Influenza B viruses co-circulate with influenza A each season and also cause significant illness, especially in children; they lead to seasonal flu outbreaks and can cause severe pneumonia and hospitalizations. Despite lower overall incidence, B strains are included because they contribute substantially to seasonal influenza burden and have distinct vaccine and treatment considerations (Owusu et al. 2019, Charlton et al. 2018).
References:
Owusu, D., Hand, J., Tenforde, M. W., Feldstein, L. R., DaSilva, J., Barnes, J., Lee, G., Tran, J., Sokol, T., Fry, A. M., Brammer, L., & Rolfes, M. A. (2020). Early Season Pediatric Influenza B/Victoria Virus Infections Associated with a Recently Emerged Virus Subclade – Louisiana, 2019. MMWR. Morbidity and mortality weekly report, 69(2), 40–43.
Charlton, C. L., Babady, E., Ginocchio, C. C., Hatchette, T. F., Jerris, R. C., Li, Y., Loeffelholz, M., McCarter, Y. S., Miller, M. B., Novak-Weekley, S., Schuetz, A. N., Tang, Y. W., Widen, R., & Drews, S. J. (2018). Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections. Clinical microbiology reviews, 32(1), e00042-18.
