Disinfection of stethoscopes: Gap between knowledge and practice in an Indian tertiary care hospital


Context: Stethoscopes are used primarily to assess the health of patients and are one of the most commonly used medical devices. Thus, are the prominent tools for the spread of health-care associated infections (HAIs). Aims: The study was conducted to assess the knowledge and awareness about handling of the stethoscope and cleaning practices followed among the healthcare workers (HCWs). Materials and Methods: A total of 80 participants were included during a 4-month study period at a tertiary care hospital in Ujjain. A semi-structured questionnaire was distributed to HCWs and the surface of the diaphragm of their stethoscopes were swabbed for bacteriological analysis using standard techniques. Results: Out of total 80 stethoscopes, 69 (86%) were found to be contaminated with at least one type of microorganism. Pseudomonas aeruginosa was the most predominant bacterial species found on 58 stethoscopes, followed by Bacillus subtilis (n = 21) and Staphylococcus spp. (n = 16). Out of total 10 S. aureus isolated, 3 were methicillin-resistant S. aureus ( MRSA). Majority (97%) of the HCWs had good knowledge about the topic, but only 22 (27%) reported to apply it in the practice. Conclusions: Our study confirmed that majority of the stethoscopes were contaminated with microorganisms. Besides having knowledge about the importance of cleaning the stethoscopes, lower percentage of HCWs reported to follow it in practice. Thus, the authors recommend regularization of reminders such as circulars, motivating posters for the HCWs to clean the diaphragm of the stethoscopes.

Keywords: Bacterial contamination, disinfection practice, India, stethoscope, teaching hospital

How to cite this article:
Jain A, Shah H, Jain A, Sharma M. Disinfection of stethoscopes: Gap between knowledge and practice in an Indian tertiary care hospital. Ann Trop Med Public Health 2013;6:236-9
How to cite this URL:
Jain A, Shah H, Jain A, Sharma M. Disinfection of stethoscopes: Gap between knowledge and practice in an Indian tertiary care hospital. Ann Trop Med Public Health [serial online] 2013 [cited 2020 Oct 31];6:236-9. Available from: https://www.atmph.org/text.asp?2013/6/2/236/116503

Health-care associated infections (HAIs) are caused by microorganisms present in the hospital enviorment and are on the rise worldwide. These infections increase morbidity and mortality, cost of therapy, and duration of hospitalization. The HAIs can be caused either via contaminated hands of healthcare workers (HCWs), contaminated instruments, and medical devices, or infected hospital environment. About one-third of all HAIs are preventable. [1] Prior to planning the preventive actions, it is essential to identify the reservoirs of microorganisms that may cause HAIs, such as surgical instruments, ventilators, endoscopes, otscopes, stethoscopes, etc. [2],[3],[4]

Stethoscopes are one of the most commonly used medical devices and are commonly used by almost all the HCWs wiz doctors, nurses, and medical and nursing students. Direct contact of a stethoscope with multiple patients makes it a potential vector for HAIs worldwide. [5],[6],[7] There are reports of the risk of transmitting antibiotic-resistant microorganisms from one patient to another via stethoscopes. [8],[9] Despite these known facts, disinfection of stethoscopes has been neglected, and generally routine disinfection of stethoscopes is hardly ever undertaken. [10] This consequently might increase the number of HAIs, specifically in the healthcare facilities of the low- and middle-income countries like India, where overcrowding and high patient pressure puts them at higher risk.

Aims and Objectives

The objectives of this study were (1) to assess knowledge, awareness, and practices (KAP) of HCWs about handling of stethoscope; (2) to study the presence of the microbial flora on diaphragm of the stethoscopes; and (3) to study antimicrobial sensitivity pattern of the identified isolates. The long-term aim of the study is to improve the practice of cleaning stethoscopes in the setting.

Materials and Methods

The study was conducted in a tertiary care teaching hospital from January to April 2011. The hospital is located in Ujjain district in Central part of India. The study was approved by the ethics committee of R. D. Gardi Medical College, Ujjain (Letter number 131-2011).

A questionnaire was locally developed to record the KAP of HCWs regarding the usage, handling, and maintenance of their stethoscopes. The authors visited various outdoor patients departments (OPDs) of the hospital for the data collection. Out of total 82 HCWs approached, two refused due to emergency duties while the rest gave their consent to participate in the study. Only those HCWs that carried stethoscopes at the time of visit were included in the study.

Each participant filled the questionnaire and the stethoscopes of all HCWs enrolled for the study were swabbed. The surface of the diaphragm was swabbed using standard laboratory techniques and transferred to the microbiology laboratory. The swabs were inoculated directly on blood and MacConkey agar and incubated aerobically for 24-48 h at 37°C. The positive growths were subsequently identified using standard microbiological procedures. [11] Antibiotic sensitivity testing was performed on bacterial isolates using Kirby Bauer disk diffusion method and commercially available disks (Hi-Media Private Laboratories Limited, Mumbai, India).


Out of total 80 participants, 61 were doctors and the rest were nurses. Thirty-five (44%) participants were females, which included all the nursing staff.

All the HCWs (100%) were aware that stethoscopes should be disinfected regularly, while the level of this knowledge varied. In total, 35 (44%) HCWs knew that stethoscopes should be cleaned daily or more frequently, out of which 27 were doctors and the rest nurses. Forty-six HCWs (58%) expressed equivocal importance to the disinfection of stethoscope practice, whereas 16% gave least importance to it. The overall assessment of the filled questionnaires revealed that 78 (97%) HCWs had good knowledge of the role of stethoscopes in the spread of HAIs.

Out of total 61 doctors who participated in the study, only 17 (27%) reported to disinfect the stethoscope once in a week and 14 (22%) reported cleaning their stethoscopes either once in a fortnight or once in a month. Ten (16%) doctors accepted that they had never disinfected their stethoscopes. Overall, 22 (17 doctors and 5 nurses) reported using ethyl alcohol to disinfect their stethoscopes, while 6 (7.5%) doctors reported cleaning their stethoscopes by wiping them with plain cloth. Among the total 19 nursing staff recruited for the study, 9 (47%) reported that they had disinfected their stethoscopes in the last 15 days. Five nurses (26%) claimed that they had never cleaned their stethoscopes. All the nurses accepted that they share stethoscopes with their colleagues, while 68% doctors admitted sharing of stethoscopes. Majority (95%) of the HCWs reported to carry the stethoscopes with them, either around their neck or in bags.

Out of total 80 stethoscopes swabbed, 69 (86%) were found to be loaded with various microorganisms. Among these, 28 (35%) showed the presence of more than one microorganism, whereas 11 did not show any growth. Out of the total 10 Staphylococcus aureus isolates, three were methicillin-resistant S. aureus (MRSA) [Table 1].

Table 1: Distribution of bacterial isolates from stethoscopes of doctors and nurses

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The results of antibiotic sensitivity testing indicated that Pseudomonas aeruginosa had the highest sensitivity to imipenem (95%) and amikacin (80%), while gentamicin, ciprofloxacin, and piperacillin were 75% sensitive. In Staphylococcus group, amikacin (81%) was the highest effective drug other than vancomycin (100%), while gentamicin (72%), tetracycline (69%), and ciprofloxacin (68%) were less sensitive.


Infections transmitted through medical devices form an important but preventable part of HAIs. Therefore, it is essential that all the sources of infection should be blocked. Stethoscopes have more direct and frequent contact with patients, compared to other medical devices. Therefore, they play a significant role in spreading infections not only among hospitalized patients, but also among patients visiting OPDs, and consequently are a threat for the community. [12],[13] The overall assessment of the filled questionnaires revealed that majority of the HCWs had good knowledge of the role of stethoscopes in the spread of HAIs, but small percentage of HCWs apply this knowledge in routine practice.

The result of this study revealed that majority of the stethoscopes surveyed were contaminated by various microorganisms. This result is comparable to those from previous studies which reported that 71-100% of the stethoscopes were colonized by various bacteria. [14],[15],[16],[17] In a study done in Uttar Pradesh, India; 55% of the stethoscopes were found contaminated, mainly with Staphylococcus spp., out of which 7.3% were MRSA. [18] A similar study was done by Uneke et al. involving 107 respondents from various hospitals in Nigeria. The result of the study showed growth of potentially pathogenic bacteria in 78% of the sampled stethoscopes. The commonest was S. aureus followed by P. aeruginosa[19] In the present study, we found P. aeruginosa to be the predominant isolate followed by S. aureus and Bacillus sp. Isolation of MRSA from 3.7% of the samples in our study is a matter of great concern. These MRSA are the most dreadful hospital-acquired pathogens associated with prolonged carriage and serious infections that are difficult to treat. [20],[21] Also, gram-negative bacilli are the important cause of HAIs [22] and Bacillus spp. have been implicated in septicemia. [23]

Overview of several studies shows that 40-60% HCWs cleaned their stethoscope within a week. In the Nigerian study, the authors found that 48% of HCWs cleaned their stethoscopes within a week and 11% had cleaned it fortnightly. Thirty-five percentage of HCWs had never cleaned their stethoscope. [19] Whereas in another study done in London by Whittington et al.; 91% of HCWs had cleaned their stethoscope after each patient contact. [24] In our study, the percentage of those who cleaned their stethoscope within a week was lower (27%) as compared to above-mentioned studies. Also, the percentage of those who either did not remember or had never cleaned their stethoscope was higher in our study (62%). Among the HCWs who had never cleaned their stethoscopes, two admitted verbally that they never thought of cleaning it. Thus, the problem seems to be much bigger in our setting when compared with other settings.

Our study reveals that sharing of stethoscopes was a common practice amongst the nursing staff as well as doctors. The sharing of stethoscope by the nurses could be explained as most of them do not have their own stethoscope, whereas sharing of stethoscope by doctors cannot be explained at the point of time. However, this practice might contribute to the transmission of infectious agents, although we cannot comment on it as this was not within the aim of our study. Majority of the HCWs usually carry the stethoscopes around their necks or in bags and carry them back home as well, and may use the same stethoscope in the clinics at home, thus broadening the spread area for HAIs.

The results of the study show that ethyl alcohol was the most preferred agent for disinfecting the stethoscopes, if done. In 2008, the Centres for Disease Control (CDC) issued a new guideline which advises healthcare facilities to develop and implement policies and procedures to ensure that reusable patient care equipment is cleaned and reprocessed appropriately before use on another patient. [25] Despite these recommendations, not only the stethoscope cleaning practices are suboptimal, but also the healthcare personnel are stubbornly resistant to change these practices. [26] Cleaning of stethoscopes with 70% ethyl or isopropyl alcohol after every use is recommended by CDC. However, it is tedious and time consuming, especially in high-volume clinics in countries like India, where following such recommended practices is not always feasible. Few studies have shown that the level of contamination can rise from 0 to 69% if stethoscopes are not cleaned everyday. [27] A study comparing the efficacy of immediate versus daily cleaning of stethoscope using 66% ethyl alcohol showed comparable effects between the two interventions, with reduction rates of 28% and 25%, respectively. [28] Hence, to decrease the carriage of microorganisms on the stethoscopes in high-load OPDs and in-patient departments, the healthcare personnel should be advised and motivated to clean them as frequently as possible.

We have not correlated the use of stethoscopes with transmission HAIs in the settings, but our study had demonstrated that the studied stethoscopes were highly contaminated. Thus, there is an urgent need to develop strategies to decrease the spread of HAIs via stethoscopes.


The first limitation of our study is the inclusions of relatively smaller number of participants, making us unable to use any statistical tests. Also, we could not correlate the disinfection of stethoscopes with transmission of HAIs, as this was not possible due to short duration of study. Thus, we could not comment on any significant difference in the stethoscope disinfecting practices of medical personnel at different levels in the setting. Another limitation of our study is lack of fungal and viral cultures which could not be done due to financial limitations.


Stethoscopes can be a potential source of spread of HAIs due to the transfer of organisms from the patient’s skin flora to other patients and finally to the community. Thus, cleaning of the diaphragm of stethoscope after each use, with an alcohol-based disinfectant is advisable in order to reduce the HAIs effectively.

Implications and Recommendations

Training and motivation of the HCWs in understanding this aspect and converting their knowledge into practice will be challenging but an important step of future intervention. In future, individual and/or group feedback meetings will be conducted to motivate the HCWs to clean the stethoscopes. The authors along with digital pictures of the cultured plates will visit to the participants and will present the outcome of the study. This might motivate HCWs and facilitate better implication of their knowledge into practice to minimize the load of microorganisms on stethoscopes and limit the spread of HAIs in the setting.

Further, we plan to conduct similar KAP study for other frequently used clinical accessories to highlight the role of medical devices in the epidemiology of HAIs. The final aim of the study will be to reduce the percentage of HAIs related with medical devices through relevant small-scale, cost-effective interventions.


We acknowledge the participants of the study for their active participation. We express special thanks to Dr. V. K. Mahadik, Medical Director, R. D. Gardi Medical College, Ujjain, India for encouraging and permitting us to conduct the study.

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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1755-6783.116501


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