Introduction

Healthcare-associated infections (HCAIs) continues to be one of the most important public health problems in many countries throughout the world [1,2], and remain common in both developed and developing countries [3]. Further, HCAIs result in protracted hospital stays and increased the substantial cost for the healthcare system [4, 5]. It is known long ago HCAIs are caused by viral, bacterial, and fungal pathogens. And many healthcare-associated bacterial pathogens may well survive or persist on different surfaces for months and can thereby be a continuous source of transmission if no regular preventive surface disinfection is performed [6,7]. Investigators of a systematic review also reported highly virulent microorganisms, particularly those known to cause nosocomial infections in admitted patients, such as Enterococcus species, Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella species, Pseudomonas aeruginosa, and Acinetobacter species, are capable of surviving for several days on hospital surfaces [7]. Consequently, medical equipment surfaces, such as stethoscopes can easily be contaminated with these infectious agents and contribute to the spread of HCAIs [8,9,10,11,12], and may possibly cause outbreaks of hospital-acquired infections [13].

In this regard, the stethoscope, which is universally used as a medical device by healthcare workers, is more likely to be contaminated by microorganisms, if it is not disinfected and may transmit pathogens from one patient to another [14–19]. For this reason, regular cleaning with a suitable disinfectant is decisive and part of a multi-barrier strategy to prevent HCAIs; since failure to properly disinfect or sterilize equipment carries not the only risk associated with breach of host barriers but also risk for person-to-person transmission and transmission of environmental pathogens (e.g., Pseudomonas aeruginosa) [14, 20].

There is strong scientific evidence documenting the various pathogens found colonizing stethoscope surfaces [14,15,21,22]. Several studies have demonstrated that stethoscope membranes harbor bacteria, including resistant microorganisms such as Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococci (VRE) and Clostridium difficile [14,23,24,25]. It was also reported that highly resistant bacteria, MRSA can potentially survive up to 9 days on stethoscopes [26].

Effective disinfection of stethoscopes with isopropyl alcohol eliminates up to 99% of bacteria [22]. However, in the resource-constrained setting like many healthcare facilities in Ethiopia, healthcare workers infection prevention compliance [27,28,29], and instrument disinfection practice was poor [30]. In addition, a high prevalence of HCAIs was noted in hospitalized patients across the country; even if it is difficult to say that HCAI in Ethiopia is high as a result of stethoscope disinfection [31,32,33]. Yet, the available literature evidenced there is significant bacterial contaminations of stethoscopes in the country [34,35,36]. For example, a study by Shiferaw et al [34] reported that of the 176 stethoscopes examined 85.8% were contaminated and of 256 bacteria isolates, 52% were potential pathogens like S.aureus, Klebsiella spp., Citrobacter spp., P.aeruginosa, and E.coli. Although this evidence is available, there has still been a lack of studies about stethoscope disinfection in Ethiopia to overcome the problem. All the previously conducted related studies are case studies in one or similar type of hospital [34,35,36]. As well as none of the previously conducted studied include health centers in their assessment, where the vast majority of the population seeks healthcare service. According to Ethiopian health tier system health centers where the primary care level establishments providing health care services; such as family planning, maternal and child health service, delivery service, emergency and minor surgery service, pharmacy, laboratory, tuberculosis treatment service, and outpatient service. To the best of my knowledge, this study is the most extensive study, investigating stethoscope disinfection practice in both hospitals and health centers. In order to improve healthcare provider’s appropriate disinfection practice and to develop successful infection prevention programs in-depth understanding of the issues is essential. Therefore, this study aimed to assess the practice of stethoscope disinfection among healthcare providers working in healthcare facilities in Addis Ababa, Ethiopia. Furthermore, the study aimed to identify factors associated with stethoscope disinfection. The findings of the study will be used as an input for policy makers, programmers and healthcare workers to improve quality services and to prioritize interventions by decision makers to overcome the problem.

Materials and methods

Results

Socio-demographic characteristics

Five hundred forty-six participants took part in this study, for a response rate of 94.7%. Of these, 191 were male and 355 were female. Two hundred thirty-seven, (43.4%) were in the age group between 26 and 30 years old. The mean (standard deviation [SD]) age of the respondents was 29.19 (SD ± 6.3) and majorities 60.6% of them were married. A higher proportion (61.9%) of the respondents was first degree and above and 68.1% of healthcare providers were nurses by profession (Table 1).

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Table 1. Socio-demographic and other characteristics of the healthcare providers in healthcare facilities in Addis Ababa, Ethiopia 2016 (N = 546).

https://doi.org/10.1371/journal.pone.0208365.t001

Stethoscope disinfection practice and other individual related characteristics

In this study, 217(39.7%) [95% confidence interval [CI]:35.9, 44.0%] of healthcare providers reported that they disinfect their stethoscope after every use. Whereas majority (60.3%)[95%CI: 56.2, 64.7%] of the respondent do not disinfect their stethoscope after every use, of these 189 (34.6%)[95%CI:30.8,38.5%] of respondents never disinfect their stethoscopes, 84(15.4%)[95%CI:12.3,18.7%] disinfect once a week and 56(10.3%)[95%CI: 7.7,12.8%] of healthcare providers reported they disinfect once or twice a day (Table 2).

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Table 2. Self-reported stethoscope disinfection practices of healthcare providers in Addis Ababa, Ethiopia, 2016 (N = 546).

https://doi.org/10.1371/journal.pone.0208365.t002

Four hundred and fifteen (76.0%) of healthcare providers believe that stethoscope contamination can contribute to the transmission of infections. In addition, healthcare providers infection prevention (mean (SD), median) composite scores were (for knowledge = 12.43(±2.69), 13); (for practice = 13.99(± 3.33), 14) and (for attitude = 11.34(1.21), 12). Accordingly, 399(73.1%) [95%CI: 69.4, 76.7%] of healthcare providers were knowledgeable towards infection prevention and control of HCAIs and 372(68.1%) [95%CI: 64.3, 72.0] have safe infection prevention practice (S2 Table).

Factors associated with stethoscope disinfection after every use

Tables 3–5 display the results of bivariate and multivariate logistic regression analyses to identify factors of stethoscope disinfection after every use. In bivariate analyses; age, profession, working department, infection prevention training, awareness on infection prevention and patient safety (IPPS) guidelines, availability of standard operating procedures (SOP), belief that stethoscopes can transmit HCAIs, attitude towards IP, knowledge on IP and control, and self-reported IP practice were significantly associated with stethoscope disinfection after every use. The final model was checked by Hosmer and Lemeshow test for the overall goodness of fit (0.714). In multivariate analyses, the odds of disinfection after every use was likely to be decreased by 79% among physicians compared to nurses (Adjusted odds ratio [AOR] = 0.21; 95% confidence interval [CI]: 0.09, 0.49). The odd of disinfection after every use was 1.93 times higher in healthcare providers who have awareness on infection prevention guideline than healthcare providers who did not have awareness (AOR = 1.93; 95%CI: 1.31, 2.82). Among healthcare providers, the odds of disinfection after every use were significantly higher among who had a favorable attitude towards infection prevention (AOR = 1.73, 95%CI: 1.02, 2.93), and among those have safe infection prevention practice (AOR = 3.79, 95%CI: 2.45–5.84) as compared with their counterparts.

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Table 3. Socio-demographic factors bivariate analysis of factors associated with stethoscope disinfection after every use among healthcare providers in Ethiopia 2016.

https://doi.org/10.1371/journal.pone.0208365.t003

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Table 4. Individual and institutional related factors associated with stethoscope disinfection after every use.

https://doi.org/10.1371/journal.pone.0208365.t004

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Table 5. Multivariable logistic regression analysis of factors associated with stethoscope disinfection after every use α^♣.

https://doi.org/10.1371/journal.pone.0208365.t005

Discussion

Routine disinfection of stethoscopes after every use is one of the most important challenges among healthcare providers. In many developing countries, including Ethiopia healthcare provider’s stethoscope disinfection practice scarcely addressed in the scientific literature. For this, the study assessed stethoscope disinfection practice and associated factors among healthcare providers in central Ethiopia.

In this study, three out of four (76.0%) healthcare providers believe that stethoscope contamination can contribute to the transmission of infections. And, it was found that only a minority (39.7%) of healthcare providers reported that they disinfect their stethoscope after every use. The finding was higher when compared to a study conducted in different parts of Ethiopia, in Mizan-Tepi University Teaching Hospital (southwest Ethiopia) 6.4% [36], in Jimma University Specialized Hospital (Ethiopia) 2.8% [34] and in Tikur Anbessa Specialized Hospital (Ethiopia) 8.5% [35]. This finding could be attributed to different factors, including study setting, period and study participants. In the preceding studies conducted in Jimma and Tikur Anbessa Specialized Hospitals, they included medical students in their assessment [34, 35]. In addition, in Jimma Specialized Hospital almost all (97%) healthcare workers and medical students do not follow the standard protocol set to prevent infections. And all licensed doctors (specialist, resident and general practitioner) reported they didn’t disinfect their stethoscope regularly. Hence, 98% had contaminated stethoscope diaphragms [34].Whereas in the present study, only fulltime healthcare providers were included in the current assessment. In addition, the current study did not include specialized hospitals in the sample.

On one hand, different studies conducted elsewhere also reported infrequent disinfection practice, in Nepal (6.89%) of healthcare workers disinfecting after every use [14], in USA (24%) of healthcare workers disinfect after every patient [18], in Turkey cleaning of stethoscopes with various disinfectants at certain intervals was reported 50.4% [38], and in Pakistan, a considerably lower prevalence of stethoscope cleaning was observed 37.7% [39]. Moreover, in Nigeria, 87.9% of the participants did not clean their stethoscopes after examining each patient [40]. Furthermore, recent observational studies revealed that in 13 of 115 encounters (11.3%), the healthcare provider cleaned the stethoscope with an alcohol swab after patient interaction [41]. And another study reported, stethoscopes were disinfected per Centers for Disease Control and Prevention (CDC) guidelines in less than 4% of encounters and were not disinfected at all in 82% of encounters [42]. On the other hand, much higher stethoscopes disinfection practice was reported from a study conducted in French, 82% of medical students clean their stethoscopes regularly or from time to time [43]. This high discrepancy might be attributed to a choice of the study population, as in the cases of the French survey all respondents where medical students and in the present study the study participants were full-time health care providers.

The findings of the present study suggest that a significant number of healthcare providers in the study area and elsewhere in Ethiopia rarely disinfect their stethoscope. Which is a great concern, if the stethoscope is not cleaned or disinfected consistently the possibility of contamination with pathogenic microorganisms is likely and elevate the risk of HCAIs from one patient to another [34].

The study further found that a third of healthcare providers never disinfect their stethoscope. In fact, the finding was not validated by any observational data to verify the healthcare provider’s actual practice. Nonetheless, in many cases, the rates of stethoscope hygiene are low among healthcare providers in different settings [40–42]. And contamination of stethoscope is likely if it is not disinfected regularly. In support of this, a literature search by O’Flaherty et al across several databases for relevant studies on stethoscopes showed that stethoscopes were consistently harbor bacteria and the mean rate of stethoscope contamination across 28 studies was 85.1% (range: 47‒100%) [44]. A prospective study conducted in Swiss university teaching hospital to compare the contamination level of physicians’ hands and stethoscopes provide strong evidence of the potential for stethoscope-mediated transmission of microorganisms and the need to systematically disinfect stethoscopes after each use [45].

A study by Pal et al [46], try to identify factors associated with stethoscope disinfection and reported apprehension of damaging stethoscopes and lack of knowledge regarding good disinfectant were the underlying causes that prevent cleaning of the stethoscopes. In the same way, this study identified factors associated with stethoscope disinfection. Healthcare providers who had awareness of infection prevention guideline were more likely to disinfect their stethoscope than their counterpart healthcare providers. This could be due to the fact that as the healthcare provider’s exposure to such guidelines increase, healthcare providers are frequently exposed to appropriate stethoscopes disinfection practices and become more compliant. Since guidelines such as the Healthcare Infection Control Practices Advisory Committee Guideline for Disinfection and Sterilization in Healthcare Facilities recommended appropriate cleaning of stethoscopes with 70% ethyl or isopropyl alcohol after every use [20]. In addition, the Federal Ministry of Health of Ethiopia infection prevention and patient safety guideline strongly suggest, following contact with patient’s skin stethoscopes should be disinfected with suitable disinfectant after every use [47].

In this study, it was found that healthcare providers who had a favorable attitude towards infection prevention were almost two times more likely to disinfect their stethoscope after very use than healthcare providers who had an unfavorable attitude. The current finding was in agreement with a study conducted by Gazibara et al [48], which reported a positive correlation between a higher frequency of stethoscope cleaning and stronger positive notion that a stethoscope should be cleaned.

The results of this study showed that healthcare providers who had safe infection prevention practice were four times more likely to disinfect their stethoscope as compared to those who had unsafe infection prevention practice. This can be explained by the fact that disinfection of medical equipment that comes into contact with patients is one of the core principles of infection prevention and those healthcare workers who had good compliance towards infection prevention may have better awareness and compliance towards stethoscope disinfection. Furthermore, other factors associated with stethoscope disinfection have been documented previously. A study by Wood et al [49], identified concern for damage of stethoscope, lack of time and lack of knowledge regarding best cleaner were identified as a barrier of stethoscope cleaning [49]. A study by Hyder, also reported a history of receiving information on stethoscope cleaning has been one of the strongest predictors of stethoscope hygiene [39]. Access to disinfection material and other related issues may be also another barrier for low stethoscope disinfection practice among healthcare providers [18].

The result of this study showed that physicians were less likely to disinfect their stethoscope after every use than nurses, and this is in agreement with other studies [34,49,50]. Additionally, Shiferaw et al reported 98% of studied stethoscope diaphragms were contaminated [34]. The finding of the study is also consistent with other earlier studies, which found nurses reported to have good disinfection practice than doctors [50, 51]. Moreover, studies indicated that about 97 to 100% of doctors did not follow a standard disinfection protocol [34,50,52]. In light of this finding, a study by Uneke et al described stethoscopes used by physicians were more contaminated than those used by other health workers [40]. Interestingly Horiuchi et al in there review also reported, compared to those of the physician’s dominant hand anywhere from 70 to 100% stethoscopes are contaminated after a physical examination, and only 0–11% and 0–24% of healthcare providers disinfected their stethoscope before patient contact and after the contact respectively [53].

Conclusions

The available information would suggest that stethoscopes and should be disinfected between patients (after every use) to reduce the number of pathogens and risk of transmission, which is recommended by guidelines and existing literature [20,44,45,47,53]. However, the present study confirmed approximately two-fifths of the studied healthcare providers only disinfect their stethoscopes after every use. And a third of healthcare providers never disinfect their stethoscope. Factors such as awareness on infection prevention guidelines, favorable attitude towards infection prevention and safe infection prevention practice and control of HCAIs were the independent predictors of stethoscopes disinfection after every use. The study also revealed that physicians were less likely to disinfect their stethoscope compared to nurses. The findings call for clear strategies that focus on the promotion of stethoscope disinfection in healthcare facilities in Ethiopia. In addition, short term and in-service educational program to enhance stethoscope disinfection practice may have a positive effect on disinfection compliance among healthcare providers. Moreover, access to infection prevention guidelines with visual reminders (such as instructive posters) in healthcare settings should be strengthening to enhanced compliance towards stethoscope disinfection.

Supporting information

Acknowledgments

I would like to thank all participants involved in the undertaking of the study and Addis Ababa city administration health bureau. In addition, I would like to thank all ten sub-city health department and selected healthcare facility medical directors for their cooperation and support. Finally, I would like to acknowledge Mrs. Rahel Niguse (my respected wife), for her support at a time of manuscript preparation.