Table 3.

The characteristics of epidemiological factors observed in primary cases between with and without household transmission events

	Cases with household influenza transmission (N = 114)	Cases without household influenza transmission (N = 198)	P value
Median onset month	January 2013	January 2013	0.052
Median age of primary cases (range)	11 (6–15)	12 (6–15)	0.01
Antiviral treatment for primary cases (%)	107 (93.9)	189 (95.5)	0.61
Influenza vaccination (%)	90 (45.3)	107 (42.7)	0.79
Median absent days (range)	4.5 (0–10)	4 (0–14)	0.009

Note: Primary cases only included primary school and junior high school children