Table 4 Comparison of attack rates and secondary attack rates in clusters before and after February 02, 2020a
From: Epidemiological analysis of 67 local COVID-19 clusters in Sichuan Province, China
Time | No. of cases | No. of exposed persons | Attack rate (%) | p value | No. of secondary cases | No. of exposed persons | Secondary attack rate (%) | p value |
|---|---|---|---|---|---|---|---|---|
Before February 02, 2020 | 156 | 2027 | 7.70 | 0.022 | 107 | 1990 | 5.38 | 0.022 |
After February 02, 2020 | 111 | 1100 | 10.09 | 80 | 1072 | 7.46 |