Table 2. Test results for first- and second-ring contacts, by number of nights of exposure to case-patient 1 of Hennepin County tuberculosis case cluster, Minneapolis, Minnesota, USA, 2017–2018*.
| No. nights exposed to case-patient 1 | No. contacts | No. (%) contacts evaluated | Test results* |
||
|---|---|---|---|---|---|
| No. (%) positive | No. negative | No. other† | |||
| 26–31 | 34 | 33 (97) | 9 (27) | 19 | 6 |
| 21–25 | 59 | 54 (92) | 11 (20) | 41 | 7 |
| 16–20 | 39 | 36 (92) | 7 (19) | 26 | 6 |
| 11–15 | 57 | 54 (95) | 4 (7) | 43 | 10 |
| 6–10 | 76 | 59 (78) | 8 (14) | 43‡ | 25 |
| 1–5 | 54 | 47 (87) | 2 (4) | 43 | 9 |
| 0 |
19 |
15 (79) |
1 (7) |
13 |
5 |
| Total | 338 | 298 (88) | 42 (14) | 228 | 68 |
*Contacts were tested by either the tuberculin skin test or interferon-γ release assay. †Contacts with history of a positive result by either tuberculosis test and those lost to follow-up. ‡Includes case-patient 5, who received an active tuberculosis diagnosis because his sputum was culture positive.