Flu incidence on the rise and this season could be severe, CDC says

ATLANTA  — Incidence of influenza is elevated in all but one of 10 HHS Surveillance Regions for the week ended Dec. 31, the Centers for Disease Control and Prevention recently reported. The end of the year marked the third week influenza activity was above the national baseline level of 2.2% as activity levels continue to climb.



There were several pockets of high influenza activity, including throughout New York City, Puerto Rico and 10 states  (Alabama, Georgia, Louisiana, Missouri, New Jersey, New York, Oklahoma, Oregon, South Carolina and Utah).



Influenza A (H3N2) viruses have been identified most frequently in the United States. Of respiratory samples from the United States that were analyzed by public health laboratories, 1,160 were positive for influenza, of which 1,050 (90.5%) were influenza A and 110 (9.5%) were influenza B. Of the 972 influenza A viruses that were subtyped, most (96.3%) were H3 viruses and (3.7%) were (H1N1)pdm09 viruses.



In the past, H3N2-predominant seasons have been associated with more severe illness and higher mortality, especially in older people and young children, relative to H1N1- or B-predominant season. While it’s not possible to predict which influenza viruses will predominate for the entire 2016-2017 influenza season, if H3N2 viruses continue to circulate widely, older adults and young children may be more severely impacted.