Molecular epidemiology and mapping of tuberculosis in Israel: do migrants transmit the disease to locals?

ABSTRACT

SETTING: Israel receives migrants from various countries, some of which have high tuberculosis (TB) prevalence. OBJECTIVE: To assess the predominant Mycobacterium tuberculosis strains in Israel isolated during 2008-2010 among Israeli-born and migrant patients, and to investigate possible transmission of TB from migrants to the local population. METHODS: Molecular characterisation employed 43-spacer spoligotyping and 16-loci mycobacterial interspersed repetitive units-variable number of tandem repeats typing. All patients were classified according to those who were members of a cluster and those who were not. RESULTS: Among 684 M. tuberculosis strains isolated from new patients genotyped and assigned to their specific cohort populations during the study period, major spoligotype families were Central Asian (CAS) (n = 140, 20%), Beijing (n = 101, 15%) and T (n = 160, 23%). Most Beijing strains (66%) were isolated from patients from the former Soviet Union (FSU), while CAS strains were mainly (74%) from Ethiopia, Eritrea and Sudan (EES). For the heterogeneous T-clade, patient countries of origin were 38% EES and 33% FSU. CONCLUSIONS: Predominant M. tuberculosis genotypes in Israel in 2008-2010 were similar to genotypes endemic to the migrants' countries of origin. Epidemiological investigations did not demonstrate transmission between migrants and Israeli-born patients sharing the same cluster.