date:Aug 10, 2012
the CDC's influenza division during a rencent teleconference. They tend to get respiratory illness, they tend to get cough, sore throat, muscle aches, headaches. They tend to have self-resolving illnesses like with seasonal flu.
They can be severe illnesses like seasonal flu, especially if you have underlying medical conditions that predispose you to severe illnesses with flu, he added. So based on clinical symptoms alone, they really are difficult or impossible to tell apart.