The Centers for Disease Control and Prevention (CDC) announced today of an investigation one of its laboratory workers who was recently diagnosed with Salmonella infection may have acquired their infection due to work they performed in a BSL-2 laboratory (a level of lab work involving pathogens that are common and treatable causes of illness). Salmonella is not a select agent.

Salmonella bacteria (red)/National Institute of Allergy and Infectious Diseases (NIAID)
Salmonella bacteria (red)/National Institute of Allergy and Infectious Diseases (NIAID)

Preliminary laboratory tests indicate that the worker was infected with a strain of Salmonella which matched the strain being worked on in the lab.  The worker is well and back at CDC and, based on what we know now, no other staff were exposed or sick, and there was no release outside the laboratory. The worker had hands-on training by experienced microbiologists and completed all required safety training. The worker was following standard protocols to perform a basic procedure on a frozen sample in an effort to culture or grow the bacteria. The agency is investigating to see if additional safeguards are needed to prevent exposures when performing this procedure in the future.

CDC estimates there are 1.2 million cases of Salmonella infection each year in the United States. Salmonella infections are usually acquired by eating contaminated food and usually not spread from person to person. People with this kind of infection typically have diarrhea, fever and abdominal cramps that go away without specific treatment within 4-7 days.

Laboratory science is critical to protect America’s health. However this work carries risks. CDC has implemented numerous steps over the past few years to enhance its laboratory safety program, including standing up the Office of the Associate Director of Laboratory Science and Safety, reviewing laboratory safety protocols, and establishing the Laboratory Leadership Service fellowship program. The agency has implemented rigorous steps to minimize these risks and to quickly investigate these incidents when they do occur including this recent incident.

Related: College microbiology classes linked to Salmonella Typhimurium outbreak