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Ryckman TS, Schumacher SG, Lienhardt C, Sweeney S, Dowdy DW, Mirzayev F, Kendall EA. Economic implications of novel regimens for tuberculosis treatment in three high-burden countries: a modelling analysis. Lancet Glob Health 2024; 12:e995-e1004. [PMID: 38762299 PMCID: PMC11126367 DOI: 10.1016/s2214-109x(24)00088-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/24/2024] [Accepted: 02/21/2024] [Indexed: 05/20/2024]
Abstract
BACKGROUND With numerous trials investigating novel drug combinations to treat tuberculosis, we aimed to evaluate the extent to which future improvements in tuberculosis treatment regimens could offset potential increases in drug costs. METHODS In this modelling analysis, we used an ingredients-based approach to estimate prices at which novel regimens for rifampin-susceptible and rifampin-resistant tuberculosis treatment would be cost-neutral or cost-effective compared with standards of care in India, the Philippines, and South Africa. We modelled regimens meeting targets set in the WHO's 2023 Target Regimen Profiles (TRPs). Our decision-analytical model tracked cohorts of adults initiating rifampin-susceptible or rifampin-resistant tuberculosis treatment, simulating their health outcomes and costs accumulated during and following treatment under standard-of-care and novel regimen scenarios. Price thresholds included short-term cost-neutrality (considering only savings accrued during treatment), medium-term cost-neutrality (additionally considering savings from averted retreatments and secondary cases), and cost-effectiveness (incorporating willingness-to-pay for improved health outcomes). FINDINGS Total medium-term costs per person treated using standard-of-care regimens were estimated at US$450 (95% uncertainty interval 310-630) in India, $560 (350-860) in the Philippines, and $730 (530-1090) in South Africa for rifampin-susceptible tuberculosis (current drug costs $46) and $2100 (1590-2810) in India, $2610 (2090-3280) in the Philippines, and $3790 (3090-4630) in South Africa for rifampin-resistant tuberculosis (current drug costs $432). A rifampin-susceptible tuberculosis regimen meeting the optimal targets defined in the TRPs could be cost-neutral in the short term at drug costs of $140 (90-210) per full course in India, $230 (130-380) in the Philippines, and $280 (180-460) in South Africa. For rifampin-resistant tuberculosis, short-term cost-neutral thresholds were higher with $930 (720-1230) in India, $1180 (980-1430) in the Philippines, and $1480 (1230-1780) in South Africa. Medium-term cost-neutral prices were approximately $50-100 higher than short-term cost-neutral prices for rifampin-susceptible tuberculosis and $250-550 higher for rifampin-resistant tuberculosis. Health system cost-neutral prices that excluded patient-borne costs were 45-70% lower (rifampin-susceptible regimens) and 15-50% lower (rifampin-resistant regimens) than the cost-neutral prices that included patient costs. Cost-effective prices were substantially higher. Shorter duration was the most important driver of medium-term savings with novel regimens, followed by ease of adherence. INTERPRETATION Improved tuberculosis regimens, particularly shorter regimens or those that facilitate better adherence, could reduce overall costs, potentially offsetting higher prices. FUNDING WHO.
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Affiliation(s)
- Theresa S Ryckman
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | | | - Christian Lienhardt
- Institut de Recherche pour le Développement, Université de Montpellier, Montpellier, France; Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK
| | - Sedona Sweeney
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Emily A Kendall
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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2
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Shrestha S, Mishra G, Hamal M, Dhital R, Shrestha S, Shrestha A, Shah NP, Khanal M, Gurung S, Caws M. Quantifying the potential epidemiological impact of a 2-year active case finding for tuberculosis in rural Nepal: a model-based analysis. BMJ Open 2023; 13:e062123. [PMID: 37914308 PMCID: PMC10626874 DOI: 10.1136/bmjopen-2022-062123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 09/22/2023] [Indexed: 11/03/2023] Open
Abstract
OBJECTIVES Active case finding (ACF) is an important tuberculosis (TB) intervention in high-burden settings. However, empirical evidence garnered from field data has been equivocal about the long-term community-level impact, and more data at a finer geographic scale and data-informed methods to quantify their impact are necessary. METHODS Using village development committee (VDC)-level data on TB notification and demography between 2016 and 2017 in four southern districts of Nepal, where ACF activities were implemented as a part of the IMPACT-TB study between 2017 and 2019, we developed VDC-level transmission models of TB and ACF. Using these models and ACF yield data collected in the study, we estimated the potential epidemiological impact of IMPACT-TB ACF and compared its efficiency across VDCs in each district. RESULTS Cases were found in the majority of VDCs during IMPACT-TB ACF, but the number of cases detected within VDCs correlated weakly with historic case notification rates. We projected that this ACF intervention would reduce the TB incidence rate by 14% (12-16) in Chitwan, 8.6% (7.3-9.7) in Dhanusha, 8.3% (7.3-9.2) in Mahottari and 3% (2.5-3.2) in Makwanpur. Over the next 10 years, we projected that this intervention would avert 987 (746-1282), 422 (304-571), 598 (450-782) and 197 (172-240) cases in Chitwan, Dhanusha, Mahottari and Makwanpur, respectively. There was substantial variation in the efficiency of ACF across VDCs: there was up to twofold difference in the number of cases averted in the 10 years per case detected. CONCLUSION ACF data confirm that TB is widely prevalent, including in VDCs with relatively low reporting rates. Although ACF is a highly efficient component of TB control, its impact can vary substantially at local levels and must be combined with other interventions to alter TB epidemiology significantly.
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Affiliation(s)
- Sourya Shrestha
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Gokul Mishra
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, Liverpool, UK
- Birat Nepal Medical Trust, Kathmandu, Nepal
| | - Mukesh Hamal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | | | | | | | | | - Suman Gurung
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, Liverpool, UK
- Birat Nepal Medical Trust, Kathmandu, Nepal
| | - Maxine Caws
- Birat Nepal Medical Trust, Kathmandu, Nepal
- Liverpool School of Tropical Medicine, Liverpool, UK
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3
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Prasad R, Singh A, Gupta N. Can Pan-TB shorter regimens be a promising hope for ending TB in India by 2025 in ongoing COVID-19 era? Indian J Tuberc 2022; 69:377-382. [PMID: 36460365 PMCID: PMC9221684 DOI: 10.1016/j.ijtb.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 12/15/2022]
Affiliation(s)
- Rajendra Prasad
- Department of Pulmonary Medicine, Era Medical College, Lucknow, Uttar Pradesh, India.
| | - Abhijeet Singh
- Department of Pulmonary & Critical Care Medicine, Fortis Hospital, Vasant Kunj, New Delhi, India
| | - Nikhil Gupta
- Department of Internal Medicine, Dr Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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4
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Alame Emane AK, Guo X, Takiff HE, Liu S. Highly transmitted M. tuberculosis strains are more likely to evolve MDR/XDR and cause outbreaks, but what makes them highly transmitted? Tuberculosis (Edinb) 2021; 129:102092. [PMID: 34102584 DOI: 10.1016/j.tube.2021.102092] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/10/2021] [Accepted: 05/17/2021] [Indexed: 11/17/2022]
Abstract
Multi-Drug-Resistant strains of Mycobacterium tuberculosis (MDR-TB) are a serious obstacle to global TB eradication. While most MDR-TB strains are infrequently transmitted, a few cause large transmission clusters that contribute substantially to local MDR-TB burdens. Here we examine whether the known mutations in these strains can explain their success. Drug resistance mutations differ in fitness costs and strains can also acquire compensatory mutations (CM) to restore fitness, but some highly transmitted MDR strains have no CM. The acquisition of resistance mutations that maintain high transmissibility seems to occur by chance and are more likely in strains that are intrinsically highly transmitted and cause many cases. Modern Beijing lineage strains have caused several large outbreaks, but MDR outbreaks are also caused by ancient Beijing and lineage 4 strains, suggesting the lineage is less important than the characteristics of the individual strain. The development of fluoroquinolone resistance appears to represent another level of selection, in which strains must surmount unknown fitness costs of gyrA mutations. The genetic determinants of high transmission are poorly defined but may involve genes encoding proteins involved in molybdenum acquisition and the Esx systems. In addition, strains eliciting lower cytokine responses and producing more caseating granulomas may have advantages for transmission. Successful MDR/XDR strains generally evolve from highly transmitted drug sensitive parent strains due to selection pressures from deficiencies in local TB control programs. Until TB incidence is considerably reduced, there will likely be highly transmitted strains that develop resistance to any new antibiotic.
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Affiliation(s)
- Amel Kevin Alame Emane
- Shenzhen Nanshan Center for Chronic Disease Control, 7 Huaming Road, Nanshan, Shenzhen City, Guangdong Province, China.
| | - Xujun Guo
- Shenzhen Nanshan Center for Chronic Disease Control, 7 Huaming Road, Nanshan, Shenzhen City, Guangdong Province, China.
| | - Howard E Takiff
- Shenzhen Nanshan Center for Chronic Disease Control, 7 Huaming Road, Nanshan, Shenzhen City, Guangdong Province, China; Integrated Mycobacterial Pathogenomics Unit, Institut Pasteur, 28 Rue du Dr Roux, Paris, 75015, France; Laboratorio de Genética Molecular, CMBC, IVIC, Km. 11 Carr. Panamericana, Caracas, Venezuela.
| | - Shengyuan Liu
- Shenzhen Nanshan Center for Chronic Disease Control, 7 Huaming Road, Nanshan, Shenzhen City, Guangdong Province, China.
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5
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Trauer JM, Dodd PJ, Gomes MGM, Gomez GB, Houben RMGJ, McBryde ES, Melsew YA, Menzies NA, Arinaminpathy N, Shrestha S, Dowdy DW. The Importance of Heterogeneity to the Epidemiology of Tuberculosis. Clin Infect Dis 2020; 69:159-166. [PMID: 30383204 PMCID: PMC6579955 DOI: 10.1093/cid/ciy938] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/31/2018] [Indexed: 12/23/2022] Open
Abstract
Although less well-recognized than for other infectious diseases, heterogeneity is a defining feature of tuberculosis (TB) epidemiology. To advance toward TB elimination, this heterogeneity must be better understood and addressed. Drivers of heterogeneity in TB epidemiology act at the level of the infectious host, organism, susceptible host, environment, and distal determinants. These effects may be amplified by social mixing patterns, while the variable latent period between infection and disease may mask heterogeneity in transmission. Reliance on notified cases may lead to misidentification of the most affected groups, as case detection is often poorest where prevalence is highest. Assuming that average rates apply across diverse groups and ignoring the effects of cohort selection may result in misunderstanding of the epidemic and the anticipated effects of control measures. Given this substantial heterogeneity, interventions targeting high-risk groups based on location, social determinants, or comorbidities could improve efficiency, but raise ethical and equity considerations.
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Affiliation(s)
- James M Trauer
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Peter J Dodd
- Health Economic and Decision Science, University of Sheffield, United Kingdom
| | - M Gabriela M Gomes
- Liverpool School of Tropical Medicine, United Kingdom.,CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Portugal
| | - Gabriela B Gomez
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Rein M G J Houben
- Tuberculosis Centre, London School of Hygiene and Tropical Medicine, United Kingdom.,Infectious Disease Epidemiology Department, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Emma S McBryde
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland
| | - Yayehirad A Melsew
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Nicolas A Menzies
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Nimalan Arinaminpathy
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, United Kingdom
| | - Sourya Shrestha
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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6
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Kendall EA, Malhotra S, Cook-Scalise S, Denkinger CM, Dowdy DW. Estimating the impact of a novel drug regimen for treatment of tuberculosis: a modeling analysis of projected patient outcomes and epidemiological considerations. BMC Infect Dis 2019; 19:794. [PMID: 31500572 PMCID: PMC6734288 DOI: 10.1186/s12879-019-4429-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Regimens that could treat both rifampin-resistant (RR) and rifampin-susceptible tuberculosis (TB) while shortening the treatment duration have reached late-stage clinical trials. Decisions about whether and how to implement such regimens will require an understanding of their likely clinical impact and how this impact depends on local epidemiology and implementation strategy. METHODS A Markov state-transition model of 100,000 representative South African adults with TB was used to simulate implementation of the regimen BPaMZ (bedaquiline, pretomanid, moxifloxacin, and pyrazinamide), either for RR-TB only or universally for all patients. Patient outcomes, including cure rates, time with active TB, and time on treatment, were compared to outcomes under current care. Sensitivity analyses varied the drug-resistance epidemiology, rifampin susceptibility testing practices, and regimen efficacy. RESULTS Using BPaMZ exclusively for RR-TB increased the proportion of all RR-TB that was cured by initial treatment from 60 ± 1% to 67 ± 1%. Expanding use of BPaMZ to all patients increased cure of RR-TB to 89 ± 1% and cure of all TB from 87.3 ± 0.1% to 89.5 ± 0.1%, while shortening treatment by 1.9 months/person. In sensitivity analyses, reducing the coverage of rifampin susceptibility testing resulted in lower projected proportions of patients cured under all regimen scenarios (current care, RR-only BPaMZ, and universal BPaMZ), compared to the proportions projected using South Africa's high coverage; however, this reduced coverage resulted in greater expected incremental benefits of universal BPaMZ implementation, both when compared to RR-only BPaMZ implementation and when compared to to current care under the same low rifampin susceptibility testing coverage. In settings with higher RR-TB prevalence, the benefits of BPaMZ were magnified both for RR-specific and universal BPaMZ implementation. CONCLUSIONS Novel regimens such as BPaMZ could improve RR-TB outcomes and shorten treatment for all patients, particularly with universal use. Decision-makers weighing early options for implementing such regimens at scale will want to consider the expected impact on patient outcomes and on the burden of treatment in their local context.
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Affiliation(s)
- Emily A Kendall
- Division of Infectious Diseases and Center for Tuberculosis Research, Johns Hopkins University School of Medicine, CRB2 Room 106, 1550 Orleans St, Baltimore, MD, 21287, USA.
| | - Shelly Malhotra
- Global Alliance for TB Drug Development, New York, NY, USA
- International AIDS Vaccine Initiative, New York, NY, USA
| | | | - Claudia M Denkinger
- Division of Tropical Medicine, Center of Infectious Disease, Heidelberg University, Heidelberg, Germany
- Tuberculosis Programme, FIND, Geneva, Switzerland
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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7
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Niewiadomska AM, Jayabalasingham B, Seidman JC, Willem L, Grenfell B, Spiro D, Viboud C. Population-level mathematical modeling of antimicrobial resistance: a systematic review. BMC Med 2019; 17:81. [PMID: 31014341 PMCID: PMC6480522 DOI: 10.1186/s12916-019-1314-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Mathematical transmission models are increasingly used to guide public health interventions for infectious diseases, particularly in the context of emerging pathogens; however, the contribution of modeling to the growing issue of antimicrobial resistance (AMR) remains unclear. Here, we systematically evaluate publications on population-level transmission models of AMR over a recent period (2006-2016) to gauge the state of research and identify gaps warranting further work. METHODS We performed a systematic literature search of relevant databases to identify transmission studies of AMR in viral, bacterial, and parasitic disease systems. We analyzed the temporal, geographic, and subject matter trends, described the predominant medical and behavioral interventions studied, and identified central findings relating to key pathogens. RESULTS We identified 273 modeling studies; the majority of which (> 70%) focused on 5 infectious diseases (human immunodeficiency virus (HIV), influenza virus, Plasmodium falciparum (malaria), Mycobacterium tuberculosis (TB), and methicillin-resistant Staphylococcus aureus (MRSA)). AMR studies of influenza and nosocomial pathogens were mainly set in industrialized nations, while HIV, TB, and malaria studies were heavily skewed towards developing countries. The majority of articles focused on AMR exclusively in humans (89%), either in community (58%) or healthcare (27%) settings. Model systems were largely compartmental (76%) and deterministic (66%). Only 43% of models were calibrated against epidemiological data, and few were validated against out-of-sample datasets (14%). The interventions considered were primarily the impact of different drug regimens, hygiene and infection control measures, screening, and diagnostics, while few studies addressed de novo resistance, vaccination strategies, economic, or behavioral changes to reduce antibiotic use in humans and animals. CONCLUSIONS The AMR modeling literature concentrates on disease systems where resistance has been long-established, while few studies pro-actively address recent rise in resistance in new pathogens or explore upstream strategies to reduce overall antibiotic consumption. Notable gaps include research on emerging resistance in Enterobacteriaceae and Neisseria gonorrhoeae; AMR transmission at the animal-human interface, particularly in agricultural and veterinary settings; transmission between hospitals and the community; the role of environmental factors in AMR transmission; and the potential of vaccines to combat AMR.
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Affiliation(s)
- Anna Maria Niewiadomska
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA
| | - Bamini Jayabalasingham
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA.,Present Address: Elsevier Inc., 230 Park Ave, Suite B00, New York, NY, 10169, USA
| | - Jessica C Seidman
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA
| | | | - Bryan Grenfell
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA.,Princeton University, Princeton, NJ, USA
| | - David Spiro
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA
| | - Cecile Viboud
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, USA.
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8
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Reid MJA, Arinaminpathy N, Bloom A, Bloom BR, Boehme C, Chaisson R, Chin DP, Churchyard G, Cox H, Ditiu L, Dybul M, Farrar J, Fauci AS, Fekadu E, Fujiwara PI, Hallett TB, Hanson CL, Harrington M, Herbert N, Hopewell PC, Ikeda C, Jamison DT, Khan AJ, Koek I, Krishnan N, Motsoaledi A, Pai M, Raviglione MC, Sharman A, Small PM, Swaminathan S, Temesgen Z, Vassall A, Venkatesan N, van Weezenbeek K, Yamey G, Agins BD, Alexandru S, Andrews JR, Beyeler N, Bivol S, Brigden G, Cattamanchi A, Cazabon D, Crudu V, Daftary A, Dewan P, Doepel LK, Eisinger RW, Fan V, Fewer S, Furin J, Goldhaber-Fiebert JD, Gomez GB, Graham SM, Gupta D, Kamene M, Khaparde S, Mailu EW, Masini EO, McHugh L, Mitchell E, Moon S, Osberg M, Pande T, Prince L, Rade K, Rao R, Remme M, Seddon JA, Selwyn C, Shete P, Sachdeva KS, Stallworthy G, Vesga JF, Vilc V, Goosby EP. Building a tuberculosis-free world: The Lancet Commission on tuberculosis. Lancet 2019; 393:1331-1384. [PMID: 30904263 DOI: 10.1016/s0140-6736(19)30024-8] [Citation(s) in RCA: 223] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 12/20/2018] [Accepted: 12/25/2018] [Indexed: 11/22/2022]
Affiliation(s)
- Michael J A Reid
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA; Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA.
| | - Nimalan Arinaminpathy
- School of Public Health, Imperial College London, London, UK; Faculty of Medicine, Imperial College London, London, UK
| | - Amy Bloom
- Tuberculosis Division, United States Agency for International Development, Washington, DC, USA
| | - Barry R Bloom
- Department of Global Health and Population, Harvard University, Cambridge, MA, USA
| | | | - Richard Chaisson
- Departments of Medicine, Epidemiology, and International Health, Johns Hopkins School of Medicine, Baltimore, MA, USA
| | | | | | - Helen Cox
- Department of Pathology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Mark Dybul
- Department of Medicine, Centre for Global Health and Quality, Georgetown University, Washington, DC, USA
| | | | - Anthony S Fauci
- National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Maryland, MA, USA
| | | | - Paula I Fujiwara
- Department of Tuberculosis and HIV, The International Union Against Tuberculosis and Lung Disease, Paris, France
| | - Timothy B Hallett
- School of Public Health, Imperial College London, London, UK; Faculty of Medicine, Imperial College London, London, UK
| | | | | | - Nick Herbert
- Global TB Caucus, Houses of Parliament, London, UK
| | - Philip C Hopewell
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Chieko Ikeda
- Department of GLobal Health, Ministry of Heath, Labor and Welfare, Tokyo, Japan
| | - Dean T Jamison
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA; Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Aamir J Khan
- Interactive Research & Development, Karachi, Pakistan
| | - Irene Koek
- Global Health Bureau, United States Agency for International Development, Washington, DC, USA
| | - Nalini Krishnan
- Resource Group for Education and Advocacy for Community Health, Chennai, India
| | - Aaron Motsoaledi
- South African National Department of Health, Pretoria, South Africa
| | - Madhukar Pai
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada; McGill International TB Center, McGill University, Montreal, QC, Canada
| | - Mario C Raviglione
- University of Milan, Milan, Italy; Global Studies Institute, University of Geneva, Geneva, Switzerland
| | - Almaz Sharman
- Academy of Preventive Medicine of Kazakhstan, Almaty, Kazakhstan
| | - Peter M Small
- Global Health Institute, School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | | | - Zelalem Temesgen
- Department of Infectious Diseases, Mayo Clinic, Rochester, MI, USA
| | - Anna Vassall
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK; Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam, Netherlands
| | | | | | - Gavin Yamey
- Center for Policy Impact in Global Health, Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Bruce D Agins
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA; Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
| | - Sofia Alexandru
- Institutul de Ftiziopneumologie Chiril Draganiuc, Chisinau, Moldova
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Naomi Beyeler
- Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Stela Bivol
- Center for Health Policies and Studies, Chisinau, Moldova
| | - Grania Brigden
- Department of Tuberculosis and HIV, The International Union Against Tuberculosis and Lung Disease, Paris, France
| | - Adithya Cattamanchi
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Danielle Cazabon
- McGill International TB Center, McGill University, Montreal, QC, Canada
| | - Valeriu Crudu
- Center for Health Policies and Studies, Chisinau, Moldova
| | - Amrita Daftary
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada; McGill International TB Center, McGill University, Montreal, QC, Canada
| | - Puneet Dewan
- Bill & Melinda Gates Foundation, New Delhi, India
| | - Laurie K Doepel
- National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Maryland, MA, USA
| | - Robert W Eisinger
- National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Maryland, MA, USA
| | - Victoria Fan
- T H Chan School of Public Health, Harvard University, Cambridge, MA, USA; Office of Public Health Studies, University of Hawaii, Mānoa, HI, USA
| | - Sara Fewer
- Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Jennifer Furin
- Division of Infectious Diseases & HIV Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jeremy D Goldhaber-Fiebert
- Centers for Health Policy and Primary Care and Outcomes Research, Stanford University, Stanford, CA, USA
| | - Gabriela B Gomez
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Stephen M Graham
- Department of Tuberculosis and HIV, The International Union Against Tuberculosis and Lung Disease, Paris, France; Department of Paediatrics, Center for International Child Health, University of Melbourne, Melbourne, VIC, Australia; Burnet Institute, Melbourne, VIC, Australia
| | - Devesh Gupta
- Revised National TB Control Program, New Delhi, India
| | - Maureen Kamene
- National Tuberculosis, Leprosy and Lung Disease Program, Ministry of Health, Nairobi, Kenya
| | | | - Eunice W Mailu
- National Tuberculosis, Leprosy and Lung Disease Program, Ministry of Health, Nairobi, Kenya
| | | | - Lorrie McHugh
- Office of the Secretary-General's Special Envoy on Tuberculosis, United Nations, Geneva, Switzerland
| | - Ellen Mitchell
- International Institute of Social Studies, Erasmus University Rotterdam, The Hague, Netherland
| | - Suerie Moon
- Department of Global Health and Population, Harvard University, Cambridge, MA, USA; Global Health Centre, The Graduate Institute Geneva, Geneva, Switzerland
| | | | - Tripti Pande
- McGill International TB Center, McGill University, Montreal, QC, Canada
| | - Lea Prince
- Centers for Health Policy and Primary Care and Outcomes Research, Stanford University, Stanford, CA, USA
| | | | - Raghuram Rao
- Ministry of Health and Family Welfare, New Delhi, India
| | - Michelle Remme
- International Institute for Global Health, United Nations University, Kuala Lumpur, Malaysia
| | - James A Seddon
- Department of Medicine, Imperial College London, London, UK; Faculty of Medicine, Imperial College London, London, UK; Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa
| | - Casey Selwyn
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Priya Shete
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | | | | | - Juan F Vesga
- School of Public Health, Imperial College London, London, UK; Faculty of Medicine, Imperial College London, London, UK
| | | | - Eric P Goosby
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA; Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
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9
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Kendall EA, Azman AS, Cobelens FG, Dowdy DW. MDR-TB treatment as prevention: The projected population-level impact of expanded treatment for multidrug-resistant tuberculosis. PLoS One 2017; 12:e0172748. [PMID: 28273116 PMCID: PMC5342197 DOI: 10.1371/journal.pone.0172748] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/10/2017] [Indexed: 01/12/2023] Open
Abstract
Background In 2013, approximately 480,000 people developed active multidrug-resistant tuberculosis (MDR-TB), while only 97,000 started MDR-TB treatment. We sought to estimate the impact of improving access to MDR-TB diagnosis and treatment, under multiple diagnostic algorithm and treatment regimen scenarios, on ten-year projections of MDR-TB incidence and mortality. Methods We constructed a dynamic transmission model of an MDR-TB epidemic in an illustrative East/Southeast Asian setting. Using approximate Bayesian computation, we investigated a wide array of potential epidemic trajectories consistent with current notification data and known TB epidemiology. Results Despite an overall projected decline in TB incidence, data-consistent simulations suggested that MDR-TB incidence is likely to rise between 2015 and 2025 under continued 2013 treatment practices, although with considerable uncertainty (median 17% increase, 95% Uncertainty Range [UR] -38% to +137%). But if, by 2017, all identified active TB patients with previously-treated TB could be tested for drug susceptibility, and 85% of those with MDR-TB could initiate MDR-appropriate treatment, then MDR-TB incidence in 2025 could be reduced by 26% (95% UR 4–52%) relative to projections under continued current practice. Also expanding this drug-susceptibility testing and appropriate MDR-TB treatment to treatment-naïve as well as previously-treated TB cases, by 2020, could reduce MDR-TB incidence in 2025 by 29% (95% UR 6–55%) compared to continued current practice. If this diagnosis and treatment of all MDR-TB in known active TB cases by 2020 could be implemented via a novel second-line regimen with similar effectiveness and tolerability as current first-line therapy, a 54% (95% UR 20–74%) reduction in MDR-TB incidence compared to current-practice projections could be achieved by 2025. Conclusions Expansion of diagnosis and treatment of MDR-TB, even using current sub-optimal second-line regimens, is expected to significantly decrease MDR-TB incidence at the population level. Focusing MDR diagnostic efforts on previously-treated cases is an efficient first-step approach.
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Affiliation(s)
- Emily A. Kendall
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| | - Andrew S. Azman
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Frank G. Cobelens
- Amsterdam Institute for Global Health and Development, Academic Medical Centre, Amsterdam, Netherlands
| | - David W. Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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10
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A Multistrain Mathematical Model To Investigate the Role of Pyrazinamide in the Emergence of Extensively Drug-Resistant Tuberculosis. Antimicrob Agents Chemother 2017; 61:AAC.00498-16. [PMID: 27956422 PMCID: PMC5328532 DOI: 10.1128/aac.00498-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 11/17/2016] [Indexed: 11/20/2022] Open
Abstract
Several infectious diseases of global importance—e.g., HIV infection and tuberculosis (TB)—require prolonged treatment with combination antimicrobial regimens typically involving high-potency core agents coupled with additional companion drugs that protect against the de novo emergence of mutations conferring resistance to the core agents. Often, the most effective (or least toxic) companion agents are reused in sequential (first-line, second-line, etc.) regimens. We used a multistrain model of Mycobacterium tuberculosis transmission in Southeast Asia to investigate how this practice might facilitate the emergence of extensive drug resistance, i.e., resistance to multiple core agents. We calibrated this model to regional TB and drug resistance data using an approximate Bayesian computational approach. We report the proportion of data-consistent simulations in which the prevalence of pre-extensively drug-resistant (pre-XDR) TB—defined as resistance to both first-line and second-line core agents (rifampin and fluoroquinolones)—exceeds predefined acceptability thresholds (1 to 2 cases per 100,000 population by 2035). The use of pyrazinamide (the most effective companion agent) in both first-line and second-line regimens increased the proportion of simulations in which the prevalence exceeded the pre-XDR acceptability threshold by 7-fold compared to a scenario in which patients with pyrazinamide-resistant TB received an alternative drug. Model parameters related to the emergence and transmission of pyrazinamide-resistant TB and resistance amplification were among those that were the most strongly correlated with the projected pre-XDR prevalence, indicating that pyrazinamide resistance acquired during first-line treatment subsequently promotes amplification to pre-XDR TB under pyrazinamide-containing second-line treatment. These findings suggest that the appropriate use of companion drugs may be critical to preventing the emergence of strains resistant to multiple core agents.
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11
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Gomez GB, Dowdy DW, Bastos ML, Zwerling A, Sweeney S, Foster N, Trajman A, Islam MA, Kapiga S, Sinanovic E, Knight GM, White RG, Wells WA, Cobelens FG, Vassall A. Cost and cost-effectiveness of tuberculosis treatment shortening: a model-based analysis. BMC Infect Dis 2016; 16:726. [PMID: 27905897 PMCID: PMC5131398 DOI: 10.1186/s12879-016-2064-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 11/08/2016] [Indexed: 12/05/2022] Open
Abstract
Background Despite improvements in treatment success rates for tuberculosis (TB), current six-month regimen duration remains a challenge for many National TB Programmes, health systems, and patients. There is increasing investment in the development of shortened regimens with a number of candidates in phase 3 trials. Methods We developed an individual-based decision analytic model to assess the cost-effectiveness of a hypothetical four-month regimen for first-line treatment of TB, assuming non-inferiority to current regimens of six-month duration. The model was populated using extensive, empirically-collected data to estimate the economic impact on both health systems and patients of regimen shortening for first-line TB treatment in South Africa, Brazil, Bangladesh, and Tanzania. We explicitly considered ‘real world’ constraints such as sub-optimal guideline adherence. Results From a societal perspective, a shortened regimen, priced at USD1 per day, could be a cost-saving option in South Africa, Brazil, and Tanzania, but would not be cost-effective in Bangladesh when compared to one gross domestic product (GDP) per capita. Incorporating ‘real world’ constraints reduces cost-effectiveness. Patient-incurred costs could be reduced in all settings. From a health service perspective, increased drug costs need to be balanced against decreased delivery costs. The new regimen would remain a cost-effective option, when compared to each countries’ GDP per capita, even if new drugs cost up to USD7.5 and USD53.8 per day in South Africa and Brazil; this threshold was above USD1 in Tanzania and under USD1 in Bangladesh. Conclusion Reducing the duration of first-line TB treatment has the potential for substantial economic gains from a patient perspective. The potential economic gains for health services may also be important, but will be context-specific and dependent on the appropriate pricing of any new regimen. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-2064-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- G B Gomez
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Trinity Building C, Pietersbergweg 17, Amsterdam, 1105 BM, The Netherlands. .,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK.
| | - D W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - M L Bastos
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Tuberculosis Scientific League, Rio de Janeiro, Brazil
| | - A Zwerling
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - S Sweeney
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - N Foster
- Health Economics Unit, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
| | - A Trajman
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Tuberculosis Scientific League, Rio de Janeiro, Brazil.,McGill University, Montreal, Canada
| | - M A Islam
- BRAC Health Nutrition and Population Programme, BRAC Centre, Dhaka, Bangladesh
| | - S Kapiga
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - E Sinanovic
- Health Economics Unit, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
| | - G M Knight
- TB Modelling Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - R G White
- TB Modelling Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - W A Wells
- Global Alliance for TB Drug Development, New York, USA.,Present address: United States Agency for International Development, Washington, DC, USA
| | - F G Cobelens
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Trinity Building C, Pietersbergweg 17, Amsterdam, 1105 BM, The Netherlands.,KNCV Tuberculosis Foundation, The Hague, Netherlands
| | - A Vassall
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
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12
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Knight GM, Colijn C, Shrestha S, Fofana M, Cobelens F, White RG, Dowdy DW, Cohen T. The Distribution of Fitness Costs of Resistance-Conferring Mutations Is a Key Determinant for the Future Burden of Drug-Resistant Tuberculosis: A Model-Based Analysis. Clin Infect Dis 2016; 61Suppl 3:S147-54. [PMID: 26409276 DOI: 10.1093/cid/civ579] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Drug resistance poses a serious challenge for the control of tuberculosis in many settings. It is well established that the expected future trend in resistance depends on the reproductive fitness of drug-resistant Mycobacterium tuberculosis. However, the variability in fitness between strains with different resistance-conferring mutations has been largely ignored when making these predictions. METHODS We developed a novel approach for incorporating the variable fitness costs of drug resistance-conferring mutations and for tracking this distribution of fitness costs over time within a transmission model. We used this approach to describe the effects of realistic fitness cost distributions on the future prevalence of drug-resistant tuberculosis. RESULTS The shape of the distribution of fitness costs was a strong predictor of the long-term prevalence of resistance. While, as expected, lower average fitness costs of drug resistance-conferring mutations were associated with more severe epidemics of drug-resistant tuberculosis, fitness distributions with greater variance also led to higher levels of drug resistance. For example, compared to simulations in which the fitness cost of resistance was fixed, introducing a realistic amount of variance resulted in a 40% increase in prevalence of drug-resistant tuberculosis after 20 years. CONCLUSIONS The differences in the fitness costs associated with drug resistance-conferring mutations are a key determinant of the future burden of drug-resistant tuberculosis. Future studies that can better establish the range of fitness costs associated with drug resistance-conferring mutations will improve projections and thus facilitate better public health planning efforts.
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Affiliation(s)
- Gwenan M Knight
- Tuberculosis Modelling Group, Centre for the Mathematical Modelling of Infectious Diseases, Tuberculosis Centre, Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine
| | - Caroline Colijn
- Department of Mathematics, Imperial College London, United Kingdom
| | - Sourya Shrestha
- Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Mariam Fofana
- Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Frank Cobelens
- Amsterdam Institute for Global Health and Development, Academic Medical Center KNCV Tuberculosis Foundation, The Hague, The Netherlands
| | - Richard G White
- Tuberculosis Modelling Group, Centre for the Mathematical Modelling of Infectious Diseases, Tuberculosis Centre, Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Ted Cohen
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, Connecticut
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13
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Kendall EA, Fofana MO, Dowdy DW. Burden of transmitted multidrug resistance in epidemics of tuberculosis: a transmission modelling analysis. THE LANCET RESPIRATORY MEDICINE 2015; 3:963-72. [PMID: 26597127 PMCID: PMC4684734 DOI: 10.1016/s2213-2600(15)00458-0] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/22/2015] [Accepted: 10/25/2015] [Indexed: 11/26/2022]
Abstract
Background Multidrug-resistant tuberculosis (MDR-TB) can be acquired through de novo mutation during TB treatment or through transmission from other individuals with active MDR-TB. Understanding the balance between these two mechanisms is essential when allocating resources for MDR-TB. Methods We constructed a dynamic transmission model of an MDR-TB epidemic, allowing for both treatment-related acquisition and person-to-person transmission of resistance. We used national TB notification data to inform Bayesian estimates of the fraction of each country’s 2013 MDR-TB incidence that resulted from MDR transmission rather than treatment-related MDR acquisition. Findings Global estimates of 3·5% MDR-TB prevalence among new TB notifications and 20·5% among retreatment notifications translate into an estimate that resistance transmission rather than acquisition accounts for a median 96% (95% UR: 68–100%) of all incident MDR-TB, and 61% (16–95%) of incident MDR-TB in previously-treated individuals. The estimated percentage of MDR-TB resulting from transmission varied substantially with different countries’ notification data; for example, we estimated this percentage at 48% (30–75%) of MDR-TB in Bangladesh, versus 99% (91–100%) in Uzbekistan. Estimates were most sensitive to estimates of the transmissibility of MDR strains, the probability of acquiring MDR during tuberculosis treatment, and the responsiveness of MDR TB to first-line treatment. Interpretation Notifications of MDR prevalence from most high-burden settings are most consistent with the vast majority of incident MDR-TB resulting from transmission rather than new treatment-related acquisition of resistance. Merely improving the treatment of drug-susceptible TB is unlikely to greatly reduce future MDR-TB incidence. Improved diagnosis and treatment of MDR-TB – including new tests and drug regimens – should be highly prioritized.
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Affiliation(s)
- Emily A Kendall
- Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, MD, USA.
| | - Mariam O Fofana
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Mathematical Modelling and Tuberculosis: Advances in Diagnostics and Novel Therapies. Adv Med 2015; 2015:907267. [PMID: 26556559 PMCID: PMC4590968 DOI: 10.1155/2015/907267] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 02/18/2015] [Accepted: 02/26/2015] [Indexed: 11/18/2022] Open
Abstract
As novel diagnostics, therapies, and algorithms are developed to improve case finding, diagnosis, and clinical management of patients with TB, policymakers must make difficult decisions and choose among multiple new technologies while operating under heavy resource constrained settings. Mathematical modelling can provide helpful insight by describing the types of interventions likely to maximize impact on the population level and highlighting those gaps in our current knowledge that are most important for making such assessments. This review discusses the major contributions of TB transmission models in general, namely, the ability to improve our understanding of the epidemiology of TB. We focus particularly on those elements that are important to appropriately understand the role of TB diagnosis and treatment (i.e., what elements of better diagnosis or treatment are likely to have greatest population-level impact) and yet remain poorly understood at present. It is essential for modellers, decision-makers, and epidemiologists alike to recognize these outstanding gaps in knowledge and understand their potential influence on model projections that may guide critical policy choices (e.g., investment and scale-up decisions).
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