Mohammad Reza Allahyar Torkaman1, Mohammad Javad Nasiri2, Parissa Farnia3, Mohammad Hasan Shahhosseiny3, Mohadeseh Mozafari1, Ali Akbar Velayati4. 1. Post Graduate, Department of Microbiology, Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD),Shahid Beheshti University of Medical Sciences , Tehran, Iran . 2. PhD Student, Department of Microbiology, Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD),Shahid Beheshti University of Medical Sciences , Tehran, Iran . 3. Associated Professor, Department of Microbiology, Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD),Shahid Beheshti University of Medical Sciences , Tehran, Iran . 4. Professor, Department of Microbiology, Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD),Shahid Beheshti University of Medical Sciences , Tehran, Iran .
Abstract
BACKGROUND: Iran has extended borders with high-TB burden countries (Afghanistan and Pakistan) and immigrations of these populations influences TB distribution in the region and threatens the control strategies. The aim of this study was to evaluate the extent of recent TB transmission among Iranian and Afghan cases. MATERIALS AND METHODS: Spoligotyping and 15-locus variable number tandem repeat (VNTR) typing were applied to genotype 102 MTB isolates (2009 to 2010). Phylogenetic relationships were analysed by two methods: a cluster-graph method and a minimum spanning tree (MST) method. Furthermore, evaluation of recent TB transmission was assessed with three indices including, RTIn, RTIn-1 and TMI. RESULTS: Using molecular typing, 35 different spoligotypes were detected among the studied isolates. Seventy seven cases (75.4%) were distributed into 10 clusters and the remaining 25 (24.5%) isolates had a unique pattern. The cluster sizes also ranged from 2 to 21 isolates. The most frequent spoligotype in our populations belong to Haarlem (n=30, 29.4%) followed by CAS (n= 29, 28.4%) and Beijing (n=16, 15.6%) lineages. The used indices give the following values: RTIn = 0.75, RTIn-1 = 0.65 and TMI = 0.24. CONCLUSION: The low rate of TB transmission in our findings (24%) showed that the mode of TB transmission in Iran is mostly associated with reactivation of a previous TB infection and that recently a transmitted disease has a minor role. However, the increasing incidence of the intra-community transmission in recent years highlights the need for establishing new strategies for control of TB.
BACKGROUND: Iran has extended borders with high-TB burden countries (Afghanistan and Pakistan) and immigrations of these populations influences TB distribution in the region and threatens the control strategies. The aim of this study was to evaluate the extent of recent TB transmission among Iranian and Afghan cases. MATERIALS AND METHODS: Spoligotyping and 15-locus variable number tandem repeat (VNTR) typing were applied to genotype 102 MTB isolates (2009 to 2010). Phylogenetic relationships were analysed by two methods: a cluster-graph method and a minimum spanning tree (MST) method. Furthermore, evaluation of recent TB transmission was assessed with three indices including, RTIn, RTIn-1 and TMI. RESULTS: Using molecular typing, 35 different spoligotypes were detected among the studied isolates. Seventy seven cases (75.4%) were distributed into 10 clusters and the remaining 25 (24.5%) isolates had a unique pattern. The cluster sizes also ranged from 2 to 21 isolates. The most frequent spoligotype in our populations belong to Haarlem (n=30, 29.4%) followed by CAS (n= 29, 28.4%) and Beijing (n=16, 15.6%) lineages. The used indices give the following values: RTIn = 0.75, RTIn-1 = 0.65 and TMI = 0.24. CONCLUSION: The low rate of TB transmission in our findings (24%) showed that the mode of TB transmission in Iran is mostly associated with reactivation of a previous TB infection and that recently a transmitted disease has a minor role. However, the increasing incidence of the intra-community transmission in recent years highlights the need for establishing new strategies for control of TB.
Authors: J D van Embden; M D Cave; J T Crawford; J W Dale; K D Eisenach; B Gicquel; P Hermans; C Martin; R McAdam; T M Shinnick Journal: J Clin Microbiol Date: 1993-02 Impact factor: 5.948
Authors: Philip Supply; Caroline Allix; Sarah Lesjean; Mara Cardoso-Oelemann; Sabine Rüsch-Gerdes; Eve Willery; Evgueni Savine; Petra de Haas; Henk van Deutekom; Solvig Roring; Pablo Bifani; Natalia Kurepina; Barry Kreiswirth; Christophe Sola; Nalin Rastogi; Vincent Vatin; Maria Cristina Gutierrez; Maryse Fauville; Stefan Niemann; Robin Skuce; Kristin Kremer; Camille Locht; Dick van Soolingen Journal: J Clin Microbiol Date: 2006-09-27 Impact factor: 5.948