Table 5.

Characteristics of emerging space-time clusters of COVID-19 cases at machi-level in Nagasaki Prefecture from 2020/4/1 to 2021/9/8

Cluster	Period	Duration (Days)	Radius (km)	Observed Cases	Expected Cases	RR	P-value	Machi (Total)	Machi (RR > 1)	Population
1	2021/7/26–2021/9/8	44	3.65	268	22.31	12.58	< 0.001	77	49	65,595
2	2020/12/21–2021/9/8	261	2.39	556	133.16	4.54	< 0.001	96	74	67,231
3	2021/1/3–2021/9/8	248	4.21	405	125.19	3.41	< 0.001	31	19	66,506
4	2021/1/4–2021/9/8	247	1.87	252	69.81	3.74	< 0.001	39	28	66,433
5	2021/8/4–2021/9/8	35	7.69	130	18.34	7.24	< 0.001	42	16	67,402
6	2021/4/23–2021/9/8	138	6.11	232	68.43	3.5	< 0.001	45	24	65,127
7	2021/8/1–2021/9/8	38	8.36	111	19.99	5.65	< 0.001	69	21	67,786
8	2021/7/26–2021/9/8	44	11.65	115	23.24	5.03	< 0.001	87	21	68,308
9	2021/8/2–2021/9/8	37	8.67	98	19.54	5.09	< 0.001	87	25	68,027
10	2021/8/3–2021/9/8	36	4.86	86	18.6	4.68	< 0.001	31	12	66,504
11	2021/8/16–2021/9/8	23	5.03	29	2.38	12.22	< 0.001	22	3	13,143
13	2021/8/6–2021/9/8	33	11.81	54	17.33	3.14	< 0.001	134	9	67,441
14	2021/8/16–2021/9/8	23	0	3	0.0089	337.64	< 0.05	1	1	49