Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis.
Delays in identifying and treating individuals with infectious tuberculosis (TB) contribute to poor health outcomes and allow ongoing community transmission of M. tuberculosis (Mtb). Current recommendations for screening for tuberculosis specify community characteristics (e.g., areas with high local...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2025-01-01
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| Series: | PLOS Global Public Health |
| Online Access: | https://doi.org/10.1371/journal.pgph.0004040 |
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| author | Melanie H Chitwood Elizabeth L Corbett Victor Ndhlovu Benjamin Sobkowiak Caroline Colijn Jason R Andrews Rachael M Burke Patrick G T Cudahy Peter J Dodd Jeffrey W Imai-Eaton David M Engelthaler Megan Folkerts Helena R A Feasey Yu Lan Jen Lewis Jennifer McNichol Nicolas A Menzies Geoffrey Chipungu Marriott Nliwasa Daniel M Weinberger Joshua L Warren Joshua A Salomon Peter MacPherson Ted Cohen |
| author_facet | Melanie H Chitwood Elizabeth L Corbett Victor Ndhlovu Benjamin Sobkowiak Caroline Colijn Jason R Andrews Rachael M Burke Patrick G T Cudahy Peter J Dodd Jeffrey W Imai-Eaton David M Engelthaler Megan Folkerts Helena R A Feasey Yu Lan Jen Lewis Jennifer McNichol Nicolas A Menzies Geoffrey Chipungu Marriott Nliwasa Daniel M Weinberger Joshua L Warren Joshua A Salomon Peter MacPherson Ted Cohen |
| author_sort | Melanie H Chitwood |
| collection | DOAJ |
| description | Delays in identifying and treating individuals with infectious tuberculosis (TB) contribute to poor health outcomes and allow ongoing community transmission of M. tuberculosis (Mtb). Current recommendations for screening for tuberculosis specify community characteristics (e.g., areas with high local tuberculosis prevalence) that can be used to target screening within the general population. However, areas of higher tuberculosis burden are not necessarily areas with higher rates of transmission. We investigated the transmission of Mtb using high-resolution surveillance data in Blantyre, Malawi. We extracted and performed whole genome sequencing on mycobacterial DNA from cultured M. tuberculosis isolates obtained from culture-positive tuberculosis cases at the time of tuberculosis (TB) notification in Blantyre, Malawi between 2015-2019. We constructed putative transmission networks identified using TransPhylo and investigated individual and pair-wise demographic, clinical, and spatial factors associated with person-to-person transmission. We found that 56% of individuals with sequenced isolates had a probable transmission link to at least one other individual in the study. We identified thirteen putative transmission networks that included five or more individuals. Five of these networks had a single spatial focus of transmission in the city, and each focus centered in a distinct neighborhood in the city. We also found that approximately two-thirds of inferred transmission links occurred between individuals residing in different geographic zones of the city. While the majority of detected tuberculosis transmission events in Blantyre occurred between people living in different zones, there was evidence of distinct geographical concentration for five transmission networks. These findings suggest that targeted interventions in areas with evidence of localized transmission may be an effective local tactic, but will likely need to be augmented by city-wide interventions to improve case finding to have sustained impact. |
| format | Article |
| id | doaj-art-34c156b107954e76b802a68dc77f192d |
| institution | OA Journals |
| issn | 2767-3375 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLOS Global Public Health |
| spelling | doaj-art-34c156b107954e76b802a68dc77f192d2025-08-20T02:33:47ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752025-01-0154e000404010.1371/journal.pgph.0004040Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis.Melanie H ChitwoodElizabeth L CorbettVictor NdhlovuBenjamin SobkowiakCaroline ColijnJason R AndrewsRachael M BurkePatrick G T CudahyPeter J DoddJeffrey W Imai-EatonDavid M EngelthalerMegan FolkertsHelena R A FeaseyYu LanJen LewisJennifer McNicholNicolas A MenziesGeoffrey ChipunguMarriott NliwasaDaniel M WeinbergerJoshua L WarrenJoshua A SalomonPeter MacPhersonTed CohenDelays in identifying and treating individuals with infectious tuberculosis (TB) contribute to poor health outcomes and allow ongoing community transmission of M. tuberculosis (Mtb). Current recommendations for screening for tuberculosis specify community characteristics (e.g., areas with high local tuberculosis prevalence) that can be used to target screening within the general population. However, areas of higher tuberculosis burden are not necessarily areas with higher rates of transmission. We investigated the transmission of Mtb using high-resolution surveillance data in Blantyre, Malawi. We extracted and performed whole genome sequencing on mycobacterial DNA from cultured M. tuberculosis isolates obtained from culture-positive tuberculosis cases at the time of tuberculosis (TB) notification in Blantyre, Malawi between 2015-2019. We constructed putative transmission networks identified using TransPhylo and investigated individual and pair-wise demographic, clinical, and spatial factors associated with person-to-person transmission. We found that 56% of individuals with sequenced isolates had a probable transmission link to at least one other individual in the study. We identified thirteen putative transmission networks that included five or more individuals. Five of these networks had a single spatial focus of transmission in the city, and each focus centered in a distinct neighborhood in the city. We also found that approximately two-thirds of inferred transmission links occurred between individuals residing in different geographic zones of the city. While the majority of detected tuberculosis transmission events in Blantyre occurred between people living in different zones, there was evidence of distinct geographical concentration for five transmission networks. These findings suggest that targeted interventions in areas with evidence of localized transmission may be an effective local tactic, but will likely need to be augmented by city-wide interventions to improve case finding to have sustained impact.https://doi.org/10.1371/journal.pgph.0004040 |
| spellingShingle | Melanie H Chitwood Elizabeth L Corbett Victor Ndhlovu Benjamin Sobkowiak Caroline Colijn Jason R Andrews Rachael M Burke Patrick G T Cudahy Peter J Dodd Jeffrey W Imai-Eaton David M Engelthaler Megan Folkerts Helena R A Feasey Yu Lan Jen Lewis Jennifer McNichol Nicolas A Menzies Geoffrey Chipungu Marriott Nliwasa Daniel M Weinberger Joshua L Warren Joshua A Salomon Peter MacPherson Ted Cohen Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. PLOS Global Public Health |
| title | Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. |
| title_full | Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. |
| title_fullStr | Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. |
| title_full_unstemmed | Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. |
| title_short | Distribution and transmission of M. tuberculosis in a high-HIV prevalence city in Malawi: A genomic and spatial analysis. |
| title_sort | distribution and transmission of m tuberculosis in a high hiv prevalence city in malawi a genomic and spatial analysis |
| url | https://doi.org/10.1371/journal.pgph.0004040 |
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