Microbial Analysis of Stethoscopes and Otoscopes used by Staff as Potential Sources of Nosocomial Infections in Komfo Anokye Teaching Hospital-KATH

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Nosocomial infections have been recognized as a critical problem affecting the quality of health care provided in hospitals as they lead to significant morbidity and mortality and as well increased health care costs. Disinfection of routinely used apparatus in the clinical setting is generally accepted as a method of reducing nosocomial infections although compliance by health care providers is of concern. This study was undertaken to determine bacterial agents contaminating stethoscopes and otoscopes used by medical staff in Komfo Anokye Teaching Hospital (KATH); to compare the effectiveness of common cleaning methods (i.e. dry cotton wool, soapy water, 70% alcohol, and savlon) in disinfecting stethoscopes and otoscopes; to determine the stethoscope and otoscope cleaning practices among staff of KATH and to determine views of staff in KATH concerning stethoscopes and otoscopes as possible sources of spread of nosocomial infections. One hundred and sixty (160) consented participants were enrolled in this study. Participants were made up of students, house officers, resident physicians and nurses from the various departments of KATH including the Ear, Eye, Nose and Throat (EENT), Obstetrics and Gynecology (O&G), Surgery, Medicine and Child health Departments. Participants were asked among questions on demographic information, the average number of patient their devices were used on daily, whether they had ever received any form of tutelage on cleaning of these devices, how often they clean them and what their cleansing agent of choice was. Swabs were then obtained from the diaphragms/surfaces of the devices. Two samples were obtained; one from one-half of the device surfaces before cleaning and the other sample from the other half after cleaning. Results showed that 100% of all otoscope earpieces were disinfected after single use with 70% alcohol and savlon. There was no bacterial growth on any of the otoscope earpieces sampled. The same could not be said of the stethoscopes. Only 26% (N=38) of the participants clean their stethoscope after single use, 39% (N=57) did this daily with 24.7% (N=36) cleaning them between twice weekly and once monthly. 10.3% (N=15) never clean their stethoscopes. 70% Alcohol was the most commonly used agent for cleaning [78.8% (N=115)]. 39.7% (N=58) of the 146 stethoscopes analyzed had bacterial contaminations with a mean colony count (MCC) of 15.14 colonies per membrane. All the isolates were nonpathogenic or opportunistic pathogens, mainly coagulase-negative staphylococci. The results indicate that otoscopes used in KATH are safe and play no role in nosocomial infection spread. The stethoscope though potentially playing a role in transmitting microorganisms in the KATH environment, may only play a minor role. They may however be ruled out as sources of infection spread by cleansing them regularly with 70% alcohol, the most cost effective of all the disinfectants assessed. This data should be helpful to authorities in the planning of hospital acquired infection control programmes in KATH and other hospitals in Ghana.
A thesis submitted to the Department of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, in partial fulfillment of the requirements for the degree of Clinical Microbiology