Last week the CDC announced the investigation of a multistate outbreak of a laboratory strain of Salmonella Typhimurium associated with teaching and clinical microbiology laboratories. The investigation is still ongoing. The CDC and many state public health agencies are working to genetically link cases to the commercially available strain of Salmonella Typhimurium used in teaching and clinical laboratories identified by the New Mexico Department of Health as being identical to the outbreak isolates.
Between August 20, 2010 and March 8, 2011 a total of 73 cases were reported in 35 states. The median age was 24 years old (age range 1 to 91), and 63% were female. Of the 73 cases, 14 were hospitalized with one fatality. Surveys conducted with 32 ill persons revealed that 60% of ill persons had contact with a teaching or clinical microbiology laboratory in the week before their illness. Many ill people reported either working with Salmonella Typhimurium in a microbiology laboratory or being in a household of someone who did. It seems clear that several people infected themselves or carried Salmonella home with them. This investigation is a good reminder to all of us who work or study in a microbiology (or virology) lab that we can not only contract the agents we work with but also carry them home our families and friends.
Biosafety guidelines for students and employees of microbiology laboratories can be found on the CDC investigation page. Remember proper hand washing is vital for your protection and the protection of others. The full CDC handbook Biosafety in Microbiology and Biomedical Laboratories (BMBL, 5th Edition) is available online and in printed form.