RATIONALE: Programs to prevent the incidence rate of tuberculosis (TB) from increasing in many low-incidence countries are challenged by international travel and immigration from high-burden countries. OBJECTIVES: The current study aimed to determine the effect of such immigration on the genetic diversity of Mycobacterium tuberculosis isolates in an entire nation's population during 1994-2005. METHODS: A total of 3,131 patients were notified with TB during the 12-year period. Of these, 2,284 (73%) had TB verified by culture, and isolates from 2,173 (96%) of these were analyzed by IS6110 restriction fragment length polymorphism. MEASUREMENTS AND MAIN RESULTS: Only 31% of the included strains were isolated from nonimmigrants, the remaining 69% were isolated from immigrants. Although the incidence increased throughout the period, the genetic diversity remained high. A total of 135 clusters were identified; the percentage of recent disease was reduced among nonimmigrants, and remained stable among the immigrants during the study period. Although 69% of the isolates originated from immigrants from high-incidence countries, the established TB control program in the receiving country was adequate for the prevention of disease transmission. On average per year, only 2 nonimmigrants and 13 immigrants developed disease as a result of infection within the country by imported M. tuberculosis. CONCLUSIONS: Twelve years of M. tuberculosis importation as a result of immigration from high-incidence countries had little influence on the transmission of this pathogen in the receiving low-incidence country. To prevent future increase of transmission of TB, the current control strategies of low-incidence countries are adequate but must be maintained.
RATIONALE: Programs to prevent the incidence rate of tuberculosis (TB) from increasing in many low-incidence countries are challenged by international travel and immigration from high-burden countries. OBJECTIVES: The current study aimed to determine the effect of such immigration on the genetic diversity of Mycobacterium tuberculosis isolates in an entire nation's population during 1994-2005. METHODS: A total of 3,131 patients were notified with TB during the 12-year period. Of these, 2,284 (73%) had TB verified by culture, and isolates from 2,173 (96%) of these were analyzed by IS6110 restriction fragment length polymorphism. MEASUREMENTS AND MAIN RESULTS: Only 31% of the included strains were isolated from nonimmigrants, the remaining 69% were isolated from immigrants. Although the incidence increased throughout the period, the genetic diversity remained high. A total of 135 clusters were identified; the percentage of recent disease was reduced among nonimmigrants, and remained stable among the immigrants during the study period. Although 69% of the isolates originated from immigrants from high-incidence countries, the established TB control program in the receiving country was adequate for the prevention of disease transmission. On average per year, only 2 nonimmigrants and 13 immigrants developed disease as a result of infection within the country by imported M. tuberculosis. CONCLUSIONS: Twelve years of M. tuberculosis importation as a result of immigration from high-incidence countries had little influence on the transmission of this pathogen in the receiving low-incidence country. To prevent future increase of transmission of TB, the current control strategies of low-incidence countries are adequate but must be maintained.
Authors: Patricia R Blank; Andreas U Freiburghaus; Bernhard R Ruf; Matthias M Schwenkglenks; Thomas D Szucs Journal: Med Klin (Munich) Date: 2009-01-23
Authors: David Stucki; Marie Ballif; Matthias Egger; Hansjakob Furrer; Ekkehardt Altpeter; Manuel Battegay; Sara Droz; Thomas Bruderer; Mireia Coscolla; Sonia Borrell; Kathrin Zürcher; Jean-Paul Janssens; Alexandra Calmy; Jesica Mazza Stalder; Katia Jaton; Hans L Rieder; Gaby E Pfyffer; Hans H Siegrist; Matthias Hoffmann; Jan Fehr; Marisa Dolina; Reno Frei; Jacques Schrenzel; Erik C Böttger; Sebastien Gagneux; Lukas Fenner Journal: J Clin Microbiol Date: 2016-05-18 Impact factor: 5.948
Authors: Lukas Fenner; Sebastien Gagneux; Peter Helbling; Manuel Battegay; Hans L Rieder; Gaby E Pfyffer; Marcel Zwahlen; Hansjakob Furrer; Hans H Siegrist; Jan Fehr; Marisa Dolina; Alexandra Calmy; David Stucki; Katia Jaton; Jean-Paul Janssens; Jesica Mazza Stalder; Thomas Bodmer; Beatrice Ninet; Erik C Böttger; Matthias Egger Journal: J Clin Microbiol Date: 2011-11-23 Impact factor: 5.948
Authors: Ingunn Harstad; Geir W Jacobsen; Einar Heldal; Brita A Winje; Saeed Vahedi; Anne-Sofie Helvik; Sigurd L Steinshamn; Helge Garåsen Journal: BMC Public Health Date: 2010-11-04 Impact factor: 3.295