influenza
"Co-worker was diagnosed with the flu. 48 hours later I had fever, headache, joint aches and cough and went to doctor. Nasal smear confirmed strain A. Within 24 hours of starting Tamiflu, symptoms were better.  Three days after starting Tamiflu feeling much better with no fever or headache. Still have cough but getting better. First time I have taken this medicine. But it made me a believer!"