Activity of influenza-like illness (ILI) was at its highest level so far for week 18 of the 2015-2016 flu season, according to the Centers for Disease Control and Prevention.
That increased activity put Arizona and Puerto Rico at level 10 on the CDC’s 1-10 scale of ILI activity for the week ending Feb. 13. Joining them in the “high” range of activity was Oklahoma at level 8, the CDC reported Feb. 19.
The percentage of visits for ILI in week 18 was 3.1%, higher than the national baseline of 2.1% and the highest level of the flu season. For the week, 30 states were at level 2 or higher on the CDC’s 1-10 scale, which is the highest number for the season. States in the “moderate” range were Arkansas, Connecticut, Illinois, and New Mexico at level 7 and Florida, Hawaii, Maryland, Nevada, New Jersey, Texas, and Utah at level 6. California and South Carolina (level 5) and Georgia, Louisiana, Mississippi, and North Carolina (level 4) took their place in the “low” range, data from the CDC’s Outpatient Influenza-like Illness Surveillance Network show.
Two ILI-related pediatric deaths were reported for the week – one of which occurred during the week ending Jan. 16 – bringing the total to 13 for the season. Three of those deaths occurred in Florida and two in California, with Arizona, Illinois, Louisiana, Michigan, Nevada, Puerto Rico, Tennessee, and Washington each reporting one death, the CDC said.
Since Oct. 1, 2015, the overall ILI-related hospitalization rate is 4.1 per 100,000 population, with 1,147 laboratory-confirmed flu hospitalizations reported. Among all hospitalizations, 71.1% were associated with influenza A, 26.4% with influenza B, 1.7% with influenza A and B coinfection, and 0.8% had no virus type information. Hospitalization data come from the Influenza Hospitalization Surveillance Network, which covers more than 70 counties in 10 states as well as 3 additional states.