Olmsted County Public Health believes a small local outbreak of whooping cough or pertussisis limited to Rochester Youth Hockey Association participants.

Six recent cases of pertussis have been confirmed to be "epidemiologically" linked to the youth hockey teams, said Public Health Communications Coordinator Kari Etrheim. That discovery led to the department sending out letters to the families with children in the hockey association.

Pertussis is a highly contagious respiratory infection that can cause severe coughing and trouble breathing, often producing a whooping sound for which it's named. The condition can prove fatal for infants and elderly, but is most commonly found among adolescents.

"Right now it doesn't look like this is going beyond hockey. That's the good news," she said. "We haven't seen any transmission within the school setting."

The department has confirmed an index case or original patient, who became symptomatic on Sept. 30. Etrheim says it's unknown where that first youth contracted pertussis.

This small outbreak brings Olmsted County's confirmed pertussis cases to 11 for 2019, so far, That's a pretty routine total for the county, Etrheim said.

In 2016, Olmsted County was hit with a summer/fall outbreak of 246 pertussis confirmed cases with an annual total of at least 261 cases. That was a record-breaking year with Olmsted County leading the state in pertussis cases.

As the best way to prevent whooping cough, a vaccine is often given with diphtheria and tetanus vaccinations, with five doses through a child's first four to six years. After that, immunity can wane by age 11 and physicians recommend boosters throughout adulthood, especially for people who deal with children on a regular basis.

Other steps can help decrease the spread of illness, according to the Olmsted County Health Department. They include covering mouths while coughing, washing hands often and staying home when ill.

"This time of year there's always an increase of illness. Healthy behaviors are really more important now, so people need to wash those hands and cover those coughs," said Etrheim.