Western Pennsylvania’s wait for flu season appears to be over.
After escaping November, December and January with few cases of the seasonal virus, local doctors have seen a doubling of new, confirmed flu patients this month. Allegheny County last week recorded two flu-related deaths, its first in 2016, county health director Karen Hacker said.
“The people we’re always most concerned about are the people who are vulnerable from other conditions. They’re usually the ones who end up hospitalized” or dying, Dr. Hacker said.
County officials confirmed 30 new flu cases last week, bringing the total to 113 since early October. The statewide tally reached 2,179 for the same period, including six flu-related fatalities, according to the Pennsylvania Department of Health.
Doctors diagnosed about 800 of those patients in the first couple of weeks in February. While only a sliver of influenza cases are confirmed through formal tests, clinicians said growing numbers suggest the season may not peak for weeks.
“Certainly we’ve recently experienced fairly cold weather, especially at the end of January and into February. More people are inside at this time of year because of the weather, so person-to-person transmission is more likely,” said Marc Itskowitz, an internal medicine physician with the North Side-based Allegheny Health Network.
Even with the boost, total flu numbers in Pennsylvania are trailing many recent seasons. By mid-February last year, Allegheny County alone had seen more than 4,600 confirmed cases and 23 flu-related deaths.
The 2014-15 season ranked among the worst in a decade, peaking in January. Flu activity in the state can gather momentum as early as October and linger through May, according to state health officials. They cast the current season as average.
“It’s picking up, but it’s still, to this point, much less intense — less frequent cases with less amount of bad illness” compared with more severe flu seasons, said Donald M. Yealy, the emergency medicine chairman for Downtown-based UPMC.
He said several influences are probably at work. The main flu strains in circulation this year may be less damaging or less prevalent, and people may be doing more to keep from getting sick, Dr. Yealy said.
Some doctors also pointed to warm weather earlier in the winter and an effective flu vaccine. They said abnormally balmy conditions kept people outdoors longer, perhaps preventing transmission in close quarters inside.
Meanwhile, the vaccine formula, which can change each year, appears to be 60 percent to 80 percent effective in preventing flu-related illness, Dr. Itskowitz said. Last season’s vaccine was a worse match for the dominant flu strains, with effectiveness estimated at 23 percent.
“Anyone who hasn’t been vaccinated yet would still benefit from getting vaccinated,” said Lynnette Brammer, an epidemiologist at the Atlanta-based Centers for Disease Control and Prevention. She cautioned that flu viruses can surge late in the season.
At the county health department, Dr. Hacker urged fundamentals — thorough hand-washing and directing coughs into a shoulder — to undermine the bug.
“It ain’t over until it’s over,” she said of the season.