Table 2.
Space-time PTB clusters in Zhaotong in the period 2011/1/1–2015/12/31
| Cluster type | Time period | Centre and radius (km) | Areas covered (n) | Observed cases (n) | Expected cases (n) | RRa | P-value |
|---|---|---|---|---|---|---|---|
| Most likely cluster | 2013/3/1–2015/8/31 | Wufeng 45.51 | 29 | 5994 | 3418 | 2.01 | < 0.001 |
| Secondary cluster 1 | 2014/4/1–2014/6/30 | Fenghuang 7.06 | 3 | 155 | 45 | 3.47 | < 0.001 |
| Secondary cluster 2 | 2011/2/1–2013/7/31 | Dousha 13.76 | 3 | 362 | 214 | 1.70 | < 0.001 |
| Secondary cluster 3 | 2011/3/1–2012/10/31 | Cuihua 0 | 1 | 119 | 58 | 2.06 | < 0.001 |
| Secondary cluster 4 | 2015/12/1–2015/12/31 | Zhongming 9.04 | 2 | 23 | 6 | 3.91 | 0.030 |
| Secondary cluster 5 | 2012/2/1–2012/5/31 | Xiluodu 17.84 | 4 | 81 | 45 | 1.82 | 0.162 |
| Secondary cluster 6 | 2012/1/1–2012/7/31 | Baihetan 0 | 1 | 86 | 51 | 1.68 | 0.704 |
aRelative risk