At least 73 individuals have been infected with an outbreak strain of Salmonella Typhimurium in 35 states from August 20, 2010 to March 8, 2011, including one death, associated with exposure to clinical and teaching microbiology laboratories.

According to the U.S. Centers for Disease Control, illnesses have been identified among students in microbiology teaching laboratories and employees in clinical microbiology laboratories. Ill persons (60%) were significantly more likely than control persons (2%) to report exposure to a microbiology laboratory in the week before the illness began. Additionally, multiple ill persons reported working specifically with salmonella bacteria in microbiology laboratories. The New Mexico Department of Health found that the outbreak strain was indistinguishable from a commercially available Salmonella Typhimurium strain used in laboratory settings. This commercially available strain was known to be present in several teaching or clinical laboratories associated with ill students or employees infected with the outbreak strain. These data suggest this strain is the source of some of these illnesses. Additionally, several children who live in households with a person who works or studies in a microbiology laboratory have become ill with the outbreak strain.