of isolates from stethoscopes at Jimma University Specialized Hospital. Ann Clin Microbiol Antimicrob 12: 39. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10. Jenkins IH, Monash B, Wu J, Amin A, 2015. The third hand: low rates of stethoscope hygiene on general medical services. J Hosp Med 10: 457–458. [DOI] [PubMed] [Google Scholar]
- 11. The Third Hand Available at: https://diskcover.com/the-third-hand/. Accessed March 19, 2022.
- 12. AseptiScope A Clean Glove for the Clinician’s Third Hand. Available at: https://infection-control-solutions.medicaltechoutlook.com/vendor/aseptiscope-a-clean-glove-for-the-clinician-s-third-hand-cid-877-mid-85.html. Accessed March 19, 2022.
- 13. Martínez J, Macías JH, Arreguín V, Álvarez JA, Macías AE, Mosqueda-Gómez JL, 2017. Isopropyl alcohol is as efficient as chlorhexidine to prevent contamination of blood cultures. Am J Infect Control 45: 350–353. [DOI] [PubMed] [Google Scholar]
- 14. Jain A, Shah H, Jain A, Sharma M, 2013. Disinfection of stethoscopes: gap between knowledge and practice in an Indian tertiary care hospital. Ann Trop Med Public Health 6: 236. [Google Scholar]
- 15. Fenelon L, Holcroft L, Waters N, 2009. Contamination of stethoscopes with MRSA and current disinfection practices. J Hosp Infect 71: 376–378. [DOI] [PubMed] [Google Scholar]
- 16. Lavanya J, Jais M, Kumar V, Dutta R, 2013. Accessories of health care workers: a boon or a curse to patients in pediatric ICU and nursery. Int J Curr Microbiol Appl Sci 2: 441–447. [Google Scholar]
- 17. Carugati M. et al. , 2016. Antistaphylococcal β-lactams versus vancomycin for treatment of infective endocarditis due to methicillin-susceptible coagulase-negative Staphylococci: a prospective cohort study from the International Collaboration on Endocarditis. Antimicrob Agents Chemother 60: 6341–6349. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. Melander RJ, Melander C, 2017. The challenge of overcoming antibiotic resistance: an adjuvant approach? ACS Infect Dis 3: 559–563. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Lewis PO, Heil EL, Covert KL, Cluck DB, 2018. Treatment strategies for persistent methicillin‐resistant Staphylococcus aureus bacteraemia. J Clin Pharm Ther 43: 614–625. [DOI] [PubMed] [Google Scholar]
- 20. Campos-Murguía A, León-Lara X, Muñoz JM, Macías AE, Álvarez JA, 2014. Stethoscopes as potential intrahospital carriers of pathogenic microorganisms. Am J Infect Control 42: 82–83. [DOI] [PubMed] [Google Scholar]
- 21. Knecht VR, McGinniss JE, Shankar HM, Clarke EL, Kelly BJ, Imai I, Fitzgerald AS, Bittinger K, Bushman FD, Collman RG, 2019. Molecular analysis of bacterial contamination on stethoscopes in an intensive care unit. Infect Control Hosp Epidemiol 40: 171–177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22. Kumburu HH, Sonda T, van Zwetselaar M, Leekitcharoenphon P, Lukjancenko O, Mmbaga BT, Alifrangis M, Lund O, Aarestrup FM, Kibiki GS, 2019. Using WGS to identify antibiotic resistance genes and predict antimicrobial resistance phenotypes in MDR Acinetobacter baumannii in Tanzania. J Antimicrob Chemother 74: 1484–1493. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Al-Khafaji Z, Al-Samaree M, 2017. Design of synthetic antimicrobial peptides against resistant Acinetobacter baumannii using computational approach. Int J Pharm Sci Res 8: 2033–2039. [Google Scholar]
- 24. Malik M, Malik MI, Akhtar FK, 2019. Microbiological profile and antibiogram of lower respiratory tract infections at Lahore General Hospital, Lahore. J Postgrad Med Inst 33: 23–29. [Google Scholar]
- 25. Daoudi A, El IdrissiSlitine N, Bennaoui F, Alaoui M, Soraa N, Maoulainine FM, 2017. Study of bacterial contamination of mobile phones and stethoscopes in neonatal intensive care unit. Int J Pediatr 5: 6139–6142. [Google Scholar]
- 26. Ahmed K, Shaikh S, Rehman R, Ali SM, 2018. Frequency of awareness and practice of stethoscope hygiene with regards to guideline among medical students, residents and doctors in Karachi. J Bahria Univ Med Dental Coll 8: 31–34. [Google Scholar]
- 27. Bošković S, Sharawy K, Rodriguez AS, Savić B, 2015. Bacterial contamination of stethoscopes in university hospitals: multicenter study. Medicinskipodmladak 66: 55–60. [Google Scholar]
- 28. Centers for Disease Control and Prevention, National Center for Preparedness, Detection, and Control of Infectious Diseases, Division of Healthcare Quality Promotion Guideline for Disinfection and Sterilization in Healthcare Facilities—2008. Available at: https://www.cdc.gov/infectioncontrol/guidelines/disinfection/index.html. Accessed December 12, 2008.
- 29. Boulée D, Kalra S, Haddock A, Johnson TD, Peacock WF, 2019. Contemporary stethoscope cleaning practices: what we haven’t learned in 150 years. Am J Infect Control 47: 238–242. [DOI] [PubMed] [Google Scholar]
- 30. Longtin Y, Schneider A, Tschopp C, Renzi G, Gayet-Ageron A, Schrenzel J, Pittet D, 2014. Contamination of stethoscopes and physicians’ hands after a physical examination. Mayo Clin Proc 89: 291–299. [DOI] [PubMed] [Google Scholar]
- 31. Whittington AM, Whitlow G, Hewson D, Thomas C, Brett SJ, 2009. Bacterial contamination of stethoscopes on the intensive care unit. Anaesthesia 64: 620–624. [DOI] [PubMed] [Google Scholar]
- 32. Muniz J, Sethi RK, Zaghi J, Ziniel SI, Sandora TJ, 2012. Predictors of stethoscope disinfection among pediatric health care providers. Am J Infect Control 40: 922–925. [DOI] [PubMed] [Google Scholar]
- 33. Bukharie HA, Al-Zahrani H, Rubaish AM, Abdulmohsen MF, 2004. Bacterial contamination of stethoscopes. J Family Community Med 11: 31–33. [PMC free article] [PubMed] [Google Scholar]
- 34. Uneke CJ, Ogbonna A, Oyibo PG, Onu CM, 2010. Bacterial contamination of stethoscopes used by health workers: public health implications. J Infect Dev Ctries 4: 436–441. [DOI] [PubMed] [Google Scholar]
- 35. Lee R, Choi SM, Jo SJ, Han S, Park YJ, Choi MA, Kong BK, 2021. A quasi-experimental study on stethoscopes contamination with multidrug-resistant bacteria: its role as a vehicle of transmission. PLOS One 16: e0250455. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36. Vasudevan R, Shin JH, Chopyk J, Peacock WF, Torriani FJ, Maisel AS, Pride DT, 2020. Aseptic barriers allow a clean contact for contaminated stethoscope diaphragms. Mayo Clin Proc Innov Qual Outcomes 4: 21–30. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37. Amin A, 2021. Keeping the stethoscope, the clinician’s third hand, clean. Infect Control Today 25. Available at: https://www.infectioncontroltoday.com/view/keeping-the-stethoscope-the-clinician-s-third-hand-clean. Accessed March 19, 2022.
- 38. Vasudevan RS, Horiuchi Y, Torriani FJ, Cotter B, Maisel SM, Dadwal SS, Gaynes R, Maisel AS, 2020. Persistent value of the stethoscope in the age of COVID-19. Am J Med 133: 1143–1150. [DOI] [PMC free article] [PubMed] [Google Scholar]