Every day, Pine-Richland High School Nurse Susan Leonberg sees 30 to 40 students come through her office door.
She said the number of students is average, but the number of flu cases she's seen isn't. So far, no confirmed flu cases have been reported.
“Many times, we do not get notified of confirmed cases," Leonberg said. "But as far as clinically, I don’t think we have seen it. We’ve had sick children, but not flu sick. You know, the normal kind of stuff.”
In Allegheny County, there have been 416 confirmed flu cases since the seasonal count began in the last week of September. That is well below 4,862, the number of cases at the same time the year before.
“Last year’s season was pretty severe,” said Kristen Mertz, a medical epidemiologist at the Allegheny County Health Department. “I think one of the problems last year was the vaccine was not a good match for the viruses that were circulating.”
Every year, groups like the Centers for Disease Control and the World Health Organization look at which flu strains are circulating, then consult each other to create a vaccine for the three or four strains they think pose the highest risk. That work begins six to nine months before the vaccine is distributed.
Mertz said this year, the vaccine makers guessed right, and that is one of the leading reasons why the current season has been mild so far.
“Another reason might be that a lot of people got sick last year and now have immunity, because the same strains are circulating this year, as were circulating last year,” Mertz said.
An old adage says once you get a particular flu strain, you’ll never get it again. That played out in the flu epidemic of 2009, when relatively low numbers of seniors got sick. Experts said that was most likely because the same strain that passed through the county that year was likely the same one they experienced as kids.
However, the 2015-16 flu season is starting to blossom. Thirty-nine percent of the cases (162) confirmed in Allegheny County this season were reported in the first week of March. The uptick is being seen by MedExpress Area Medical Director Angela Hollis. But she said not all of the suspected cases that her doctors have seen were sent to the lab for confirmation.
“We do test quite a few, but there are some that certainly, if their family members have had the flu and they have classic flu symptoms, we don’t test everyone," Hollis said. "It's one of those, if it walks like a duck and quacks like a duck, it's probably a duck.”
Such underreporting is not unusual and is even expected.
Hollis said the slower-than-normal season could have an impact on next year’s flu season.
“It may give a little false sense of security that it wasn’t bad this year, so maybe they don’t need to get it (the flu vaccination)," Hollis said. "But people need to remember that that’s why we had a better year probably.”
In the meantime, Mertz said it looks like the peak of the 2015-16 flu season is still to come, so it's not too late to get a flu shot.
“It doesn’t only protect you from the flu, it helps protect those who are more vulnerable,” Mertz said. “So, for example, in the elderly, the flu vaccine is less effective than it is in younger people. So, if younger people will get the vaccine, it prevents them from transmitting to the elderly.”
Barring that, she said, wash your hands, cough into your elbow and stay home if you are sick.
