Patients with influenza B had similar rates of associated disease severity and ICU admission compared with patients with influenza A(H1N1) during two recent influenza seasons in Jerusalem, researchers reported.

“The role of influenza B virus as a cause of severe disease and ICU admissions has been overcast for years by the magnitude of disease associated with influenza A viruses,” Maya Korem, MD, senior physician in the department of clinical microbiology and infectious diseases at Hadassah Hebrew University Medical Center, and colleagues wrote. “In recent years, influenza B has been increasingly recognized as a cause of hospitalization and mortality, especially among children, yet the number of comparative reports of the clinical severity of influenza A and B in adults is still limited.”

For their study, Korem and colleagues included all adult and pediatric patients with laboratory-confirmed influenza admitted to three major medical centers from November 2015 to April 2016, and from November 2017 to April 2018.

During the two seasons, 964 patients were diagnosed with influenza, and the majority of cases were influenza A(H1N1)pdm09 and influenza B.