Bacterial colonization of stethoscope used in the tertiary care teaching hospital: a potential source of nosocomial infection

Jeyakumari D., Nagajothi S., Praveen Kumar R., Ilayaperumal G., Vigneshwaran S.


Background: Hospital acquired infections (HAI) are a major problem in each hospital. HAI remains a significant hazard for hospitalized patients and health care workers are potential sources of these infections. Health care workers can transmit pathogens through their hands and contaminated medical devices such as stethoscopes, Blood pressure cuff etc. Hence we intended to determine the level of bacterial contamination of stethoscopes using in present hospital.

Methods: Total of 50 stethoscopes were sampled before and after cleaning with 70% isopropyl alcohol by using sterile swab soaked in sterile saline. Samples were processed as per standard microbiological procedures.

Results: Out of 50 stethoscopes, 30 (60%) stethoscopes were showing significant bacterial colonization, 7 (14%) showed insignificant colonization, and in 13 (26%) stethoscopes no growth was observed. The bacteria isolated were Methicillin Resistant Staphylococcus aurues (MRSA) (14%), Methicillin Sensitive Staphylococcus aureus (MSSA) (12%), Coagulase Negative Staphylococcus (CNS) (14%), Klebsiella species (20%).

Conclusions: Our study concluded that stethoscopes used by health care workers were colonized by both pathogens and non-pathogenic microorganisms. Strict protocol of cleaning the stethoscopes in between the patients will eliminate the colonization and there by spread of infections.


Disinfection, Hospital acquired infections, Nosocomial infections, Stethoscopes

Full Text:



Uneke CJ, Ogbonna A, Oyibo PA, Ekuma U. Bacteriological assessment of stethoscopes used by medical students in Nigeria: Implications for nosocomial infection control. World Health Popul. 2008;10:53-61.

Whittington AM, Whitlow G, Hewson D, Thomas C, Brett SJ. Bacterial contamination of Stethoscopes on the intensive care unit. Anaesthesia. 2009;64:620-4.

Gopinath KG, Stanley S, Mathai E, Chandy GM. Pagers and Stethoscopes as vehicles of potential nosocomial pathogens in a tertiary care hospital in a developing country. Trop Doct. 2011;41(1):48-5.

Fenelon L, Holcroft L, Waters. “Contamination of stethoscopes with MRSA and current disinfection practices.” J Hosp Infect. 2009;71(4):376-8.

Wilkins RL, Restrepo RD, Bourne KC, Daher N. Contamination level of stethoscopes used by physicians and physicians Assistants. The J of Physician Assistant Edu. 2007;18:41-3.

Alothman A, Bukhari A, Aljohani S, Muhanaa A. Should we recommend stethoscope disinfection before daily usage as an infection control rule? Open Infect Dis J. 2009;3(1):80-2.

Parmar RC, Valvi CC, Siva P, kamatJ. A prospective, randomized, double - blind study of comparative efficacy of immediate versus daily cleaning of stethoscope using 66% ethylalcohol. Indian J Med Sci. 2004;58(10):423-30.

Nolson J, Biven SA, Shinn A, Wanzer L, Kasper C. Microbial flora on operating room telephones. AORN. 2006;83(3):607-23.

Association Francaise de Normalisation Antiseptiqueset Desinfections, Paris La Defense. France AFNOR 1989.

Africa –Purino FMC, DYEER, Coronel RF. Stethescopes:a potential source of nosocomial infections. Phil J Microbiol Infect Dis. 2000;29(2):9-13.

Zuliani Maluf ME, Maldonado AF, Bercial ME, Pedroso SA. Stethoscope: a friend or an enemy? Sao Paulo Med J. 2002;120:13-5.

Youngster I, Borkovitch M, Heyman E, Lazarovitch Z, Goldman M. The stethoscope as a vector of infectious diseases in the paediatric division. ActaPaediatric. 2008;97:1253-55.

Marinella MA, Pierson C, Chenoweth C. The Stethoscope- a potential source of nosocomial infection? Arch Intern Med. 1997;157:786-70.

Wood MW, Lund RC, Stevenson KB. Bacterial contamination of stethoscopes with antimicrobial diaphragm covers. Am Med J Infect Contr. 2007;35:263-6.

Chigozie JU, Annayo O Patrick GO, Christian MO. Bacteria contamination of stethoscopes used by health workers: public health implications. J Infect DevCtries. 2010;4(7):436-41.

Shiferaw T, Beyene G, Kassa T, Sewonet T. Bacterial contamination, bacteria profile and antimicrobial susceptibility pattern of isolates from stethoscopes at Jimma University Specialized Hospital. Ann clinMicrobiol Antimicrobiol. 2013;12:39.

Gastmeier P, Sehwab F, Barwolf S,Ruden H, Grundmann H. Correlation between the genetic diversity of nosocomial pathogens and their survival time in intensive care units. J Hosp Infect. 2006;6(22):181-6.

Saxena AK, Panhotra BR, AL-Mulhim AS. Contaminated physicians’ stethoscope- a potential source of transmission of infection in the hospital. Need of frequent disinfection after use. Saudi Med J 2005;26:348-50.

Patentstorm. Disposable cover for stethoscope head 2004. Available: 574775/. html.