Bend residents will remember the winter of 2017 as one of the worst in a long time. And data from the emergency room at St. Charles Bend supports that notion.

Doctors saw an increase in head and neck injuries in the first quarter of the year that may reflect a larger number of slips and falls, according to emergency room data.

Reports from early in the year suggested a number of people had fallen while trying to clean the snow off their roofs. The number of emergency room patients with head injuries rose 45 percent, from 55 in the first quarter of 2016 to 80 this year.

Cases of neck strain rose 28 percent, from 67 patients last year to 86 in 2017.

Another large change was the number of flu and pneumonia cases — it decreased. The number of patients presenting with flu symptoms was cut in half, from 130 in 2016 to 61 in 2017. Pneumonia cases, which often start with flu infections, dropped from 91 to 59.

That could represent the cyclical nature of the flu. Some years, flu strains spread more easily and cause more severe illness. Other years, flu seasons are much more mild.

What’s odd about the 2017 flu numbers, however, is that most of Oregon experienced its worst flu season in a long time.

“By all of our measures this year, flu was particularly bad,” said Dr. Ann Thomas, public health physicians with Oregon Public Health Division.

OHA tracks flu hospitalizations in the Portland tri-county area, and by that measure, the state had never seen a flu season this bad. Before 2017, flu hospitalizations had peaked around 800. This year, they hit 1,614.

Thomas attributes that to the circulating strain, an influenza A H3N2 strain that is associated with more severe illness and deaths, especially in older people and young children. Oregon also broke the record for the number of flu outbreaks reported to the state this past flu season.

So why were emergency visits for flu cut in half from the previous year in Bend?

It may also be due to the record snowfall. The heavy snows and concerns over the safety of school roofs resulted in an almost unprecedented number of snow days for Bend-La Pine Schools. After not a single snow day in the first quarter of 2016, schools were closed six to eight days in 2017. (Not all schools reopened at the same time.)

Scores of studies have documented that schools play a major role in the community transmission of the flu virus. Kids are enclosed in tight quarters through much of the day, allowing them to pass on the virus quickly and efficiently.

Studies have shown the usual winter break impacts flu transmission rates, with cases dropping during the vacation then picking up again when students return.

That’s why many public health emergency plans for dealing with flu pandemics include the possibility of closing schools. The Centers for Disease Control and Prevention analyzed the experiences of two school districts in Texas during the 2009 H1N1 pandemic, one of which shut down schools as a precaution. In the district where schools were closed, there was no increase in flu-related emergency room visits. But in the district that kept schools opened, emergency room visits doubled.

While it would be difficult to conclusively prove school closures in Bend kept flu in check, Thomas said it’s a viable theory.

“School-age kids are the ones that spread it around a lot, especially in middle school and high school, where you’re not just infecting 30 other kids, it’s like 150 going to different classes each period,” she said. “And then they bring it home and spread it to their families and grandparents.”

Then again, flu behavior is notoriously hard to predict and often just as difficult to explain.

“You never know enough,” Thomas said. •