Everyone knows that doctors should wash their hands before examining patients. But what about their stethoscopes?
A study published recently in the Annals of Emergency Medicine has found that the instruments--arguably the most commonly used in medicine--are an important and largely overlooked source of infection because they are cleaned infrequently, if at all.
Researchers at Butterworth Hospital, affiliated with Michigan State University, surveyed 150 emergency medical personnel (doctors, nurses and Emergency Medical Service technicians) to determine how often they cleaned their stethoscopes.
Forty-eight percent of those surveyed said they cleaned their stethoscopes daily or weekly. No one cleaned them after every patient, and 37% said they cleaned them once a month. Seven percent said they disinfected annually, and another 7% said they never disinfected their stethoscopes.
The most popular method of cleaning was an alcohol swab. (No significant differences were found among the groups.)
The research team led by Dr. Jeffrey S. Jones, an emergency room physician, then cultured the instruments for bacteria. They found that 89% were contaminated with staphylococci, a common bacteria that can cause skin infections. In 19% of cases, researchers detected Staphylococcus aureus, a more virulent form of the organism.
As a group, nurses' stethoscopes had the lowest levels of contamination.
Although the presence of staph is probably not harmful to many patients, Jones and his colleagues noted that contamination does pose a potential problem to those with open wounds, such as burns. In addition, they noted, contaminated stethoscopes could serve as a method of transmitting drug-resistant bacteria, a serious problem in many hospitals.