Influenza-like illness (ILI) activity reached a new national high for the 2015-2016 flu season during the week ending Feb. 20, according to the Centers for Disease Control and Prevention.
Nationwide, the proportion of outpatient visits for ILI was 3.2%, up from 3.1% the week before and well over the national baseline of 2.1%. Arizona and Puerto Rico were still at level 10 on the CDC’s 1-10 scale for ILI activity, and they were joined in the “high” range of activity by California, New Mexico, North Carolina, Texas, and Utah, which were all at level 8, the CDC reported Feb. 26.
States in the “moderate” range of activity for week 19 of the 2015-2016 flu season (week 7 of calendar year 2016) were Arkansas, Florida, and New Jersey at level 7 and Connecticut, Illinois, and Oregon at level 6. There were 13 states in the “low” range of activity – five at level 5 and eight states at level 4 – and 24 states in the “minimal” range, of which 13 were at level 1. Colorado and the District of Columbia had insufficient data to determine activity level, according to data from the CDC’s Outpatient Influenza-like Illness Surveillance Network.
For the week, one flu-related pediatric death, associated with an influenza B virus, was reported to the CDC, bringing the total to 14 for the season. The only states reporting more that one death are California (two) and Florida (three), the CDC said. The average number of deaths for the three previous flu seasons is over 143.
During week 19, a total of 18,844 respiratory specimens were tested, 13.8% of which were positive: 76.1% for influenza A and 23.9% for influenza B. Since Oct. 1, 2015, 4.2% of specimens have tested positive for influenza, with a 70% to 30% split between influenza A and B, the CDC report showed.