News and Alerts

CDC Finds Salmonella Outbreak Related to Clinical and Teaching Labs

The Centers for Disease Control and Prevention issued it final report on their investigation of a multistate outbreak of Salmonella typhimurium infections on 1/17/12. Their analysis indicates the outbreak was the result of exposure in clinical and teaching microbiology laboratories. The investigation focused on potential risk factors in microbiology laboratories that work with infectious agents like the strain of Salmonella typhimurium. CDC collaborated with state and local health departments, the American Society for Microbiology, and the Association of Public Health Laboratories to conduct a survey to identify areas where improvements in biosafety and laboratory safety training can be made to prevent future illnesses.

Between August 20, 2010 and June 29, 2011, a total of 109 individuals infected with the same strain of Salmonella typhimurium were reported from 38 states . Infected individuals ranged in age from less than 1 year to 91 years old, and the median age was 21 years. Sixty-one percent of patients were female. Twelve percent of patients were hospitalized. One death was reported. Several of those sickened are children who live with someone who works or studies in a microbiology lab.

Please review the advice to lab workers and supervisors from CDC below. For full details on the CDC investigation go to > http://www.cdc.gov/salmonella/typhimurium-laboratory/011712/index.html

Advice to Students and Employees in Clinical and Teaching Microbiology Laboratories

  • Be aware that bacteria used in microbiology laboratories can make you or others who live in your household sick, especially young children, even if they have never visited the laboratory.
    • If you work in a laboratory, it is possible for you to bring bacteria home through contaminated lab coats, pens, notebooks, and other items that you use in the microbiology laboratory.
    • Avoid taking laboratory supplies outside of the laboratory o to limit contamination.
  • Persons working with any infectious agents, including Salmonella bacteria, must be aware of potential hazards, and must be trained and proficient in biosafety practices and techniques required for handling such agents safely, in particular, to:
    • Wash hands frequently while working in and immediately before leaving the microbiology laboratory and follow proper hand washing practices. This is especially important to do before preparing food or baby bottles, before eating and before contact with young children.
    • Leave food, drinks or personal items like car keys, cell phones and mp3 players outside of the laboratory. These items may become contaminated if you bring them into the laboratory or touch them while working in the laboratory.
  • Wear a lab coat or other protective garment over personal clothing when working in a microbiology laboratory. Remove protective garment before leaving for non-laboratory areas (e.g., cafeteria, library, or administrative offices). Dispose of protective garment appropriately or deposit it for laundering. Lab coats should be removed from the laboratory only when they are to be laundered by the institution.
  • If you work with Salmonella bacteria in a microbiology laboratory, be aware that these bacteria can make you sick. Watch for symptoms of Salmonella infection, such as diarrhea, fever, and abdominal cramps. Call your health care provider if you or a family member has any of these symptoms.

Advice to Laboratory Directors, Managers, and Faculty Involved with Clinical and Teaching Microbiology Laboratories

  • A comprehensive set of biosafety guidelines for work with Salmonella and other similar human pathogens can be found in the Biosafety Level 2 section of the CDC/NIH Biosafety in Microbiological and Biomedical Laboratories manual, the Guidelines for Safe Work Practices in Human and Animal Medical Diagnostic Laboratories MMWR Supplement, and the Guidelines for Biosafety Laboratory Competency MMWR Supplement.
  • Either non-pathogenic or attenuated bacterial strains should be used when possible, especially in teaching laboratories. This practice will help reduce the risk of students and/or their family members becoming ill.
  • Persons working with infectious agents, including Salmonella bacteria, must be aware of potential hazards and trained and proficient in the practices and techniques required for handling such agents safely.
  • Advise all persons working in the laboratory to watch for symptoms of Salmonella infection, such as diarrhea, fever, and abdominal cramps, and to call their health care provider if they or a family member have any of these symptoms.
  • All students and employees using the laboratory should be trained in biosafety practices.
  • Ensure that handwashing sinks have soap and paper towels. Require students and employees to wash their hands before leaving the laboratory.
  • Do not allow lab coats to leave the microbiology laboratory, except to be cleaned by the institution.
  • Do not allow food, drinks or personal items like car keys, cell phones and mp3 players to be used while working in the laboratory or placed on laboratory work surfaces.
  • Provide students with dedicated writing utensils, paper, and other supplies at each laboratory station. These items should not be allowed to leave the laboratory.

If you work with Salmonella bacteria in a microbiology laboratory, watch for symptoms of Salmonella infection, such as diarrhea, fever and abdominal cramps. Call your health care provider if you or a family member has any of these symptoms.

News and Alerts Archive


Printer-friendly version Print