Tuberculosis among undocumented boat migrants to Malta: implications for a migrant tuberculosis policy

Malta, 2002-2005.

To describe the demography and tuberculosis (TB) epidemiology of undocumented immigrants to Malta to tailor TB control strategies to this population.

Retrospective population study of undocumented immigrants to Malta using national TB surveillance data.

Overall, 85% (4570/5383) of undocumented immigrants were screened on entry using chest X-ray (CXR). Undocumented immigrants were mostly young adults aged 15-34 years (81%) and predominately male (86%), mostly originating from Africa (88%). On screening, 3.5% (160/4570) had CXR suggestive of TB, of whom 12.5% (20/160) had active TB. Using both active and passive surveillance, 33 cases of active TB were diagnosed in these immigrants, 94% of whom were diagnosed during their first 12 months of residence in Malta. Entry screening detected 61% (20/33) of cases (yield 0.44%). Of the total TB cases in Malta, the proportion of undocumented immigrants increased markedly from 33% in 2002 to 60% in 2005. The reported TB incidence among immigrants was 390/100,000 compared to 2.1/100,000 in the Malta-born.

Tailoring TB control strategies to this migrant population is essential for TB control in Malta. Awareness of increased risk of TB needs to be ongoing, not just at entry but for many years after arrival, even in resettlement countries.