That happened to me twice when I came back on trips from Brasil, its a bummer!
One morning I woke up before landing at ATL with a sore throat and that was it till I caugh the flight to CVG and on there it really started hitting me. By the evening, just laying on the couch not moving my body hurt, not ached but hurt!
Apparently I had strep.. and was probably the same thing three weeks earlier my doctor said.
I drink straight whiskey for that when I get a cold. Doubt it does much but feels strong enough to kill

Tchau

DA-