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Berrocal-Almanza LC, Harris RJ, Collin SM, Muzyamba MC, Conroy OD, Mirza A, O'Connell AM, Altass L, Anderson SR, Thomas HL, Campbell C, Zenner D, Phin N, Kon OM, Smith EG, Lalvani A. Effectiveness of nationwide programmatic testing and treatment for latent tuberculosis infection in migrants in England: a retrospective, population-based cohort study. THE LANCET PUBLIC HEALTH 2022; 7:e305-e315. [PMID: 35338849 PMCID: PMC8967722 DOI: 10.1016/s2468-2667(22)00031-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/14/2022] [Accepted: 01/26/2022] [Indexed: 12/11/2022] Open
Abstract
Background In low-incidence countries, tuberculosis mainly affects migrants, mostly resulting from reactivation of latent tuberculosis infection (LTBI) acquired in high-incidence countries before migration. A nationwide primary care-based LTBI testing and treatment programme for migrants from high-incidence countries was therefore established in high tuberculosis incidence areas in England. We aimed to assess the effectiveness of this programme. Methods We did a retrospective, population-based cohort study of migrants who registered in primary care between Jan 1, 2011, and Dec 31, 2018, in 55 high-burden areas with programmatic LTBI testing and treatment. Eligible individuals were aged 16–35 years, born in a high-incidence country, and had entered England in the past 5 years. Individuals who tested interferon-γ release assay (IGRA)-negative were advised about symptoms of tuberculosis, whereas those who tested IGRA-positive were clinically assessed to rule out active tuberculosis and offered preventive therapy. The primary outcome was incident tuberculosis notified to the national Enhanced Tuberculosis Surveillance system. Findings Our cohort comprised 368 097 eligible individuals who had registered in primary care, of whom 37 268 (10·1%) were tested by the programme. 1446 incident cases of tuberculosis were identified: 166 cases in individuals who had IGRA testing (incidence 204 cases [95% CI 176–238] per 100 000 person-years) and 1280 in individuals without IGRA testing (82 cases [77–86] per 100 000 person-years). Overall, in our primary analysis including all diagnosed tuberculosis cases, a time-varying association was identified between LTBI testing and treatment and lower risk of incident tuberculosis (hazard ratio [HR] 0·76 [95% CI 0·63–0·91]) when compared with no testing. In stratified analysis by follow-up period, the intervention was associated with higher risk of tuberculosis diagnosis during the first 6 months of follow-up (9·93 [7·63–12·9) and a lower risk after 6 months (0·57 [0·41–0·79]). IGRA-positive individuals had higher risk of tuberculosis diagnosis than IGRA-negative individuals (31·9 [20·4–49·8]). Of 37 268 migrants who were tested, 6640 (17·8%) were IGRA-positive, of whom 1740 (26·2%) started preventive treatment. LTBI treatment lowered the risk of tuberculosis: of 135 incident cases in the IGRA-positive cohort, seven cases were diagnosed in the treated group (1·87 cases [95% CI 0·89–3·93] per 1000 person-years) and 128 cases were diagnosed in the untreated group (10·9 cases [9·16–12·9] per 1000 person-years; HR 0·14 [95% CI 0·06–0·32]). Interpretation A low proportion of eligible migrants were tested by the programme and a small proportion of those testing positive started treatment. Despite this, programmatic LTBI testing and treatment of individuals migrating to a low-incidence region is effective at diagnosing active tuberculosis earlier and lowers the long-term risk of progression to tuberculosis. Increasing programme participation and treatment rates for those testing positive could substantially impact national tuberculosis incidence. Funding National Institute for Health Research Health Protection Research Unit in Respiratory Infections.
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Ordaz-Vázquez A, Torres-González P, Cruz-Hervert P, Ferreyra-Reyes L, Delgado-Sánchez G, García-García L, Kato-Maeda M, Ponce-De-León A, Sifuentes-Osornio J, Bobadilla-Del-Valle M. Genetic diversity and primary drug resistance transmission in Mycobacterium tuberculosis in southern Mexico. INFECTION GENETICS AND EVOLUTION 2021; 93:104994. [PMID: 34245908 DOI: 10.1016/j.meegid.2021.104994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/28/2021] [Accepted: 07/04/2021] [Indexed: 11/30/2022]
Abstract
Tuberculosis is a global human health threat, especially in developing countries. The present study aimed to describe the genetic diversity of Mycobacterium tuberculosis and to measure the transmission rates of primary and acquired resistance. A total of 755 M. tuberculosis isolates from a cohort study of patients with culture-confirmed pulmonary tuberculosis in Orizaba, Veracruz, performed between 1995 and 2010 were genotyped by the 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) method. Drug susceptibility was determined. Logistic regression models were constructed to identify the variables associated with resistance and clusters. The recent transmission index (RTI), the Hunter-Gaston discrimination index (HGDI) for the MIRU-VNTR test and allelic diversity (h) were calculated. The Haarlem and LAM lineages were the most common in the population. A total of 519 isolates were grouped into 128 clusters. The overall drug resistance rate was 19%, isoniazid monoresistance (10%) was the most common, and 3.4% of the isolates were multidrug resistant. Among the 116 isolates resistant to at least one drug, the primary and acquired resistance rates were 81.9% and 18.1%, respectively. Primary resistance was associated with belonging to a cluster (aOR 4.05, 95% CI 1.5-11.2, p = 0.007). Previous treatment history (aOR 9.05, 95% CI 3.6-22.5, p < 0.001) and LAM lineage (aOR 4.25, 95% CI 1.4-12.7, p = 0.010) were associated with multidrug-resistant tuberculosis (MDR-TB). The RTI was 51.7%, and the 24-locus MIRU-VNTR HGDI was 0.98. The alleles with the greatest diversity were 4056-QUB26 (h = 0.84), 2163b-QUB11b (h = 0.79), and 424-Mtub04 (h = 0.72). Primary resistance transmission, high LAM lineage prevalence and its association with MDR-TB represent public health problems. The implementation of molecular tools is needed to improve the existing control surveillance tuberculosis program.
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Affiliation(s)
- Anabel Ordaz-Vázquez
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Mexico
| | - Pedro Torres-González
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Mexico
| | - Pablo Cruz-Hervert
- Departamento de Salud Pública y Epidemiología Oral, Facultad de Odontología, Universidad Nacional Autonoma de Mexico, Ciudad de México, Mexico
| | - Leticia Ferreyra-Reyes
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | - Guadalupe Delgado-Sánchez
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | - Lourdes García-García
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | - Midori Kato-Maeda
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Alfredo Ponce-De-León
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Mexico
| | - José Sifuentes-Osornio
- Departamento de Medicina, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Mexico
| | - Miriam Bobadilla-Del-Valle
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Mexico.
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Winter JR, Smith CJ, Davidson JA, Lalor MK, Delpech V, Abubakar I, Stagg HR. The impact of HIV infection on tuberculosis transmission in a country with low tuberculosis incidence: a national retrospective study using molecular epidemiology. BMC Med 2020; 18:385. [PMID: 33308204 PMCID: PMC7734856 DOI: 10.1186/s12916-020-01849-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/10/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV is known to increase the likelihood of reactivation of latent tuberculosis to active TB disease; however, its impact on tuberculosis infectiousness and consequent transmission is unclear, particularly in low-incidence settings. METHODS National surveillance data from England, Wales and Northern Ireland on tuberculosis cases in adults from 2010 to 2014, strain typed using 24-locus mycobacterial-interspersed-repetitive-units-variable-number-tandem-repeats was used retrospectively to identify clusters of tuberculosis cases, subdivided into 'first' and 'subsequent' cases. Firstly, we used zero-inflated Poisson regression models to examine the association between HIV status and the number of subsequent clustered cases (a surrogate for tuberculosis infectiousness) in a strain type cluster. Secondly, we used logistic regression to examine the association between HIV status and the likelihood of being a subsequent case in a cluster (a surrogate for recent acquisition of tuberculosis infection) compared to the first case or a non-clustered case (a surrogate for reactivation of latent infection). RESULTS We included 18,864 strain-typed cases, 2238 were the first cases of clusters and 8471 were subsequent cases. Seven hundred and fifty-nine (4%) were HIV-positive. Outcome 1: HIV-positive pulmonary tuberculosis cases who were the first in a cluster had fewer subsequent cases associated with them (mean 0.6, multivariable incidence rate ratio [IRR] 0.75 [0.65-0.86]) than those HIV-negative (mean 1.1). Extra-pulmonary tuberculosis (EPTB) cases with HIV were less likely to be the first case in a cluster compared to HIV-negative EPTB cases. EPTB cases who were the first case had a higher mean number of subsequent cases (mean 2.5, IRR (3.62 [3.12-4.19]) than those HIV-negative (mean 0.6). Outcome 2: tuberculosis cases with HIV co-infection were less likely to be a subsequent case in a cluster (odds ratio 0.82 [0.69-0.98]), compared to being the first or a non-clustered case. CONCLUSIONS Outcome 1: pulmonary tuberculosis-HIV patients were less infectious than those without HIV. EPTB patients with HIV who were the first case in a cluster had a higher number of subsequent cases and thus may be markers of other undetected cases, discoverable by contact investigations. Outcome 2: tuberculosis in HIV-positive individuals was more likely due to reactivation than recent infection, compared to those who were HIV-negative.
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Affiliation(s)
- Joanne R Winter
- Institute for Global Health, University College London, London, UK
| | - Colette J Smith
- Institute for Global Health, University College London, London, UK
| | - Jennifer A Davidson
- Tuberculosis Unit, National Infection Service, Public Health England, London, UK
| | - Maeve K Lalor
- Tuberculosis Unit, National Infection Service, Public Health England, London, UK
| | - Valerie Delpech
- HIV Unit, National Infection Service, Public Health England, London, UK
| | - Ibrahim Abubakar
- Institute for Global Health, University College London, London, UK.
| | - Helen R Stagg
- Institute for Global Health, University College London, London, UK.,Usher Institute, University of Edinburgh, Edinburgh, UK
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Brooks-Pollock E, Danon L, Korthals Altes H, Davidson JA, Pollock AMT, van Soolingen D, Campbell C, Lalor MK. A model of tuberculosis clustering in low incidence countries reveals more transmission in the United Kingdom than the Netherlands between 2010 and 2015. PLoS Comput Biol 2020; 16:e1007687. [PMID: 32218567 PMCID: PMC7141699 DOI: 10.1371/journal.pcbi.1007687] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 04/08/2020] [Accepted: 01/16/2020] [Indexed: 11/18/2022] Open
Abstract
Tuberculosis (TB) remains a public health threat in low TB incidence countries, through a combination of reactivated disease and onward transmission. Using surveillance data from the United Kingdom (UK) and the Netherlands (NL), we demonstrate a simple and predictable relationship between the probability of observing a cluster and its size (the number of cases with a single genotype). We demonstrate that the full range of observed cluster sizes can be described using a modified branching process model with the individual reproduction number following a Poisson lognormal distribution. We estimate that, on average, between 2010 and 2015, a TB case generated 0.41 (95% CrI 0.30,0.60) secondary cases in the UK, and 0.24 (0.14,0.48) secondary cases in the NL. A majority of cases did not generate any secondary cases. Recent transmission accounted for 39% (26%,60%) of UK cases and 23%(13%,37%) of NL cases. We predict that reducing UK transmission rates to those observed in the NL would result in 538(266,818) fewer cases annually in the UK. In conclusion, while TB in low incidence countries is strongly associated with reactivated infections, we demonstrate that recent transmission remains sufficient to warrant policies aimed at limiting local TB spread.
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Affiliation(s)
- Ellen Brooks-Pollock
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- Bristol Veterinary School, University of Bristol, Bristol, United Kingdom
- * E-mail:
| | - Leon Danon
- College of Engineering and Mathematical Sciences, University of Exeter, Exeter, United Kingdom
- The Alan Turing Institute, London, United Kingdom
| | - Hester Korthals Altes
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | | | | | - Dick van Soolingen
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
- Departments of Clinical Microbiology and Pulmonary Diseases, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Colin Campbell
- TB Section, Public Health England, London, United Kingdom
| | - Maeve K. Lalor
- TB Section, Public Health England, London, United Kingdom
- Institute for Global Health, University College London, London, United Kingdom
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Skuce R, Breadon E, Allen A, Milne G, McCormick C, Hughes C, Rutherford D, Smith G, Thompson S, Graham J, Harwood R, Byrne A. Longitudinal dynamics of herd-level Mycobacterium bovis MLVA type surveillance in cattle in Northern Ireland 2003-2016. INFECTION GENETICS AND EVOLUTION 2019; 79:104131. [PMID: 31786341 DOI: 10.1016/j.meegid.2019.104131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/28/2019] [Accepted: 11/27/2019] [Indexed: 02/02/2023]
Abstract
Investigating genetically-structured diversity in pathogen populations over time is important to better understand disease maintenance and spread. Herd-level surveillance of Mycobacterium bovis genotypes (multi-locus VNTR analysis types, MLVA types) from all culture-confirmed bovine tuberculosis (TB) herd cases was undertaken in Northern Ireland (NI), generating an unparalleled, longitudinal, population-level 14-year survey for this pathogen. Across this population, 295 genetically-distinct M. bovis MLVA types were identified in the 19,717 M. bovis isolates surveyed. Of these, the most frequent was MLVA type 002 (23.0%); 151 MLVA types were represented more than once, in groups ranging from 2 to 4438 isolates. Only 23 MLVA types were isolated in all 14 years. Investigating inter-annual frequency of M. bovis MLVA types, examples of statistically-significant expansions (MLVA types 002, 004, 006, 009 and 027), contractions (MLVA types 001, 007 and 011) and maintenance (MLVA types 003 and 005) were disclosed, during a period of fluctuating bovine TB herd-level incidence at the NI scale. The fixed period frequency distribution of MLVA types remained highly right-skewed. Novel VNTR copy number variant MLVA types (N = 242; an average of 17 per annum) were identified throughout the survey. The MLVA type distribution in the landscape was not random; MLVA types showed statistically-significant geographical localization and strong spatial associations with Divisional Veterinary Office (DVO) regions. There was also evidence of differential risk of particular MLVA types across breeds (Holstein/Friesian vs. other), age-class, and sex and some evidence of an association between the number of animals testing positive for bovine TB during the disclosing test and particular MLVA types, although there was substantial variation.
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Affiliation(s)
- R Skuce
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK; School of Biological Sciences, Queen's University Belfast, Belfast BT7 1NN, UK.
| | - E Breadon
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - A Allen
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - G Milne
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - C McCormick
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK; Veterinary Service and Animal Health Group, Department of Agriculture, Environment and Rural Affairs, Dundonald House, Stormont, Belfast BT4 3SB, UK
| | - C Hughes
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - D Rutherford
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK; Faculty of Electrical Engineering, Czech Technical University, Prague, Czech Republic (⁎)current address
| | - G Smith
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - S Thompson
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - J Graham
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK
| | - R Harwood
- Veterinary Service and Animal Health Group, Department of Agriculture, Environment and Rural Affairs, Dundonald House, Stormont, Belfast BT4 3SB, UK
| | - A Byrne
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), Stoney Road, Stormont, Belfast BT4 3SD, UK; School of Biological Sciences, Queen's University Belfast, Belfast BT7 1NN, UK; One-Health Unit, Surveillance, Animal By-Products and TSEs (SAT), Division Department of Agriculture, Food and Marine (DAFM), Agriculture House, Dublin 2, Ireland
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McIntosh AI, Jenkins HE, Horsburgh CR, Jones-López EC, Whalen CC, Gaeddert M, Marques-Rodrigues P, Ellner JJ, Dietze R, White LF. Partitioning the risk of tuberculosis transmission in household contact studies. PLoS One 2019; 14:e0223966. [PMID: 31639145 PMCID: PMC6804987 DOI: 10.1371/journal.pone.0223966] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/02/2019] [Indexed: 01/25/2023] Open
Abstract
Household contact studies of tuberculosis (TB) are a common way to study disease transmission dynamics. However these studies lack a mechanism for accounting for community transmission, which is known to be significant, particularly in high burden settings. We illustrate a statistical approach for estimating both the correlates with transmission of TB in a household setting and the probability of community transmission using a modified Bayesian mixed-effects model. This is applied to two household contact studies in Vitória, Brazil from 2008-2013 and Kampala, Uganda from 1995-2004 that enrolled households with an individual that was recently diagnosed with pulmonary TB. We estimate the probability of community transmission to be higher in Uganda (ranging from 0.21 to 0.69, depending on HHC age and HIV status of the index case) than in Brazil (ranging from 0.13 for young children to 0.50 in adults). These estimates are consistent with a higher overall burden of disease in Uganda compared to Brazil. Our method also estimates an increasing risk of community-acquired TB with age of the household contact, consistent with existing literature. This approach is a useful way to integrate the role of the community in understanding TB disease transmission dynamics in household contact studies.
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Affiliation(s)
- Avery I. McIntosh
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Helen E. Jenkins
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - C. Robert Horsburgh
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
- Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Edward C. Jones-López
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Christopher C. Whalen
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States of America
| | - Mary Gaeddert
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
| | | | - Jerrold J. Ellner
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
| | | | - Laura F. White
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
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The Changing Landscape of Childhood Tuberculosis in the United Kingdom: A Retrospective Cohort (2000-2015). Pediatr Infect Dis J 2019; 38:470-475. [PMID: 30256311 DOI: 10.1097/inf.0000000000002200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The epidemiology of tuberculosis (TB) is changing in the United Kingdom and globally. Childhood TB is a key indicator of recent transmission and provides a marker of wider TB control. We describe the recent epidemiology of childhood TB in the United Kingdom, how this compares to TB in adults, and document changes with time. METHODS TB cases notified in the United Kingdom between 2000 and 2015 were categorized as children (<15 years of age) or adults (≥15 years of age). Descriptive analyses were carried out on demographic, clinical and microbiologic data. We carried out logistic regressions to identify risk factors associated with children having no microbiologic confirmation. RESULTS In the study period, 6293 TB cases (5%) in the United Kingdom were notified in children. Childhood TB incidence declined from 487 cases in 2000 (3.4 per 100,000) to 232 cases (2.0 per 100,000) in 2015. The majority (68%) of children with TB were UK born, with a high proportion of Pakistani (24%) and Black-African (22%) ethnicity. Sixty-four percent of children had pulmonary disease. Culture confirmation was low (24%). Children who were younger, UK born and those with extrapulmonary disease were less likely to have microbiologically confirmed TB. A high proportion (87%) of children completed treatment at last-recorded outcome, with few deaths (39 cases; 0.7%). CONCLUSIONS The incidence of TB in children in the United Kingdom has decreased in the past 16 years, with the majority of children completing TB treatment. Ongoing monitoring of childhood TB will provide a measure of the effectiveness of the national TB program.
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