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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Public Health</journal-id>
<journal-title-group>
<journal-title>Frontiers in Public Health</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Public Health</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2296-2565</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3389/fpubh.2026.1771140</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Original Research</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Epidemiology of drug&#x2013;resistant tuberculosis in Hunan China over a 10&#x2013;year period</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Liu</surname>
<given-names>Yi</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/3283049"/>
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<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Wang</surname>
<given-names>Jue</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Wan</surname>
<given-names>Xiaojie</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Peng</surname>
<given-names>Wang</given-names>
</name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Guo</surname>
<given-names>Jingwei</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Yang</surname>
<given-names>Xi</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Zhou</surname>
<given-names>Di</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Li</surname>
<given-names>Wenbin</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Duan</surname>
<given-names>Jie</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
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<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="validation" vocab-term-identifier="https://credit.niso.org/contributor-roles/validation/">Validation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &#x0026; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &#x0026; editing</role>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Zeng</surname>
<given-names>Xuan</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Bai</surname>
<given-names>Hua</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Chen</surname>
<given-names>Zhenhua</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="resources" vocab-term-identifier="https://credit.niso.org/contributor-roles/resources/">Resources</role>
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</contrib>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Luo</surname>
<given-names>Fangzhen</given-names>
</name>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>&#x002A;</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/1123754"/>
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</contrib>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Tan</surname>
<given-names>Yunhong</given-names>
</name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>&#x002A;</sup></xref>
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<aff id="aff1"><label>1</label><institution>Hunan Provincial Tuberculosis Prevention and Control Institute &#x0026; Hunan Chest Hospital</institution>, <city>Changsha</city>, <state>Hunan</state>, <country country="cn">China</country></aff>
<aff id="aff2"><label>2</label><institution>Guangzhou Huazhun Medical Laboratory Co., Ltd.</institution>, <city>Guangzhou</city>, <state>Guangdong</state>, <country country="cn">China</country></aff>
<aff id="aff3"><label>3</label><institution>Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China</institution>, <city>Hengyang</city>, <country country="cn">China</country></aff>
<author-notes>
<corresp id="c001"><label>&#x002A;</label>Correspondence: Yunhong Tan, <email xlink:href="mailto:tanyunhongl@163.com">tanyunhongl@163.com</email>; Fangzhen Luo, <email xlink:href="mailto:luofz@usc.edu.cn">luofz@usc.edu.cn</email></corresp>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-02-23">
<day>23</day>
<month>02</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2026</year>
</pub-date>
<volume>14</volume>
<elocation-id>1771140</elocation-id>
<history>
<date date-type="received">
<day>19</day>
<month>12</month>
<year>2025</year>
</date>
<date date-type="rev-recd">
<day>17</day>
<month>01</month>
<year>2026</year>
</date>
<date date-type="accepted">
<day>03</day>
<month>02</month>
<year>2026</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#x00A9; 2026 Liu, Wang, Wan, Peng, Guo, Yang, Zhou, Li, Duan, Zeng, Bai, Chen, Luo and Tan.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Liu, Wang, Wan, Peng, Guo, Yang, Zhou, Li, Duan, Zeng, Bai, Chen, Luo and Tan</copyright-holder>
<license>
<ali:license_ref start_date="2026-02-23">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<sec>
<title>Background</title>
<p>Drug&#x2013;resistant tuberculosis (DR&#x2013;TB) remains a major public health challenge in China, yet long&#x2013;term epidemiological data from key regions such as Hunan Province in South&#x2013;Central China are still limited.</p>
</sec>
<sec>
<title>Objective</title>
<p>This study aimed to characterize the epidemiological trends, spatial distribution, and risk factors of Single drug&#x2013;resistant tuberculosis (SDR&#x2013;TB), poly&#x2013;drug&#x2013;resistant tuberculosis (PDR&#x2013;TB), multidrug&#x2013;resistant tuberculosis (MDR&#x2013;TB), rifampicin&#x2013;resistant tuberculosis (RR&#x2013;TB), and isoniazid&#x2013;resistant tuberculosis (INH&#x2013;R TB) in Hunan Province between 2014 and 2023, to inform region&#x2013;specific control strategies.</p>
</sec>
<sec>
<title>Methods</title>
<p>It was a retrospective analysis that was conducted on 6,597 laboratory&#x2013;confirmed DR&#x2013;TB cases. Data were obtained from the Provincial Tuberculosis Control Institute. All patients underwent phenotypic drug susceptibility testing. Independent risk factors for DR&#x2013;TB subtypes were identified through multivariable logistic regression, with adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) calculated.</p>
</sec>
<sec>
<title>Results</title>
<p>A total of 6,597 patients with DR&#x2013;TB were included in this 10&#x2013;year analysis. Among them, 74.97% were male and 64.44% were farmers. The highest case burden was observed in the 50&#x2013;59 age group (24.78%). Spatially, cases clustered mainly in the Changsha (16.39%), Shaoyang (13.78%), and Loudi (9.05%). The most common resistance subtypes were INH&#x2013;R TB (56.27%) and MDR&#x2013;TB (52.37%). The distribution of all DR&#x2013;TB subtypes varied significantly across age groups (<italic>p</italic>&#x202F;&#x003C;&#x202F;0.05), with peaks in middle&#x2013;aged and older adults. Over time, the detection rate of MDR&#x2013;TB was highest in 2018, while RR&#x2013;TB remained the most frequently detected resistance type. Multivariable analysis identified significant regional and demographic disparities. The eastern region of Hunan was associated with an increased risk of SDR&#x2013;TB (OR&#x202F;=&#x202F;1.334) and PDR&#x2013;TB (OR&#x202F;=&#x202F;1.208), whereas the western region carried the highest risk for MDR&#x2013;TB (OR&#x202F;=&#x202F;1.734). Female patients consistently showed lower risks of MDR&#x2013;TB (OR&#x202F;=&#x202F;0.819) and RR&#x2013;TB (OR&#x202F;=&#x202F;0.784) compared with males.</p>
</sec>
<sec>
<title>Conclusion</title>
<p>This study presents a 10&#x2013;year epidemiological assessment of DR&#x2013;TB in Hunan Province, China, covering 2014&#x2013;2023. A disproportionately high burden was observed among middle&#x2013;aged and older male farmers. The predominance of INH&#x2013;R TB and MDR&#x2013;TB, together with distinct regional and demographic risk profiles, underscores an urgent need to strengthen TB control measures. These results support the implementation of targeted interventions, including intensified screening in high&#x2013;risk populations and in high&#x2013;incidence areas, along with optimized treatment regimens, to curb the ongoing DR&#x2013;TB epidemic in South&#x2013;Central China.</p>
</sec>
</abstract>
<kwd-group>
<kwd>China</kwd>
<kwd>drug&#x2013;resistant tuberculosis</kwd>
<kwd>epidemiology</kwd>
<kwd>Hunan</kwd>
<kwd><italic>Mycobacterium tuberculosis</italic></kwd>
<kwd>retrospective study</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. This research was supported by the National Key Research and Development Program of China (Grant No. 2023YFC2307201, 2023YFC2307202), the National Natural Science Foundation of China (Grant No. 82202557), the Hunan Provincial Natural Science Foundation (Grant No. 2025JJ80681, 2025JJ90186, 2025JJ60614), and the Hunan Provincial Major Scientific Research Project for Health High -Level Talents (Grant No. R2023098) and the Health Research Project of Hunan Provincial Health Commission (Grant No. W20243061).</funding-statement>
</funding-group>
<counts>
<fig-count count="4"/>
<table-count count="2"/>
<equation-count count="0"/>
<ref-count count="34"/>
<page-count count="8"/>
<word-count count="5320"/>
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<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Infectious Diseases: Epidemiology and Prevention</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec sec-type="intro" id="sec1">
<title>Introduction</title>
<p>Tuberculosis (TB) remains a leading cause of mortality from infectious diseases worldwide (<xref ref-type="bibr" rid="ref1">1</xref>). The emergence and spread of Drug&#x2013;resistant tuberculosis (DR&#x2013;TB) have posed serious challenges to global TB control (<xref ref-type="bibr" rid="ref2">2</xref>, <xref ref-type="bibr" rid="ref3">3</xref>). As one of the countries with the highest TB burden, China faces a particularly high prevalence of DR&#x2013;TB, posing significant challenges to national TB control efforts (<xref ref-type="bibr" rid="ref4">4</xref>). South&#x2013;Central China, including Hunan Province, is characterized by a large population, substantial internal migration, and diverse socioeconomic conditions (<xref ref-type="bibr" rid="ref5">5</xref>, <xref ref-type="bibr" rid="ref6">6</xref>). Although this region plays a critical role in national TB control, there is a lack of long&#x2013;term systematic research on DR&#x2013;TB in this area. A clear and comprehensive understanding of DR&#x2013;TB trends and characteristics in this region is crucial for designing effective prevention and control strategies at regional and national levels.</p>
<p>The global incidence of DR&#x2013;TB has increased, driven primarily by the widespread use of anti&#x2013;TB drugs and inadequate adherence to treatment (<xref ref-type="bibr" rid="ref7">7</xref>, <xref ref-type="bibr" rid="ref8">8</xref>). DR&#x2013;TB can be classified into several resistance patterns (<xref ref-type="bibr" rid="ref9">9</xref>). In this study, we focused on five major types: monoresistant tuberculosis (SDR&#x2013;TB), poly&#x2013;drug&#x2013;resistant tuberculosis (PDR&#x2013;TB), multidrug&#x2013;resistant tuberculosis (MDR&#x2013;TB), rifampicin&#x2013;resistant tuberculosis (RR&#x2013;TB), and isoniazid&#x2013;resistant tuberculosis (INH&#x2013;R TB). The management of DR&#x2013;TB is prolonged and costly, with poorer treatment outcomes, placing substantial physical, psychological, and economic burdens on patients and creating major challenges for public health systems (<xref ref-type="bibr" rid="ref10 ref11 ref12">10&#x2013;12</xref>).</p>
<p>A clear understanding of the epidemiological characteristics, temporal trends in drug resistance, and related risk factors of DR&#x2013;TB in South&#x2013;Central China is vital for designing targeted interventions. To address this need, we conducted a 10&#x2013;year retrospective analysis of DR&#x2013;TB in the region to describe its epidemiology, assess temporal trends in drug resistance, and identify demographic and geographic risk factors.</p>
</sec>
<sec sec-type="materials|methods" id="sec2">
<title>Materials and methods</title>
<sec id="sec3">
<title>Data source</title>
<p>This study retrospectively analyzed data from patients diagnosed with TB at the Hunan Chest Hospital between January 1, 2014, and August 1, 2023. Located in South&#x2013;Central China, the hospital is a provincial&#x2013;level designated TB institute and clinical center. Demographic and clinical date&#x2013;such as sex, age, occupation, place of residence, diagnostic results, and drug&#x2013;susceptibility profiles&#x2013;were extracted from the hospital&#x2019;s information system. All personally identifiable data were anonymized prior to analysis to protect patient confidentiality.</p>
</sec>
<sec id="sec4">
<title>Inclusion and exclusion criteria</title>
<p>Eligible patients were residents of Hunan Province and had a laboratory&#x2013;confirmed diagnosis of DR&#x2013;TB, established through drug susceptibility testing (DST). Patients with a history of repeated hospital admissions, incomplete medical records, or residence outside Hunan Province were excluded. In total, 6,597 patients were included in the final analysis.</p>
</sec>
<sec id="sec5">
<title>Research methods</title>
<p>Phenotypic drug susceptibility testing for first&#x2013;line anti&#x2013;TB drugs&#x2013;isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and pyrazinamide (PZA)&#x2013;was conducted using the absolute concentration method on solid media. Fresh colonies grown on L&#x00F6;wenstein&#x2013;Jensen (L&#x2013;J) medium were harvested, homogenized, and adjusted to a concentration of 1&#x202F;mg/mL. The suspension was subsequently diluted 100&#x2013;fold with sterile saline, and 0.1&#x202F;mL of the diluted inoculum was inoculated onto solid medium slopes. After thorough mixing, the medium were incubated at 37&#x202F;&#x00B0;C, and results were evaluated after 4 weeks. All procedures were performed in a Class II biosafety cabinet in accordance established with laboratory safety guidelines.</p>
</sec>
<sec id="sec6">
<title>Quality control</title>
<p>All laboratory staff underwent proficiency training provided by National Tuberculosis Reference Laboratory (NTRL). Each batch of culture medium underwent sterility testing and was verified with the H37Rv reference strain to ensure accuracy and reproducibility. All testing procedures were conducted in compliance with established quality&#x2013;control standards.</p>
</sec>
<sec id="sec7">
<title>Statistical analysis</title>
<p>Data cleaning and statistical analysis were conducted in R (version 4.2.2) using RStudio. Figures were produced in R and Excel. Descriptive statistics summarized the distribution of DR&#x2013;TB. Associations with age, sex, occupation, and region were examined using chi&#x2013;square tests for categorical variables and Mann&#x2013;Whitney U tests for continuous variables. Multivariable logistic regression was fitted including the following factors: year, region, age group, occupation and sex. Odds ratios (ORs) with 95% confidence intervals (CIs) and two&#x2013;sided <italic>P</italic>&#x2013;values were calculated; <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05 was considered statistically significant.</p>
</sec>
</sec>
<sec sec-type="results" id="sec8">
<title>Results</title>
<sec id="sec9">
<title>Epidemiology of DR&#x2013;TB</title>
<p>This study included 6,597 patients with DR&#x2013;TB diagnosed at Hunan Chest Hospital between 2014 and 2023. Among them, 4,946 were male and 1,651 were female, with a male&#x2013;to&#x2013;female ratio of 3.00:1. Ages ranged from 5 to 88&#x202F;years, with a median of 50&#x202F;years (interquartile range (IQR): 34&#x2013;60). The 50&#x2013;59 age group accounted for the highest proportion of cases (24.78%, 1,635/6,597), followed by the 60&#x2013;69 age group (17.34%, 1,144/6,597; <xref ref-type="fig" rid="fig1">Figure 1A</xref>). Given the small number of cases aged &#x003C; 10&#x202F;years (<italic>n</italic>&#x202F;=&#x202F;3), this group was merged with the &#x2264; 20&#x202F;years category for subsequent analyses. By occupation, farmers accounted for the largest proportion of cases (64.44%, 4,251/6,597), followed by unemployed individuals (8.70%, 574/6,597) and public&#x2013;sector employees (7.91%, 522/6,597) (<xref ref-type="fig" rid="fig1">Figure 1B</xref>). Temporal trend analysis (<xref ref-type="fig" rid="fig1">Figure 1C</xref>) showed that the number of DR&#x2013;TB cases was relatively high between 2016&#x2013;2018, peaking in 2017, and declined from 2019 to 2021. Regional analysis (<xref ref-type="fig" rid="fig1">Figure 1D</xref>) indicated that cases were concentrated in Changsha (16.39%, 1,081/6,597), Shaoyang (13.78%, 909/6,597), and Loudi (9.05%, 597/6,597), together accounting for 39.22% of all cases; fewer cases occurred in Xiangxi (0.26%, 17/6,597) and Zhangjiajie (1.00%, 66/6,597). Spatial distributions of DR&#x2013;TB subtypes are shown in <xref rid="SM1" ref-type="supplementary-material">Appendix Table S1</xref>.</p>
<fig position="float" id="fig1">
<label>Figure 1</label>
<caption>
<p>The distributions of DR&#x2013;TB in Hunan, China, from 2014 to 2023. <bold>(A)</bold> Age distribution; <bold>(B)</bold> occupational distribution; <bold>(C)</bold> temporal distribution; and <bold>(D)</bold> spatial distribution.</p>
</caption>
<graphic xlink:href="fpubh-14-1771140-g001.tif" mimetype="image" mime-subtype="tiff">
<alt-text content-type="machine-generated">Panel A displays a pie chart showing age distribution for cases, with the largest group aged forty to forty-nine years. Panel B features a pie chart indicating occupation distribution, where farmers represent the majority. Panel C presents a vertical bar chart illustrating annual case numbers from 2014 to 2023, with the highest in 2017. Panel D is a choropleth map highlighting the geographic distribution of cases across regions, with darker red indicating higher case counts.</alt-text>
</graphic>
</fig>
</sec>
<sec id="sec10">
<title>Patterns of drug resistance subtypes</title>
<p>In this study, INH&#x2013;R TB had the highest positivity rate (56.27%; 95% CI: 55.07&#x2013;57.67), followed by MDR&#x2013;TB (52.37%; 95% CI: 51.17&#x2013;53.58). The rates for SDR&#x2013;TB and RR&#x2013;TB were similar, at 32.71% (95% CI: 31.58&#x2013;33.84) and 31.47% (95% CI: 30.35&#x2013;32.59), respectively. In contrast, PDR&#x2013;TB had the lowest rate (13.75%; 95% CI: 12.92&#x2013;14.58). Detailed results are shown in <xref ref-type="table" rid="tab1">Table 1</xref>. The distribution of different DR&#x2013;TB types across age groups was examined using the chi&#x2013;square test, with results presented in <xref ref-type="table" rid="tab2">Table 2</xref>. Among the 6,597 patients included, MDR&#x2013;TB (3,455 cases) and INH&#x2013;R TB (3,712 cases) were the most common types. Age distributions differed significantly across all resistance categories (<italic>p</italic>&#x202F;&#x003C;&#x202F;0.05). Overall, the number of DR&#x2013;TB cases increased with age before declining, with a peak in the 50&#x2013;59 age group. Specifically, INH&#x2013;R TB and MDR&#x2013;TB showed similar age&#x2013;specific patterns, with the highest proportions in the 50&#x2013;59 age group (INH&#x2013;R TB: 961 cases, 25.9%; MDR&#x2013;TB: 894 cases, 25.9%), followed by the 40&#x2013;49 age group. In contrast, RR&#x2013;TB, SDR&#x2013;TB, and PDR&#x2013;TB were also concentrated mainly in middle&#x2013;aged and older adults, but their proportions within the &#x2265; 70 age group differed. <xref ref-type="fig" rid="fig2">Figure 2</xref> illustrates the predominant subtypes of DR&#x2013;TB across age groups.</p>
<table-wrap position="float" id="tab1">
<label>Table 1</label>
<caption>
<p>Prevalence and 95% CI of DR&#x2013;TB subtypes.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" valign="top">Subtypes</th>
<th align="center" valign="top">Yes (<italic>n</italic>, %)</th>
<th align="center" valign="top">No (<italic>n</italic>, %)</th>
<th align="center" valign="top">Proportion (95% CI)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" valign="top">SDR&#x2013;TB</td>
<td align="char" valign="bottom" char="(">2,158 (32.71)</td>
<td align="char" valign="bottom" char="(">4,439 (67.29)</td>
<td align="char" valign="top" char="(">32.71 (31.58&#x2013;33.84)</td>
</tr>
<tr>
<td align="left" valign="top">PDR&#x2013;TB</td>
<td align="char" valign="bottom" char="(">907 (13.75)</td>
<td align="char" valign="bottom" char="(">5,690 (86.25)</td>
<td align="char" valign="top" char="(">13.75 (12.92&#x2013;14.58)</td>
</tr>
<tr>
<td align="left" valign="top">MDR&#x2013;TB</td>
<td align="char" valign="bottom" char="(">3,455 (52.37)</td>
<td align="char" valign="bottom" char="(">3,142 (47.63)</td>
<td align="char" valign="top" char="(">52.37 (51.17&#x2013;53.58)</td>
</tr>
<tr>
<td align="left" valign="top">RR&#x2013;TB</td>
<td align="char" valign="bottom" char="(">2076 (31.47)</td>
<td align="char" valign="bottom" char="(">4,521 (68.53)</td>
<td align="char" valign="top" char="(">31.47 (30.35&#x2013;32.59)</td>
</tr>
<tr>
<td align="left" valign="top">INH&#x2013;R TB</td>
<td align="char" valign="bottom" char="(">3,712 (56.27)</td>
<td align="char" valign="bottom" char="(">2,885 (43.73)</td>
<td align="char" valign="top" char="(">56.27 (55.07&#x2013;57.67)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<p>TB, tuberculosis; DR&#x2013;TB, drug&#x2013;resistant tuberculosis; SDR&#x2013;TB, single drug&#x2013;resistant tuberculosis; PDR&#x2013;TB, poly&#x2013;drug&#x2013;resistant tuberculosis; MDR&#x2013;TB, multidrug&#x2013;resistant tuberculosis; RR&#x2013;TB, rifampicin&#x2013;resistant tuberculosis; INH&#x2013;R TB, isoniazid&#x2013;resistant tuberculosis. The classification of DR&#x2013;TB includes, but is not limited to, the subtypes listed.</p>
</table-wrap-foot>
</table-wrap>
<table-wrap position="float" id="tab2">
<label>Table 2</label>
<caption>
<p>Distribution of DR&#x2013;TB subtypes across different age groups.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" valign="top" rowspan="2">Subtypes</th>
<th align="center" valign="top" colspan="8">No. of cases in each age group (years)</th>
<th align="center" valign="top" rowspan="2">Total</th>
<th align="center" valign="top" rowspan="2">
<italic>&#x03C7;<sup>2</sup></italic>
</th>
<th align="center" valign="top" rowspan="2">
<italic>p</italic>
</th>
</tr>
<tr>
<th align="center" valign="top">&#x003C;20</th>
<th align="center" valign="top">20~</th>
<th align="center" valign="top">30~</th>
<th align="center" valign="top">40~</th>
<th align="center" valign="top">50~</th>
<th align="center" valign="top">60~</th>
<th align="center" valign="top">70~</th>
<th align="center" valign="top">&#x2265;80</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" valign="top">SDR&#x2013;TB</td>
<td align="center" valign="top">111</td>
<td align="center" valign="top">335</td>
<td align="center" valign="top">228</td>
<td align="center" valign="top">310</td>
<td align="center" valign="top">504</td>
<td align="center" valign="top">376</td>
<td align="center" valign="top">244</td>
<td align="center" valign="top">50</td>
<td align="center" valign="top">2,158</td>
<td align="char" valign="bottom" char=".">109.656</td>
<td align="char" valign="bottom" char=".">0.000</td>
</tr>
<tr>
<td align="left" valign="top">PDR&#x2013;TB</td>
<td align="center" valign="top">50</td>
<td align="center" valign="top">127</td>
<td align="center" valign="top">100</td>
<td align="center" valign="top">139</td>
<td align="center" valign="top">220</td>
<td align="center" valign="top">164</td>
<td align="center" valign="top">84</td>
<td align="center" valign="top">23</td>
<td align="center" valign="top">907</td>
<td align="char" valign="bottom" char=".">18.667</td>
<td align="char" valign="bottom" char=".">0.009</td>
</tr>
<tr>
<td align="left" valign="top">MDR&#x2013;TB</td>
<td align="center" valign="top">136</td>
<td align="center" valign="top">456</td>
<td align="center" valign="top">476</td>
<td align="center" valign="top">711</td>
<td align="center" valign="top">894</td>
<td align="center" valign="top">590</td>
<td align="center" valign="top">168</td>
<td align="center" valign="top">24</td>
<td align="center" valign="top">3,455</td>
<td align="char" valign="bottom" char=".">163.308</td>
<td align="char" valign="bottom" char=".">0.000</td>
</tr>
<tr>
<td align="left" valign="top">RR&#x2013;TB</td>
<td align="center" valign="top">97</td>
<td align="center" valign="top">291</td>
<td align="center" valign="top">219</td>
<td align="center" valign="top">304</td>
<td align="center" valign="top">498</td>
<td align="center" valign="top">381</td>
<td align="center" valign="top">277</td>
<td align="center" valign="top">40</td>
<td align="center" valign="top">2076</td>
<td align="char" valign="bottom" char=".">105.798</td>
<td align="char" valign="bottom" char=".">0.000</td>
</tr>
<tr>
<td align="left" valign="top">INH&#x2013;R TB</td>
<td align="center" valign="top">144</td>
<td align="center" valign="top">488</td>
<td align="center" valign="top">505</td>
<td align="center" valign="top">758</td>
<td align="center" valign="top">961</td>
<td align="center" valign="top">641</td>
<td align="center" valign="top">188</td>
<td align="center" valign="top">27</td>
<td align="center" valign="top">3,712</td>
<td align="char" valign="bottom" char=".">170.558</td>
<td align="char" valign="bottom" char=".">0.000</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<p>The classification of DR&#x2013;TB includes, but is not limited to, the subtypes presented. Analysis of variance was applied for intergroup comparisons, <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05.</p>
</table-wrap-foot>
</table-wrap>
<fig position="float" id="fig2">
<label>Figure 2</label>
<caption>
<p>Subtypes of DR&#x2013;TB in each age group (years). This figure illustrates the distribution of DR&#x2013;TB subtypes by proportion across age groups (in descending order). The classification of DR&#x2013;TB encompasses, but is not limited to, the subtypes displayed.</p>
</caption>
<graphic xlink:href="fpubh-14-1771140-g002.tif" mimetype="image" mime-subtype="tiff">
<alt-text content-type="machine-generated">A table graphic lists subtypes of drug-resistant tuberculosis by age group ranging from under 20 years to 80 years and older, with categories INH-R TB, MDR-TB, SDR-TB, RR-TB, and PDR-TB shown for each group.</alt-text>
</graphic>
</fig>
</sec>
<sec id="sec11">
<title>Temporal profiling of DR&#x2013;TB</title>
<p>From 2014 to 2023, detection rates of the different DR&#x2013;TB types showed distinct patterns (<xref ref-type="fig" rid="fig3">Figure 3</xref>). RR&#x2013;TB consistently had the highest rate and displayed a temporal trend similar to MDR&#x2013;TB. The MDR&#x2013;TB rate peaked in 2018, then declined with fluctuations. SDR&#x2013;TB and INH&#x2013;R TB remained relatively stable, generally ranging from 30 to 40%, with parallel trends and only minor variations. PDR&#x2013;TB had the lowest rate throughout the study period. Chi&#x2013;square tests indicated that, except for RR&#x2013;TB, distributions of the other subtypes varied significantly by year (SDR&#x2013;TB, PDR&#x2013;TB, MDR&#x2013;TB, and INH&#x2013;R TB: <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05; <italic>&#x03C7;</italic><sup>2</sup>&#x202F;=&#x202F;27.797, 10.322, 39.609, and 36.990, respectively). Detailed results are provided in <xref rid="SM1" ref-type="supplementary-material">Appendix Table S1</xref>.</p>
<fig position="float" id="fig3">
<label>Figure 3</label>
<caption>
<p>Temporal trends in detection rates of different DR&#x2013;TB types, 2014&#x2013;2023. The <italic>Y</italic>&#x2013;axis represents the proportion of each DR&#x2013;TB type, calculated as its case count divided by the total number of DR&#x2013;TB cases for that year.</p>
</caption>
<graphic xlink:href="fpubh-14-1771140-g003.tif" mimetype="image" mime-subtype="tiff">
<alt-text content-type="machine-generated">A Line graph compares five TB drug resistance types from 2014 to 2023 by percentage: SDR-TB declines then rises, PDR-TB trends upward, MDR-TB and RR-TB stay stable, INH-R TB peaks then drops.</alt-text>
</graphic>
</fig>
</sec>
<sec id="sec12">
<title>Differences by region, sex, and occupation</title>
<p>Based on geographic location, the 14 prefecture&#x2013;level divisions of Hunan Province were grouped into five regions: eastern (Changsha, Xiangtan, Zhuzhou), southern (Hengyang, Yongzhou, Chenzhou), western (Zhangjiajie, Xiangxi, Huaihua), northern (Yueyang, Changde), and central (Loudi, Yiyang, Shaoyang). Regional analysis showed significant differences in the distribution of SDR&#x2013;TB, PDR&#x2013;TB, MDR&#x2013;TB, RR&#x2013;TB, and INH&#x2013;R TB across these regions (<italic>&#x03C7;</italic><sup>2</sup>&#x202F;=&#x202F;134.501, 16.524, 197.853, 123.445, and 165.209, respectively; <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05). Gender&#x2013;based analysis revealed that males constituted a significantly higher proportion of cases than females for SDR&#x2013;TB, MDR&#x2013;TB, RR&#x2013;TB, and INH&#x2013;R TB (<italic>&#x03C7;</italic><sup>2</sup>&#x202F;=&#x202F;4.350, 163.308, 105.798, and 170.558, respectively; <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05). Regarding occupational distribution, farmers represented the largest subgroup within the study population. Chi&#x2013;square tests indicated significant variation in the distribution of SDR&#x2013;TB, MDR&#x2013;TB, RR&#x2013;TB, and INH&#x2013;R TB across occupational categories (<italic>&#x03C7;</italic><sup>2</sup>&#x202F;=&#x202F;39.165, 58.294, 34.275, and 64.518, respectively; <italic>p</italic>&#x202F;&#x003C;&#x202F;0.05). Detailed results are shown in <xref rid="SM1" ref-type="supplementary-material">Appendix Table S1</xref> and <xref rid="SM1" ref-type="supplementary-material">Supplementary Figure S1</xref>.</p>
</sec>
<sec id="sec13">
<title>Multivariable analysis of risk factors</title>
<p>The results of the multivariate logistic regression analysis are summarized in <xref ref-type="fig" rid="fig4">Figure 4</xref>. For SDR&#x2013;TB, the incidence risk generally decreased from 2015 to 2023 compared with 2014. Geographically, the eastern region had a significantly higher risk (OR&#x202F;=&#x202F;1.334), whereas the northern, southern, and western regions had lower risks. For PDR&#x2013;TB, the risk was significantly higher in 2016 (OR&#x202F;=&#x202F;1.515) and 2021 (OR&#x202F;=&#x202F;1.574) compared with 2014, and the eastern region also showed increased risk (OR&#x202F;=&#x202F;1.208). For MDR&#x2013;TB, the risk was significantly elevated in 2016, 2018, and 2019 compared with 2014. Spatially, the eastern region had lower risk (OR&#x202F;=&#x202F;0.658), whereas the northern (OR&#x202F;=&#x202F;1.219), southern (OR&#x202F;=&#x202F;1.388), and western (OR&#x202F;=&#x202F;1.734) regions had higher risks. Individuals aged 20&#x2013;69&#x202F;years were at significantly higher risk than those under 20&#x202F;years, and females had a lower risk than males (OR&#x202F;=&#x202F;0.819). For RR&#x2013;TB, the risk increased significantly in 2018 (OR&#x202F;=&#x202F;1.344). The eastern region had lower risk, while the southern and western regions had higher risks. The 20&#x2013;69 age group had elevated risk, and females had a lower risk than males (OR&#x202F;=&#x202F;0.784). For INH-R TB, the risk decreased in 2018 and 2021. The eastern region showed higher risk, whereas other regions had lower risks. Females were at significantly higher risk than males (OR&#x202F;=&#x202F;1.137). Detailed results are provided in <xref rid="SM1" ref-type="supplementary-material">Appendix Table S2</xref>.</p>
<fig position="float" id="fig4">
<label>Figure 4</label>
<caption>
<p>Forest plot of the multivariable analysis. Forest plot of multivariable analyses showing the associations between various risk factors and different DR&#x2013;TB subtypes.</p>
</caption>
<graphic xlink:href="fpubh-14-1771140-g004.tif" mimetype="image" mime-subtype="tiff">
<alt-text content-type="machine-generated">Five vertically aligned clustered error bar line charts compare odds ratios (OR) and 95% confidence intervals (CI) for SDR-TB, PDR-TB, MDR-TB, RR-TB, and INH-R-TB across time, region, age, occupation, and sex. Each subgroup is color-coded, with data points and CIs marked by colored symbols and vertical lines, clearly dividing demographic and temporal categories.</alt-text>
</graphic>
</fig>
</sec>
</sec>
<sec sec-type="discussion" id="sec14">
<title>Discussion</title>
<p>This 10&#x2013;year retrospective study examines the DR&#x2013;TB epidemic in Hunan Province, South&#x2013;Central China. The analysis identifies distinct temporal, geographic, and demographic patterns, providing evidence to inform targeted public health strategies.</p>
<p>The predominance of RR&#x2013;TB and INH&#x2013;R TB among resistance types is noteworthy. Both showed temporal trends similar to MDR&#x2013;TB, with all three peaking in 2018. This pattern may be attributed to the widespread use of RIF and INH as first&#x2013;line anti&#x2013;TB drugs. Inconsistent treatment adherence and non&#x2013;standardized medication practices can create selective pressure, promoting the emergence and transmission of resistant strains. This phenomenon aligns with findings from other high&#x2013;TB&#x2013;burden regions (<xref ref-type="bibr" rid="ref13">13</xref>, <xref ref-type="bibr" rid="ref14">14</xref>). The subsequent rebound in resistance rates observed in 2023 may reflect disruptions in TB control services during the COVID&#x2013;19 pandemic, such as resource reallocation and interruptions in patient follow&#x2013;up (<xref ref-type="bibr" rid="ref15 ref16 ref17">15&#x2013;17</xref>), underscoring the necessity for sustained vigilance in the post&#x2013;pandemic era. It should be noted, however, that data collection for 2023 was incomplete due to a hospital information system upgrade concluding in August, which may have influenced the annual estimates.</p>
<p>Geographically, we observed clear spatial disparities in the distribution of DR&#x2013;TB. The western and southern regions of Hunan had the highest burden of MDR&#x2013;TB, showing an inverse association with socioeconomic development, consistent with prior studies (<xref ref-type="bibr" rid="ref18 ref19 ref20">18&#x2013;20</xref>). This pattern may reflect limited healthcare access and suboptimal treatment adherence in the mountainous west. In the south, a major source of out&#x2013;migrant labor, treatment interruption among mobile populations could facilitate transmission of resistant strains (<xref ref-type="bibr" rid="ref21">21</xref>, <xref ref-type="bibr" rid="ref22">22</xref>). By contrast, the more developed eastern region showed lower odds of MDR&#x2013;TB (OR&#x202F;=&#x202F;0.658), likely due to stronger TB control infrastructure, including broader DOTS coverage and wider availability of rapid molecular DST (<xref ref-type="bibr" rid="ref23">23</xref>).</p>
<p>Across most DR&#x2013;TB subtypes, male patients constituted a significantly higher proportion of cases (73&#x2013;77%), exceeding the corresponding figures reported in countries such as Mexico and Japan (<xref ref-type="bibr" rid="ref24">24</xref>, <xref ref-type="bibr" rid="ref25">25</xref>). This gender disparity may be attributable to factors including a higher prevalence of smoking among men&#x2013;which can impair pulmonary immunity&#x2013;greater occupational exposure to silica dust and other hazardous agents (e.g., in mining or construction), and a tendency to delay seeking medical care (<xref ref-type="bibr" rid="ref26 ref27 ref28">26&#x2013;28</xref>). Individuals aged 30&#x2013;59&#x202F;years exhibited a higher incidence of MDR&#x2013;TB and RR&#x2013;TB, indicating increased vulnerability potentially linked to high social mobility, greater work&#x2013;related stress, and heavier comorbidity burdens. Although healthcare resources for this age group are generally sufficient, competing job demands and delayed healthcare&#x2013;seeking may limit their timely access to TB services.</p>
<p>Farmers accounted for the majority of DR&#x2013;TB cases (64.44%), highlighting substantial weaknesses in rural TB control. This vulnerability may be linked to insufficient health insurance, low health literacy, physically demanding work, and poor nutrition among agricultural workers, factors that can elevate the risk of TB infection and drug resistance (<xref ref-type="bibr" rid="ref29 ref30 ref31">29&#x2013;31</xref>). The unemployed comprised 8.70% of cases; we speculate that many lost their work capacity due to TB, with unemployment further aggravating economic and social marginalization, thereby perpetuating a vicious cycle of poverty and disease. This pattern underscores the profound impact of DR&#x2013;TB on patients&#x2019; livelihoods and social functioning.</p>
<p>Multivariable logistic regression confirmed an elevated risk of MDR&#x2013;TB in the western region (OR&#x202F;=&#x202F;1.734) and among adults aged 30&#x2013;49&#x202F;years (OR &#x003E; 2.0). Public sector employees had a significantly lower risk compared with farmers (OR&#x202F;=&#x202F;0.710), suggesting that occupational disparities in healthcare access are a potential target for intervention (<xref ref-type="bibr" rid="ref32">32</xref>). The modestly increased risk of INH&#x2013;R TB among females (OR&#x202F;=&#x202F;1.137) warrants further investigation into potential sex&#x2013;based differences in drug metabolism (e.g., N&#x2013;acetyltransferase 2 activity) and caregiving&#x2013;related exposure (<xref ref-type="bibr" rid="ref33">33</xref>, <xref ref-type="bibr" rid="ref34">34</xref>).</p>
<p>Despite insights from this large, decade&#x2013;long analysis of the DR&#x2013;TB epidemic in Hunan Province, several limitations should be considered. First, the single&#x2013;center, retrospective design may limit generalizability and preclude causal inference. Second, the absence of genotyping data limits analysis of transmission dynamics and molecular clustering. Third, missing data on key confounders&#x2013;including HIV or diabetes comorbidity, behavioral factors (e.g., smoking and alcohol use), and detailed treatment history&#x2013;may bias risk&#x2013;factor analyses. Finally, because some second&#x2013;line and newer antituberculosis drugs were introduced unevenly during the study period, drug&#x2013;resistant tuberculosis (XDR&#x2013;TB) and pre&#x2013;extensively drug&#x2013;resistant tuberculosis (pre&#x2013;XDR&#x2013;TB) were not included in the epidemiologic analyses.</p>
<p>Future multicenter, prospective studies that incorporate whole&#x2013;genome sequencing (WGS) and qualitative assessments of treatment adherence are needed to address these limitations and clarify the epidemiology of DR&#x2013;TB.</p>
</sec>
<sec sec-type="conclusions" id="sec15">
<title>Conclusion</title>
<p>The DR-TB epidemic in Hunan Province shows marked spatiotemporal heterogeneity and distinctive demographic clustering. To address these challenges, precision public health interventions are essential. Key priorities include (1) expanding the use of rapid molecular diagnostics and DST in high&#x2013;burden western and southern regions; (2) implementing flexible, community&#x2013;based directly observed therapy programs tailored to farmers and migrant populations; and (3) enhancing medical security and health education for high&#x2013;risk occupational groups through coordinated cross&#x2013;sectoral action. These findings provide a robust evidence base for developing region-specific DR&#x2013;TB control guidelines in China and comparable settings.</p>
</sec>
</body>
<back>
<sec sec-type="data-availability" id="sec16">
<title>Data availability statement</title>
<p>The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.</p>
</sec>
<sec sec-type="ethics-statement" id="sec17">
<title>Ethics statement</title>
<p>The studies involving humans were approved by Ethics Committee of Hunan Chest Hospital. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation was not required from the participants or the participants&#x2019; legal guardians/next of kin in accordance with the national legislation and institutional requirements.</p>
</sec>
<sec sec-type="author-contributions" id="sec18">
<title>Author contributions</title>
<p>YL: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Writing &#x2013; original draft. JW: Data curation, Formal analysis, Methodology, Validation, Writing &#x2013; original draft. XW: Data curation, Formal analysis, Methodology, Validation, Writing &#x2013; review &#x0026; editing. WP: Investigation, Methodology, Validation, Writing &#x2013; review &#x0026; editing. JG: Investigation, Methodology, Validation, Writing &#x2013; review &#x0026; editing. XY: Investigation, Project administration, Resources, Writing &#x2013; review &#x0026; editing. DZ: Data curation, Formal analysis, Software, Validation, Visualization, Writing &#x2013; review &#x0026; editing. WL: Investigation, Supervision, Validation, Writing &#x2013; review &#x0026; editing. JD: Investigation, Methodology, Validation, Writing &#x2013; review &#x0026; editing. XZ: Investigation, Methodology, Writing &#x2013; review &#x0026; editing. HB: Resources, Supervision, Writing &#x2013; review &#x0026; editing. ZC: Resources, Supervision, Validation, Writing &#x2013; review &#x0026; editing. FL: Funding acquisition, Project administration, Supervision, Writing &#x2013; review &#x0026; editing. YT: Conceptualization, Funding acquisition, Project administration, Supervision, Writing &#x2013; review &#x0026; editing.</p>
</sec>
<ack>
<title>Acknowledgments</title>
<p>The authors acknowledge the staff of the Hunan Institute for Tuberculosis Control and the Hunan Chest Hospital. Their assistance was essential in collecting the clinical data for this study.</p>
</ack>
<sec sec-type="COI-statement" id="sec19">
<title>Conflict of interest</title>
<p>WP was employed by Guangzhou Huazhun Medical Laboratory Co., Ltd.</p>
<p>The remaining author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
</sec>
<sec sec-type="ai-statement" id="sec20">
<title>Generative AI statement</title>
<p>The author(s) declared that Generative AI was not used in the creation of this manuscript.</p>
<p>Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.</p>
</sec>
<sec sec-type="disclaimer" id="sec21">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p>
</sec>
<sec sec-type="supplementary-material" id="sec22">
<title>Supplementary material</title>
<p>The Supplementary material for this article can be found online at: <ext-link xlink:href="https://www.frontiersin.org/articles/10.3389/fpubh.2026.1771140/full#supplementary-material" ext-link-type="uri">https://www.frontiersin.org/articles/10.3389/fpubh.2026.1771140/full#supplementary-material</ext-link></p>
<supplementary-material xlink:href="Image_1.jpeg" id="SM1" mimetype="image/jpeg" xmlns:xlink="http://www.w3.org/1999/xlink"/>
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<supplementary-material xlink:href="Table_2.docx" id="SM3" mimetype="application/vnd.openxmlformats-officedocument.wordprocessingml.document" xmlns:xlink="http://www.w3.org/1999/xlink"/>
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<ref-list>
<title>References</title>
<ref id="ref1"><label>1.</label><mixed-citation publication-type="journal"><collab id="coll1">The Lancet Public Health</collab>. <article-title>Taking tuberculosis out of the shadows</article-title>. <source>Lancet Public Health</source>. (<year>2023</year>) <volume>8</volume>:<fpage>e247</fpage>. doi: <pub-id pub-id-type="doi">10.1016/S2468&#x2013;2667(23)00063&#x2013;4</pub-id></mixed-citation></ref>
<ref id="ref2"><label>2.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Tiberi</surname><given-names>S</given-names></name> <name><surname>Utjesanovic</surname><given-names>N</given-names></name> <name><surname>Galvin</surname><given-names>J</given-names></name> <name><surname>Centis</surname><given-names>R</given-names></name> <name><surname>D'Ambrosio</surname><given-names>L</given-names></name> <name><surname>van den Boom</surname><given-names>M</given-names></name> <etal/></person-group>. <article-title>Drug resistant TB &#x2013;latest developments in epidemiology, diagnostics and management</article-title>. <source>Int J Infect Dis</source>. (<year>2022</year>) <volume>124</volume>:<fpage>S20</fpage>&#x2013;<lpage>5</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.ijid.2022.03.026</pub-id></mixed-citation></ref>
<ref id="ref3"><label>3.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Dookie</surname><given-names>N</given-names></name> <name><surname>Ngema</surname><given-names>SL</given-names></name> <name><surname>Perumal</surname><given-names>R</given-names></name> <name><surname>Naicker</surname><given-names>N</given-names></name> <name><surname>Padayatchi</surname><given-names>N</given-names></name> <name><surname>Naidoo</surname><given-names>K</given-names></name></person-group>. <article-title>The changing paradigm of drug&#x2013;resistant tuberculosis treatment: successes, pitfalls, and future perspectives</article-title>. <source>Clin Microbiol Rev</source>. (<year>2022</year>) <volume>35</volume>:<fpage>e0018019</fpage>. doi: <pub-id pub-id-type="doi">10.1128/cmr.00180&#x2013;19</pub-id>, <pub-id pub-id-type="pmid">36200885</pub-id></mixed-citation></ref>
<ref id="ref4"><label>4.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Pei</surname><given-names>S</given-names></name> <name><surname>Song</surname><given-names>Z</given-names></name> <name><surname>Yang</surname><given-names>W</given-names></name> <name><surname>He</surname><given-names>W</given-names></name> <name><surname>Ou</surname><given-names>X</given-names></name> <name><surname>Zhao</surname><given-names>B</given-names></name> <etal/></person-group>. <article-title>The catalogue of <italic>Mycobacterium tuberculosis</italic> mutations associated with drug resistance to 12 drugs in China from a nationwide survey: a genomic analysis</article-title>. <source>Lancet Microbe</source>. (<year>2024</year>) <volume>5</volume>:<fpage>100899</fpage>. doi: <pub-id pub-id-type="doi">10.1016/S2666&#x2013;5247(24)00131&#x2013;9</pub-id>, <pub-id pub-id-type="pmid">39353459</pub-id></mixed-citation></ref>
<ref id="ref5"><label>5.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Akalu</surname><given-names>TY</given-names></name> <name><surname>Clements</surname><given-names>ACA</given-names></name> <name><surname>Xu</surname><given-names>Z</given-names></name> <name><surname>Bai</surname><given-names>L</given-names></name> <name><surname>Alene</surname><given-names>KA</given-names></name></person-group>. <article-title>Mapping drug&#x2013;resistant tuberculosis treatment outcomes in Hunan Province, China</article-title>. <source>Trop Med Infect Dis</source>. (<year>2024</year>) <volume>10</volume>:<fpage>3</fpage>. doi: <pub-id pub-id-type="doi">10.3390/tropicalmed10010003</pub-id>, <pub-id pub-id-type="pmid">39852654</pub-id></mixed-citation></ref>
<ref id="ref6"><label>6.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Zhao</surname><given-names>LL</given-names></name> <name><surname>Chen</surname><given-names>Y</given-names></name> <name><surname>Chen</surname><given-names>ZN</given-names></name> <name><surname>Liu</surname><given-names>HC</given-names></name> <name><surname>Hu</surname><given-names>PL</given-names></name> <name><surname>Sun</surname><given-names>Q</given-names></name> <etal/></person-group>. <article-title>Prevalence and molecular characteristics of drug&#x2013;resistant <italic>Mycobacterium tuberculosis</italic> in Hunan, China</article-title>. <source>Antimicrob Agents Chemother</source>. (<year>2014</year>) <volume>58</volume>:<fpage>3475</fpage>&#x2013;<lpage>80</lpage>. doi: <pub-id pub-id-type="doi">10.1128/AAC.02426&#x2013;14</pub-id></mixed-citation></ref>
<ref id="ref7"><label>7.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Farhat</surname><given-names>M</given-names></name> <name><surname>Cox</surname><given-names>H</given-names></name> <name><surname>Ghanem</surname><given-names>M</given-names></name> <name><surname>Denkinger</surname><given-names>CM</given-names></name> <name><surname>Rodrigues</surname><given-names>C</given-names></name> <name><surname>Abd El Aziz</surname><given-names>MS</given-names></name> <etal/></person-group>. <article-title>Drug&#x2013;resistant tuberculosis: a persistent global health concern</article-title>. <source>Nat Rev Microbiol</source>. (<year>2024</year>) <volume>22</volume>:<fpage>617</fpage>&#x2013;<lpage>35</lpage>. doi: <pub-id pub-id-type="doi">10.1038/s41579-024-01025-1</pub-id>, <pub-id pub-id-type="pmid">38519618</pub-id></mixed-citation></ref>
<ref id="ref8"><label>8.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Sahasrabudhe</surname><given-names>T</given-names></name> <name><surname>Nilgiri</surname><given-names>KM</given-names></name></person-group>. <article-title>Quantitative study of physical, social, psychological, and environmental challenges faced by patients with drug&#x2013;resistant tuberculosis</article-title>. <source>Cureus</source>. (<year>2024</year>) <volume>16</volume>:<fpage>e69694</fpage>. doi: <pub-id pub-id-type="doi">10.7759/cureus.69694</pub-id>, <pub-id pub-id-type="pmid">39435239</pub-id></mixed-citation></ref>
<ref id="ref9"><label>9.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Bagcchi</surname><given-names>S</given-names></name></person-group>. <article-title>WHO'S global tuberculosis report 2022</article-title>. <source>Lancet Microbe</source>. (<year>2023</year>) <volume>4</volume>:<fpage>e20</fpage>. doi: <pub-id pub-id-type="doi">10.1016/S2666&#x2013;5247(22)00359&#x2013;7</pub-id>, <pub-id pub-id-type="pmid">36521512</pub-id></mixed-citation></ref>
<ref id="ref10"><label>10.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Song</surname><given-names>WM</given-names></name> <name><surname>Li</surname><given-names>YF</given-names></name> <name><surname>Liu</surname><given-names>YX</given-names></name> <name><surname>Liu</surname><given-names>Y</given-names></name> <name><surname>Yu</surname><given-names>CB</given-names></name> <name><surname>Liu</surname><given-names>JY</given-names></name> <etal/></person-group>. <article-title>Drug&#x2013;resistant tuberculosis among children: a systematic review and meta&#x2013;analysis</article-title>. <source>Front Public Health</source>. (<year>2021</year>) <volume>9</volume>:<fpage>721817</fpage>. doi: <pub-id pub-id-type="doi">10.3389/fpubh.2021.721817</pub-id>, <pub-id pub-id-type="pmid">34490197</pub-id></mixed-citation></ref>
<ref id="ref11"><label>11.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chiang</surname><given-names>SS</given-names></name> <name><surname>Brooks</surname><given-names>MB</given-names></name> <name><surname>Jenkins</surname><given-names>HE</given-names></name> <name><surname>Rubenstein</surname><given-names>D</given-names></name> <name><surname>Seddon</surname><given-names>JA</given-names></name> <name><surname>van de Water Bj</surname></name> <etal/></person-group>. <article-title>Concordance of drug&#x2013;resistance profiles between persons with drug&#x2013;resistant tuberculosis and their household contacts: a systematic review and meta&#x2013;analysis</article-title>. <source>Clin Infect Dis</source>. (<year>2021</year>) <volume>73</volume>:<fpage>250</fpage>&#x2013;<lpage>63</lpage>. doi: <pub-id pub-id-type="doi">10.1093/cid/ciaa613</pub-id></mixed-citation></ref>
<ref id="ref12"><label>12.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Wilkinson</surname><given-names>T</given-names></name> <name><surname>Garcia&#x2013;Prats</surname><given-names>AJ</given-names></name> <name><surname>Sachs</surname><given-names>T</given-names></name> <name><surname>Paradkar</surname><given-names>M</given-names></name> <name><surname>Suryavanshi</surname><given-names>N</given-names></name> <name><surname>Kinikar</surname><given-names>A</given-names></name> <etal/></person-group>. <article-title>Pharmaceutical cost dynamics for the treatment of rifampicin&#x2013;resistant tuberculosis in children and adolescents in South Africa, India, and the Philippines</article-title>. <source>PLoS One</source>. (<year>2024</year>) <volume>19</volume>:<fpage>e0305930</fpage>. doi: <pub-id pub-id-type="doi">10.1371/journal.pone.0305930</pub-id>, <pub-id pub-id-type="pmid">39042708</pub-id></mixed-citation></ref>
<ref id="ref13"><label>13.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Podany</surname><given-names>AT</given-names></name> <name><surname>Leon&#x2013;Cruz</surname><given-names>J</given-names></name> <name><surname>Hakim</surname><given-names>J</given-names></name> <name><surname>Supparatpinyo</surname><given-names>K</given-names></name> <name><surname>Omoz&#x2013;Oarhe</surname><given-names>A</given-names></name> <name><surname>Langat</surname><given-names>D</given-names></name> <etal/></person-group>. <article-title>Nevirapine pharmacokinetics in HIV&#x2013;infected persons receiving rifapentine and isoniazid for TB prevention</article-title>. <source>J Antimicrob Chemother</source>. (<year>2021</year>) <volume>76</volume>:<fpage>718</fpage>&#x2013;<lpage>21</lpage>. doi: <pub-id pub-id-type="doi">10.1093/jac/dkaa470</pub-id>, <pub-id pub-id-type="pmid">33241266</pub-id></mixed-citation></ref>
<ref id="ref14"><label>14.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Scott</surname><given-names>NA</given-names></name> <name><surname>Sadowski</surname><given-names>C</given-names></name> <name><surname>Vernon</surname><given-names>A</given-names></name> <name><surname>Arevalo</surname><given-names>B</given-names></name> <name><surname>Beer</surname><given-names>K</given-names></name> <name><surname>Borisov</surname><given-names>A</given-names></name> <etal/></person-group>. <article-title>Using a medication event monitoring system to evaluate self&#x2013;report and pill count for determining treatment completion with self&#x2013;administered, once&#x2013;weekly isoniazid and rifapentine</article-title>. <source>Contemp Clin Trials</source>. (<year>2023</year>) <volume>129</volume>:<fpage>107173</fpage>. doi: <pub-id pub-id-type="doi">10.1016/j.cct.2023.107173</pub-id>, <pub-id pub-id-type="pmid">37004811</pub-id></mixed-citation></ref>
<ref id="ref15"><label>15.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Abdool Karim</surname><given-names>Q</given-names></name> <name><surname>Baxter</surname><given-names>C</given-names></name></person-group>. <article-title>COVID&#x2013;19: impact on the HIV and tuberculosis response, service delivery, and research in South Africa</article-title>. <source>Curr HIV AIDS Rep</source>. (<year>2022</year>) <volume>19</volume>:<fpage>46</fpage>&#x2013;<lpage>53</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s11904&#x2013;021&#x2013;00588&#x2013;5</pub-id>, <pub-id pub-id-type="pmid">35064888</pub-id></mixed-citation></ref>
<ref id="ref16"><label>16.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Syal</surname><given-names>K</given-names></name></person-group>. <article-title>The interplay of tuberculosis and COVID&#x2013;19: insights into global health challenges</article-title>. <source>J Biosci</source>. (<year>2025</year>) <volume>50</volume>:<fpage>14</fpage>. doi: <pub-id pub-id-type="doi">10.1007/s12038-025-00496-5</pub-id>, <pub-id pub-id-type="pmid">40098402</pub-id></mixed-citation></ref>
<ref id="ref17"><label>17.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>MacLean</surname><given-names>EL</given-names></name> <name><surname>Villa&#x2013;Castillo</surname><given-names>L</given-names></name> <name><surname>Espinoza&#x2013;Lopez</surname><given-names>P</given-names></name> <name><surname>Caceres</surname><given-names>T</given-names></name> <name><surname>Sulis</surname><given-names>G</given-names></name> <name><surname>Kohli</surname><given-names>M</given-names></name> <etal/></person-group>. <article-title>Integrating tuberculosis and COVID&#x2013;19 molecular testing in Lima, Peru: a cross&#x2013;sectional, diagnostic accuracy study</article-title>. <source>Lancet Microbe</source>. (<year>2023</year>) <volume>4</volume>:<fpage>e452</fpage>&#x2013;<lpage>60</lpage>. doi: <pub-id pub-id-type="doi">10.1016/S2666&#x2013;5247(23)00042&#x2013;3</pub-id></mixed-citation></ref>
<ref id="ref18"><label>18.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Yu</surname><given-names>Y</given-names></name> <name><surname>Xiang</surname><given-names>Y</given-names></name> <name><surname>Liu</surname><given-names>H</given-names></name> <name><surname>Yang</surname><given-names>S</given-names></name> <name><surname>Li</surname><given-names>M</given-names></name> <name><surname>Liu</surname><given-names>B</given-names></name> <etal/></person-group>. <article-title>Analysis of epidemiological characteristics of extrapulmonary tuberculosis from south&#x2013;Central China</article-title>. <source>Front Public Health</source>. (<year>2024</year>) <volume>12</volume>:<fpage>1405358</fpage>. doi: <pub-id pub-id-type="doi">10.3389/fpubh.2024.1405358</pub-id>, <pub-id pub-id-type="pmid">39086797</pub-id></mixed-citation></ref>
<ref id="ref19"><label>19.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Fang</surname><given-names>T</given-names></name> <name><surname>Yang</surname><given-names>S</given-names></name> <name><surname>Liu</surname><given-names>B</given-names></name> <name><surname>Li</surname><given-names>W</given-names></name> <name><surname>Sun</surname><given-names>Q</given-names></name> <name><surname>Liu</surname><given-names>H</given-names></name> <etal/></person-group>. <article-title>Analysis on the epidemiological and drug resistance characteristics of osteoarticular tuberculosis in south&#x2013;Central China</article-title>. <source>Front Public Health</source>. (<year>2024</year>) <volume>12</volume>:<fpage>1432071</fpage>. doi: <pub-id pub-id-type="doi">10.3389/fpubh.2024.1432071</pub-id>, <pub-id pub-id-type="pmid">39281085</pub-id></mixed-citation></ref>
<ref id="ref20"><label>20.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname><given-names>BB</given-names></name> <name><surname>Hu</surname><given-names>PL</given-names></name> <name><surname>Chen</surname><given-names>ZH</given-names></name> <name><surname>Yi</surname><given-names>SL</given-names></name> <name><surname>Zhang</surname><given-names>XP</given-names></name> <name><surname>Tan</surname><given-names>YH</given-names></name></person-group>. <article-title>Prevalence and transmission of pyrazinamide&#x2013;resistant <italic>Mycobacterium tuberculosis</italic> in Hunan Province,China</article-title>. <source>Zhonghua Jie He He Hu Xi Za Zhi</source>. (<year>2022</year>) <volume>45</volume>:<fpage>677</fpage>&#x2013;<lpage>85</lpage> <comment>Chinese.</comment> doi: <pub-id pub-id-type="doi">10.3760/cma.j.cn112147&#x2013;20211219&#x2013;00904</pub-id>, <pub-id pub-id-type="pmid">35768376</pub-id></mixed-citation></ref>
<ref id="ref21"><label>21.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Alene</surname><given-names>KA</given-names></name> <name><surname>Xu</surname><given-names>Z</given-names></name> <name><surname>Bai</surname><given-names>L</given-names></name> <name><surname>Yi</surname><given-names>H</given-names></name> <name><surname>Tan</surname><given-names>Y</given-names></name> <name><surname>Gray</surname><given-names>DJ</given-names></name> <etal/></person-group>. <article-title>Spatiotemporal patterns of tuberculosis in Hunan Province, China</article-title>. <source>Int J Environ Res Public Health</source>. (<year>2021</year>) <volume>18</volume>:<fpage>6778</fpage>. doi: <pub-id pub-id-type="doi">10.3390/ijerph18136778</pub-id>, <pub-id pub-id-type="pmid">34202504</pub-id></mixed-citation></ref>
<ref id="ref22"><label>22.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Huang</surname><given-names>G</given-names></name> <name><surname>Xu</surname><given-names>Z</given-names></name> <name><surname>Bai</surname><given-names>L</given-names></name> <name><surname>Liu</surname><given-names>J</given-names></name> <name><surname>Yu</surname><given-names>S</given-names></name> <name><surname>Yao</surname><given-names>H</given-names></name></person-group>. <article-title>Spatiotemporal analysis of tuberculosis in the Hunan Province, China, 2014&#x2013;2022</article-title>. <source>Front Public Health</source>. (<year>2024</year>) <volume>12</volume>:<fpage>1426503</fpage>. doi: <pub-id pub-id-type="doi">10.3389/fpubh.2024.1426503</pub-id>, <pub-id pub-id-type="pmid">39175902</pub-id></mixed-citation></ref>
<ref id="ref23"><label>23.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Akalu</surname><given-names>TY</given-names></name> <name><surname>Clements</surname><given-names>ACA</given-names></name> <name><surname>Xu</surname><given-names>Z</given-names></name> <name><surname>Bai</surname><given-names>L</given-names></name> <name><surname>Alene</surname><given-names>KA</given-names></name></person-group>. <article-title>Determinants of drug&#x2013;resistant tuberculosis in Hunan province, China: a case&#x2013;control study</article-title>. <source>BMC Infect Dis</source>. (<year>2024</year>) <volume>24</volume>:<fpage>198</fpage>. doi: <pub-id pub-id-type="doi">10.1186/s12879&#x2013;024&#x2013;09106&#x2013;5</pub-id>, <pub-id pub-id-type="pmid">38350860</pub-id></mixed-citation></ref>
<ref id="ref24"><label>24.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Mej&#x00ED;a&#x2013;Ponce</surname><given-names>PM</given-names></name> <name><surname>Ramos&#x2013;Gonz&#x00E1;lez</surname><given-names>EJ</given-names></name> <name><surname>Ramos&#x2013;Garc&#x00ED;a</surname><given-names>AA</given-names></name> <name><surname>Lara&#x2013;Ram&#x00ED;rez</surname><given-names>EE</given-names></name> <name><surname>Soriano&#x2013;Herrera</surname><given-names>AR</given-names></name> <name><surname>Medell&#x00ED;n&#x2013;Luna</surname><given-names>MF</given-names></name> <etal/></person-group>. <article-title>Genomic epidemiology analysis of drug&#x2013;resistant <italic>Mycobacterium tuberculosis</italic> distributed in Mexico</article-title>. <source>PLoS One</source>. (<year>2023</year>) <volume>18</volume>:<fpage>e0292965</fpage>. doi: <pub-id pub-id-type="doi">10.1371/journal.pone.0292965</pub-id>, <pub-id pub-id-type="pmid">37831695</pub-id></mixed-citation></ref>
<ref id="ref25"><label>25.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Mizukoshi</surname><given-names>F</given-names></name> <name><surname>Kobayashi</surname><given-names>N</given-names></name> <name><surname>Kirikae</surname><given-names>F</given-names></name> <name><surname>Ohta</surname><given-names>K</given-names></name> <name><surname>Tsuyuguchi</surname><given-names>K</given-names></name> <name><surname>Yamada</surname><given-names>N</given-names></name> <etal/></person-group>. <article-title>Molecular epidemiology of drug&#x2013;resistant <italic>Mycobacterium tuberculosis</italic> in Japan</article-title>. <source>mSphere</source>. (<year>2021</year>) <volume>6</volume>:<fpage>e0097820</fpage>. doi: <pub-id pub-id-type="doi">10.1128/mSphere.00978&#x2013;20</pub-id></mixed-citation></ref>
<ref id="ref26"><label>26.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Wang</surname><given-names>L</given-names></name> <name><surname>Chen</surname><given-names>B</given-names></name> <name><surname>Zhou</surname><given-names>H</given-names></name> <name><surname>Mathema</surname><given-names>B</given-names></name> <name><surname>Chen</surname><given-names>L</given-names></name> <name><surname>Li</surname><given-names>X</given-names></name> <etal/></person-group>. <article-title>Emergence and evolution of drug&#x2013;resistant <italic>Mycobacterium tuberculosis</italic> in eastern China: a six&#x2013;year prospective study</article-title>. <source>Genomics</source>. (<year>2023</year>) <volume>115</volume>:<fpage>110640</fpage>. doi: <pub-id pub-id-type="doi">10.1016/j.ygeno.2023.110640</pub-id>, <pub-id pub-id-type="pmid">37187254</pub-id></mixed-citation></ref>
<ref id="ref27"><label>27.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname><given-names>D</given-names></name> <name><surname>Huang</surname><given-names>F</given-names></name> <name><surname>Li</surname><given-names>Y</given-names></name> <name><surname>Mao</surname><given-names>L</given-names></name> <name><surname>He</surname><given-names>W</given-names></name> <name><surname>Wu</surname><given-names>S</given-names></name> <etal/></person-group>. <article-title>Transmission characteristics in tuberculosis by WGS: nationwide cross&#x2013;sectional surveillance in China</article-title>. <source>Emerg Microbes Infect</source>. (<year>2024</year>) <volume>13</volume>:<fpage>2348505</fpage>. doi: <pub-id pub-id-type="doi">10.1080/22221751.2024.2348505</pub-id>, <pub-id pub-id-type="pmid">38686553</pub-id></mixed-citation></ref>
<ref id="ref28"><label>28.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Lee</surname><given-names>JH</given-names></name> <name><surname>Garg</surname><given-names>T</given-names></name> <name><surname>Lee</surname><given-names>J</given-names></name> <name><surname>McGrath</surname><given-names>S</given-names></name> <name><surname>Rosman</surname><given-names>L</given-names></name> <name><surname>Schumacher</surname><given-names>SG</given-names></name> <etal/></person-group>. <article-title>Impact of molecular diagnostic tests on diagnostic and treatment delays in tuberculosis: a systematic review and meta&#x2013;analysis</article-title>. <source>BMC Infect Dis</source>. (<year>2022</year>) <volume>22</volume>:<fpage>940</fpage>. doi: <pub-id pub-id-type="doi">10.1186/s12879&#x2013;022&#x2013;07855&#x2013;9</pub-id>, <pub-id pub-id-type="pmid">36517736</pub-id></mixed-citation></ref>
<ref id="ref29"><label>29.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Alehegn</surname><given-names>E</given-names></name> <name><surname>Gebreyohanns</surname><given-names>A</given-names></name> <name><surname>Berhane</surname><given-names>BW</given-names></name> <name><surname>Wright</surname><given-names>JA</given-names></name> <name><surname>Hundie</surname><given-names>GB</given-names></name> <name><surname>Geremew</surname><given-names>RA</given-names></name> <etal/></person-group>. <article-title>Phenotypic drug resistance pattern and mutation characteristics of <italic>Mycobacterium tuberculosis</italic> from different body fluids among extra pulmonary patients presented in selected hospitals in Addis Ababa, Ethiopia</article-title>. <source>Infect Drug Resist</source>. (<year>2023</year>) <volume>16</volume>:<fpage>5511</fpage>&#x2013;<lpage>22</lpage>. doi: <pub-id pub-id-type="doi">10.2147/IDR.S415906</pub-id>, <pub-id pub-id-type="pmid">37638071</pub-id></mixed-citation></ref>
<ref id="ref30"><label>30.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Alehegn</surname><given-names>E</given-names></name> <name><surname>Gebreyohanns</surname><given-names>A</given-names></name> <name><surname>Berhane</surname><given-names>B</given-names></name> <name><surname>Wright</surname><given-names>J</given-names></name> <name><surname>Fantahun</surname><given-names>M</given-names></name> <name><surname>Hailu</surname><given-names>M</given-names></name> <etal/></person-group>. <article-title>Burden of <italic>mycobacterium tuberculosis</italic> and associated factors among presumptive extra pulmonary tuberculosis patients from selected health facilities, Addis Ababa, Ethiopia</article-title>. <source>IJID Reg</source>. (<year>2023</year>) <volume>7</volume>:<fpage>199</fpage>&#x2013;<lpage>205</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.ijregi.2023.03.007</pub-id>, <pub-id pub-id-type="pmid">37114203</pub-id></mixed-citation></ref>
<ref id="ref31"><label>31.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Han</surname><given-names>N</given-names></name> <name><surname>Yan</surname><given-names>L</given-names></name> <name><surname>Yuan</surname><given-names>M</given-names></name> <name><surname>Chen</surname><given-names>Z</given-names></name> <name><surname>Zeng</surname><given-names>Y</given-names></name> <name><surname>Tang</surname><given-names>H</given-names></name></person-group>. <article-title>Characteristics and risk factors of drug&#x2013;resistant tuberculosis in Sichuan, China: an observational study</article-title>. <source>Trop Med Int Health</source>. (<year>2025</year>) <volume>30</volume>:<fpage>704</fpage>&#x2013;<lpage>11</lpage>. doi: <pub-id pub-id-type="doi">10.1111/tmi.14126</pub-id>, <pub-id pub-id-type="pmid">40371607</pub-id></mixed-citation></ref>
<ref id="ref32"><label>32.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Borah</surname><given-names>P</given-names></name> <name><surname>Deb</surname><given-names>PK</given-names></name> <name><surname>Venugopala</surname><given-names>KN</given-names></name> <name><surname>Al-Shar&#x2019;i</surname><given-names>NA</given-names></name> <name><surname>Singh</surname><given-names>V</given-names></name> <name><surname>Deka</surname><given-names>S</given-names></name> <etal/></person-group>. <article-title>Tuberculosis: an update on pathophysiology, molecular mechanisms of drug resistance, newer anti&#x2013;TB drugs, treatment regimens and host&#x2013;directed therapies</article-title>. <source>Curr Top Med Chem</source>. (<year>2021</year>) <volume>21</volume>:<fpage>547</fpage>&#x2013;<lpage>70</lpage>. doi: <pub-id pub-id-type="doi">10.2174/1568026621999201211200447</pub-id>, <pub-id pub-id-type="pmid">33319660</pub-id></mixed-citation></ref>
<ref id="ref33"><label>33.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Borah</surname><given-names>P</given-names></name> <name><surname>Deb</surname><given-names>PK</given-names></name> <name><surname>Venugopala</surname><given-names>KN</given-names></name> <name><surname>Al&#x2013;Shar'i</surname><given-names>NA</given-names></name> <name><surname>Singh</surname><given-names>V</given-names></name> <name><surname>Deka</surname><given-names>S</given-names></name> <etal/></person-group>. <article-title>Epidemiological characteristics and risk factors related to drug&#x2013;resistant tuberculosis in Luanda, Angola</article-title>. <source>Am J Trop Med Hyg</source>. (<year>2022</year>) <volume>106</volume>:<fpage>779</fpage>&#x2013;<lpage>84</lpage>. doi: <pub-id pub-id-type="doi">10.4269/ajtmh.21&#x2013;0659</pub-id></mixed-citation></ref>
<ref id="ref34"><label>34.</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Madaki</surname><given-names>S</given-names></name> <name><surname>Mohammed</surname><given-names>Y</given-names></name> <name><surname>Rogo</surname><given-names>LD</given-names></name> <name><surname>Yusuf</surname><given-names>M</given-names></name> <name><surname>Bala</surname><given-names>YG</given-names></name></person-group>. <article-title>Age and gender in drug resistance tuberculosis: a cross&#x2013;sectional case study at a national tuberculosis reference hospital in Nigeria</article-title>. <source>J Glob Antimicrob Resist</source>. (<year>2024</year>) <volume>39</volume>:<fpage>175</fpage>&#x2013;<lpage>83</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.jgar.2024.09.002</pub-id>, <pub-id pub-id-type="pmid">39299497</pub-id></mixed-citation></ref>
</ref-list>
<fn-group>
<fn fn-type="custom" custom-type="edited-by" id="fn0001">
<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/1665560/overview">Arash Ghodousi</ext-link>, Vita-Salute San Raffaele University, Italy</p>
</fn>
<fn fn-type="custom" custom-type="reviewed-by" id="fn0002">
<p>Reviewed by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/298148/overview">Liu Dongxin</ext-link>, National Institute for Communicable Disease Control and Prevention (China CDC), China</p>
<p><ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/3286525/overview">Hamdiye Turan</ext-link>, Harran University, T&#x00FC;rkiye</p>
</fn>
</fn-group>
<fn-group>
<fn fn-type="abbr" id="abbr1">
<label>Abbreviations:</label>
<p>CIs, confidence intervals; DST, drug susceptibility testing; DR&#x2013;TB, drug&#x2013;resistant tuberculosis; EMB, ethambutol; INH, isoniazid; INH&#x2013;R TB, isoniazid&#x2013;resistant tuberculosis; L&#x2013;J, L&#x00F6;wenstein&#x2013;Jensen; MDR&#x2013;TB, multidrug&#x2013;resistant tuberculosis; NTRL, National Tuberculosis Reference Laboratory; ORs, odds ratios; PDR&#x2013;TB, poly&#x2013;drug&#x2013;resistant tuberculosis; PZA, pyrazinamide; pre&#x2013;XDR&#x2013;TB, pre&#x2013;extensively drug&#x2013;resistant tuberculosis; RIF, rifampicin; RR&#x2013;TB, rifampicin&#x2013;resistant tuberculosis; SDR&#x2013;TB, single drug&#x2013;resistant tuberculosis; TB, tuberculosis; XDR&#x2013;TB, extensively drug&#x2013;resistant tuberculosis.</p>
</fn>
</fn-group>
</back>
</article>