Estimation of the Basic Reproduction Number of Novel Influenza A (H1N1) pdm09 in Elementary Schools Using the SIR Model

Table 2: The result of optimal R₀ values and predicted cumulative infected rate for 3 periods.

Data period	Overall		Small-scale group		Medium-scale group		Large-scale group
Data period	R₀	Cumulative infection rate*4	R₀	Cumulative infection rate*4	R₀	Cumulative infection rate*4	R₀	Cumulative infection rate*4
12 week *1	1.31	43.4% (-1.5 %)	1.36	47.6% (10.5 %)	1.32	44.3% (-0.1 %)	1.31	43.6% (3.0 %)
24 week *2	1.33	45.4% (0.4 %)	1.30	41.6% (4.5 % )	1.33	45.2% (0.8 % )	1.35	47.3% (-0.7 % )
30 week *3	1.33	44.4% ( -0.5 % )	1.26	36.8% ( -0.3 % )	1.32	44.3% ( -0.1 % )	1.34	46.4% ( -0.2 % )

*1: Period from 36th week to 47th week (1 Sep 2009 to 22 Nov 2009)
*2: Period from 36th week to 5th week (1 Sep 2009 to 7 Feb 2010)
*3: Period from 36th week to 12th week: overall data (1 Sep 2009 to 28 Mar 2010)
*4: Predicted value in 30 weeks (Parenthesis: difference between observation)