Header graphic for print
Marler Blog Providing Commentary on Food Poisoning Outbreaks & Litigation

73 Salmonella Typhimurium Infections Associated with Exposure to Microbiology Laboratories


According to the CDC, preliminary analysis has suggested exposure to clinical and teaching microbiology laboratories is a possible source of illness. 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.

Screen shot 2011-04-28 at 8.11.43 PM.png

73 individuals infected with the outbreak strain of Salmonella Typhimurium have been reported from 35 states: AK (1), AL (3), AZ (2), CA (1), GA (5), IA (1), ID (2), IL (3), IN (1), KS (1), KY (3), MA (2), MD (2), MI (2), MN (4), MO (2), NC (1), ND (1), NE (2), NJ (2), NM (3), NV (1), NY (1), OH (1), OK (1), OR (1), PA (6), SC (2), SD (1), TN (2), TX (1), UT (3), WA (5), WI (3), WY (1).

So, how did this happen?

  • Carl Custer

    “The numbers of new cases have declined substantially during the past several months, and reports associated with this outbreak strain appear to have returned to the expected baseline of approximately 0 to 4 cases reported per week. ”
    The reduction could be students gaining more lab experience.
    There are lots of ways to spread bugs around a lab. Technicians and microbiologists should know better but I’ve seen some who don’t.
    Long ago (just after fire was invented :^) a micro lab instructor at A&M would hand out a hot strain of Staph aureus. He would demonstrate how to sterilize an inoculating needle to prevent an aerosol. Then the students were to streak the staph on an agar plate and properly sterilize the needle. Any student with pustules at the next class flunked the exercise. And yes, there were always a few with bright red pustules on their faces. Doubt that would be permitted now.

  • Gabrielle Meunier

    Is it possible that Salmonella Typh could be more like a “spore” like Clostridium Difficile (C-Diff) and thus transportable? When my son was poisoned by peanut paste, he was diagnosed with both Salmonella and Clostridium Difficile. Very strange because usually C-Diff is associated with antibiotic use which he had never been on and never used. C-Diff is a spore and can be carried on a person. This is a very strange coincidence in that this article seems to insinuate that this Salmonella Typh. is being transferred among households. I’m sure they are washing their hands and not transmitting in the “known” fecal/oral way . . . Hmmmm — I’d like to know if they all were tested for C-diff?

  • Minkpuppy

    You just can’t wash your hands enough when working in a microbiology lab. I expect the parents got sloppy with the handwashing or spilled culture broth on their clothes and then took it home to the kiddos. It’s common to slack off when you’re around the stuff all the time. I know I did back in my college days. You would think they’d know better though.

  • Interesting how some blame consumers for cross-contamination or under-cooking food and these lab rats can not seem to get it right either.

  • “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.”
    Ack this is definitely something to be concerned about! It’s quite odd to think that this is occurring though. In a microbiology laboratory, you would expect the utmost cleanliness. I imagine this is probably a human error just as much if not more than the lab’s fault.

  • 4LabRats

    Bill Marler: What exactly do you mean by ‘these lab rats’? Do you have hostile feelings for people that do laboratory work? You can get help. Serenity now brother. Serenity now.

  • I love lab folks and I love rats – I am a lawyer.