Latent and active tuberculosis infections in migrants and travellers: A retrospective analysis from the Spanish +REDIVI collaborative network

Abstract

Background: Tuberculosis (TB) is the leading cause of infectious disease mortality worldwide. We analysed active and latent TB infections (LTBI) from the Spanish Network for the Study of Imported Infectious Diseases by Travellers and Immigrants (+REDIVI).

Methods: Observational, retrospective, multicentre study of TB and LTBI registered in the +REDIVI network from October 2009 to December 2016.

Results: Of 1008 cases of LTBI, 884 (87.7%) were immigrants; 93 (4.5%), immigrants visiting friends and relatives (VFR); 2 (0.9%), VFR-travellers; and 29 (1.1%), travellers. Absolute (N = 157 vs. N = 75) and relative (12.5% vs. 5.9%) frequency decreased over the study period (p = 0.003). Median time to diagnosis was 24.6 months (females 50.3 vs males 11.9; p < 0.001). Of 448 TB cases, 405 (90.4%) were in immigrants; 30 (6.7%), VFR-immigrants; 6 (1.3%), VFR-travellers; and 7 (1.6%), travellers. Median time to diagnosis was 62.5 months (females 86.6 vs males 70.1; p = 0.0075). There were 8 multidrug resistant TB cases and 1 extensively drug resistant case of TB, all in immigrants.

Conclusion: TB was frequently diagnosed more than 5 years after arrival in Spain. Screening programmes for TB and LTBI in immigrants should be considered beyond this time point. Women showed a higher diagnostic delay for both latent and active TB.

Keywords: Emigrants and immigrants; Latent tuberculosis; Travel; Travel-related illness; Tuberculosis.