Transmission dynamics of pulmonary tuberculosis between autochthonous and immigrant sub-populations (migration and tuberculosis – MuT study)

Funding: German Research Foundation (DFG, Deutsche Forschungsgemeinschaft)/Federal Ministry of Health (BMGS, Bundesministerium für Gesundheit)

Time frame: 2003 - 2006

Scientists (Section Clinical Tropical Medicine): T. Junghanss, J. Barniol (Doktorandin)

Cooperating partners:

● H. Becher (Sektion Biostatistik und Epidemiologie, Universitätsklinikum Heidelberg)

● W. Haas, Robert-Koch-Institut, Berlin

● E. Göhring-Zwacka, C. Dreweck, Landesgesundheitsamt Baden-Württemberg

● S. Niemann, S. Rüsch-Gerdes, National TB Reference Laboratory - Borstel, Germany

 

 

Project objectives: i) To prospectively describe tuberculosis (TB) transmission dynamics within and between sub-populations from TB high-prevalence countries (immigrants) and TB low-prevalence countries (Germans) in Baden-Württemberg using molecular epidemiological tools and social science techniques; ii) to capture transmission patterns and social interactions.

Project results: A total of 749 culture-positive pulmonary tuberculosis patients were enrolled in the study, representing 57.8% of all cases diagnosed during the study period. Of the 555 (74%) cases with available fingerprinting results, 132 (24%) were classified into 47 DNA fingerprint clusters. The probability of a mixed cluster to be caused by an immigrant was 19.2%. We observed a trend to mixed clusters with increasing time spent by immigrants in the host country. This group also presented comparatively higher integration indexes than immigrants in immigrant-only clusters.

Conclusions: Our results confirm the findings of other studies that there is no significant TB transmission from TB high-prevalence immigrant to TB low-prevalence autochthonous population; it is only one third of the rate to be expected under random transmission. This may be explained by the good performance of tuberculosis screening programmes for certain groups arriving in Germany from high-prevalence countries, by a low degree of mixing of immigrants with the local population or by a combination of both.