Table 2. Significant geographic clusters of pertussis risk in Florida, 2010–2018.

Cluster	Population		Observed number of cases	Expected number of cases	Risk per 100,000 people	Risk ratio	p-value
1		1,307,906	556	264.45	43.10	2.10	0.001
2		67,924	79	13.7	116.3	5.75	0.001
3		1,106,654	340	223.7	32.28	1.52	0.001
4		75,569	51	15.2	67.48	3.34	0.001
5		893,858	281	180.7	31.88	1.55	0.001
6		656,466	212	132.7	32.44	1.59	0.001
7		338,270	127	68.3	37.54	1.86	0.001
8		304,654	117	61.6	38.40	1.89	0.001
9		160,475	60	32.4	38.01	1.85	0.001
10		44,263	22	8.9	49.70	2.46	0.01
11		99,646	37	20.1	37.13	1.83	0.029