The US flu season trails on, and though influenza activity decreased since last week, it remains relatively high for this time of year, the Centers for Disease Control and Prevention (CDC) said today in its weekly FluView update.
The week ending on Mar 30 was the 19th straight week with influenza-like illnesses (ILI) at or above the national baseline.
The proportion of patients seeking healthcare for ILI decreased from 3.8% to 3.2% last week. The most recent data indicate that ILI activity for the season peaked the week ending February 16 (week 7) at 5.1%, the CDC said. During the severe 2017-18 flu season, the peak ILI rate was 7.5%.
More weeks of flu expected
In another sign of flu's decline, the CDC reported that fewer lab-tested specimens were positive for influenza last week.
"Nationally, the percentage of respiratory specimens testing positive for influenza viruses in clinical laboratories during the week ending March 30 was 18.1%, a decrease from 22.5% the prior week," the CDC said in an accompanying FluView summary.
But the CDC said it expects flu to circulate still for a number of weeks.
Of the 18.1% positive lab samples, 92.8% were influenza A, and 7.2% were influenza B. Of subtyped influenza A specimens, 26.4% were H1N1 and 73.6% were H3N2. Of subtyped influenza B specimens, 75% were Victoria lineage.
H3N2—which typically causes more severe disease—has now been the predominant strain for 6 weeks in a row.
Only six states reported high ILI activity for the week, down from 20 in the previous week. But flu activity is still widespread in Puerto Rico and 33 states, down by only 1 state.
Kids' deaths rise to 82, more hospitalizations
Despite signs of a dwindling flu season, the CDC recorded five more pediatric deaths from flu-related complications, raising the total number of pediatric flu deaths for the 2018-19 season to 82.
The three previous flu seasons saw 95, 110, and 185 pediatric flu deaths over the entire season, respectively, according to CDC data.
As is typical at the end of a flu season, the CDC reported an increase in hospitalizations. The overall hospitalization rate was 56.4 per 100,000 population, up from 52.5 the prior week. The highest rate of hospitalization was among adults ages 65 and older (181.8 per 100,000 population), followed by adults ages 50 to 64 (71.9 per 100,000 population) and children ages 0 to 4 years (66.1 per 100,000 population).
Apr 5 CDC FluView
Apr 5 CDC FluView summary