Molecular epidemiology of a bacillus cereus outbreak

Bacillus cereus is an infrequent cause of infections however several outbreaks in vulnerable patients have been described. In January 2011, a massive recall of potentially contaminated alcohol prep pads was initiated after The Children's Hospital, in Aurora, CO, identified a cluster of invasive B. cereus infections, which was epidemiologically linked to use of non-sterile, alcohol pads on hospitalized children in October 2010. Investigation of this outbreak included molecular methods to examine relatedness of B. cereus isolated from cultures of the implicated prep pads. Shortly after this outbreak was reported, a local healthcare facility in Salt Lake City, UT had observed an unusual increase in respiratory cultures containing Bacillus cereus. An extensive epidemiologic investigation was conducted and several Bacillus cereus isolates were cultured on a variety of environmental sources but not on respiratory equipment. Through use of molecular typing the outbreak was discovered to be polyclonal in nature and unrelated to contaminated medical equipment, No single factor was identified and after extensive Infection Control interventions targeting environmental hygiene and hand hygiene, B. cereus positive culture rates decreased.