Table 2.
TB and LTBI among immigrants aged <35 years arriving in Norway in 2008–2011 by country of origin (only top 10 source countries for TB in Norway listed by country)
| Country of origin (WHO-estimated annual TB incidence rate per 100 000)* | Arrivals in Norway in 2008–2011† (<35 years) | Estimated number of LTBI cases‡ | Notified TB in Norway first 5 years after arrival (<40 years) |
Time in Norway prior to TB diagnosis (months) | TB within 12 months after arrival | Person-years under observation§ | Observation years lost due to emigration¶ | ||||
| <1 | 1–6 | 7–12 | 13–60 | ||||||||
| (n) | (n) | (n) | NR | (n) | (n) | (n) | (n) | (%) | (n) | (proportion) | |
| By country | |||||||||||
| Myanmar (369) | 900 | 255 | 18 | 419 | 1 | 7 | 4 | 6 | 67 | 4300 | 0.06 |
| Philippines (288) | 6700 | 1909 | 64 | 358 | 1 | 29 | 14 | 20 | 69 | 17 900 | 0.47 |
| Somalia (274) | 7400 | 2019 | 252 | 900 | 23 | 74 | 54 | 101 | 60 | 28 000 | 0.25 |
| Pakistan (270) | 2000 | 520 | 12 | 174 | 0 | 3 | 2 | 7 | 42 | 6900 | 0.29 |
| Ethiopia (207) | 2400 | 651 | 46 | 667 | 5 | 8 | 9 | 24 | 48 | 6900 | 0.42 |
| Afghanistan (189) | 6800 | 1417 | 44 | 238 | 4 | 10 | 7 | 23 | 48 | 18 500 | 0.46 |
| Thailand (171) | 3900 | 776 | 20 | 120 | 1 | 6 | 2 | 11 | 45 | 16 600 | 0.14 |
| India (167) | 2800 | 682 | 18 | 167 | 1 | 3 | 2 | 12 | 28 | 10 800 | 0.23 |
| Vietnam (140) | 900 | 177 | 12 | 364 | 0 | 9 | 1 | 2 | 83 | 3300 | 0.25 |
| Eritrea (78) | 6900 | 1888 | 82 | 307 | 10 | 21 | 15 | 36 | 56 | 26 700 | 0.22 |
| Horn of Africa** | 16 700 | 4558 | 380 | 679 | 38 | 103 | 78 | 161 | 58 | 61 700 | 0.26 |
| Countries grouped by estimated TB incidence rate* | |||||||||||
| >150/100 000 | 37 100 | 7058 | 533 | 446 | 43 | 161 | 104 | 225 | 58 | 119 400 | 0.36 |
| >200/100 000 | 23 300 | 5485 | 428 | 595 | 35 | 137 | 87 | 169 | 61 | 72 000 | 0.38 |
| >200/100 000†† | 37 000 | 8692 | 554 | 473 | 49 | 167 | 110 | 228 | 59 | 117 200 | 0.37 |
*From the 2014 WHO Global tuberculosis control report.6
†Number of immigrants, rounded to the nearest hundred. Data were obtained from Statistics Norway and the Norwegian Directorate of Immigration.
‡Interferon-gamma release assay positivity was used as a proxy for LTBI (estimates are based on published data, including Norwegian data).
§Adjusted according to estimated time in Norway before emigration for immigrants arriving in Norway in 2008–2011.
¶Estimated proportion observation years lost due to emigration within the first 5 years after arrival.
**Including Somalia, Eritrea and Ethiopia.
††Includes countries with TB IRs >200/100 000 and Eritrea and Afghanistan (in line with the current Norwegian guidelines).
IR, incidence rate; LTBI, latent tuberculosis infection; NR, notification rate per 100 000 person-years under observation; TB, tuberculosis.