Skip to main content

Table 10 Asymptomatic ratios (in%) with 95% confidence intervals based on combination of symptoms

From: Asymptomatic ratio for seasonal H1N1 influenza infection among schoolchildren in Taiwan

Symptoms Asymptomatic ratio (%)
Fever 65.1 (54.7-75.6)
Fever + cough 70.5 (60.6-80.5)
Fever + (cough or vomiting) 67.2 (56.9-77.5)
Fever + (cough or headache) 63.8 (53.2-74.3)
Fever + (cough or nose) 63.9 (53.3-74.4)
Fever + (cough or vomiting or headache) 61.2 (50.5-71.9)
Fever + sore throat 77.9 (68.8-87.0)
Fever + ( sore throat or vomiting) 73.7 (64.1-83.4)
Fever + ( sore throat or headache) 71.1 (61.1-81.0)
Fever + ( sore throat or nose) 66.7 (56.3-77.0)
Fever + ( sore throat or vomiting or headache) 68.9 (58.8-79.1)
Any symptom 55.6 (44.7-66.4)
Fever + (cough or sore throat)* 66.9 (56.6-77.2)
Fever + (cough or sore throat or nose) + (headache or pain or fatigue)# 73.0 (63.3-82.8)
  1. *denotes US-CDC criteria for ILI; #denotes TCDC criteria for ILI.