The 2018-19 flu season was moderate, but the longest lasting season in 10 years. And moderate though it may have been, it still resulted in somewhere between 36,000 and 61,000 deaths in the United States. (The data is still being analyzed.)
Here’s what the Centers for Disease Control and Prevention says about this past flu season.
- The 2018-19 influenza season was a moderate severity season with two waves of influenza A activity of similar magnitude during the season: A(H1N1)pdm09 predominated from October 2018 to mid-February 2019, and A(H3N2) activity increased from mid-February through mid-May.
- Nationally, influenza-like illness activity began increasing in November (2018), peaked during mid-February (2019), and returned to below baseline in mid-April (2019). The season lasted 21 weeks, making it the longest season in 10 years.
- During October 1, 2018–April 30, 2019, a total of 18,847 laboratory-confirmed influenza-related hospitalizations were reported (cumulative incidence for all age groups=65.3 per 100,000 population). The overall peak occurred during the week ending March 16, 2019 (week 11). The hospitalization rate was highest among persons aged =65 years, who accounted for approximately 47% of reported influenza-associated hospitalizations.
- Using data available from October 1, 2018, to May 4, 2019, CDC estimates that influenza virus infection has caused 37.4 million–42.9 million symptomatic illnesses; 17.3 million–20.1 million medical visits; 531,000–647,000 hospitalizations; and 36,400–61,200 deaths in the United States.
- The 2019-2020 vaccine recommendations; WHO and the Food and Drug Administration’s Vaccines and Related Biologic Products Advisory Committee made the influenza vaccine composition recommendation for the United States. Both agencies recommend that influenza trivalent vaccines contain an A/Brisbane/02/2018 A(H1N1)pdm09-like virus, an A/Kansas/14/2017 A(H3N2)-like virus, and a B/Colorado/06/2017-like (B/Victoria lineage) virus. The quadrivalent vaccine recommendation included the trivalent vaccine viruses and a B/Phuket/3073/2013-like (B/Yamagata lineage) virus.
- Complete medical chart abstraction data in FluSurv-NET were not expected to be finalized until later in 2019; however, as of June 13, 2019, data were available for 7,531 (40.0%) hospitalized adults and children with laboratory-confirmed influenza. Among 6,399 hospitalized adults with information on underlying medical conditions, 92.6% had at least one reported underlying medical condition that placed them at high risk for influenza-associated complications. The most commonly reported underlying medical conditions among adults were cardiovascular disease (45.0%), metabolic disorders (42.9%), obesity (39.4%), and chronic lung disease (29.9%). Among 1,132 hospitalized children with such information, 55.0% had at least one underlying medical condition; those most commonly reported were asthma (27.1%) and neurologic disorder (14.7%). Among 759 hospitalized females aged 15–44 years with information on pregnancy status, 152 (28.7%) were pregnant.
Source: CDC Morbidity and Mortality Weekly Report, June 21, 2019