U.S. flu infections still are surging, and health officials say it's a severe season that's likely to get worse.

At least 14 states and Washington, DC, are seeing high and very high levels of flu, mainly caused by a surprise new influenza mutation called subclade K.

As flu cases rise across the U.S., those who end up contracting the virus have treatments available that may help reduce ...

A new form of the flu, which is highly contagious and aggressive, is sweeping the nation this season. A mutation of influenza ...

Flu is rising rapidly across the U.S., driven by a new variant of the virus. The Centers for Disease Control and Prevention ...

Subclade K has become the dominant form of flu and is slightly different from the virus targeted by this year’s flu vaccine.

This year’s influenza virus has been dubbed the “super flu” for how quickly it’s spreading — and how hard it’s hitting.

Known as subclade K, a new, mutated flu strain that has dominated in Europe and Asia is now rapidly spreading across the US.

The new variant of Influenza A, or H3N2, has been given the nickname 'super flu.' The fast-spreading virus has caused ...

U.S. flu infections are still surging, and health officials say it's a severe season that's likely to get worse.