Patients with underlying medical conditions (UMCs) were more likely to be hospitalized for influenza than those without UMCs, according to a retrospective study across 4 flu seasons published in The Journal of Infectious Diseases. Among 1,403 patients hospitalized with influenza at least once within a season, flu-related hospitalization was highest for patients with congestive heart failure (adjusted rate ratio, 4.2, 95% confidence interval: 3.6–4.9), followed by those with chronic obstructive pulmonary disease (COPD). Multiple UMCs also had an effect on hospitalization rates. For those with 4 or more UMCs, compared to those with no UMCs, flu-associated hospitalization rates were about 60% higher.
Multiple symptoms: The most recent flu tracking for this season posted on March 22, 2025, shows positivity rates are down more than 10% over the previous week. There have been at least 44 million illnesses, 580,000 hospitalizations, and 25,000 deaths from flu for the 2024-2025 season.