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Advice for Livestock Handlers & Veterinarians

Salmonella Heidelberg Infections Linked to Contact with Dairy Bull Calves (Final Update)

This outbreak investigation is over. However, infections in calves continue to be reported and people can still get a Salmonella infection from contact with livestock. Read more information about Salmonella and livestock and how people can reduce the chance they will get an infection.

Advice for Livestock Handlers

This outbreak is a reminder to use a One Health approach to preventing illness, which recognizes that the health of people is connected to the health of animals and the environment. Follow these steps prevent illness when handling any livestock, like dairy bull calves:

  • Always wash hands thoroughly with soap and water right after touching livestock, equipment for animals, or anything in the area where animals live and roam.
    • This is especially important to do before preparing or consuming food or drink for yourself or others.
    • Adults should supervise hand washing for young children.
    • Use hand sanitizer if soap and water are not available right away.
  • Use dedicated shoes, work gloves, and clothing that you only use when working with livestock. Keep these items outside of your home.
    • Do not eat or drink in the areas where livestock live and roam.
    • Do not allow toys, pacifiers, spill-proof cups, baby bottles, strollers, or similar items in livestock areas.
    • Wash hands after removing any clothes and shoes you wore while working with livestock.
  • Work with your veterinarian to keep your livestock healthy.
    • If you think your livestock are sick, talk to your veterinarian as soon as possible and take extra care to wash your hands after working with the animals and use separate clothes when caring for them.
    • Children, adults over age 65, and people with compromised immune systems should limit their contact with sick animals.

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.
    • Laboratory testing, to include antimicrobial susceptibility testing, is recommended among dairy bull calves diagnosed with Salmonella Heidelberg, especially those associated with human illness.
    • 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.
    • 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.
    • 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.
    • 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.
    • 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.
    • Direct clients to the Advice for Livestock Handlers above.

Information for Health Care Providers

Salmonella bacteria live in the intestinal tracts of animals, including cattle. Cattle may become ill from Salmonella, but usually have no signs of illness. Young calves are more susceptible to being ill. The primary mode of transmission to humans is fecal-oral and is associated with contact with animals or their environments.

Clinicians should consider multidrug-resistant (MDR) Salmonella Heidelberg infection in the differential diagnosis of patients with exposure to cattle, farms, or farm workers and symptoms compatible with salmonellosis (e.g., diarrhea, fever, and abdominal cramps).

Guidance for clinicians whose patients have suspected or confirmed Salmonella Heidelberg infection related to this outbreak:

  • Testing
    • Obtain a culture (stool or blood, as indicated by symptoms and signs).
    • Request antimicrobial susceptibility testing.
  • Treatment
    • Most patients with nontyphoidal Salmonella do not require antibiotic treatment (exceptions may include patients <6 months, >50 years, and those who are immunocompromised or severely ill; please refer to treatment guidelines [PDF – 21 page] for additional information).
      • If treatment is indicated and MDR Salmonella Heidelberg infection is suspected, clinicians should begin treatment with azithromycin until susceptibility results of the patient’s isolate are available.
  • Follow up
    • Obtain follow-up stool cultures for patients who have culture-confirmed MDR Salmonella Heidelberg and who are:
      • Food handlers
      • Health care workers
      • Childcare workers or attendees
  • Patient counseling
    • Counsel patients to follow prevention practices. Key messages for counseling patients with salmonellosis:
      • Wash hands carefully with soap after going to the bathroom.
      • Don’t prepare food for others while ill. After you recover, wash hands carefully with soap before preparing food for others.
    • Before returning to work or childcare, these patients should have two consecutive negative stool cultures taken at least 24 hours apart and at least 48 hours after resolution of symptoms.