Flu season is finally winding down in Clark County after five months of influenza viruses sickening people in the community.
Flu activity picked up in early November and just recently dropped below the 10 percent positivity rate that indicates flu transmission is occurring in the community. For the week of March 26 to April 1 — the most recent data available — 7.3 percent of flu tests came back positive.
“It’s been a long flu season and it’s been a bit more severe than before,” said Dr. Alan Melnick, Clark County health officer and public health director.
So far this flu season, Clark County Public Health has recorded 25 flu-associated deaths. Nearly all of those deaths occurred in elderly people or people with other underlying health conditions, Melnick said.
Clark County has seen considerably more flu deaths this year than in past years. Last year, eight county residents died; the previous year, there were five deaths.
However, Melnick said, those numbers come with a caveat. This year, medical providers are testing more people for influenza. Last year, providers conducted 3,000 tests. This year, they performed 6,000 tests, Melnick said.
A person must have had a positive flu test in order for their death to be considered a flu-associated.
“We’ve gone from eight (deaths) to 25, but we’ve also doubled the number of tests we’ve done,” Melnick said.
Long-term care facilities in Clark County were also hit hard this flu season. Eighteen facilities had flu outbreaks this year. Last year, there were five outbreaks, Melnick said.
“It’s been a worse flu season all around,” he said.
A variety of factors can determine the severity of a flu season, Melnick said. Those factors include the virus itself — some years the circulating virus is more virulent — how many people received a flu shot and how good of a match the vaccine is to the virus, Melnick said.
This year’s vaccine was a “pretty good match,” Melnick said. Early data released by the Centers for Disease Control and Prevention found that the vaccines have been about 48 percent effective.
Most influenza infections this year were caused by the influenza A (H3N2) virus, against which the vaccine was 43 percent effective. The vaccine was 73 percent effective against the influenza B virus, according to initial CDC data.
