You may be able to pass on the virus, even if you don't feel sick yet. The flu incubation period is the time from when you come into contact with the flu virus to when you develop symptoms.

Influenza levels in the US are the highest they've been in 15 years amid winter weather and a second wave of the virus.

The flu can also cause a general feeling of fatigue or malaise, Ray says, as well as gastrointestinal issues like diarrhea ...

the incubation periods typically about seven days average. And so and that's from the onset of symptoms because you can have the flu and not really exhibit many symptoms for the first couple of days.

So once you are infected or the incubation period before symptoms appear, usually the average symptoms are around five days," she said. She said the HMPV virus is very contagious because people with ...