Finally the number of flu cases in Allegheny County has begun dropping, but not by much.
It's already a record flu season, which promises to persist now that another strain -- Type B Yamagata -- has taken over where Type A Brisbane left off in previous weeks.
Guillermo Cole, Allegheny County Health Department spokesman, said the worst may be over, but the flu season could continue until mid-May.
"I think we've peaked, although we're still at a fairly significant level in the number of cases over the last two weeks," he said. "It's still hanging on."
In the past two weeks, Type B Yamagata has become the predominant strain of influenza. Like Type A Brisbane, which predominated for most of the season, Type B Yamagata is not included in this year's flu vaccine.
"It's different than what's in the vaccine, so we're still seeing a significant number of cases, and it opens up the possibility of people getting the flu twice," Mr. Cole said.
For that reason, he said, the flu's persistence could repeat what occurred in 2004-05, when the season continued into mid-May.
The number of confirmed cases in the past two weeks was 141, which is only a slight decline over the previous two-week total of 149 cases. That brings this season's total number of confirmed cases, as determined by positive laboratory cultures, to 478. That tops the 2004-05 record of 395 confirmed cases.
Suspected cases, as determined by rapid antigen tests done in doctors' offices, now number 1,264 for the year, which tops the previous record of 545 for the entire 2004-05 flu season.
The total of 1,742 confirmed and suspected cases this flu season is almost double the previous record total of 940 in 2004-05.
The Health Department said there likely are hundreds of unreported flu cases for every case that's confirmed.
David Templeton can be reached at email@example.com or 412-263-1578.