ND Department of Health The incidence of influenza in North Dakota is represented in these graphs, showing the breakdown of cases by gender and age. Most cases through Dec. 21 have been diagnosed in children and young people.

Trinity Health, like much of North Dakota, is seeing a spike in influenza cases as the holiday season brings people in close contact.

The biggest days at Trinity came Dec. 23 and 24 when about 15 cases were confirmed, said Sue Niebuhr, coordinator of Infection Prevention and Control at Trinity.

“We are definitely seeing a slight increase, and I expect that to continue, just because of Christmas and people visiting,” Niebuhr said.

Total Trinity cases as of Thursday reached 62, which includes around 10 cases from its Williston clinic.

The North Dakota Department of Health reported 1,343 cases statewide through Dec. 21, up from 613 cases at the same time a year ago despite last year’s early start for the flu. The largest share of confirmed cases have been in Cass County.

The health department noted influenza case numbers rose sharply during the week ended Dec. 21. The 645 confirmed cases that week were nearly triple the cases from the previous week. The number of counties now seeing the flu also has increased, the department stated. Only seven of 53 counties have not yet reported cases.

While influenza-related hospitalizations have continued, there have been zero deaths attributed to flu in North Dakota. A majority of cases have been in children, which is a typical pattern for seasons in which the 2009 H1N1 strain dominates, although the health department reports it has not seen that dominance this year.

Niebuhr said Trinity has been finding Type B virus in its testing.

“This is extremely rare,” she said. “Last year all of our flu were pretty much strain A.”

More typical, she said, is to start the flu season with A, with B showing up toward the end. The H1N1 virus is an example of Type A. Statewide, only about 13% of confirmed cases were identified as Type A.

Niebuhr said Trinity has hospitalized only one patient. The patient entered the hospital shortly before Christmas and since has been released.

As has been the statewide trend, influenza has shown up more frequently in children, Niebuhr said. People aged 65 and older also have been more commonly affected, she said.

Trinity has no visiting restrictions on its facilities at this time. However, Niebuhr said people who are ill should avoid places and situations in which they might expose others. The flu is considered contagious when a fever is present so the Centers of Disease Control and Prevention recommends people stay home until they have been free of a fever (100 degrees or higher) for 24 hours.