2015 | 2016 | 2017 | 2018 | 2019 | 2020* | |
No of household members tested during index case investigation | 11 601† | 8479 | 7638 | 10 782 | 14 963 | 8511 |
Median age (years) of investigated index cases | – | 15 (IQR: 7–25) | 16 (IQR: 8–26) | 16 (IQR: 7–25) | 18 (IQR: 8–28) | 17 (IQR: 8–26) |
Fraction of index cases who are male (%) | 49.7 | 41.6 | 43.7 | 47.4 | 48.5 | 53.0 |
No of positive investigated people (secondary cases) (%) | 591† (5.1%) | 365 (4.3%) | 319 (4.2%) | 445 (4.1%) | 544 (3.6%) | 267 (3.1%) |
No of positive investigated people (secondary cases) performed from January to April (%) | 169 (6.7%) | 167 (4.9%) | 74 (4.7%) | 164 (4.8%) | 177 (5.1%) | 267 (3.7%) |
Probability to find a secondary case during investigation (95% CI) | 0.048† (0.045 to 0.052) | 0.041 (0.037 to 0.045) | 0.040 (0.036 to 0.044) | 0.040 (0.036 to 0.043) | 0.035 (0.032 to 0.038) | 0.030 (0.027 to 0.034) |
*Time period 1 January to 30 April.
†Data available from 1 January to 16 September.