Symptom(s)	Influenza Infection		Positive Predictive Value* (%)
	Present (n=2740) (%)	Absent (n=1274) (%)
Cough	93	80	69
Fever ( 37.8°C)	68	40	77
Cough and fever	64	33	79
Nasal congestion	91	81

* During documented community outbreak, no differences for weakness (94%), myalgia (94%), sore throat (84%), nausea (86% to 92%), or headache (89% to 91%).

Reprinted with permission from 76.