By Lorna Benson

MPR.org/90.1 FM

State and federal health officials are investigating an outbreak of multi-drug-resistant salmonella that has been linked to contact with dairy bull calves.

The outbreak has sickened 21 people in eight states, including two in Minnesota. The first illnesses started in January, and occurred as recently as Oct. 24.

According to the Minnesota Department of Health, one case involved a 16-year-old boy who got sick with the Salmonella Heidelberg outbreak strain in early July.

Just prior to his illness the boy had purchased calves from a Wisconsin dealer for a 4-H project, said Carrie Klumb, an epidemiologist with the department.

“So that’s something that’s maybe a little bit unique about this outbreak is that it’s dairy bull calves that are being collected from a variety of dairy farms in Wisconsin and then being resold to people,” she said.

Investigators are still trying to figure out if the sick calves came from one farm or several farms.

The Health Department says the Minnesota boy recovered from his salmonella infection without being hospitalized. Typically healthy people do not need antibiotics to fight a salmonella infection.

But older people, very young children and people with compromised immune systems may depend on antibiotic treatment to recover, and that’s what worries health officials most about this outbreak.

“Most of the antibiotics won’t work against this,” said Klumb.

No deaths have been reported in any states, but eight people have been hospitalized.

To avoid getting sick, health officials say people should always wash hands thoroughly with soap and water after touching livestock or anything in the area where the animals live.