STETHOSCOPES - A POTENTIAL VECTOR OF INFECTION

Study objectives: To survey emergency care providers about their steth oscope-cleaning measures and to determine the correlation between thes e measures and the extent of Staphylococcus carriage. Design: Prospect ive cross-sectional analysis. Setting: University-affiliated community hospital ED. Participants: One hundred fifty health care providers, c omprising emergency medicine house staff and attending physicians (n=5 0), ED nurses (n=50), and prehospital personnel working in Kent County , Michigan(n=50). Interventions: Providers were asked how often they c leaned their stethoscopes and which cleaning agents were used. We then cultured each stethoscope by pressing the diaphragm on mannitol agar and incubating the culture aerobically for 48 hours. Staphylococcus au reus was identified by means of standard measures. We examined the eff ects of different cleaning agents on 24 stethoscopes. The numbers of c olony-forming units (CFUs) before and after cleaning with alcohol, non ionic detergent, and antiseptic soap were noted. Results: Overall, 48% of health care providers (74 of 750) cleaned their stethoscopes daily or weekly, 37% monthly, and 7% yearly; and 7% had never cleaned their stethoscopes. No significant differences were found in the hygiene ro utines of the three groups of providers surveyed. Use of an alcohol sw ab was the preferred method of cleaning. One hundred thirty-three stet hoscopes (89%) grew staphylococcal 25(19%) yielded S aureus. Mean stap hylococcal bacterial counts (+/-SD) were 52+/-78 CFUs per stethoscope among physicians, 46+/-92 CFUs among emergency medical service personn el, and 13+/-21 CFUs from the nursing staff (ANOVA, P=.01). Cleaning t he stethoscope diaphragm resulted in immediate reduction in the bacter ial count: by 94% with alcohol swabs, 90% with nonionic detergent, and 75% with antiseptic soap. Conclusion: Our results confirm that stetho scopes used in emergency practice are often contaminated with staphylo cocci and are therefore a potential vector of infection. This contamin ation is greatly reduced by frequent cleaning with alcohol or nonionic detergent.