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Three years of universal molecular epidemiology of tuberculosis in Almeria (Spain), a setting with a high proportion of TB in immigrants

Abstract number: 1733_1333

Martínez M., García de Viedma D., Sánchez M., Rogado M., Cabezas M., SánchezYebra W., Herranz M., Fernández R., Martínez J., Lucerna M., Barroso P., Cabeza-Barrera I., Díez F., Rodriguez M., Escámez M., Marín P., Lazo A., Gamir J., Vazquez J., Gutierrez on behalf of the INDAL-TB group C.

Objective: To evaluate the TB transmission patterns in a population with a high proportion of immigrant cases.

Background: Almeria has a high intensive agriculture production, responsible of a calling effect for immigrants.

Methods: 469 TB cases were communicated in the period 2003–2005, among them 283 (60.3%) microbiologically confirmed and 233 (49.7%) in foreigners [Africa-Magreb 94 (40.3%) cases, Africa Sub-Saharan 56 (24.0%), East-Europe 38 (16.3%), Latin-America 33 (14.2%)]. Microbiology: Samples were inoculated on to Löwenstein and BacT/ALERT®MP (bioMérieux) media. The isolates were identified by means of a genomic probe (Gen Probe, USA). Genotyping: M. tuberculosis (MTB) isolates were fingerprinted by IS6110 RFLP, Spoligotyping, and MIRU-VNTR with the set of 15 loci. MTB isolates were considered to be clustered if their MTB genotypes shared identical RFLPtypes (for patterns with more than 6 bands) or also identical spoligotypes and MIRUtypes (for cases with less than 6 RFLP bands). Cases with suspicious of being false positive due to laboratory cross-transmission were excluded. Epidemiology: data were obtained from the Register of the ``Sistema de Vigilancia Epidemiológica de Andalucía'' and from standardised interviews of the clustered cases.

Results: At least one MTB isolate from each of 256 (90.5%) patients were genotyped. Seventy-eight cases (30.6%) were grouped into 26 clusters (range 2–6 members) and the remaining cases (69.4%) were infected with isolates not shared by other members in the population. Thirty-eight (27.0%) of 141 foreign-born patients and 40 (34.8%) of 115 Spaniard cases were clustered (p 0.176). Nine clusters (34.6%) included only autochthonous cases; eight (30.8%) only foreign patients and the remaining nine clusters included both autochthonous and foreign cases (34.6%). The standard contact tracing identified epidemiological links in only 2 of the 8 clusters constituted by four or more members. However, the standardised interview of clustered cases could reveal links for 7 clusters.

Conclusions: Our data suggest the occurrence of TB transmission among the foreign-born population and between the autochthonous and foreign cases in Almeria. Molecular epidemiology is required in addition to the traditional contact tracing to reveal novel TB transmission routes in this area with a high socio-epidemiological complexity.

Finance: Fondo Inv. Sanitaria (PI030986-PI030654), J. Andalucía (248–03, 151–05) and F. Progreso y Salud (14033)

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Subject:
Location: ICC, Munich, Germany
Presentation type:
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