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Coussens AK, Zaidi SMA, Allwood BW, Dewan PK, Gray G, Kohli M, Kredo T, Marais BJ, Marks GB, Martinez L, Ruhwald M, Scriba TJ, Seddon JA, Tisile P, Warner DF, Wilkinson RJ, Esmail H, Houben RMGJ. Classification of early tuberculosis states to guide research for improved care and prevention: an international Delphi consensus exercise. THE LANCET. RESPIRATORY MEDICINE 2024; 12:484-498. [PMID: 38527485 PMCID: PMC7616323 DOI: 10.1016/s2213-2600(24)00028-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 03/27/2024]
Abstract
The current active-latent paradigm of tuberculosis largely neglects the documented spectrum of disease. Inconsistency with regard to definitions, terminology, and diagnostic criteria for different tuberculosis states has limited the progress in research and product development that are needed to achieve tuberculosis elimination. We aimed to develop a new framework of classification for tuberculosis that accommodates key disease states but is sufficiently simple to support pragmatic research and implementation. Through an international Delphi exercise that involved 71 participants representing a wide range of disciplines, sectors, income settings, and geographies, consensus was reached on a set of conceptual states, related terminology, and research gaps. The International Consensus for Early TB (ICE-TB) framework distinguishes disease from infection by the presence of macroscopic pathology and defines two subclinical and two clinical tuberculosis states on the basis of reported symptoms or signs of tuberculosis, further differentiated by likely infectiousness. The presence of viable Mycobacterium tuberculosis and an associated host response are prerequisites for all states of infection and disease. Our framework provides a clear direction for tuberculosis research, which will, in time, improve tuberculosis clinical care and elimination policies.
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Affiliation(s)
- Anna K Coussens
- Infectious Diseases and Immune Defence Division, The Walter and Eliza Hall Institute of Medical Research (WEHI), Parkville, VIC, Australia; Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, and Department of Pathology, University of Cape Town, Cape Town, South Africa; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Syed M A Zaidi
- WHO Collaborating Centre on Tuberculosis Research and Innovation, Institute for Global Health, and MRC Clinical Trials Unit, University College London, London, UK; Department of Public Health, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Brian W Allwood
- Division of Pulmonology, Department of Medicine, Stellenbosch University, Stellenbosch, South Africa
| | - Puneet K Dewan
- Tuberculosis and HIV, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Glenda Gray
- Health Systems Research Unit, South Africa Medical Research Council, Cape Town, South Africa
| | | | - Tamara Kredo
- Health Systems Research Unit, South Africa Medical Research Council, Cape Town, South Africa
| | - Ben J Marais
- Sydney Infectious Diseases Institute, University of Sydney, Sydney, NSW, Australia; WHO Collaborating Centre in Tuberculosis, University of Sydney, Sydney, NSW, Australia
| | - Guy B Marks
- Department of Clinical Medicine, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Leo Martinez
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | | | - Thomas J Scriba
- Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa; South African Tuberculosis Vaccine Initiative, University of Cape Town, Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, and Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - James A Seddon
- Department of Infectious Disease, Imperial College London, London, UK; Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | | | - Digby F Warner
- Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, and Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Robert J Wilkinson
- Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa; Department of Infectious Disease, Imperial College London, London, UK; The Francis Crick Institute, London, UK
| | - Hanif Esmail
- Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa; WHO Collaborating Centre on Tuberculosis Research and Innovation, Institute for Global Health, and MRC Clinical Trials Unit, University College London, London, UK.
| | - Rein M G J Houben
- TB Modelling Group, TB Centre, and Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
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2
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Kiwanuka N, Zalwango S, Kakaire R, Castellanos ME, Quach THT, Whalen CC. M. tuberculosis Infection Attributable to Exposure in Social Networks of Tuberculosis Cases in an Urban African Community. Open Forum Infect Dis 2024; 11:ofae200. [PMID: 38737427 PMCID: PMC11083641 DOI: 10.1093/ofid/ofae200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 04/11/2024] [Indexed: 05/14/2024] Open
Abstract
Background The persistence of tuberculosis today and its global disparity send a powerful message that effective tuberculosis control must respond to its regional epidemiology. Active case finding through contact investigation is a standard protocol used for tuberculosis control, but its effectiveness has not been established, especially in endemic areas. Methods To quantify the potential effectiveness of contact investigation in Kampala, Uganda, we used a cross-sectional design to evaluate the social networks of 123 tuberculosis index cases and 124 controls without tuberculosis. Results Tuberculous infection was present in 515 of 989 tuberculosis case contacts (52.1%) and 396 of 1026 control contacts (38.6%; adjusted prevalence ratio, 1.4; 95% CI, 1.3-1.6). The proportion of infected participants with known exposure within the social network of the tuberculosis case was 35%. The population-attributable fraction was 11.1% for any known exposure, with 7.3% attributable to household exposure and 3.4% attributable to extrahousehold exposure. Conclusions This low population-attributable fraction indicates that contact tracing in the social networks of index cases will have only a modest effect in reducing tuberculous infection in a community. New approaches to community-level active case finding are needed.
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Affiliation(s)
- Noah Kiwanuka
- Department of Epidemiology and Biostatistics, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Sarah Zalwango
- Department of Public Health and Environment, Kampala Capital City Authority, Kampala, Uganda
| | - Robert Kakaire
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, USA
| | - Maria Eugenia Castellanos
- Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia
| | - Trang Ho Thu Quach
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, USA
| | - Christopher C Whalen
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, USA
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3
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Banholzer N, Schmutz R, Middelkoop K, Hella J, Egger M, Wood R, Fenner L. Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002800. [PMID: 38236801 PMCID: PMC10796007 DOI: 10.1371/journal.pgph.0002800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/18/2023] [Indexed: 01/22/2024]
Abstract
The COVID-19 pandemic renewed interest in airborne transmission of respiratory infections, particularly in congregate indoor settings, such as schools. We modeled transmission risks of tuberculosis (caused by Mycobacterium tuberculosis, Mtb) and COVID-19 (caused by SARS-CoV-2) in South African, Swiss and Tanzanian secondary schools. We estimated the risks of infection with the Wells-Riley equation, expressed as the median with 2.5% and 97.5% quantiles (credible interval [CrI]), based on the ventilation rate and the duration of exposure to infectious doses (so-called quanta). We computed the air change rate (ventilation) using carbon dioxide (CO2) as a tracer gas and modeled the quanta generation rate based on reported estimates from the literature. The share of infectious students in the classroom is determined by country-specific estimates of pulmonary TB. For SARS-CoV-2, the number of infectious students was estimated based on excess mortality to mitigate the bias from country-specific reporting and testing. Average CO2 concentration (parts per million [ppm]) was 1,610 ppm in South Africa, 1,757 ppm in Switzerland, and 648 ppm in Tanzania. The annual risk of infection for Mtb was 22.1% (interquartile range [IQR] 2.7%-89.5%) in South Africa, 0.7% (IQR 0.1%-6.4%) in Switzerland, and 0.5% (IQR 0.0%-3.9%) in Tanzania. For SARS-CoV-2, the monthly risk of infection was 6.8% (IQR 0.8%-43.8%) in South Africa, 1.2% (IQR 0.1%-8.8%) in Switzerland, and 0.9% (IQR 0.1%-6.6%) in Tanzania. The differences in transmission risks primarily reflect a higher incidence of SARS-CoV-2 and particularly prevalence of TB in South Africa, but also higher air change rates due to better natural ventilation of the classrooms in Tanzania. Global comparisons of the modeled risk of infectious disease transmission in classrooms can provide high-level information for policy-making regarding appropriate infection control strategies.
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Affiliation(s)
- Nicolas Banholzer
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Remo Schmutz
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Keren Middelkoop
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Desmond Tutu Health Centre, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Jerry Hella
- Ifakara Health Institute, Dar-es-Salaam, Tanzania
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Centre for Infectious Disease Epidemiology & Research, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Desmond Tutu Health Centre, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
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4
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Bayly H, Mei W, Egeren D, Stoddard M, Chakravarty A, White LF. Accuracy of Inferences About the Reproductive Number and Superspreading Potential of SARS-CoV-2 with Incomplete Contact Tracing Data. RESEARCH SQUARE 2023:rs.3.rs-3760127. [PMID: 38234843 PMCID: PMC10793487 DOI: 10.21203/rs.3.rs-3760127/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
The basic reproductive number (R0) and superspreading potential ( k ) are key epidemiological parameters that inform our understanding of a disease's transmission. Often these values are estimated using the data obtained from contact tracing studies. Here we performed a simulation study to understand how incomplete data due to preferential contact tracing impacted the accuracy and inferences about the transmission of SARS-CoV-2. Our results indicate that as the number of positive contacts traced decreases, our estimates of R0 tend to decrease and our estimates of ktend to increase. Notably, when there are large amounts of positive contacts missed in the tracing process, we can conclude that there is no indication of superspreading even if we know there is. The results of this study highlight the need for a unified public health response to transmissible diseases.
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Affiliation(s)
| | - Winnie Mei
- University of Washington School of Public Health
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5
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Williams CM, Muhammad AK, Sambou B, Bojang A, Jobe A, Daffeh GK, Owolabi O, Pan D, Pareek M, Barer MR, Sutherland JS, Haldar P. Exhaled Mycobacterium tuberculosis Predicts Incident Infection in Household Contacts. Clin Infect Dis 2023; 76:e957-e964. [PMID: 36350995 PMCID: PMC9907542 DOI: 10.1093/cid/ciac455] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Halting transmission of Mycobacterium tuberculosis (Mtb) by identifying infectious individuals early is key to eradicating tuberculosis (TB). Here we evaluate face mask sampling as a tool for stratifying the infection risk of individuals with pulmonary TB (PTB) to their household contacts. METHODS Forty-six sputum-positive PTB patients in The Gambia (August 2016-November 2017) consented to mask sampling prior to commencing treatment. Incident Mtb infection was defined in 181 of their 217 household contacts as QuantiFERON conversion or an increase in interferon-γ of ≥1 IU/mL, 6 months after index diagnosis. Multilevel mixed-effects logistical regression analysis with cluster adjustment by household was used to identify predictors of incident infection. RESULTS Mtb was detected in 91% of PTB mask samples with high variation in IS6110 copies (5.3 × 102 to 1.2 × 107). A high mask Mtb level (≥20 000 IS6110 copies) was observed in 45% of cases and was independently associated with increased likelihood of incident Mtb infection in contacts (adjusted odds ratio, 3.20 [95% confidence interval, 1.26-8.12]; P = .01), compared with cases having low-positive/negative mask Mtb levels. Mask Mtb level was a better predictor of incident Mtb infection than sputum bacillary load, chest radiographic characteristics, or sleeping proximity. CONCLUSIONS Mask sampling offers a sensitive and noninvasive tool to support the stratification of individuals who are most infectious in high-TB-burden settings. Our approach can provide better insight into community transmission in complex environments.
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Affiliation(s)
- Caroline M Williams
- Correspondence: C. Williams, Department of Respiratory Sciences, University of Leicester, University Road, Leicester LE1 9HN, UK ()
| | - Abdul K Muhammad
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Basil Sambou
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Adama Bojang
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Alhaji Jobe
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Georgetta K Daffeh
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Olumuyiwa Owolabi
- Vaccines and Immunology Theme, Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Daniel Pan
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| | - Manish Pareek
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
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Foster M, Hill PC, Setiabudiawan TP, Koeken VACM, Alisjahbana B, van Crevel R. BCG-induced protection against Mycobacterium tuberculosis infection: Evidence, mechanisms, and implications for next-generation vaccines. Immunol Rev 2021; 301:122-144. [PMID: 33709421 PMCID: PMC8252066 DOI: 10.1111/imr.12965] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 12/20/2022]
Abstract
The tuberculosis (TB) vaccine Bacillus Calmette-Guérin (BCG) was introduced 100 years ago, but as it provides insufficient protection against TB disease, especially in adults, new vaccines are being developed and evaluated. The discovery that BCG protects humans from becoming infected with Mycobacterium tuberculosis (Mtb) and not just from progressing to TB disease provides justification for considering Mtb infection as an endpoint in vaccine trials. Such trials would require fewer participants than those with disease as an endpoint. In this review, we first define Mtb infection and disease phenotypes that can be used for mechanistic studies and/or endpoints for vaccine trials. Secondly, we review the evidence for BCG-induced protection against Mtb infection from observational and BCG re-vaccination studies, and discuss limitations and variation of this protection. Thirdly, we review possible underlying mechanisms for BCG efficacy against Mtb infection, including alternative T cell responses, antibody-mediated protection, and innate immune mechanisms, with a specific focus on BCG-induced trained immunity, which involves epigenetic and metabolic reprogramming of innate immune cells. Finally, we discuss the implications for further studies of BCG efficacy against Mtb infection, including for mechanistic research, and their relevance to the design and evaluation of new TB vaccines.
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Affiliation(s)
- Mitchell Foster
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
| | - Philip C. Hill
- Centre for International HealthUniversity of OtagoDunedinNew Zealand
| | - Todia Pediatama Setiabudiawan
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI)Radboud University Medical CenterNijmegenThe Netherlands
| | - Valerie A. C. M. Koeken
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI)Radboud University Medical CenterNijmegenThe Netherlands
- Department of Computational Biology for Individualised Infection MedicineCentre for Individualised Infection Medicine (CiiM) & TWINCOREJoint Ventures between The Helmholtz‐Centre for Infection Research (HZI) and The Hannover Medical School (MHH)HannoverGermany
| | - Bachti Alisjahbana
- Tuberculosis Working GroupFaculty of MedicineUniversitas PadjadjaranBandungIndonesia
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI)Radboud University Medical CenterNijmegenThe Netherlands
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7
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Verrall AJ, Alisjahbana B, Apriani L, Novianty N, Nurani AC, van Laarhoven A, Ussher JE, Indrati A, Ruslami R, Netea MG, Sharples K, van Crevel R, Hill PC. Early Clearance of Mycobacterium tuberculosis: The INFECT Case Contact Cohort Study in Indonesia. J Infect Dis 2021; 221:1351-1360. [PMID: 31298280 DOI: 10.1093/infdis/jiz168] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/10/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Early clearance of Mycobacterium tuberculosis is the eradication of infection before an adaptive immune response develops. We aimed to identify host factors associated with early clearance. METHODS Indonesian household contacts patients with smear-positive tuberculosis (TB) had an interferon-γ release assay (IGRA) at baseline and 14 weeks later. Early clearance was defined as a persistently negative IGRA. Contact characteristics, exposure, and disease phenotype were assessed for association with a positive IGRA at each time point. RESULTS Of 1347 contacts of 462 TB cases, 780 (57.9%) were IGRA positive and 490 (36.3%) were IGRA negative. After 14 weeks, 116 of 445 (26.1%) initially negative contacts were IGRA converters; 317 (71.2%) remained persistently negative. BCG vaccination reduced the risk of a positive baseline IGRA (relative risk [RR], 0.89 [95% confidence interval {CI} .83-.97]; P = .01), and strongly reduced the risk of IGRA conversion (RR, 0.56 [95% CI, .40-.77]; P < .001). BCG protection decreased with increasing exposure (P = .05) and increasing age (P = .004). Risk of IGRA conversion was positively associated with hemoglobin concentration (P = .04). CONCLUSIONS A quarter of household TB case contacts were early clearers. Protection against M. tuberculosis infection was strongly associated with BCG vaccination. Lower protection from BCG with increasing M. tuberculosis exposure and age can inform vaccine development.
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Affiliation(s)
- Ayesha J Verrall
- Department of Pathology and Molecular Medicine, University of Otago, Wellington, New Zealand
| | - Bachti Alisjahbana
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
- Department of Internal Medicine, Faculty of Medicine, Universitas Padajdaran, Hasan Sadikin Hospital, Bandung, Indonesia
| | - Lika Apriani
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
- Department of Public Health, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Novianty Novianty
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Andini C Nurani
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Arjan van Laarhoven
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - James E Ussher
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Agnes Indrati
- Department of Clinical Pathology, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Rovina Ruslami
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
- Division of Pharmacology and Therapy, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
- Human Genomics Laboratory, Craiova University of Medicine and Pharmacy, Romania
| | - Katrina Sharples
- Department of Mathematics and Statistics, Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Philip C Hill
- Centre for International Health, Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
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Verrall AJ, Schneider M, Alisjahbana B, Apriani L, van Laarhoven A, Koeken VACM, van Dorp S, Diadani E, Utama F, Hannaway RF, Indrati A, Netea MG, Sharples K, Hill PC, Ussher JE, van Crevel R. Early Clearance of Mycobacterium tuberculosis Is Associated With Increased Innate Immune Responses. J Infect Dis 2021; 221:1342-1350. [PMID: 30958547 DOI: 10.1093/infdis/jiz147] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 04/02/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND A proportion of tuberculosis (TB) case contacts do not become infected, even when heavily exposed. We studied the innate immune responses of TB case contacts to understand their role in protection against infection with Mycobacterium tuberculosis, termed "early clearance." METHODS Indonesian household contacts of TB cases were tested for interferon-γ release assay (IGRA) conversion between baseline and 14 weeks post recruitment. Blood cell populations and ex vivo innate whole blood cytokine responses were measured at baseline and, in a subgroup, flow cytometry was performed at weeks 2 and 14. Immunological characteristics were measured for early clearers, defined as a persistently negative IGRA at 3 months, and converters, whose IGRA converted from negative to positive. RESULTS Among 1347 case contacts, 317 were early clearers and 116 were converters. Flow cytometry showed a resolving innate cellular response from 2 to 14 weeks in persistently IGRA-negative contacts but not converters. There were no differences in cytokine responses to mycobacterial stimuli, but compared to converters, persistently IGRA-negative contacts produced more proinflammatory cytokines following heterologous stimulation with Escherichia coli and Streptococcus pneumoniae. CONCLUSIONS Early clearance of M. tuberculosis is associated with enhanced heterologous innate immune responses similar to those activated during induction of trained immunity.
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Affiliation(s)
- Ayesha J Verrall
- Department of Pathology and Molecular Medicine, University of Otago, Wellington, New Zealand
| | - Marion Schneider
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Bachti Alisjahbana
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Nijmegen, The Netherlands.,Department of Internal Medicine, Faculty of Medicine, Universitas Padajdaran, Hasan Sadikin Hospital, Nijmegen, The Netherlands
| | - Lika Apriani
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Nijmegen, The Netherlands.,Department of Public Health, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Arjan van Laarhoven
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Nijmegen, The Netherlands
| | - Valerie A C M Koeken
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Nijmegen, The Netherlands
| | - Suszanne van Dorp
- Department of Haematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Emira Diadani
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Nijmegen, The Netherlands
| | - Fitri Utama
- TB-HIV Research Center, Faculty of Medicine, Universitas Padjadjaran, Nijmegen, The Netherlands
| | - Rachel F Hannaway
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Agnes Indrati
- Department of Clinical Pathology, Faculty of Medicine, Universitas Padjadjaran, Hasan Sadikin Hospital, Bandung, Indonesia
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Nijmegen, The Netherlands.,Human Genomics Laboratory, Craiova University of Medicine and Pharmacy, Romania
| | - Katrina Sharples
- Department of Mathematics and Statistics, Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
| | - Philip C Hill
- Centre for International Health, Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
| | - James E Ussher
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Nijmegen, The Netherlands
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9
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Owolabi OA, Jallow AO, Jallow M, Sowe G, Jallow R, Genekah MD, Donkor S, Wurrie A, Kampmann B, Sutherland J, Togun T. Delay in the diagnosis of pulmonary tuberculosis in The Gambia, West Africa: A cross-sectional study. Int J Infect Dis 2020; 101:102-106. [PMID: 32949776 PMCID: PMC7493728 DOI: 10.1016/j.ijid.2020.09.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVES To investigate the pattern of tuberculosis (TB) care initiation and risk factors for TB diagnostic delay in The Gambia. METHODS In this cross-sectional study, adult patients diagnosed with pulmonary TB (pTB) in public facilities in the Greater Banjul Area of The Gambia were consecutively recruited from October 2016 to March 2017. Diagnostic delay was defined as >21 days from the onset of at least one symptom suggestive of pTB to diagnosis. Logistic regression analyses were used to investigate risk factors for diagnostic delay. RESULTS Overall, 216 pTB patients were included in the study; the median (Interquartile Range (IQR)) age was 30 (23-39) years and 167 (77%) were male patients. Of the 216 patients, 110 (50.9%) of them initiated care-seeking in the formal and informal private sector and 181/216 (83.8%) had TB diagnostic delay. The median (IQR) duration from the onset of symptoms to TB diagnosis was 34 (28-56) days. Age groups 18-29 years (aOR 3.2; 95% CI 1.2-8.8 [p = 0.02]) and 30-49 years (aOR 5.1; 95% CI 1.6-16.2 [p = 0.006]) and being employed (aOR 4.2; 95% CI 1.7-10.5 [p = 0.002]) were independent risk factors for TB diagnostic delay. CONCLUSION There is considerable TB diagnostic delay in The Gambia, and this is likely to be worsened by the COVID-19 pandemic.
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Affiliation(s)
- Olumuyiwa A Owolabi
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Alpha O Jallow
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Momodou Jallow
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Gambia Sowe
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Rohey Jallow
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Monica D Genekah
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Simon Donkor
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Alieu Wurrie
- The Gambia National Leprosy and Tuberculosis Control Programme (NLTBCP), Kanifing Municipal, Serrekunda, Gambia
| | - Beate Kampmann
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia; The Vaccine Centre, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, United Kingdom
| | - Jayne Sutherland
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia
| | - Toyin Togun
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine (MRCG at LSHTM), Atlantic Boulevard, Fajara, Gambia; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, United Kingdom.
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10
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Bashorun AO, Linda C, Omoleke S, Kendall L, Donkor SD, Kinteh MA, Danso B, Leigh L, Kandeh S, D'Alessandro U, Adetifa IMO. Knowledge, attitude and practice towards tuberculosis in Gambia: a nation-wide cross-sectional survey. BMC Public Health 2020; 20:1566. [PMID: 33069220 PMCID: PMC7568354 DOI: 10.1186/s12889-020-09685-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/13/2020] [Indexed: 11/30/2022] Open
Abstract
Background Early diagnosis and treatment of tuberculosis (TB) are the mainstay of global and national TB control efforts. However, the gap between expected and reported cases persists for various reasons attributable to the TB services and care-seeking sides of the TB care cascade. Understanding individual and collective perspectives of knowledge, attitudes, beliefs and other social circumstances around TB can inform an evidence-based approach in engaging communities and enhance their participation in TB case detection and treatment. Methods The study was conducted during the Gambian survey of TB prevalence. This was a nationwide cross-sectional multistage cluster survey with 43,100 participants aged ≥15 years in 80 clusters. The study sample, a random selection of 10% of the survey population within each cluster responded to a semi-structured questionnaire administered by trained fieldworkers to assess the knowledge, attitudes and practice of the participants towards TB. Overall knowledge, attitude and practice scores were dichotomised using the computed mean scores and analysed using descriptive, univariable and multivariable logistic regression. Results All targeted participants (4309) were interviewed. Majority were females 2553 (59.2%), married 2614 (60.7%), had some form of education 2457 (57%), and were unemployed 2368 (55%). Although 3617 (83.9%) of the participants had heard about TB, only 2883 (66.9%) were considered to have good knowledge of TB. Overall 3320 (77%) had unfavourable attitudes towards TB, including 1896 (44%) who indicated a preference for staying away from persons with TB rather than helping them. However, 3607(83.7%) appeared to have the appropriate health-seeking behaviours with regard to TB as 4157 (96.5%) of them were willing to go to the health facility if they had symptoms suggestive of TB. Conclusions About 3 in 10 Gambians had poor knowledge on TB, and significant stigma towards TB and persons with TB persists. Interventions to improve TB knowledge and address stigma are required as part of efforts to reduce the burden of undiagnosed TB in the country. Supplementary information Supplementary information accompanies this paper at 10.1186/s12889-020-09685-3.
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Affiliation(s)
- Adedapo Olufemi Bashorun
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia.
| | - Christopher Linda
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Semeeh Omoleke
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Lindsay Kendall
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Simon D Donkor
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Ma-Ansu Kinteh
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Baba Danso
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Lamin Leigh
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Sheriff Kandeh
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Umberto D'Alessandro
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Ifedayo Morayo O Adetifa
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia.,Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
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11
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Kakaire R, Kiwanuka N, Zalwango S, Sekandi JN, Quach THT, Castellanos ME, Quinn F, Whalen CC. Excess Risk of Tuberculous Infection among Extra-Household Contacts of Tuberculosis Cases in an African City. Clin Infect Dis 2020; 73:e3438-e3445. [PMID: 33064142 DOI: 10.1093/cid/ciaa1556] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Indexed: 01/14/2023] Open
Abstract
RATIONALE Although households of tuberculosis cases represent a setting for intense transmission of M. tuberculosis, household exposure accounts for less than 20% of transmission within a community. OBJECTIVES To estimate excess risk of M. tuberculosis infection among household and extra-household contacts of index cases. METHODS We performed a cross-sectional study in Kampala, Uganda, to delineate social networks of tuberculosis cases and matched controls without tuberculosis. We estimated the age-stratified prevalence difference of tuberculous infection between case and control networks, partitioned as household and extra-household contacts. RESULTS We enrolled 123 index cases, 124 index controls, and 2415 first-degree network contacts. The prevalence of infection was highest among household contacts of cases (61.5%), lowest among household contacts of controls (25.2%), and intermediary among extra-household tuberculosis contacts (44.9%) and extra-household control contacts (41.2%). The age-adjusted prevalence difference between extra-household contacts of cases and their controls was 5.4%. The prevalence of infection was similar among the majority of extra-household case contacts and corresponding controls (47%). CONCLUSIONS Most first-degree social network members of tuberculosis cases do not have adequate contact with the index case to experience additional risk for infection but appear instead to acquire infection through unrecognized exposures with infectious cases in the community.
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Affiliation(s)
- Robert Kakaire
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, United States.,Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States
| | - Noah Kiwanuka
- Department of Epidemiology and Biostatistics, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Juliet N Sekandi
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, United States.,Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States
| | - Trang Ho Thu Quach
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, United States.,Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States.,Faculty of Pharmacy, Ho Chi Minh City University of Technology (HUTECH), Vietnam
| | - Maria Eugenia Castellanos
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, United States.,Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States
| | - Frederick Quinn
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States
| | - Christopher C Whalen
- Global Health Institute, College of Public Health, University of Georgia, Athens, Georgia, United States.,Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, United States
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12
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Basu Roy R, Sambou B, Sissoko M, Holder B, Gomez MP, Egere U, Sillah AK, Koukounari A, Kampmann B. Protection against mycobacterial infection: A case-control study of mycobacterial immune responses in pairs of Gambian children with discordant infection status despite matched TB exposure. EBioMedicine 2020; 59:102891. [PMID: 32675024 PMCID: PMC7502674 DOI: 10.1016/j.ebiom.2020.102891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Children are particularly susceptible to tuberculosis. However, most children exposed to Mycobacterium tuberculosis are able to control the pathogen without evidence of infection. Correlates of human protective immunity against tuberculosis infection are lacking, and their identification would aid vaccine design. METHODS We recruited pairs of asymptomatic children with discordant tuberculin skin test status but the same sleeping proximity to the same adult with sputum smear-positive tuberculosis in a matched case-control study in The Gambia. Participants were classified as either Highly TB-Exposed Uninfected or Highly TB-Exposed Infected children. Serial luminescence measurements using an in vitro functional auto-luminescent Bacillus Calmette-Guérin (BCG) whole blood assay quantified the dynamics of host control of mycobacterial growth. Assay supernatants were analysed with a multiplex cytokine assay to measure associated inflammatory responses. FINDINGS 29 pairs of matched Highly TB-Exposed Uninfected and Highly TB-Exposed Infected children aged 5 to 15 years old were enroled. Samples from Highly TB-Exposed Uninfected children had higher levels of mycobacterial luminescence at 96 hours than Highly TB-Exposed Infected children. Highly TB-Exposed Uninfected children also produced less BCG-specific interferon-γ than Highly TB-Exposed Infected children at 24 hours and at 96 hours. INTERPRETATION Highly TB-Exposed Uninfected children showed less control of mycobacterial growth compared to Highly TB-Exposed Infected children in a functional assay, whilst cytokine responses mirrored infection status. FUNDING Clinical Research Training Fellowship funded under UK Medical Research Council/Department for International Development Concordat agreement and part of EDCTP2 programme supported by European Union (MR/K023446/1). Also MRC Program Grants (MR/K007602/1, MR/K011944/1, MC_UP_A900/1122).
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Affiliation(s)
- Robindra Basu Roy
- Department of Academic Paediatrics, Section of Paediatric Infectious Disease, Imperial College London, St. Mary's Hospital, Praed Street, London W2 1NY, United Kingdom; Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia; Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Basil Sambou
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Muhamed Sissoko
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Beth Holder
- Department of Academic Paediatrics, Section of Paediatric Infectious Disease, Imperial College London, St. Mary's Hospital, Praed Street, London W2 1NY, United Kingdom; Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion & Reproduction, Imperial College London, Du Cane Road, W12 0HS, United Kingdom
| | - Marie P Gomez
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Uzochukwu Egere
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia; Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place L3 5QA, United Kingdom
| | - Abdou K Sillah
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Artemis Koukounari
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Beate Kampmann
- Vaccines and Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia; Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; The Vaccine Centre, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
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13
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Tola HH, Khadoura KJ, Jimma W, Nedjat S, Majdzadeh R. Multidrug resistant tuberculosis treatment outcome in children in developing and developed countries: A systematic review and meta-analysis. Int J Infect Dis 2020; 96:12-18. [PMID: 32289559 DOI: 10.1016/j.ijid.2020.03.064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/16/2020] [Accepted: 03/25/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND We aimed to compare and contrast the proportions of treatment outcome between developing and developed countries in children treated for multidrug resistance tuberculosis (MDR-TB). METHODS We conducted a systematic review and meta-analysis of articles published on children treated for MDR-TB. We searched published articles from electronic databases: PubMed/Medline, EMBASE, Scopus and Web of Science for English articles without restricting publication year. We employed random-effects meta-analysis model to estimate the pooled proportions of treatment success, death, treatment failure and lost to follow up. RESULTS We pooled data of 1,343 children obtained from 17 included studies, and the overall pooled treatment success was 77.0% (95% Confidence Interval (CI), 69.0-85.0). Pooled treatment success in developing countries was 73.0% (63.0-83.0), while in developed countries 87.0% (81.0-94.0). The overall pooled treatment failure was 3.0% (1.0-6.0), while death 8.0% (4.0-11.0) and lost to follow up 10.0% (6.0-4). CONCLUSION MDR-TB treatment success in children is well achieved in both developed and developing countries by currently available drugs. Improving MDR-TB treatment programme is vital to achieve the maximum treatment successful. Promoting research on pediatric MDR-TB treatment outcome could also help to fill evidence gap.
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Affiliation(s)
- Habteyes Hailu Tola
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University Medical, Tehran, Iran; Tuberculosis/HIV Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
| | - Khalid Jamal Khadoura
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University Medical, Tehran, Iran; Departiment of Internal Medicine, Shifa Complex Hospital, Gaza, Palestine.
| | - Worku Jimma
- Department of Information Science, College of Natural Sciences, Jimma University, Jimma, Ethiopia.
| | - Saharnaz Nedjat
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University Medical, Tehran, Iran; Knowledge Utilization Research Center, Tehran University Medical Sciences, Tehran, Iran.
| | - Reza Majdzadeh
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University Medical, Tehran, Iran; Knowledge Utilization Research Center, Tehran University Medical Sciences, Tehran, Iran.
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14
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Basu Roy R, Whittaker E, Seddon JA, Kampmann B. Tuberculosis susceptibility and protection in children. THE LANCET. INFECTIOUS DISEASES 2019; 19:e96-e108. [PMID: 30322790 PMCID: PMC6464092 DOI: 10.1016/s1473-3099(18)30157-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 01/27/2018] [Accepted: 02/09/2018] [Indexed: 12/14/2022]
Abstract
Children represent both a clinically important population susceptible to tuberculosis and a key group in whom to study intrinsic and vaccine-induced mechanisms of protection. After exposure to Mycobacterium tuberculosis, children aged under 5 years are at high risk of progressing first to tuberculosis infection, then to tuberculosis disease and possibly disseminated forms of tuberculosis, with accompanying high risks of morbidity and mortality. Children aged 5-10 years are somewhat protected, until risk increases again in adolescence. Furthermore, neonatal BCG programmes show the clearest proven benefit of vaccination against tuberculosis. Case-control comparisons from key cohorts, which recruited more than 15 000 children and adolescents in total, have identified that the ratio of monocytes to lymphocytes, activated CD4 T cell count, and a blood RNA signature could be correlates of risk for developing tuberculosis. Further studies of protected and susceptible populations are necessary to guide development of novel tuberculosis vaccines that could facilitate the achievement of WHO's goal to eliminate deaths from tuberculosis in childhood.
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Affiliation(s)
- Robindra Basu Roy
- Centre for International Child Health, Department of Paediatrics, Imperial College London, London, UK; Vaccines and Immunity Theme MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Elizabeth Whittaker
- Centre for International Child Health, Department of Paediatrics, Imperial College London, London, UK
| | - James A Seddon
- Centre for International Child Health, Department of Paediatrics, Imperial College London, London, UK
| | - Beate Kampmann
- Centre for International Child Health, Department of Paediatrics, Imperial College London, London, UK; Vaccines and Immunity Theme MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia.
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15
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Stein CM, Zalwango S, Malone LL, Thiel B, Mupere E, Nsereko M, Okware B, Kisingo H, Lancioni CL, Bark CM, Whalen CC, Joloba ML, Boom WH, Mayanja-Kizza H. Resistance and Susceptibility to Mycobacterium tuberculosis Infection and Disease in Tuberculosis Households in Kampala, Uganda. Am J Epidemiol 2018; 187:1477-1489. [PMID: 29304247 DOI: 10.1093/aje/kwx380] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 12/15/2017] [Indexed: 11/14/2022] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major public health problem. Household contact studies identify children and adults along the spectrum from Mtb exposure to disease. In the Kawempe Community Health Study (conducted in Kampala, Uganda), 872 culture-confirmed pulmonary TB cases and their 2,585 contacts were enrolled during 2002-2012 and followed for up to 2 years each. Risk factors identified by time-to-event analysis for secondary TB differed among children, women, and men. Younger age (P = 0.0061), human immunodeficiency virus (HIV) (P = 0.0002), thinness (P = 0.01), absent bacille Calmette-Guérin vaccination (P = 0.002), and epidemiologic risk score (P < 0.0001) were risks for children. For women, risks were HIV (P < 0.0001), thinness (World Health Organization criteria; P < 0.0001), and epidemiologic risk score (P = 0.003). For men, HIV (P = 0.0007) and low body mass index (P = 0.008) resulted in faster progression to TB. Tuberculin skin testing (TST) identified contacts with Mtb infection and those with persistently negative TST. Risks for faster time to Mtb infection were identified, and included age (P = 0.0007), baseline TST induration (P < 0.0001), and epidemiologic risk score (P < 0.0001) only in children. Those with persistently negative TST comprised 10% of contacts but had no unique epidemiologic characteristics among adults. The burden of Mtb infection and disease is high in TB households, and risk factors for progression from exposure to infection and disease differ among children, women, and men.
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Affiliation(s)
- Catherine M Stein
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Center for Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | | | - LaShaunda L Malone
- Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Bonnie Thiel
- Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Ezekiel Mupere
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Departments of Pediatrics and Child Health, and Medicine, School of Medicine, Makerere University and Mulago Hospital, Kampala, Uganda
| | - Mary Nsereko
- Uganda-CWRU Research Collaboration, Kampala, Uganda
| | | | | | | | - Charles M Bark
- Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Christopher C Whalen
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia
| | - Moses L Joloba
- School for Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - W Henry Boom
- Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Harriet Mayanja-Kizza
- Departments of Pediatrics and Child Health, and Medicine, School of Medicine, Makerere University and Mulago Hospital, Kampala, Uganda
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16
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Garand M, Goodier M, Owolabi O, Donkor S, Kampmann B, Sutherland JS. Functional and Phenotypic Changes of Natural Killer Cells in Whole Blood during Mycobacterium tuberculosis Infection and Disease. Front Immunol 2018. [PMID: 29520269 PMCID: PMC5827559 DOI: 10.3389/fimmu.2018.00257] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Tuberculosis (TB) is still a global health concern, especially in resource-poor countries such as The Gambia. Defining protective immunity to TB is challenging: its pathogenesis is complex and involves several cellular components of the immune system. Recent works in vaccine development suggest important roles of the innate immunity in natural protection to TB, including natural killer (NK) cells. NK cells mediate cellular cytotoxicity and cytokine signaling in response to Mycobacterium tuberculosis (Mtb). NK cells can display specific memory-type markers to previous antigen exposure; thus, bridging innate and adaptive immunity. However, major knowledge gaps exist on the contribution of NK cells in protection against Mtb infection or TB. We performed a cross-sectional assessment of NK cells phenotype and function in four distinct groups of individuals: TB cases pre-treatment (n = 20) and post-treatment (n = 19), and household contacts with positive (n = 9) or negative (n = 18) tuberculin skin test (TST). While NK cells frequencies were similar between all groups, significant decreases in interferon-γ expression and degranulation were observed in NK cells from TB cases pre-treatment compared to post-treatment. Conversely, CD57 expression, a marker of advanced NK cells differentiation, was significantly lower in cases post-treatment compared to pre-treatment. Finally, NKG2C, an activation and imprinted-NK memory marker, was significantly increased in TST+ (latently infected) compared to TB cases pre-treatment and TST- (uninfected) individuals. The results of this study provide valuable insights into the role of NK cells in Mtb infection and TB disease, demonstrating potential markers for distinguishing between infection states and monitoring of TB treatment response.
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Affiliation(s)
- Mathieu Garand
- Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, Gambia
| | - Martin Goodier
- London School of Hygiene and Tropical Medicine, Bloomsbury, London, United Kingdom
| | - Olumuyiwa Owolabi
- Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, Gambia
| | - Simon Donkor
- Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, Gambia
| | - Beate Kampmann
- Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, Gambia
| | - Jayne S Sutherland
- Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, Gambia
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17
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Martinez L, Sekandi JN, Castellanos ME, Zalwango S, Whalen CC. Infectiousness of HIV-Seropositive Patients with Tuberculosis in a High-Burden African Setting. Am J Respir Crit Care Med 2016; 194:1152-1163. [PMID: 27181053 PMCID: PMC5114446 DOI: 10.1164/rccm.201511-2146oc] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/28/2016] [Indexed: 12/11/2022] Open
Abstract
RATIONALE Policy recommendations on contact investigation of HIV-seropositive patients with tuberculosis have changed several times. Current epidemiologic evidence informing these recommendations is considered low quality, and few large studies investigating the infectiousness of HIV-seropositive and -seronegative index cases have been performed in sub-Saharan Africa. OBJECTIVES We assessed the infectiousness of HIV-seropositive and -seronegative patients with tuberculosis to their household contacts and examined potential modifiers of this relationship. METHODS Adults suffering from their first episode of pulmonary tuberculosis were identified in Kampala, Uganda. Field workers visited index households and enrolled consenting household contacts. Latent tuberculosis infection was measured through tuberculin skin testing, and relative risks were calculated using modified Poisson regression models. Standard assessments of interaction between latent tuberculosis infection, the HIV serostatus of index cases, and other variables were performed. MEASUREMENTS AND MAIN RESULTS Latent tuberculosis infection was found in 577 of 878 (65.7%) and 717 of 974 (73.6%) household contacts of HIV-seropositive and -seronegative tuberculosis cases (relative risk, 0.89; 95% confidence interval, 0.82-0.97). On further stratification, cavitary lung disease (P < 0.0001 for interaction) and smear status (P = 0.02 for interaction) of tuberculosis cases modified the infectiousness of HIV-seropositive indexes. Cough duration of index cases did not display interaction (P = 0.499 for interaction). CONCLUSIONS This study suggests that HIV-seropositive tuberculosis cases may be less infectious than HIV-seronegative patients only when they are smear-negative or lack cavitary lung disease. These results may explain heterogeneity between prior studies and provide evidence suggesting that tuberculosis contact investigation should include HIV-seropositive index cases in high disease burden settings.
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Affiliation(s)
- Leonardo Martinez
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia
| | - Juliet N. Sekandi
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia
- School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda; and
| | - María E. Castellanos
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia
| | - Sarah Zalwango
- Uganda–CWRU Research Collaboration, Makerere University and Mulago Hospital, Kampala, Uganda
| | - Christopher C. Whalen
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia
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18
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Perez-Porcuna TM, Pereira-da-Silva HD, Ascaso C, Malheiro A, Bührer S, Martinez-Espinosa F, Abellana R. Prevalence and Diagnosis of Latent Tuberculosis Infection in Young Children in the Absence of a Gold Standard. PLoS One 2016; 11:e0164181. [PMID: 27783642 PMCID: PMC5082652 DOI: 10.1371/journal.pone.0164181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 09/21/2016] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION For adequate disease control the World Health Organization has proposed the diagnosis and treatment of latent tuberculous infection (LTBI) in groups of risk of developing the disease such as children. There is no gold standard (GS) test for the diagnosis of LTBI. The objective of this study was to estimate the prevalence of LTBI in young children in contact with a household case of tuberculosis (TB-HCC) and determine the accuracy and precision of the Tuberculin Skin Test (TST) and QuantiFERON-TB Gold in-tube (QFT) used in the absence of a GS. METHODS We conducted a cross-sectional study in children up to 6 years of age in Manaus/Brazil during the years 2009-2010. All the children had been vaccinated with the BCG and were classified into two groups according to the presence of a TB-HCC or no known contact with tuberculosis (TB). The variables studied were: the TST and QFT results and the intensity and length of exposure to the index tuberculosis case. We used the latent class model to determine the prevalence of LTBI and the accuracy of the tests. RESULTS Fifty percent of the children with TB-HCC had LTBI, with the prevalence depending on the intensity and length of exposure to the index case. The sensitivity and specificity of TST were 73% [95% confidence interval (CI): 53-91] and 97% (95%CI: 89-100), respectively, versus 53% (95%CI: 41-66) and 81% (95%CI:71-90) for QFT. The positive predictive value of TST in children with TB-HCC was 91% (95%CI: 61-99), being 74% for QFT (95%CI: 47-95). CONCLUSIONS This is one of the first studies to estimate the prevalence of LTBI in children and the parameters of the main diagnostic tests using a latent class model. Our results suggest that children in contact with an index case have a high risk of infection. The accuracy and the predictive value of the two tests did not significantly differ. Combined use of the two tests showed scarce improvement in the diagnosis of LTBI.
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Affiliation(s)
- Tomas Maria Perez-Porcuna
- Departament de Salut Pública, Facultat de Medicina, Universitat de Barcelona, Barcelona, Catalunya, Spain
- Servei de Pediatria, CAP Valldoreix, Unitat de Investigació Fundació Mútua Terrassa, Hospital Universitari Mútua Terrassa, Terrassa, Catalunya, Spain
- * E-mail: (RA); (TPP)
| | | | - Carlos Ascaso
- Departament de Salut Pública, Facultat de Medicina, Universitat de Barcelona, Barcelona, Catalunya, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Catalunya, Spain
| | - Adriana Malheiro
- Laboratório Multidisciplinar - Fundação de Hematologia e Hemoterapia do Amazonas, Manaus, Amazonas, Brazil
- Instituto de Ciências Biológicas, Universidade Federal do Amazonas, Manaus, Amazonas, Brazil
| | - Samira Bührer
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiás, Goiânia, Brazil
| | - Flor Martinez-Espinosa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil
- Instituto Leônidas e Maria Deane - Fiocruz Amazônia, Fundação Oswaldo Cruz, Manaus, Amazonas, Brazil
| | - Rosa Abellana
- Departament de Salut Pública, Facultat de Medicina, Universitat de Barcelona, Barcelona, Catalunya, Spain
- * E-mail: (RA); (TPP)
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Secondary Attack Rate (SAR) of Tuberculosis in Hamedan Province, 2005 - 2013. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2016. [DOI: 10.5812/archcid.32962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Owolabi O, Agbla S, Owiafe P, Donkor S, Togun T, Sillah AK, Ota MOC, Sutherland JS. Elevated serum 25-hydroxy (OH) vitamin D levels are associated with risk of TB progression in Gambian adults. Tuberculosis (Edinb) 2016; 98:86-91. [PMID: 27156622 PMCID: PMC4869593 DOI: 10.1016/j.tube.2016.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/22/2016] [Accepted: 02/29/2016] [Indexed: 12/18/2022]
Abstract
Background Vitamin D is essential in the host defence against tuberculosis (TB) as an immune modulator. The aim of this study was to determine the level of 25-hydroxyvitamin D (25 (OH) D) from adult TB index cases before and after treatment and their exposed household contacts (HHC) in The Gambia. Methods Serum from adult index TB cases and their TB-exposed household contacts (HHC) was analysed for 25(OH) D and Vitamin D binding protein (VDBP) concentrations. Tuberculin skin test (TST) status was used as a measure of Mycobacterium tuberculosis (Mtb) infectivity in the HHC. In addition, HHC who later progressed to active TB (incident cases) were assessed alongside non-progressors to determine the influence of 25 (OH) D levels on TB risk. Results Eighty-three TB cases, 46 TST+ and 52 TST− HHC were analysed. Generally levels of 25(OH) D were considered insufficient in all subjects. However, median levels of 25(OH) D and VDBP were significantly higher in TB cases compared to both TST+ and TST− HHC at recruitment and were significantly reduced after TB therapy (p < 0.0001 for all). In addition, levels of serum 25(OH) D at recruitment were significantly higher in TB progressors compared to non-progressors (median (IQR): 25.0(20.8–29.2) in progressors and 20.3 (16.3–24.6) ng/ml in non-progressors; p = 0.007). Conclusion In The Gambia, an equatorial country, 25(OH) D levels are higher in serum of TB progressors and those with active disease compared to latently infected and uninfected subjects. These results contrast to findings in non-equatorial countries.
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Affiliation(s)
- Olumuyiwa Owolabi
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia.
| | - Schadrac Agbla
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia
| | - Patrick Owiafe
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia; Department of Medical Laboratory Science, University of Health and Allied Sciences, PMB 31 Ho, Volta Region, Ghana
| | - Simon Donkor
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia
| | - Toyin Togun
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia
| | - Abdou K Sillah
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia
| | - Martin O C Ota
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia; World Health Organisation Regional Office, Brazzaville, Congo
| | - Jayne S Sutherland
- Vaccines & Immunity Theme, Medical Research Council Unit, Atlantic Road, Fajara, Gambia
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Gehre F, Kumar S, Kendall L, Ejo M, Secka O, Ofori-Anyinam B, Abatih E, Antonio M, Berkvens D, de Jong BC. A Mycobacterial Perspective on Tuberculosis in West Africa: Significant Geographical Variation of M. africanum and Other M. tuberculosis Complex Lineages. PLoS Negl Trop Dis 2016; 10:e0004408. [PMID: 26964059 PMCID: PMC4786107 DOI: 10.1371/journal.pntd.0004408] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/05/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Phylogenetically distinct Mycobacterium tuberculosis lineages differ in their phenotypes and pathogenicity. Consequently, understanding mycobacterial population structures phylogeographically is essential for design, interpretation and generalizability of clinical trials. Comprehensive efforts are lacking to date to establish the West African mycobacterial population structure on a sub-continental scale, which has diagnostic implications and can inform the design of clinical TB trials. METHODOLOGY/PRINCIPAL FINDINGS We collated novel and published genotyping (spoligotyping) data and classified spoligotypes into mycobacterial lineages/families using TBLineage and Spotclust, followed by phylogeographic analyses using statistics (logistic regression) and lineage axis plot analysis in GenGIS, in which a phylogenetic tree constructed in MIRU-VNTRplus was analysed. Combining spoligotyping data from 16 previously published studies with novel data from The Gambia, we obtained a total of 3580 isolates from 12 countries and identified 6 lineages comprising 32 families. By using stringent analytical tools we demonstrate for the first time a significant phylogeographic separation between western and eastern West Africa not only of the two M. africanum (West Africa 1 and 2) but also of several major M. tuberculosis sensu stricto families, such as LAM10 and Haarlem 3. Moreover, in a longitudinal logistic regression analysis for grouped data we showed that M. africanum West Africa 2 remains a persistent health concern. CONCLUSIONS/SIGNIFICANCE Because of the geographical divide of the mycobacterial populations in West Africa, individual research findings from one country cannot be generalized across the whole region. The unequal geographical family distribution should be considered in placement and design of future clinical trials in West Africa.
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Affiliation(s)
- Florian Gehre
- Mycobacterial Unit, Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Vaccines and Immunity Theme, Medical Research Council (MRC) Unit, Fajara, The Gambia
| | - Samrat Kumar
- Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lindsay Kendall
- Statistics and Bioinformatics Department, Medical Research Council (MRC) Unit, Fajara, The Gambia
| | - Mebrat Ejo
- Mycobacterial Unit, Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- University of Gondar, Gondar, Ethiopia
| | - Oumie Secka
- Vaccines and Immunity Theme, Medical Research Council (MRC) Unit, Fajara, The Gambia
| | - Boatema Ofori-Anyinam
- Mycobacterial Unit, Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Vaccines and Immunity Theme, Medical Research Council (MRC) Unit, Fajara, The Gambia
| | - Emmanuel Abatih
- Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Martin Antonio
- Vaccines and Immunity Theme, Medical Research Council (MRC) Unit, Fajara, The Gambia
| | - Dirk Berkvens
- Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Bouke C. de Jong
- Mycobacterial Unit, Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Vaccines and Immunity Theme, Medical Research Council (MRC) Unit, Fajara, The Gambia
- Division of Infectious Diseases, Department of Medicine, New York University (NYU), New York, New York, United States of America
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Shah L, Rojas M, Mori O, Zamudio C, Kaufman JS, Otero L, Gotuzzo E, Seas C, Brewer TF. Implementation of a stepped-wedge cluster randomized design in routine public health practice: design and application for a tuberculosis (TB) household contact study in a high burden area of Lima, Peru. BMC Public Health 2015; 15:587. [PMID: 26109173 PMCID: PMC4481074 DOI: 10.1186/s12889-015-1883-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 05/28/2015] [Indexed: 11/26/2022] Open
Abstract
Background We designed a pragmatic stepped-wedge cluster randomized controlled trial in order to evaluate provider-initiated evaluation of household contacts (HCs) of smear positive tuberculosis (TB) cases within a routine TB program in Lima, Peru. Methods/Design National TB program (NTP) officers of San Juan de Lurigancho District (Lima, Peru) and university-based researchers jointly designed a pragmatic stepped-wedge cluster randomized trial design in order to evaluate a planned active case finding (ACF) program for all HCs of smear-positive TB cases in 34 district healthcare centres. Randomization of time to intervention initiation was stratified by health centre TB case rate. The ACF intervention included provider-initiated home visits of all new sputum smear positive TB patients in order to evaluate household contacts for active TB. Active TB was diagnosed using symptom screening, sputum screening, chest x-ray and clinical evaluation. Once initiated, ACF was provided by NTP staff and integrated into the routine DOTS TB program activities. Discussion This study protocol describes the pragmatic stepped-wedge cluster randomized trial of active household contact evaluations within an NTP. The stepped-wedge design met overlapping needs of local TB programmers and researchers to adequately evaluate the large-scale roll out of a new control program in a TB endemic setting. Multiple planning meetings were required to develop the necessary networks and in order to understand the operations, needs and goals of the NTP staff and researchers collaborating on this project. The advantages and challenges of using this study design in practice and within existing routine TB programs in a middle-income country context are discussed. Trial registration ClinicalTrials.gov NCT02174380. Registered 24 Jun 2014
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Affiliation(s)
- Lena Shah
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Purvis Hall, 1020 Pine Ave. West, Montreal, QC, Canada.
| | - Marlene Rojas
- Red de Salud de San Juan de Lurigancho, Dirección de Salud Lima IV Este, Ministerio de Salud, Lima, Peru.
| | - Oscar Mori
- Red de Salud de San Juan de Lurigancho, Dirección de Salud Lima IV Este, Ministerio de Salud, Lima, Peru.
| | - Carlos Zamudio
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Jay S Kaufman
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Purvis Hall, 1020 Pine Ave. West, Montreal, QC, Canada.
| | - Larissa Otero
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Eduardo Gotuzzo
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Departamento de Enfermedades Infecciosas, Tropicales y Dermatológicas, Hospital Nacional Cayetano Heredia, Lima, Peru.
| | - Carlos Seas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Departamento de Enfermedades Infecciosas, Tropicales y Dermatológicas, Hospital Nacional Cayetano Heredia, Lima, Peru.
| | - Timothy F Brewer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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Minchella PA, Donkor S, McDermid JM, Sutherland JS. Iron homeostasis and progression to pulmonary tuberculosis disease among household contacts. Tuberculosis (Edinb) 2015; 95:288-93. [PMID: 25764944 DOI: 10.1016/j.tube.2015.02.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 02/16/2015] [Indexed: 12/26/2022]
Abstract
Early identification of individuals at risk for progressing to active tuberculosis (TB) disease may limit new transmission and improve clinical outcomes. Evidence indicates altered iron homeostasis may identify those at greater risk of disease progression in HIV co-infection. We aimed to investigate iron homeostasis biomarkers as risk factors for progression to TB. Archived plasma samples were analyzed from household contacts of pulmonary TB index cases in The Gambia. Contacts were classified as asymptomatic non-progressors (n = 17) or TB-progressors (n = 10), which included two HIV-infected participants. Iron homeostasis (hemoglobin, ferritin, hepcidin, soluble transferrin receptor, transferrin) was assessed in all contacts at study recruitment. Plasma was collected a median of 910 days prior to TB diagnosis. Low transferrin around the time of known exposure to infectious TB was a disease progression risk factor among all TB-progressors (Poisson incidence rate ratio: 0.55; 95% CI: 0.35-0.89). Iron homeostasis also differed between early and delayed TB-progressors, with higher ferritin and hepcidin concentrations observed among early TB-progressors (mean ferritin 50.2 vs. 26.2 ng/ml; P = 0.027; mean hepcidin 37.7 vs. 5.6 ng/ml; P = 0.036). Iron homeostasis is associated with progression to TB among household contacts. Further studies are needed to elucidate mechanisms and determine the clinical utility of monitoring iron homeostasis biomarkers.
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Affiliation(s)
| | - Simon Donkor
- Vaccinology Theme, Medical Research Council Unit, Fajara, Gambia
| | - Joann M McDermid
- Division of Nutritional Sciences, Cornell University, Ithaca, USA.
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Buchwald UK, Adetifa IMO, Bottomley C, Owiafe PK, Donkor S, Bojang AL, Sutherland JS. Broad adaptive immune responses to M. tuberculosis antigens precede TST conversion in tuberculosis exposed household contacts in a TB-endemic setting. PLoS One 2014; 9:e116268. [PMID: 25549338 PMCID: PMC4280211 DOI: 10.1371/journal.pone.0116268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 12/05/2014] [Indexed: 12/11/2022] Open
Abstract
Background The identification of Mycobacterium-tuberculosis (Mtb) infected individuals remains a challenge due to an insufficient understanding of immune responses detected with the current diagnostic tests for latent tuberculosis i.e. the tuberculin skin test (TST) or IFN–γ release assays (IGRAs) and an inability to distinguish infection stages with current immunologic assays. Further classification based on markers other than IFN–γ may help to define markers of early Mtb infection. Methods We assessed the TST status of Mtb-exposed household contacts at baseline and at 6 months. Contacts were classified into those with initial positive TST (TST+); those with baseline negative TST but TST conversion at 6 months (TST converters, TSTC) and those with persistently negative TST (PTST−). We assessed their short- and long-term immune responses to PPD and ESAT–6/CFP–10 (EC) via IFN–γ ELISPOT and a multiplex cytokine array in relation to TST status and compared them to those of TB cases to identify immune profiles associated with a spectrum of infection stages. Results After 1 and 6 days stimulation with EC, 12 cytokines (IFN–γ, IL–2, IP–10, TNF–α, IL–13, IL–17, IL–10, GMCSF, MIP–1β, MCP–3, IL–2RA and IL–1A) were not different in TSTC compared to TST+ suggesting that robust adaptive Mtb-specific immune responses precede TST conversion. Stratifying contacts by baseline IFN–γ ELISPOT to EC in combination with TST results revealed that IP–10 and IL–17 were highest in the group of TST converters with positive baseline ELISPOT, suggesting they might be markers for recent infection. Conclusion We describe a detailed analysis of Mtb-specific biomarker profiles in exposed household contacts in a TB endemic area that provides insights into the dynamic immune responses to Mtb infection and may help to identify biomarkers for ‘at-risk’ populations beyond TST and IGRA.
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Affiliation(s)
- Ulrike K. Buchwald
- Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia
- * E-mail: (JSS); (UKB)
| | - Ifedayo M. O. Adetifa
- Disease Control and Elimination Theme, Medical Research Council Unit, Banjul, The Gambia
| | - Christian Bottomley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Patrick K. Owiafe
- Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia
| | - Simon Donkor
- Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia
| | - Adama L. Bojang
- Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia
| | - Jayne S. Sutherland
- Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia
- * E-mail: (JSS); (UKB)
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Chakhaia T, Magee MJ, Kempker RR, Gegia M, Goginashvili L, Nanava U, Blumberg HM. High utility of contact investigation for latent and active tuberculosis case detection among the contacts: a retrospective cohort study in Tbilisi, Georgia, 2010-2011. PLoS One 2014; 9:e111773. [PMID: 25379809 PMCID: PMC4224404 DOI: 10.1371/journal.pone.0111773] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 10/02/2014] [Indexed: 12/04/2022] Open
Abstract
SETTING The study was conducted at the National Center for Tuberculosis and Lung Diseases (NCTBLD) in Tbilisi, Georgia. OBJECTIVE To assess the utility of contact investigation for tuberculosis (TB) case detection. We also assessed the prevalence and risk factors for active TB disease and latent TB infection (LTBI) among contacts of active pulmonary TB cases. DESIGN A retrospective cohort study was conducted among the contacts of active pulmonary TB cases registered in 2010-2011 at the NCTBLD in Tbilisi, Georgia. Contacts of active TB patients were investigated according to an "invitation model": they were referred to the NCTBLD by the index case; were queried about clinical symptoms suggestive of active TB disease; tuberculin skin testing and chest radiographs were performed. Demographic, laboratory, and clinical data of TB patients and their contacts were abstracted from existing records up to February 2013. RESULTS 869 contacts of 396 index cases were enrolled in the study; a median of 2 contacts were referred per index case. Among the 869 contacts, 47 (5.4%) were found to have or developed active TB disease: 30 (63.8%) were diagnosed with TB during the baseline period (co-prevalent cases) and 17 (36.2%) developed active TB disease during the follow-up period (mean follow up of 21 months) (incident TB cases). The incidence rate of active TB disease among contacts was 1126.0 per 100,000 person years (95% CI 655.7-1802.0 per 100,000 person-years). Among the 402 contacts who had a tuberculin skin test (TST) performed, 52.7% (95% CI 47.7-57.7%) had LTBI. CONCLUSIONS A high prevalence of LTBI and active TB disease was found among the contacts of TB cases in Tbilisi, Georgia. Our findings demonstrated that an "invitation" model of contact investigation was an effective method of case detection. Therefore, contact investigation should be scaled up in Georgia.
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Affiliation(s)
- Tsira Chakhaia
- University Research Co., LLC. Branch in Georgia, USAID Georgia TB Prevention Project, Tbilisi, Georgia
| | - Matthew J. Magee
- Division of Epidemiology and Biostatistics, School of Public Health, Georgia State University, Atlanta, Georgia, United States of America
- Departments of Epidemiology and Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Russell R. Kempker
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Medea Gegia
- University Research Co., LLC. Branch in Georgia, USAID Georgia TB Prevention Project, Tbilisi, Georgia
| | | | - Ucha Nanava
- National Center for Tuberculosis and Lung Disease, Tbilisi, Georgia
| | - Henry M. Blumberg
- Departments of Epidemiology and Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, United States of America
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Mycobacterium tuberculosis infection in young children: analyzing the performance of the diagnostic tests. PLoS One 2014; 9:e97992. [PMID: 24879374 PMCID: PMC4039466 DOI: 10.1371/journal.pone.0097992] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 04/27/2014] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE This study evaluated the performance of the Tuberculin Skin Test (TST) and Quantiferon-TB Gold in-Tube (QFT) and the possible association of factors which may modify their results in young children (0-6 years) with recent contact with an index tuberculosis case. MATERIALS AND METHODS A cross-sectional study including 135 children was conducted in Manaus, Amazonas-Brazil. The TST and QFT were performed and the tests results were analyzed in relation to the personal characteristics of the children studied and their relationship with the index case. RESULTS The rates of positivity were 34.8% (TST) and 26.7% (QFT), with 14.1% of indeterminations by the QFT. Concordance between tests was fair (Kappa = 0.35 P<0.001). Both the TST and QFT were associated with the intensity of exposure (Linear OR = 1.286, P = 0.005; Linear OR = 1.161, P = 0.035 respectively) with only the TST being associated with the time of exposure (Linear OR = 1.149, P = 0.009). The presence of intestinal helminths in the TST+ group was associated with negative QFT results (OR = 0.064, P = 0.049). In the TST- group lower levels of ferritin were associated with QFT+ results (Linear OR = 0.956, P = 0.036). CONCLUSIONS Concordance between the TST and QFT was lower than expected. The factors associated with the discordant results were intestinal helminths, ferritin levels and exposure time to the index tuberculosis case. In TST+ group, helminths were associated with negative QFT results suggesting impaired cell-mediated immunity. The TST-&QFT+ group had a shorter exposure time and lower ferritin levels, suggesting that QFT is faster and ferritin may be a potential biomarker of early stages of tuberculosis infection.
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Verrall AJ, Netea MG, Alisjahbana B, Hill PC, van Crevel R. Early clearance of Mycobacterium tuberculosis: a new frontier in prevention. Immunology 2014; 141:506-13. [PMID: 24754048 DOI: 10.1111/imm.12223] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Early clearance (EC) is the successful eradication of inhaled Mycobacterium tuberculosis before an adaptive immune response develops. Evidence for EC comes from case contact studies that consistently show that a proportion of heavily exposed individuals do not develop M. tuberculosis infection. Further support for the existence of this phenotype comes from genetic loci associated with tuberculin reactivity. In this review we discuss aspects of the innate response that may underpin EC and hypotheses that can be tested through field laboratory link studies in M. tuberculosis case contacts. Specifically, we consider mechanisms whereby alveolar macrophages recognize and kill intracellular M. tuberculosis, and how other cell types, such as neutrophils, natural killer T cells, mucosa-associated invariant T cells and cd T cells may assist. How EC may be impaired by HIV infection or vitamin D deficiency is also explored. As EC is a form of protective immunity, further study may advance the development of vaccines and immunotherapies to prevent M. tuberculosis infection.
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Stein CM, Hall NB, Malone LL, Mupere E. The household contact study design for genetic epidemiological studies of infectious diseases. Front Genet 2013; 4:61. [PMID: 23641253 PMCID: PMC3639375 DOI: 10.3389/fgene.2013.00061] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/05/2013] [Indexed: 11/17/2022] Open
Abstract
Most genetic epidemiological study designs fall into one of two categories: family based and population-based (case–control). However, recent advances in statistical genetics call for study designs that combine these two approaches. We describe the household contact study design as we have applied it in our several years of study of the epidemiology of tuberculosis. Though we highlight its applicability for genetic epidemiological studies of infectious diseases, there are many facets of this design that are appealing for modern genetic studies, including the simultaneous enrollment of related and unrelated individuals, closely and distantly related individuals, collection of extensive epidemiologic and phenotypic data, and evaluation of effects of shared environment and gene by environment interaction. These study design characteristics are particularly appealing for current sequencing studies.
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Affiliation(s)
- Catherine M Stein
- Department of Epidemiology and Biostatistics, Case Western Reserve University Cleveland, OH, USA ; Uganda - Case Western Reserve University Research Collaboration Kampala, Uganda
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Singh J, Sankar MM, Kumar S, Gopinath K, Singh N, Mani K, Singh S. Incidence and prevalence of tuberculosis among household contacts of pulmonary tuberculosis patients in a peri-urban population of South Delhi, India. PLoS One 2013; 8:e69730. [PMID: 23922784 PMCID: PMC3724886 DOI: 10.1371/journal.pone.0069730] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/12/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Tuberculosis (TB), caused by Mycobacterium tuberculosis, is one of the leading causes of mortality and morbidity across all age groups throughout the world, especially in developing countries. METHODOLOGY/PRINCIPAL FINDINGS In this study, we have included 432 open index cases with their 1608 household contacts in a prospective cohort study conducted from May 2007 to March 2009. The follow-up period was 2 years. All Index cases were diagnosed on the basis of suggestive signs and symptoms and sputum being AFB positive. Among the 432 index patients, 250 (57.9%) were males and 182 (42.1%) females; with mean age of 34 ± 14.4 yr and 26 ± 11.1 yr, respectively. Out of 1608 household contacts, 866 (53.9%) were males and 742 (46.1%) females; with mean age of 26.5 ± 15.8 and 26.5 ± 16.0 yr, respectively. Of the total 432 households, 304 (70.4%) had ≤ 4 members and 128 (29.6%) had ≥ 5 members. The median size of the family was four. Of the 1608 contacts, 1206 were able to provide sputum samples, of whom 83 (6.9%) were found MTB culture positive. Household contacts belonging to adult age group were predominantly (74, 89.2%) infected as compared to the children (9, 10.8%). On screening the contact relationship status with index patients, 52 (62.7%) were first-degree relatives, 18 (34.6%) second-degree relatives and 12 (14.5%) spouses who got infected from their respective index patients. Co-prevalent and incident tuberculosis was found in 52 (4.3%) and 31 (2.6%) contacts, respectively. In incident cases, the diagnosis could be made between 4 to 24 months of follow-up, after their baseline evaluation. CONCLUSION Active household contact investigation is a powerful tool to detect and treat tuberculosis at early stages and the only method to control TB in high-TB-burden countries.
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Affiliation(s)
- Jitendra Singh
- Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Manimuthu Mani Sankar
- Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Sandeep Kumar
- Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Krishnamurthy Gopinath
- Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Niti Singh
- Lala Ram Sarup Institute of Tuberculosis and Respiratory Diseases, New Delhi, India
| | - Kalaivani Mani
- Department of Biostatics, All India Institute of Medical Sciences, New Delhi, India
| | - Sarman Singh
- Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi, India
- * E-mail:
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Zignol M, Sismanidis C, Falzon D, Glaziou P, Dara M, Floyd K. Multidrug-resistant tuberculosis in children: evidence from global surveillance. Eur Respir J 2012; 42:701-7. [PMID: 23222872 PMCID: PMC3759300 DOI: 10.1183/09031936.00175812] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Multidrug-resistant tuberculosis (MDR-TB) can affect persons of any age, but it remains unknown whether children are more or less likely than adults to have MDR-TB. Representative drug resistance surveillance data reported to the World Health Organization between 1994 and 2011 were analysed to test the association between MDR-TB and age group (children aged <15 years versus adults aged ≥15 years), using odds ratios derived by logistic regression with robust standard errors. Of 85 countries with data from nationwide surveys or surveillance systems, 35 reported at least one paediatric MDR-TB case. Aggregated data on age and drug susceptibility testing for 323 046 tuberculosis cases notified in these 35 countries were analysed. Odds ratios for MDR-TB in children compared to adults varied widely between countries. In Germany, Namibia, South Africa, the UK and the USA, MDR-TB was positively associated with age <15 years. In the remaining countries no association was established. Despite the limitations intrinsic to the use of surveillance data and to the challenges of diagnosing childhood tuberculosis, our analysis suggests that proportions of MDR-TB in children and adults are similar in many settings. Of particular concern is the association found between age <15 years and MDR-TB in southern African countries with high HIV prevalence. Surveillance data from 35 countries suggest that proportions of MDR-TB in children are not lower than those in adultshttp://ow.ly/kPgPH
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Adetifa IM, Ota MOC, Jeffries DJ, Lugos MD, Hammond AS, Battersby NJ, Owiafe PK, Donkor SD, Antonio M, Ibanga HB, Brookes RH, Aka P, Walton R, Adegbola RA, Hill PC. Interferon-γ ELISPOT as a biomarker of treatment efficacy in latent tuberculosis infection: a clinical trial. Am J Respir Crit Care Med 2012; 187:439-45. [PMID: 23220919 DOI: 10.1164/rccm.201208-1352oc] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Biomarkers that can be used to evaluate new interventions against latent tuberculosis infection (LTBI) and predict reactivation TB disease are urgently required. OBJECTIVES To evaluate ESAT-6 and CFP-10 (EC) IFN-γ ELISPOT as a biomarker for treatment efficacy in LTBI. METHODS This was a randomized, blinded, and placebo-controlled trial of INH in EC ELISPOT and Mantoux test positive participants. MEASUREMENTS AND MAIN RESULTS Participants received a 6-month course of 900 mg INH twice weekly or a matching placebo. INH acetylator genotypes were determined and urine tested for INH metabolites to confirm adherence. The proportion of positive responders for CFP-10 and ESAT-6 between treatment arms was compared using mixed effects logistic regression models. A Tweedie (compound Poisson) model was fitted to allow for zero inflation and overdispersion of quantitative response. The proportions of EC ELISPOT-positive subjects reduced over time (P < 0.001) but did not differ by study arm (P = 0.36). Median spot-forming units for ESAT-6 and CFP-10 also declined significantly with time (P < 0.001) but did not differ by study arm (P = 0.74 and 0.71, respectively). There was no evidence of an interaction between acetylator status and INH treatment with respect to ELISPOT results over time. CONCLUSIONS In contacts with LTBI, INH therapy plays no role in observed decreases in Mycobacterium tuberculosis antigen-specific T-cell responses over time. IFN-γ ELISPOT is probably not a useful biomarker of treatment efficacy in LTBI. Clinical trial registered with www.clinicaltrials.gov (NCT 00130325).
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Affiliation(s)
- Ifedayo M Adetifa
- Medical Research Council Unit, The Gambia, Fajara, P.O. Box 273, Banjul, The Gambia.
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Sutherland JS, Hill PC, Adetifa IM, de Jong BC, Donkor S, Joosten SA, Opmeer L, Haks MC, Ottenhoff THM, Adegbola RA, Ota MOC. Identification of probable early-onset biomarkers for tuberculosis disease progression. PLoS One 2011; 6:e25230. [PMID: 21966464 PMCID: PMC3179487 DOI: 10.1371/journal.pone.0025230] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 08/29/2011] [Indexed: 12/28/2022] Open
Abstract
Determining what constitutes protective immunity to TB is critical for the development of improved diagnostics and vaccines. The comparison of the immune system between contacts of TB patients, who later develop TB disease (progressors), versus contacts who remain healthy (non-progressors), allows for identification of predictive markers of TB disease. This study provides the first comprehensive analysis of the immune system of progressors and non-progressors using a well-characterised TB case-contact (TBCC) platform in The Gambia, West Africa. 22 progressors and 31 non-progressors were analysed at recruitment, 3 months and 18 months (time to progression: median[IQR] of 507[187-714] days). Immunophenotyping of PBMC, plasma cytokine levels and RT-MLPA analysis of whole blood-derived RNA was performed to capture key immune system parameters. At recruitment, progressors had lower PBMC proportions of CD4+ T cells, NKT cells and B cells relative to non-progressors. Analysis of the plasma showed higher levels of IL-18 in progressors compared to non-progressors and analysis of the RNA showed significantly lower gene expression of Bcl2 but higher CCR7 in progressors compared to non-progressors. This study shows several markers that may predict the onset of active TB at a very early stage after infection. Once these markers have been validated in larger studies, they provide avenues to prospectively identify people at risk of developing TB, a key issue in the testing of new TB vaccines.
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Affiliation(s)
- Jayne S Sutherland
- Vaccinology Theme Group, Medical Research Council Unit, Fajara, The Gambia.
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