Researchers from East Carolina University used a new technique of genotyping to identify the source of a hematology clinic outbreak of Mycobacterium mucogenicum, a gram-positive, acid-fast bacteria found in tap water. This is the first outbreak of M. mucogenicum in an ambulatory care setting; five other outbreaks have been reported in hospital settings since 1995. The study was published in the November issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.
Using repetitive sequence-based polymerase chain reaction ( Diversilab- system), the first time this genotyping method was used in an M. mucogenicum outbreak, researchers determined that a water sample from an exam room faucet with an aerator had the same bacteria as the infected patients, and all were genetically similar to control strain of M. mucogenicum. Aerators have been found to be reservoirs for bacteria in previous outbreaks.
The use of new technology to match the genetic material in the bacteria established the source of the outbreak; however, since M. mucogenicum is commonly found in tap water in the U.S. and worldwide, researchers needed to continue their investigation to determine how the bacteria was being transmitted to the patients.
The outbreak involved four young sickle cell patients. Since all four patients had long-term lines implanted (i.e., ports used to deliver medication into the bloodstream), they were probably exposed to M. mucogenicum during outpatient visits when the lines were accessed. As part of the outbreak investigation, researchers collected water samples from two faucets in the exam rooms and performed an audit of infection control practices, including hand hygiene compliance, use of appropriate techniques for injections, and other procedures.