Flu season in Clark County is winding down after a late start.
Clark County Public Health’s latest weekly influenza update pegged the county’s flu positivity at 3.4 percent for the week of April 14 through April 20. Cowlitz County had 3.2 percent flu positivity during the same week.
For the week of April 7 through April 13, the state had 9.9 percent flu positivity, according to the most recent data available. Nationwide, the Centers for Disease Control and Prevention reported 11.8 percent flu positivity for that week.
Public Health Director Dr. Alan Melnick briefed the Clark County Board of Health about the flu season at a meeting Wednesday.
“It’s been a really interesting flu season because it started out late, and it started out with H1N1, not as severe as the H3N2 virus we’ve been seeing more recently,” Melnick said.
Flu positivity is gathered through tests from Clark County testing locations operated by Legacy Health, PeaceHealth and Kaiser Permanente. Ninety-eight percent of the positive tests this season have been for influenza Type A, which causes more serious complications and symptoms than influenza Type B.
It is considered an active flu season once the positivity stays above 10 percent for two consecutive weeks. Clark County entered active flu season the week of Jan. 27 through Feb. 2, and could be out of active flu season as soon as next week if it stays below 10 percent positivity for a second straight week.
This season was the latest Clark County has entered active flu season since 2016. The last two flu seasons in Clark County started closer to November and December.
The 2017-2018 flu season was one of the worst in the United States, according to the CDC, with about 80,000 estimated deaths, including 180 children — the most since the CDC started using its latest tracking method. About 80 percent of the children who died didn’t receive a flu shot. In Clark County, the season lasted from Dec. 3 to April 28 and resulted in 15 deaths.
The 2016-2017 Clark County flu season lasted from Nov. 6 to April 29, and racked up 26 influenza-related deaths.
So far, Clark County has had three flu-associated deaths this season (two women and one man, all 70 or older). There is a delay in reporting flu deaths due to the time needed to investigate them, so that number could rise.
While this flu season has been less deadly, nationally, with more than 57,000 estimated deaths so far, it’s broken other records. It’s considered the longest flu season in the last decade with elevated flu activity for 21 weeks — the CDC defines elevated activity as the percentage of visits for influenzalike illness at or above the national or region-specific baseline.
The peak of Clark County’s flu season came March 3 through March 9, when flu positivity was at 43.5 percent, the highest percent of positivity in the last four years. Since March 9, the percentage has dropped every week.
“Things are tapering off, so I’m more optimistic about that,” Melnick said.
Wyatt Stayner: 360-735-4546; wyatt.stayner@columbian.com; twitter.com/WStayner
