The yield of tuberculosis screening of undocumented migrants from the Horn of Africa based on chest radiography.

BACKGROUND Since 2006 more than 60,000 migrants arrived in Israel from the Horn of Africa (HoA: Sudan, Eritrea, Ethiopia). They were detained in prison and screened for tuberculosis (TB) by means of an interview and chest X-ray (CXR). OBJECTIVES To evaluate the yield of this screening process. METHODS This cross-sectional study evaluated the validity of CXR in a random sample of 1087 of the 5335 HoA migrants (20.4%) who arrived in 2009, and assessed its related costs. RESULTS Sixty-two migrants (5.7%) had CXRs with TB-suspicious findings, and 11 of them were finally diagnosed with TB (17.7% of all TB-suspicious CXRs). TB point-prevalence was 1000 cases per 100,000 migrants (1.0%). As no additional TB cases were diagnosed on arrival, CXR sensitivity, specificity and positive predictive value were 100%, 96.1% and 17.7%, respectively. The interview did not contribute to the detection of migrants with TB. Direct costs related to the detection of single TB cases in prison was 17,970 shekels (US$ 4585), lower than the treating cost of 28,745 shekels ($7335). During 2008-2010, 88 HoA migrants who had been screened at the prison after crossing the border were later diagnosed with TB in the community. The average annual TB incidence was 132 cases/100,000 migrants. We traced 56 (63.6%) of the CXRs that were performed during detention. Of those, 41 (73.2%) were unremarkable, 8 (14.2%) were TB suspicious and 7 (12.5%) had non-TB-related abnormalities. CONCLUSIONS CXR-based screening is a valid and cost-saving tool for screening HoA migrants for TB; the interview has significant limitations.