Audiologists have made great strides in hearing aid technology, but an investigation shows many of them may be posing a health risk to their patients simply by neglecting to wash their hands between patient visits. Saint Louis (Mo.) University School of Medicine's Division of Audiology conducted

Many audiology patients have compromised immune systems. "We may encounter geriatric patients who are quite old, often with underlying diseases such as diabetes," indicates A.U. Bankaitis, director of audiology. "Pediatric patients who are young and have immature immune systems or HIV-infected individuals with reduced immune responses are also at risk."

The microorganisms found on the hearing aids are known as opportunistic. That is, they seek out easy entry into the body. The ear canal is one of the easiest routes for disease transmissions to follow. "The problem is cross-contamination," Bankaitis explains. "That is where those bacterial and fungal growths cross from one hearing aid, to your hands, and then to the next hearing aid you handle. You have to assume something is growing on each hearing aid. Our recommendation is for audiologists to have a written infection control plan."

He maintains that audiologists should always wear gloves to handle a hearing aid, use disinfectants, and wash their hands before and after every patient. Right now, that practice is not common. A survey of more than 300 audiologists revealed that none wear gloves when handling a patient's hearing aid, and nearly 40% don't wash their hands between patients. The finding is disturbing because the Centers for Disease Control and Prevention recognizes hand-washing as the single most important method in reducing the spread of disease, particularly in a health care setting.

The following is a list of some of the bacterial and fungal organisms found on the hearing aids sampled:

Acinetobacter Iwoffii. These organisms thrive in the ear canal. Exposure may result in the development of sepsis, a blood-poisoning ailment that causes fever, pneumonia, and is responsible for most cases of meningitis.

Diptheroids. This bacteria causes diphtheria, an acute infectious disease prevalent worldwide in poor urban areas where crowding exists.

Enterobacter cloacae. This exists in the feces of humans and animals, sewage, and water that is occasionally found in urine, pus, and other pathologic materials from animals.

Enterococci, a species of bacteria that serves as the cause of certain types of pneumonia, otitis media, and cerobrospinal meningitis.