Multidrug-resistant Salmonella outbreak linked to Dairy bull calves
Federal, state and local health officials are investigating a multistate outbreak of multidrug-resistant Salmonella Heidelberg infections, which has sickened 21 people in eight states this year.

Portrait of the cute baby bull calf/CDC
Eight people required hospitalization for their illness. No deaths have been reported.
Epidemiologic, traceback, and laboratory findings have linked this outbreak to contact with dairy bull calves purchased from livestock markets in Wisconsin. Dairy bull calves are young, male cattle that may be raised for meat.
As part of routine surveillance, the Wisconsin State Laboratory of Hygiene, one of seven regional labs affiliated with CDC’s Antibiotic Resistance Laboratory Network, conducted antibiotic resistance testing on clinical isolates from the ill people associated with this outbreak. These isolates were found to be resistant to antibiotics and shared the same DNA fingerprints, showing the isolates were likely related to one another.
Traceback information available at this time indicates that most calves in this outbreak originated in Wisconsin. Wisconsin health and agriculture officials continue to work with other states to identify herds that may be affected.
The CDC offers the following advice to prevent illness when working with any livestock, such as dairy bull calves:
- Always wash your 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.
- Use dedicated clothes, shoes, and work gloves when working with livestock. Keep and store these items outside of your home.
- Work with your veterinarian to keep your animals healthy and prevent diseases.
This investigation is ongoing.