Insights on the Mycobacterium tuberculosis population structure associated with migrants from Portuguese-speaking countries over a three-year period in greater Lisbon, Portugal: Implications at the public health level

Tuberculosis among foreign-born patients is a key indicator of country-level epidemiological profiles and, of an increasing concern in Europe given the more intensified migratory waves of refugees. Since Portugal presents a lower immigrant-associated TB incidence rate when compared to other European countries, we sought to characterize the epidemiology and transmission dynamics among the foreign-born population coming from Portuguese-speaking countries that are associated with higher TB incidences. In the present study we analyzed 133 Mycobacterium tuberculosis isolates obtained from foreign-born individuals over a three-year period in Lisbon, Portugal, using molecular epidemiological methods such as spoligotyping and 24-loci MIRU-VNTR. Moreover, all strains were subjected to drug susceptibility testing. The genetic profiles obtained suggest that strain importation from Portuguese speaking countries plays a less important role in TB epidemiology but instead argue in favor of a high degree of penetrance of Portuguese endemic strains to the migrant population, including multidrug resistant strains, which is particularly relevant to active screening programs.Financial support was provided by the European Society of Clinical Microbiology and Infectious Diseases, for which we would like to would like to acknowledge the Study Group for Mycobacterial Infections;JP was supported by a post doc fellowship [SFRH/BPD/95406/2013] from FCT. The phylogenetic analysis work at Nalin Rastogi's lab was supported by a FEDER grant financed by the European Union and Guadeloupe Region (Programme Opérationnel FEDER-Guadeloupe-Conseil Régional 2014-2020, Grant number 2015-FED-192).MV is thankful to [GHTM UID/Multi/04413/2013] from FCT and toprojects “ForDILAB-TB” and “A implementação de um novo método de identificação rápida do complexo M. tuberculosis nos Laboratórios de Referência da Tuberculose de Maputo e Beira” from Fundação Calouste Gulbenkian and the Community of the Portuguese Speaking Countries (CPLP), as well as toour colleagues Ana Tavares and Sonia Dias for their valuable contribution with the epidemiological and health-care services provided to migrants in Portugal related aspects. CS was supported by FCT [SFRH/BD/73579/2010].