{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T15:37:39Z","timestamp":1774453059499,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T00:00:00Z","timestamp":1774310400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Agence Fran\u00e7aise de D\u00e9veloppement (AFD) Group funds","award":["CZZ2579 01 L"],"award-info":[{"award-number":["CZZ2579 01 L"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Background: Tuberculosis (TB) remains a major global health challenge, with Mycobacterium tuberculosis (M. tuberculosis) causing significant morbidity and mortality mainly in high-burden countries. Following exposure to M. tuberculosis, individuals may become infected, developing TB infection (TBI) through inhalation of the bacillus: this affects approximately one-fourth of the global population and serves as a critical reservoir for potential disease reactivation and transmission. The risk of being infected with M. tuberculosis is shaped by bacterial load of people with TB, contact patterns, environmental factors, and host susceptibility, particularly in high-risk congregate settings. Elucidating these determinants is instrumental for optimising TB prevention and control strategies. Methods: A preliminary PubMed search was conducted on 25 August 2024, using the keywords \u201clatent tuberculosis infection,\u201d \u201crisk factors,\u201d and \u201csystematic review.\u201d Targeted reviews were then performed in November 2024 to examine factors influencing progression from exposure to M. tuberculosis to TBI. Systematic reviews published between January 2000 and November 2024 were included. Results: The scoping review analysed eight systematic reviews, grouping findings into three key themes: (1) proximity and behavioural risk factors; (2) environmental risk factors; and (3) host immune vulnerabilities. Close contact with people with TB in crowded settings, such as dormitories, healthcare facilities, and prisons, was strongly associated with an elevated risk of TBI. Healthcare workers travelling from low- to high-incidence regions faced the highest risk due to frequent exposure to M. tuberculosis, while military personnel and general travellers had lower risks. Environmental exposures, including second-hand smoke and inadequate ventilation, further heightened susceptibility among children and adults. Host immune risk factors, such as advanced age, low body mass index, lack of BCG vaccination, and metabolic disorders such as diabetes, markedly increase susceptibility to TBI. The interplay between proximity, behavioural and environmental risk factors, and host immune vulnerabilities highlights the multifactorial nature of TBI risk. Conclusion: Effective TBI control demands a multifaceted approach, combining robust infection prevention and control measures, comorbidity management, and mitigation of behavioural risk factors like smoking. Tailored strategies are crucial for high-risk settings such as healthcare facilities and prisons. Multisectoral collaboration is essential to address key risk factors and protect vulnerable populations from progressing to TBI.<\/jats:p>","DOI":"10.3390\/tropicalmed11040087","type":"journal-article","created":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T13:57:34Z","timestamp":1774447054000},"page":"87","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Series 2: Invisible Threats: A Global Scoping Review of Risk Factors for Tuberculosis Infection"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4422-1185","authenticated-orcid":false,"given":"Sonia","family":"Menon","sequence":"first","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"},{"name":"Epitech Research, 1160 Auderghem, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6113-9741","authenticated-orcid":false,"given":"Anthony D.","family":"Harries","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"},{"name":"Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3415-672X","authenticated-orcid":false,"given":"Riitta A.","family":"Dlodlo","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gis\u00e8le","family":"Badoum","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"},{"name":"Unit\u00e9 de Formation et de Recherche en Sciences de la Sant\u00e9 (UFR\/SDS), Universit\u00e9 Joseph KI-ZERBO, Ouagadougou P.O. Box 7021, Burkina Faso"},{"name":"Service de Pneumologie, Centre Hospitalier et Universitaire de Yalgado Ou\u00e9draogo (CNHU-YO), Ouagadougou P.O. Box 7022, Burkina Faso"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-2837-7723","authenticated-orcid":false,"given":"Mohammed F.","family":"Dogo","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olivia B.","family":"Mbitikon","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4233-0871","authenticated-orcid":false,"given":"Pranay","family":"Sinha","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"},{"name":"Section of Infectious Diseases, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA"},{"name":"Boston Medical Center, Boston, MA 02118, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7055-3183","authenticated-orcid":false,"given":"Yan","family":"Lin","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jyoti","family":"Jaju","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aung Naing","family":"Soe","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anisha","family":"Singh","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bharati","family":"Kalottee","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8928-6732","authenticated-orcid":false,"given":"Kobto G.","family":"Koura","sequence":"additional","affiliation":[{"name":"International Union Against Tuberculosis and Lung Disease, 75001 Paris, France"},{"name":"Unit\u00e9 Mixte de Recherche MERIT (UMR261), Universit\u00e9 Paris Cit\u00e9, Institut de Recherche pour le D\u00e9veloppement (IRD), 75006 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,24]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (WHO) (2026, February 19). Global Tuberculosis Report 2025, Available online: https:\/\/www.who.int\/teams\/global-tuberculosis-programme\/tb-reports."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1556\/1886.2021.00021","article-title":"Tuberculosis challenges: Resistance, co-infection, diagnosis, and treatment","volume":"12","author":"Heidary","year":"2022","journal-title":"Eur. J. Microbiol. Immunol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/S2213-2600(16)30433-7","article-title":"Outcomes, infectiousness, and transmission dynamics of patients with extensively drug-resistant tuberculosis and home-discharged patients with programmatically incurable tuberculosis: A prospective cohort study","volume":"5","author":"Dheda","year":"2017","journal-title":"Lancet Respir. Med."},{"key":"ref_4","first-page":"879","article-title":"Identification and management of latent tuberculosis infection","volume":"79","author":"Hauck","year":"2009","journal-title":"Am. Fam. Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1016\/j.tube.2015.04.003","article-title":"Latent tuberculosis infection\u2014Revisiting and revising concepts","volume":"95","author":"Salgame","year":"2015","journal-title":"Tuberculosis"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1136\/thoraxjnl-2013-203247","article-title":"How should I interpret an interferon gamma release assay result for tuberculosis infection?","volume":"68","author":"Abubakar","year":"2013","journal-title":"Thorax"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1900655","DOI":"10.1183\/13993003.00655-2019","article-title":"The global prevalence of latent tuberculosis: A systematic review and meta-analysis","volume":"54","author":"Cohen","year":"2019","journal-title":"Eur. Respir. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1128\/CMR.16.3.463-496.2003","article-title":"Mycobacterium tuberculosis pathogenesis and molecular determinants of virulence","volume":"16","author":"Smith","year":"2003","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_9","unstructured":"World Health Organization (2025, June 13). Tuberculosis Handbook, Available online: https:\/\/iris.who.int\/bitstream\/handle\/10665\/65434\/WHO_TB_98.253.pdf?sequence=1."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1164\/rccm.201208-1422OC","article-title":"Cough aerosols of Mycobacterium tuberculosis predict new infection: A household contact study","volume":"187","author":"Namugga","year":"2013","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1056\/NEJMcp1005750","article-title":"Clinical practice. Latent tuberculosis infection in the United States","volume":"364","author":"Horsburgh","year":"2011","journal-title":"N. Engl. J. Med."},{"key":"ref_12","unstructured":"Center for Disease Control and Prevention (2025, June 13). Tuberculosis Risk Factors, Available online: https:\/\/www.cdc.gov\/tb\/risk-factors\/index.html."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1164\/rccm.202101-0136OC","article-title":"Indoor Air Pollution and Susceptibility to Tuberculosis Infection in Urban Vietnamese Children","volume":"204","author":"Blount","year":"2021","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2302852","DOI":"10.1080\/22221751.2024.2302852","article-title":"Impact of fine particulate matter on latent tuberculosis infection and active tuberculosis in older adults: A population-based multicentre cohort study","volume":"13","author":"Guo","year":"2024","journal-title":"Emerg. Microbes Infect."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"467","DOI":"10.7326\/M18-0850","article-title":"PRISMA extension for scoping reviews (PRISMA-ScR): Checklist and explanation","volume":"169","author":"Tricco","year":"2018","journal-title":"Ann. Intern. Med."},{"key":"ref_16","unstructured":"(2025, June 13). Stop TB Partnership. Words Matter: Suggested Language and Usage for Tuberculosis Communications. Available online: https:\/\/www.stoptb.org\/words-matter-language-guide."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.puhe.2022.10.003","article-title":"Prevalence and risk factors of latent tuberculosis infection among college students: A systematic review and meta-analysis","volume":"213","author":"Yuan","year":"2022","journal-title":"Public Health"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e17","DOI":"10.35371\/aoem.2021.33.e17","article-title":"Tuberculosis infection status and risk factors among health workers: An updated systematic review","volume":"33","author":"Lee","year":"2021","journal-title":"Ann. Occup. Environ. Med."},{"key":"ref_19","first-page":"457","article-title":"A systematic review on the prevalence and incidence of latent tuberculosis infection among prison population","volume":"91","author":"Kawatsu","year":"2016","journal-title":"Kekkaku"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"taaa214","DOI":"10.1093\/jtm\/taaa214","article-title":"Risk of latent and active tuberculosis infection in travellers: A systematic review and meta-analysis","volume":"28","author":"Alabdulkarim","year":"2021","journal-title":"J. Travel Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1111\/j.1708-8305.2010.00424.x","article-title":"Systematic review and meta-analysis of TST conversion risk in deployed military and long-term civilian travelers","volume":"17","author":"Freeman","year":"2010","journal-title":"J. Travel Med."},{"key":"ref_22","first-page":"292","article-title":"Prevalence of latent tuberculosis infection (LTBI) in healthcare workers in Latin America and the Caribbean: Systematic review and meta-analysis","volume":"32","year":"2024","journal-title":"Infez. Med."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Patra, J., Bhatia, M., Suraweera, W., Morris, S.K., Patra, C., Gupta, P.C., and Jha, P. (2015). Exposure to second-hand smoke and the risk of tuberculosis in children and adults: A systematic review and meta-analysis of 18 observational studies. PLoS Med., 12.","DOI":"10.1371\/journal.pmed.1001835"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Zhou, G., Guo, X., Cai, S., Zhang, Y., Zhou, Y., Long, R., Zhou, Y., Li, H., Chen, N., and Song, C. (2023). Diabetes mellitus and latent tuberculosis infection: An updated meta-analysis and systematic review. BMC Infect. Dis., 23.","DOI":"10.1186\/s12879-023-08775-y"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"596","DOI":"10.1016\/j.ajic.2015.11.022","article-title":"Risk factors for nosocomial tuberculosis transmission among health care workers","volume":"44","author":"Ito","year":"2016","journal-title":"Am. J. Infect. Control"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.jclinepi.2011.12.010","article-title":"Risk factors for tuberculosis among health care workers in South India: A nested case-control study","volume":"66","author":"Mathew","year":"2013","journal-title":"J. Clin. Epidemiol."},{"key":"ref_27","unstructured":"World Health Organization (2025, June 23). WHO Policy on TB Infection Control in Health Facilities, Congregate Settings and Households, Available online: https:\/\/www.who.int\/publications\/i\/item\/9789241598323."},{"key":"ref_28","unstructured":"World Health Organization (2025, June 23). WHO Guidelines on Tuberculosis Infection Prevention and Control, 2019 Update, Available online: https:\/\/iris.who.int\/handle\/10665\/311259."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1053\/j.seminhematol.2023.08.005","article-title":"The case for prioritizing malignant hematology services in low- and middle-income countries","volume":"60","author":"Gopal","year":"2023","journal-title":"Semin. Hematol."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Morales, F., Montserrat-de la Paz, S., Leon, M.J., and Rivero-Pino, F. (2023). Effects of Malnutrition on the Immune System and Infection and the Role of Nutritional Strategies Regarding Improvements in Children\u2019s Health Status: A Literature Review. Nutrients, 16.","DOI":"10.3390\/nu16010001"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Cao, Y., Wang, X., Liu, P., Su, Y., Yu, H., and Du, J. (2022). Vitamin D and the risk of latent tuberculosis infection: A systematic review and meta-analysis. BMC Pulm. Med., 22.","DOI":"10.1186\/s12890-022-01830-5"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"613","DOI":"10.5588\/ijtld.13.0765","article-title":"Indoor air pollution from solid fuel and tuberculosis: A systematic review and meta-analysis","volume":"18","author":"Lin","year":"2014","journal-title":"Int. J. Tuberc. Lung Dis."}],"container-title":["Tropical Medicine and Infectious Disease"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2414-6366\/11\/4\/87\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T14:36:51Z","timestamp":1774449411000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2414-6366\/11\/4\/87"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,24]]},"references-count":32,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["tropicalmed11040087"],"URL":"https:\/\/doi.org\/10.3390\/tropicalmed11040087","relation":{},"ISSN":["2414-6366"],"issn-type":[{"value":"2414-6366","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,24]]}}}