At least 21 people in eight states have contracted Salmonella Heidelberg infections associated with exposure to dairy calves from Wisconsin, according to the U.S. Centers for Disease Control and Prevention (CDC). DNA testing from human and animal samples has confirmed that multiple cases of the Salmonella infection share a common genetic source.
The outbreak serves to remind veterinarians of the potential risk of exposure to pathogenic bacteria when working with livestock, and of steps to take in reducing that risk. Read more about the outbreak in Salmonella Outbreak Linked to Dairy Calves on BovineVetOnline.com.
As the investigation continues, the CDC provides these tips for veterinarians on avoiding and preventing the spread of Salmonella and other infectious diseases while working with livestock.
Advice for Veterinarians
· If veterinarians recognize ill dairy bull calves with laboratory-confirmed Salmonella Heidelberg, they should report the illness to their State Animal Health Official.
o Laboratory testing, to include antimicrobial susceptibility testing, is recommended among dairy bull calves diagnosed with Salmonella Heidelberg, especially those associated with human illness.
o A list of State Animal Health Officials can be found at here.[PDF - 15 pages]
· If you suspect that a calf has a Salmonella infection, collect a fecal sample and submit it to a state or university veterinary diagnostic laboratory for culturing and pulsed-field gel electrophoresis (PFGE) testing.
o For testing, the American Association of Veterinary Laboratory Diagnosticians (AAVLD) recommends submitting fecal samples to a state or university veterinary diagnostic laboratory for Salmonella culturing and PFGE.
o If the laboratory isolates Salmonella but cannot perform PFGE, the isolate may be forwarded to a laboratory that can perform the procedure. This may be one of the AAVLD labs in your area. To locate an AAVLD laboratory in your area, go to AAVLD Accredited Labs, or go to the AAVLD's home page and click on the "Accreditation" link on the top menu bar.
o Isolates may also be sent to USDA National Veterinary Services Laboratories (NVSL). To submit isolates to NVSL, complete Form VS 10-3 indicating whether serotyping, PFGE, or both are requested.
· Talk to your clients about reducing the risk of transmission of Salmonella illness from cattle to their family.
o Be sure to tell clients that Salmonella infections are a zoonotic disease, meaning that the infection can spread between animals and people. If the client or any of their family members are ill, encourage them to contact a health care provider immediately.
o Direct clients to the Advice for Livestock Handlers from the CDC.