Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.

<h4>Background</h4>Despite increasing interest in possible differences in virulence and transmissibility between different genotypes of M. tuberculosis, very little is known about how genotypes within a population change over decades, or about relationships to HIV infection.<h4>Met...

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Main Authors: Judith R Glynn, Saad Alghamdi, Kim Mallard, Ruth McNerney, Richard Ndlovu, Lumbani Munthali, Rein M Houben, Paul E M Fine, Neil French, Amelia C Crampin
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-08-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0012259&type=printable
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author Judith R Glynn
Saad Alghamdi
Kim Mallard
Ruth McNerney
Richard Ndlovu
Lumbani Munthali
Rein M Houben
Paul E M Fine
Neil French
Amelia C Crampin
author_facet Judith R Glynn
Saad Alghamdi
Kim Mallard
Ruth McNerney
Richard Ndlovu
Lumbani Munthali
Rein M Houben
Paul E M Fine
Neil French
Amelia C Crampin
author_sort Judith R Glynn
collection DOAJ
description <h4>Background</h4>Despite increasing interest in possible differences in virulence and transmissibility between different genotypes of M. tuberculosis, very little is known about how genotypes within a population change over decades, or about relationships to HIV infection.<h4>Methods and principal findings</h4>In a population-based study in rural Malawi we have examined smears and cultures from tuberculosis patients over a 20-year period using spoligotyping. Isolates were grouped into spoligotype families and lineages following previously published criteria. Time trends, HIV status, drug resistance and outcome were examined by spoligotype family and lineage. In addition, transmissibility was examined among pairs of cases with known epidemiological contact by assessing the proportion of transmissions confirmed for each lineage, on the basis of IS6110 RFLP similarity of the M tuberculosis strains. 760 spoligotypes were obtained from smears from 518 patients from 1986-2002, and 377 spoligotypes from cultures from 347 patients from 2005-2008. There was good consistency in patients with multiple specimens. Among 781 patients with first episode tuberculosis, the majority (76%) had Lineage 4 ("European/American") strains; 9% had Lineage 3 ("East-African/Indian"); 8% Lineage 1 ("Indo-Oceanic"); and 2% Lineage 2 ("East-Asian"); others unclassifiable. Over time the proportion of Lineage 4 decreased from >90% to 60%, with an increase in the other 3 lineages (p<0.001). Lineage 1 strains were more common in those with HIV infection, even after adjusting for age, sex and year. There were no associations with drug resistance or outcome, and no differences by lineage in the proportion of pairs in which transmission was confirmed.<h4>Conclusions</h4>This is the first study to describe long term trends in the four M. tuberculosis lineages in a population. Lineage 4 has probably been longstanding in this population, with relatively recent introductions and spread of Lineages1-3, perhaps influenced by the HIV epidemic.
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spelling doaj-art-6d3b8840c4324e2ebce9a614edaaa85d2025-08-20T03:07:40ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-08-0158e1225910.1371/journal.pone.0012259Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.Judith R GlynnSaad AlghamdiKim MallardRuth McNerneyRichard NdlovuLumbani MunthaliRein M HoubenPaul E M FineNeil FrenchAmelia C Crampin<h4>Background</h4>Despite increasing interest in possible differences in virulence and transmissibility between different genotypes of M. tuberculosis, very little is known about how genotypes within a population change over decades, or about relationships to HIV infection.<h4>Methods and principal findings</h4>In a population-based study in rural Malawi we have examined smears and cultures from tuberculosis patients over a 20-year period using spoligotyping. Isolates were grouped into spoligotype families and lineages following previously published criteria. Time trends, HIV status, drug resistance and outcome were examined by spoligotype family and lineage. In addition, transmissibility was examined among pairs of cases with known epidemiological contact by assessing the proportion of transmissions confirmed for each lineage, on the basis of IS6110 RFLP similarity of the M tuberculosis strains. 760 spoligotypes were obtained from smears from 518 patients from 1986-2002, and 377 spoligotypes from cultures from 347 patients from 2005-2008. There was good consistency in patients with multiple specimens. Among 781 patients with first episode tuberculosis, the majority (76%) had Lineage 4 ("European/American") strains; 9% had Lineage 3 ("East-African/Indian"); 8% Lineage 1 ("Indo-Oceanic"); and 2% Lineage 2 ("East-Asian"); others unclassifiable. Over time the proportion of Lineage 4 decreased from >90% to 60%, with an increase in the other 3 lineages (p<0.001). Lineage 1 strains were more common in those with HIV infection, even after adjusting for age, sex and year. There were no associations with drug resistance or outcome, and no differences by lineage in the proportion of pairs in which transmission was confirmed.<h4>Conclusions</h4>This is the first study to describe long term trends in the four M. tuberculosis lineages in a population. Lineage 4 has probably been longstanding in this population, with relatively recent introductions and spread of Lineages1-3, perhaps influenced by the HIV epidemic.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0012259&type=printable
spellingShingle Judith R Glynn
Saad Alghamdi
Kim Mallard
Ruth McNerney
Richard Ndlovu
Lumbani Munthali
Rein M Houben
Paul E M Fine
Neil French
Amelia C Crampin
Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
PLoS ONE
title Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
title_full Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
title_fullStr Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
title_full_unstemmed Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
title_short Changes in Mycobacterium tuberculosis genotype families over 20 years in a population-based study in Northern Malawi.
title_sort changes in mycobacterium tuberculosis genotype families over 20 years in a population based study in northern malawi
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0012259&type=printable
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