Table 1.

Descriptions of the 26 statistically significant clusters found between July 1995 and June 2008 in state-wide cohort of infants less than 6 months old from the TennCare population. Full results are provided in supplementary table 1.

Year	Region	Radius (km)	Start Date	Length (days)	Observed Cases / Expected Cases (Ratio)	P-Value
1995 – 1996	Nashville	12.94	12/14/1995	5	23/5.54 (4.15)	2.60E-02
	Memphis	20.96	5/1/1996	24	29/7.85 (3.69)	6.30E-03
1996 – 1997	Nashville	9.45	11/18/1996	27	36/10.64 (3.38)	1.60E-03
	Southeast	32.01	1/30/1997	1	12/1.12 (10.72)	4.60E-03
	Johnson City	170.49	2/5/1997	35	252/150.32 (1.68)	1.10E-08
1997 – 1998	Memphis	12.16	7/21/1997	25	34/7.21 (4.72)	9.70E-07
	Nashville	90.72	11/7/1997	31	199/122.94 (1.62)	2.10E-04
	Knoxville	120.11	2/13/1998	34	183/97.35 (1.88)	6.00E-09
1999 – 2000	Nashville	6.06	12/10/1999	11	12/1.21 (9.94)	1.60E-02
2001 – 2002	Nashville	44.9	11/8/2001	32	128/65.2 (1.96)	7.20E-06
	Memphis	57.97	11/30/2001	35	246/132.28 (1.86)	1.90E-13
2002 – 2003	Knoxville	104.78	2/8/2002	30	282/186.03 (1.52)	3.70E-05
	Memphis	14.88	11/9/2002	35	144/59.41 (2.42)	1.00E-13
	Nashville	28.49	12/16/2002	34	106/58.15 (1.82)	4.20E-02
2003 – 2004	Memphis	78.3	10/4/2003	33	178/85.49 (2.08)	6.40E-12
	Nashville	3.79	11/13/2003	16	21/4.18 (5.02)	1.80E-02
	Johnson City	50.53	1/27/2004	35	121/60.73 (1.99)	3.00E-05
	Chattanooga	110.97	2/10/2004	35	168/105.11 (1.6)	4.10E-02
2005 – 2006	Memphis	22.16	11/27/2005	35	117/64.19 (1.82)	3.90E-03
	Knoxville	46.58	12/12/2005	35	148/84.14 (1.76)	3.00E-04
	SW Border	131.26	2/15/2006	34	184/118.62 (1.55)	2.50E-02
2006 – 2007	Nashville	67.6	11/9/2006	35	324/207.29 (1.56)	3.60E-08
	Memphis	191.68	1/24/2007	29	320/221.39 (1.45)	5.00E-04
2007 – 2008	Memphis	21.68	11/12/2007	34	199/94 (2.12)	2.00E-15
	Nashville	41.08	12/16/2007	18	222/133.16 (1.67)	2.00E-06
	Knoxville	119.46	1/19/2008	34	430/289.3 (1.49)	2.30E-09