Which influenza type is typically associated with more severe illness, higher fevers, and widespread outbreaks?

• A. Influenza B
• B. Influenza A
• C. Influenza C
• D. Influenza D

Answer: (B)

Influenza A is the type that usually causes more severe illness, higher fevers, and widespread outbreaks because it has a large animal reservoir (including birds and pigs) and can undergo substantial genetic changes. This allows new, highly antigenically distinct strains to emerge and spread rapidly among humans, leading both seasonal epidemics and potential pandemics. Influenza B also causes seasonal outbreaks but typically with milder disease and no broad animal reservoir driving drastic changes. Influenza C tends to produce milder, localized illness and doesn’t cause large epidemics, and influenza D mostly affects cattle with little or no established human disease.