Number and results of asylum seeker children screening upon arrival in the Netherlands, 2013–2017
| Age years | Children screened n | Questionnaires taken/total number of children | Positive/total number of TST# | Positive/total number of IGRA# tests | Positive/total number of sputum cultures for M. tuberculosis | Intrathoracic TB cases n (prevalence rate per 100 000 screened) | NNS stratified by TB incidence rate per 100 000 in country of origin n | |||
| <50 | 50–99 | 100–199 | >200 | |||||||
| 0–4 | 7402 | 81 (1.1) | 4/41 (9.8) | 0/1 (0) | 0/0 (0) | 0 (0) | na | na | na | na |
| 5–11 | 14 192 | 132 (0.9) | 4/28 (14.3) | 2/2 (100) | 0/19 (0) | 2 (14) | na | na | na | 2250 |
| 12–17 | 12 563 | 471 (3.7) | 13/15 (86.6) | 4/6 (66.7) | 15/62 (24.2) | 19 (151) | na | na | 1068 | 368 |
| Total <18 | 34 157 | 684 (2.0) | 21/84 (25.0) | 6/9 (66.7) | 15/81 (18.5) | 21 (61) | ||||
Data are presented as n/N (%) unless otherwise stated. TST: tuberculin skin test (Mantoux test); IGRA: interferon-γ release assay; M. tuberculosis: Mycobacterium tuberculosis; TB: tuberculosis; NNS: number needed to screen; na: not applicable. #: The discrepancy between nine known IGRA results and 21 positive TST results can be due to referral or transfer-out, bacteriological results known before IGRA was planned, or no IGRA performed in BCG-vaccinated asymptomatic children with marginal TST results but chest radiograph repeated after 4–6 weeks.