Hospitals report more flu cases, even as school outbreaks ebb with the holiday

Minnesota hospitals admitted 117 influenza patients last week, the highest weekly total for the season, according to a Minnesota Health Department flu update on Thursday.

The department also revised the prior week's tally upward, to 114, an adjustment that reflected reporting delays. So far, 505 people have been hospitalized for the flu, which is about the midrange for recent influenza seasons.

Schools had become ground zero for many infections over the past few weeks, but as expected, there were no school outbreaks in the last full week of 2019 because of the holiday break.

Clinics are also seeing a surge of patients with flu-like symptoms, who represented 5.8% of all clinic visits last week — a level of activity often seen as the season approaches its peak.

Typical flu-like symptoms include fever, body aches, chills and coughing, as well as general upper respiratory unpleasantness.

Most of the patients tested were infected with the B strain of the virus, which, unlike previous years, emerged early in the current season.

The B strain is more likely to affect children — reflected in the surge of school outbreaks earlier this year — because fewer of them have been exposed to it in the past and had the chance to develop immunity.

"A higher fraction of adults have seen [the B strain]," said Dr. Frank Rhame, an infectious disease specialist at Allina Health.

As a result, there have only been nine outbreaks in nursing homes and other long-term care facilities this year, compared with 299 school outbreaks.

But recent holiday gatherings could mean the virus has been passed on to others who are vulnerable. "There is more intergenerational togetherness," Rhame said. "If there is an outbreak in kids, it is going to expose adults in a holiday season."

Flu generally develops 36 to 72 hours after infection.

"Influenza is remarkably good at getting around and infecting people fast," Rhame said. It spreads through the air as people cough or sneeze, as well as through physical contact.

Hand-washing and wiping down surfaces are especially important in households with young children, the elderly or those with chronic conditions or other illnesses that make them more vulnerable to infection.

The B strain tends to result in less serious flu symptoms, Rhame said, compared with the A strain, which typically emerges at the start of the flu season.

There was one flu-related death last week in Minnesota, bringing this seasons's total to eight — making it one of the least fatal among the last five seasons.

Public health officials said it's not too late to get a flu shot. They noted that influenza season can run into May, so a vaccination now still gives people time to prevent the flu or lessen the severity of the illness should they become infected.

Glenn Howatt • 612-673-7192 Twitter: @GlennHowatt