Median contact tracing yield for pulmonary index cases by clustering and whether the cluster was investigated
| Unique cases | Total clustered cases | p Value | Cases in a cluster that was investigated | Cases that were in a cluster that was not investigated | p Value | |
|---|---|---|---|---|---|---|
| Contacts screened | ||||||
| Index cases (n) | 220 | 97 | 29 | 68 | ||
| Contacts screened (n) | 959 | 561 | 191 | 370 | ||
| Median (IQR) | 3 (1–5) | 4 (2–7) | 0.007 | 4 (2–9) | 4 (2–6) | 0.474 |
| Contacts with active disease | ||||||
| Index cases with information available (n) | 131 | 47 | 14 | 33 | ||
| Contacts screened (n) | 593 | 341 | 125 | 216 | ||
| Contacts with active disease (n) | 14 | 14 | 3 | 11 | ||
| Median (IQR) | 0 (0–0) | 0 (0–0) | 0.011 | 0 (0–0) | 0 (0–0) | 0.896 |
| Contacts with latent infection | ||||||
| Index cases with information available (n) | 159 | 59 | 19 | 40 | ||
| Contacts screened (n) | 761 | 410 | 145 | 265 | ||
| Contacts with LTBI (n) | 148 | 108 | 32 | 76 | ||
| Median (IQR) | 0 (0–1) | 1 (0–2) | 0.016 | 1 (0–2) | 1 (0–2) | 0.330 |
LTBI, latent TB infection.