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Amane M, El Mazini S, Echchakery M, Hafidi M, Lemrani M, Boussaa S. Entomological, parasitological and molecular investigations in a new focus of cutaneous leishmaniasis in Youssoufia region, Morocco. Zoonoses Public Health 2024; 71:248-257. [PMID: 38105536 DOI: 10.1111/zph.13105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND AND AIMS Leishmaniasis is a neglected tropical infection caused by Leishmania parasite that affect human and animal. In Morocco, the cutaneous leishmaniasis has spread substantially to the new areas. The surveillance limited to active foci may underestimate the occurrence of cutaneous leishmaniasis (CL). This study aims to investigate the local transmission of CL in rural districts of Youssoufia province, central Morocco, as a potential focus of CL. METHODS For this purpose, parasitological, molecular and entomological investigations were carried out in this area. Data collection concerns potential vectors and human cases. Thus, 402 patients were examined for suspected leishmaniasis lesions in three localities of the province of Youssoufia. In these same localities, 983 sand flies were collected by CDC light traps and sticky paper during one-night per month during 6 months. These sand flies were all identified morphologically using the Moroccan identification key. RESULTS The results showed that among the 25 skin lesions detected in a population of 402 individuals, 18 were confirmed by kDNA nested PCR as CL positive patients, of which only 25% were positive by direct examination. Leishmania tropica and Leishmania major were identified as causative agents of CL in the study area. Direct parasitological examination showed a low sensitivity (27.78%), especially for L. major, although its specificity was evaluated at 100%. Regarding entomological results, both genera of the Moroccan sand fly were collected in the study area: Genus/Phlebotomus (75.28%) and Sergentomyia (24.72%). Phlebotomus (P) papatasi, the proven vector of L. major, was the most abundant species (33.98%), followed by Paralongicollum sergenti (22.58%), the confirmed vector of L. tropica; while Sergentomyia (S) minuta, P. longicuspis, S. fallax and P. kazeruni were collected with, respectively, 17.60%, 16.99%, 7.12% and 1.73%. CONCLUSION This study constitutes the first report of CL in the study areas, as well as the coexistence of L. tropica and L. major in these rural localities. Local transmission of CL is highly probable, as indicated by the prevalence of the two proven vectors of L. major and L. tropica. To control the spread of this disease, our results suggest the use of highly sensitive molecular methods to detect CL cases in potential leishmaniasis foci, which will improve surveillance.
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Affiliation(s)
- Mounia Amane
- Microbial Biotechnologies, Agrosciences and Environment Laboratory (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Sara El Mazini
- Laboratory of Parasitology and Vector-Borne-Diseases, Institut Pasteur du Maroc, Casablanca, Morocco
- Laboratory of Microbial Biotechnology and Bioactive Molecules, Faculty of Sciences and Technologies, Sidi Mohammed Ben Abdellah University, Fes, Morocco
| | - Mohamed Echchakery
- Microbial Biotechnologies, Agrosciences and Environment Laboratory (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
- Epidemiology and Biomedical Unit, Laboratory of Sciences and Health Technologies, Higher Institute of Health Sciences, Hassan First University, Settat, Morocco
| | - Mohamed Hafidi
- Microbial Biotechnologies, Agrosciences and Environment Laboratory (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Meryem Lemrani
- Laboratory of Parasitology and Vector-Borne-Diseases, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Samia Boussaa
- Microbial Biotechnologies, Agrosciences and Environment Laboratory (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
- ISPITS-Higher Institute of Nursing and Technical Health Occupations, Ministry of Health and Social Protection, Rabat, Morocco
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Oyeyemi OT, Ogundahunsi O, Schunk M, Fatem RG, Shollenberger LM. Neglected tropical disease (NTD) diagnostics: current development and operations to advance control. Pathog Glob Health 2024; 118:1-24. [PMID: 37872790 PMCID: PMC10769148 DOI: 10.1080/20477724.2023.2272095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023] Open
Abstract
Neglected tropical diseases (NTDs) have become important public health threats that require multi-faceted control interventions. As late treatment and management of NTDs contribute significantly to the associated burdens, early diagnosis becomes an important component for surveillance and planning effective interventions. This review identifies common NTDs and highlights the progress in the development of diagnostics for these NTDs. Leveraging existing technologies to improve NTD diagnosis and improving current operational approaches for deployment of developed diagnostics are crucial to achieving the 2030 NTD elimination target. Point-of-care NTD (POC-NTD) diagnostic tools are recommended preferred diagnostic options in resource-constrained areas for mapping risk zones and monitoring treatment efficacy. However, few are currently available commercially. Technical training of remote health care workers on the use of POC-NTD diagnostics, and training of health workers on the psychosocial consequences of these diagnostics are critical in harnessing POC-NTD diagnostic potential. While the COVID-19 pandemic has challenged the possibility of achieving NTD elimination in 2030 due to the disruption of healthcare services and dwindling financial support for NTDs, the possible contribution of NTDs in exacerbating COVID-19 pandemic should motivate NTD health system strengthening.
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Affiliation(s)
- Oyetunde T. Oyeyemi
- Department of Biosciences and Biotechnology, University of Medical Sciences, Ondo, Nigeria
- Department of Biological Sciences, Old Dominion University, Virginia, USA
| | - Olumide Ogundahunsi
- The Central Office for Research and Development (CORD), University of Medical Sciences, Ondo, Nigeria
| | - Mirjam Schunk
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU) institution, Munich, Germany
| | - Ramzy G. Fatem
- Schistosome Biological Supply Center, Theodor Bilharz Research Institute, Giza, Egypt
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Habib M, Adegnika AA, Honkpehedji J, Klug SJ, Lobmaier S, Vogg K, Bustinduy AL, Ullrich A, Reinhard-Rupp J, Esen M, Prazeres da Costa C. The challenges for women's health in sub-Saharan Africa: Lessons learned from an integrative multistakeholder workshop in Gabon. J Glob Health 2021; 11:02002. [PMID: 34552713 PMCID: PMC8442509 DOI: 10.7189/jogh.11.02002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Marrium Habib
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University of Munich (TUM), Munich, Germany.,Center for Global Health, TUM School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Ayola Akim Adegnika
- Institute for Tropical Medicine (ITM), University Clinic Tübingen, (UKT), Tübingen, Germany.,Centre de Réchèrches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Josiane Honkpehedji
- Centre de Réchèrches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Center for Infection Research (DZIF), Tübingen, Germany
| | - Stefanie J Klug
- Chair of Epidemiology, Department of Sport and Health Sciences, Technical University of Munich (TUM), Munich, Germany
| | - Silvia Lobmaier
- Clinic and Polyclinic for Gynecology, University Hospital, Klinikum Rechts der Isar (MRI), Technical University Munich (TUM), Munich, Germany
| | - Kathrin Vogg
- Clinic and Polyclinic for Gynecology, University Hospital, Klinikum Rechts der Isar (MRI), Technical University Munich (TUM), Munich, Germany
| | - Amaya L Bustinduy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom
| | | | | | - Meral Esen
- Institute for Tropical Medicine (ITM), University Clinic Tübingen, (UKT), Tübingen, Germany.,Centre de Réchèrches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Center for Infection Research (DZIF), Tübingen, Germany
| | - Clarissa Prazeres da Costa
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University of Munich (TUM), Munich, Germany.,Center for Global Health, TUM School of Medicine, Technical University of Munich (TUM), Munich, Germany.,German Center for Infection Research (DZIF), Tübingen, Germany
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4
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Botana L, Ibarra-Meneses AV, Sanchez C, Matia B, San Martin JV, Moreno J, Carrillo E. Leishmaniasis: A new method for confirming cure and detecting asymptomatic infection in patients receiving immunosuppressive treatment for autoimmune disease. PLoS Negl Trop Dis 2021; 15:e0009662. [PMID: 34339445 PMCID: PMC8360552 DOI: 10.1371/journal.pntd.0009662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 08/12/2021] [Accepted: 07/19/2021] [Indexed: 11/19/2022] Open
Abstract
Visceral leishmaniasis (VL) in patients receiving immunosuppressant drugs for autoimmune disease has been on the rise. It is important—but difficult—to know when cure has been achieved in these patients since the withdrawal of immunosuppressants during antileishmania treatment is commonly required, and there is a risk of relapse when immunosuppression is restored. The prevalence of asymptomatic infection among those immunosuppressed for autoimmune disease is also uncertain. The present work describes how cytokine release assays can be used to confirm the cure of VL, and to determine the prevalence of asymptomatic infection, in such patients. After collection of blood from volunteers (n = 108), SLA-stimulation of peripheral blood mononuclear cell cultures and of whole blood was found to induce the production of different combinations of cytokines that served to confirm recovery from VL, and asymptomatic Leishmania infection. Indeed, cure was confirmed in 14 patients, all of whom showed a specific Th1 immune response against Leishmania, and the prevalence of asymptomatic infection was determined as 21.27%. Cytokine profiles could be used to manage VL in patients with autoimmune disease, and to identify and better protect those with asymptomatic infection who are at risk of developing this disease. Cytokine release assays were used to confirm the cure of visceral leishmaniasis in patients (from an area where Leishmania infantum is endemic) with autoimmune disease. They were also used to determine the prevalence of asymptomatic Leishmania infantum infection in similar patients. Some 21.27% of those with no clinical history of leishmaniasis were shown to have been contact with the parasite.
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Affiliation(s)
- Laura Botana
- WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
- Cardiology Department, Universidad Francisco de Vitoria/Hospital Ramón y Cajal Research Unit (IRYCIS), Madrid, Spain
| | - Ana Victoria Ibarra-Meneses
- WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Carmen Sanchez
- WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Belen Matia
- Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain
| | | | - Javier Moreno
- WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Eugenia Carrillo
- WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
- * E-mail:
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Dubey P, Das A, Priyamvada K, Bindroo J, Mahapatra T, Mishra PK, Kumar A, Franco AO, Rooj B, Sinha B, Pradhan S, Banerjee I, Kumar M, Bano N, Kumar C, Prasad C, Chakraborty P, Kumar R, Kumar N, Kumar A, Singh AK, Kundan K, Babu S, Shah H, Karthick M, Roy N, Gill NK, Dwivedi S, Chaudhuri I, Hightower AW, Chapman LAC, Singh C, Sharma MP, Dhingra N, Bern C, Srikantiah S. Development and Evaluation of Active Case Detection Methods to Support Visceral Leishmaniasis Elimination in India. Front Cell Infect Microbiol 2021; 11:648903. [PMID: 33842396 PMCID: PMC8024686 DOI: 10.3389/fcimb.2021.648903] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 03/01/2021] [Indexed: 11/13/2022] Open
Abstract
As India moves toward the elimination of visceral leishmaniasis (VL) as a public health problem, comprehensive timely case detection has become increasingly important, in order to reduce the period of infectivity and control outbreaks. During the 2000s, localized research studies suggested that a large percentage of VL cases were never reported in government data. However, assessments conducted from 2013 to 2015 indicated that 85% or more of confirmed cases were eventually captured and reported in surveillance data, albeit with significant delays before diagnosis. Based on methods developed during these assessments, the CARE India team evolved new strategies for active case detection (ACD), applicable at large scale while being sufficiently effective in reducing time to diagnosis. Active case searches are triggered by the report of a confirmed VL case, and comprise two major search mechanisms: 1) case identification based on the index case's knowledge of other known VL cases and searches in nearby houses (snowballing); and 2) sustained contact over time with a range of private providers, both formal and informal. Simultaneously, house-to-house searches were conducted in 142 villages of 47 blocks during this period. We analyzed data from 5030 VL patients reported in Bihar from January 2018 through July 2019. Of these 3033 were detected passively and 1997 via ACD (15 (0.8%) via house-to-house and 1982 (99.2%) by light touch ACD methods). We constructed multinomial logistic regression models comparing time intervals to diagnosis (30-59, 60-89 and ≥90 days with <30 days as the referent). ACD and younger age were associated with shorter time to diagnosis, while male sex and HIV infection were associated with longer illness durations. The advantage of ACD over PCD was more marked for longer illness durations: the adjusted odds ratios for having illness durations of 30-59, 60-89 and >=90 days compared to the referent of <30 days for ACD vs PCD were 0.88, 0.56 and 0.42 respectively. These ACD strategies not only reduce time to diagnosis, and thus risk of transmission, but also ensure that there is a double check on the proportion of cases actually getting captured. Such a process can supplement passive case detection efforts that must go on, possibly perpetually, even after elimination as a public health problem is achieved.
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Affiliation(s)
- Pushkar Dubey
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Aritra Das
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Khushbu Priyamvada
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Joy Bindroo
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Tanmay Mahapatra
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Prabhas Kumar Mishra
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Ankur Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Ana O. Franco
- Institute for Global Health Sciences, Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States
| | - Basab Rooj
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Bikas Sinha
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Sreya Pradhan
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Indranath Banerjee
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Manash Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Nasreen Bano
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Chandan Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Chandan Prasad
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Parna Chakraborty
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Rakesh Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Niraj Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Aditya Kumar
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Abhishek Kumar Singh
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Kumar Kundan
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Sunil Babu
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Hemant Shah
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Morchan Karthick
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Nupur Roy
- National Vector Borne Disease Control Programme, Ministry of Health and Family Welfare, Government of India, Delhi, India
| | - Naresh Kumar Gill
- National Vector Borne Disease Control Programme, Ministry of Health and Family Welfare, Government of India, Delhi, India
| | - Shweta Dwivedi
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | - Indrajit Chaudhuri
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
| | | | - Lloyd A C. Chapman
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chandramani Singh
- Department of Community and Family Medicine, All India Institute of Medical Sciences, Patna, India
| | | | - Neeraj Dhingra
- National Vector Borne Disease Control Programme, Ministry of Health and Family Welfare, Government of India, Delhi, India
| | - Caryn Bern
- Institute for Global Health Sciences, Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States
| | - Sridhar Srikantiah
- Bihar Technical Support Program, CARE-India Solutions for Sustainable Development, Patna, India
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Cloots K, Marino P, Burza S, Gill N, Boelaert M, Hasker E. Visceral Leishmaniasis-HIV Coinfection as a Predictor of Increased Leishmania Transmission at the Village Level in Bihar, India. Front Cell Infect Microbiol 2021; 11:604117. [PMID: 33777831 PMCID: PMC7993201 DOI: 10.3389/fcimb.2021.604117] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/16/2021] [Indexed: 11/13/2022] Open
Abstract
Background Visceral leishmaniasis (VL) is on the verge of being eliminated as a public health problem in the Indian subcontinent. Although Post-kala-azar dermal leishmaniasis (PKDL) is recognized as an important reservoir of transmission, we hypothesized that VL patients co-infected with Human Immunodeficiency Virus (HIV) may also be important reservoirs of sustained leishmania transmission. We therefore investigated to what extent cases of PKDL or VL-HIV are associated with VL incidence at the village level in Bihar, India. Methods VL, VL-HIV, and PKDL case data from six districts within the highly VL-endemic state of Bihar, India were collected through the Kala-Azar Management Information System for the years 2014-2019. Multivariate analysis was done using negative binomial regression controlling for year as a fixed effect and block (subdistrict) as a random effect. Findings Presence of VL-HIV+ and PKDL cases were both associated with a more than twofold increase in VL incidence at village level, with Incidence Rate Ratios (IRR) of 2.16 (95% CI 1.81-2.58) and 2.37 (95% CI 2.01-2.81) for VL-HIV+ and PKDL cases respectively. A sensitivity analysis showed the strength of the association to be similar in each of the six included subdistricts. Conclusions These findings indicate the importance of VL-HIV+ patients as infectious reservoirs for Leishmania, and suggest that they represent a threat equivalent to PKDL patients towards the VL elimination initiative on the Indian subcontinent, therefore warranting a similar focus.
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Affiliation(s)
- Kristien Cloots
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Pia Marino
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Erasmus Mundus Joint Master Degree, Infectious Diseases & One Health Programme, Department of Pharmacy, University of Tours, Tours, France
| | | | - Naresh Gill
- National Vector Borne Disease Control Programme, Ministry of Health and Family Welfare, Government of India, Delhi, India
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Epco Hasker
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
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de Souza DK, Picado A, Biéler S, Nogaro S, Ndung’u JM. Diagnosis of neglected tropical diseases during and after the COVID-19 pandemic. PLoS Negl Trop Dis 2020; 14:e0008587. [PMID: 32797111 PMCID: PMC7428349 DOI: 10.1371/journal.pntd.0008587] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Dziedzom K. de Souza
- Neglected Tropical Diseases Programme, Foundation for Innovative New Diagnostics, Geneva, Switzerland
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Albert Picado
- Neglected Tropical Diseases Programme, Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Sylvain Biéler
- Neglected Tropical Diseases Programme, Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Sarah Nogaro
- Neglected Tropical Diseases Programme, Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Joseph Mathu Ndung’u
- Neglected Tropical Diseases Programme, Foundation for Innovative New Diagnostics, Geneva, Switzerland
- * E-mail:
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Nelli L, Ferguson HM, Matthiopoulos J. Achieving explanatory depth and spatial breadth in infectious disease modelling: Integrating active and passive case surveillance. Stat Methods Med Res 2019; 29:1273-1287. [PMID: 31213191 DOI: 10.1177/0962280219856380] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ideally, the data used for robust spatial prediction of disease distribution should be both high-resolution and spatially expansive. However, such in-depth and geographically broad data are rarely available in practice. Instead, researchers usually acquire either detailed epidemiological data with high resolution at a small number of active sampling sites, or more broad-ranging but less precise data from passive case surveillance. We propose a novel inferential framework, capable of simultaneously drawing insights from both passive and active data types. We developed a Bayesian latent point process approach, combining active data collection in a limited set of points, where in-depth covariates are measured, with passive case detection, where error-prone, large-scale disease data are accompanied only by coarse or remotely-sensed covariate layers. Using the example of malaria, we tested our method's efficiency under several hypothetical scenarios of reported incidence in different combinations of imperfect detection and spatial complexity of the environmental variables. We provide a simple solution to a widespread problem in spatial epidemiology, combining latent process modelling and spatially autoregressive modelling. By using active sampling and passive case detection in a complementary way, we achieved the best-of-both-worlds, in effect, a formal calibration of spatially extensive, error-prone data by localised, high-quality data.
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Affiliation(s)
- Luca Nelli
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Heather M Ferguson
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Jason Matthiopoulos
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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9
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Chapman LAC, Jewell CP, Spencer SEF, Pellis L, Datta S, Chowdhury R, Bern C, Medley GF, Hollingsworth TD. The role of case proximity in transmission of visceral leishmaniasis in a highly endemic village in Bangladesh. PLoS Negl Trop Dis 2018; 12:e0006453. [PMID: 30296295 PMCID: PMC6175508 DOI: 10.1371/journal.pntd.0006453] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/13/2018] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Visceral leishmaniasis (VL) is characterised by a high degree of spatial clustering at all scales, and this feature remains even with successful control measures. VL is targeted for elimination as a public health problem in the Indian subcontinent by 2020, and incidence has been falling rapidly since 2011. Current control is based on early diagnosis and treatment of clinical cases, and blanket indoor residual spraying of insecticide (IRS) in endemic villages to kill the sandfly vectors. Spatially targeting active case detection and/or IRS to higher risk areas would greatly reduce costs of control, but its effectiveness as a control strategy is unknown. The effectiveness depends on two key unknowns: how quickly transmission risk decreases with distance from a VL case and how much asymptomatically infected individuals contribute to transmission. METHODOLOGY/PRINCIPAL FINDINGS To estimate these key parameters, a spatiotemporal transmission model for VL was developed and fitted to geo-located epidemiological data on 2494 individuals from a highly endemic village in Mymensingh, Bangladesh. A Bayesian inference framework that could account for the unknown infection times of the VL cases, and missing symptom onset and recovery times, was developed to perform the parameter estimation. The parameter estimates obtained suggest that, in a highly endemic setting, VL risk decreases relatively quickly with distance from a case-halving within 90m-and that VL cases contribute significantly more to transmission than asymptomatic individuals. CONCLUSIONS/SIGNIFICANCE These results suggest that spatially-targeted interventions may be effective for limiting transmission. However, the extent to which spatial transmission patterns and the asymptomatic contribution vary with VL endemicity and over time is uncertain. In any event, interventions would need to be performed promptly and in a large radius (≥300m) around a new case to reduce transmission risk.
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Affiliation(s)
- Lloyd A. C. Chapman
- Zeeman Institute, University of Warwick, Coventry, UK
- School of Life Sciences, University of Warwick, Coventry, UK
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris P. Jewell
- Centre for Health Informatics, Computing And Statistics, Lancaster University, Lancaster, UK
| | - Simon E. F. Spencer
- Zeeman Institute, University of Warwick, Coventry, UK
- Department of Statistics, University of Warwick, Coventry, UK
| | | | - Samik Datta
- Zeeman Institute, University of Warwick, Coventry, UK
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Rajib Chowdhury
- National Institute of Preventive and Social Medicine (NIPSOM), Mohakhali, Dhaka, Bangladesh
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Caryn Bern
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA
| | - Graham F. Medley
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - T. Déirdre Hollingsworth
- Zeeman Institute, University of Warwick, Coventry, UK
- School of Life Sciences, University of Warwick, Coventry, UK
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
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Ghosh P, Hasnain MG, Hossain F, Khan MAA, Chowdhury R, Faisal K, Mural MA, Baker J, Nath R, Ghosh D, Maruf S, Shomik MS, Haque R, Matlashewski G, Hamano S, Duthie MS, Mondal D. Evaluation of Real-time PCR for Diagnosis of Post-Kala-azar Dermal Leishmaniasis in Endemic Foci of Bangladesh. Open Forum Infect Dis 2018; 5:ofy234. [PMID: 30320150 PMCID: PMC6176879 DOI: 10.1093/ofid/ofy234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 09/12/2018] [Indexed: 01/09/2023] Open
Abstract
Background Post-kala-azar dermal leishmaniasis (PKDL) is a sequel to visceral leishmaniasis (VL), which is found in VL-endemic countries including Bangladesh. Because of these enigmatic cases, the success of the National Kala-azar Elimination Program is under threat. To date, diagnostic methods for PKDL cases in endemic regions have been limited to clinical examination and rK39 test or microscopy, and a suitable and accurate alternative method is needed. In this study, we investigated the application of real-time polymerase chain reaction (PCR) as a potential method for diagnosis of PKDL in comparison with microscopy. Methods Ninety-one suspected macular PKDL cases from Mymensingh district, Bangladesh, were enrolled in the study after diagnosis by clinical examination and an rK39 strip test. All of them responded after completion of the treatment with miltefosine. During enrollment, a skin biopsy was done for each patient, and both microscopy and real-time PCR were performed for detection and quantification of Leishmania donovan body (LDB) and LD DNA, respectively. Results Real-time PCR detected 83 cases among all suspected PKDL patients, with an encouraging sensitivity of 91.2% (83.4%–96.1%), whereas microscopy showed 50.6% (39.9%–61.2%) sensitivity. Among all suspected PKDL cases, 42 cases were positive in both microscopy and qPCR, whereas 41 cases were detected as positive through qPCR only. Conclusions This study provides evidence that real-time PCR is a promising tool for diagnosis of PKDL in endemic regions. In addition to diagnosis, the quantitative ability of this method could be further exploited for after-treatment prognosis and cure assessment of PKDL cases.
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Affiliation(s)
- Prakash Ghosh
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.,Infectious Disease Research Institute, Seattle, Washington, USA
| | - Md Golam Hasnain
- Centre for Clinical Epidemiology and Biostatistics, School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, New South Wales, Australia
| | - Faria Hossain
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Md Anik Ashfaq Khan
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rajashree Chowdhury
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Khaledul Faisal
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Moshtaq Ahmed Mural
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - James Baker
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rupen Nath
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Debashis Ghosh
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shomik Maruf
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad Sohel Shomik
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rashidul Haque
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Greg Matlashewski
- Department of Microbiology and Immunology, McGill University, Montreal, Québec, Canada
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | | | - Dinesh Mondal
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
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Zijlstra EE, Alves F, Rijal S, Arana B, Alvar J. Post-kala-azar dermal leishmaniasis in the Indian subcontinent: A threat to the South-East Asia Region Kala-azar Elimination Programme. PLoS Negl Trop Dis 2017; 11:e0005877. [PMID: 29145397 PMCID: PMC5689828 DOI: 10.1371/journal.pntd.0005877] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background The South-East Asia Region Kala-azar Elimination Programme (KAEP) is expected to enter the consolidation phase in 2017, which focuses on case detection, vector control, and identifying potential sources of infection. Post-kala-azar dermal leishmaniasis (PKDL) is thought to play a role in the recurrence of visceral leishmaniasis (VL)/kala-azar outbreaks, and control of PKDL is among the priorities of the KAEP. Methodology and principal finding We reviewed the literature with regard to PKDL in Asia and interpreted the findings in relation to current intervention methods in the KAEP in order to make recommendations. There is a considerable knowledge gap regarding the pathophysiology of VL and PKDL, especially the underlying immune responses. Risk factors (of which previous VL treatments may be most important) are poorly understood and need to be better defined. The role of PKDL patients in transmission is largely unknown, and there is insufficient information about the importance of duration, distribution and severity of the rash, time of onset, and self-healing. Current intervention methods focus on active case detection and treatment of all PKDL cases with miltefosine while there is increasing drug resistance. The prevention of PKDL by improved VL treatment currently receives insufficient attention. Conclusion and significance PKDL is a heterogeneous and dynamic condition, and patients differ with regard to time of onset after VL, chronicity, and distribution and appearance of the rash, as well as immune responses (including tendency to self-heal), all of which may vary over time. It is essential to fully describe the pathophysiology in order to make informed decisions on the most cost-effective approach. Emphasis should be on early detection of those who contribute to transmission and those who are in need of treatment, for whom short-course, effective, and safe drug regimens should be available. The prevention of PKDL should be emphasised by innovative and improved treatment for VL, which may include immunomodulation.
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Affiliation(s)
- Eduard E. Zijlstra
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
- Rotterdam Centre for Tropical Medicine, Rotterdam, the Netherlands
- * E-mail:
| | - Fabiana Alves
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Suman Rijal
- Drugs for Neglected Diseases initiative, India Office, New Delhi, India
| | - Byron Arana
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Jorge Alvar
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
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12
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Chapman LAC, Dyson L, Courtenay O, Chowdhury R, Bern C, Medley GF, Hollingsworth TD. Quantification of the natural history of visceral leishmaniasis and consequences for control. Parasit Vectors 2015; 8:521. [PMID: 26490668 PMCID: PMC4618734 DOI: 10.1186/s13071-015-1136-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/03/2015] [Indexed: 01/20/2023] Open
Abstract
Background Visceral leishmaniasis has been targeted for elimination as a public health problem (less than 1 case per 10,000 people per year) in the Indian sub-continent by 2017. However, there is still a high degree of uncertainty about the natural history of the disease, in particular about the duration of asymptomatic infection and the proportion of asymptomatically infected individuals that develop clinical visceral leishmaniasis. Quantifying these aspects of the disease is key for guiding efforts to eliminate visceral leishmaniasis and maintaining elimination once it is reached. Methods Data from a detailed epidemiological study in Bangladesh in 2002–2004 was analysed to estimate key epidemiological parameters. The role of diagnostics in determining the probability and rate of progression to clinical disease was estimated by fitting Cox proportional hazards models. A multi-state Markov model of the natural history of visceral leishmaniasis was fitted to the data to estimate the asymptomatic infection period and the proportion of asymptomatic individuals going on to develop clinical symptoms. Results At the time of the study, individuals were taking several months to be diagnosed with visceral leishmaniasis, leading to many opportunities for ongoing transmission. The probability of progression to clinical disease was strongly associated with initial seropositivity and even more strongly with seroconversion, with most clinical symptoms developing within a year. The estimated average durations of asymptomatic infection and symptomatic infection for our model of the natural history are 147 days (95 % CI 130–166) and 140 days (95 % CI 123–160), respectively, and are significantly longer than previously reported estimates. We estimate from the data that 14.7 % (95 % CI 12.6-20.0 %) of asymptomatic individuals develop clinical symptoms—a greater proportion than previously estimated. Conclusions Extended periods of asymptomatic infection could be important for visceral leishmaniasis transmission, but this depends critically on the relative infectivity of asymptomatic and symptomatic individuals to sandflies. These estimates could be informed by similar analysis of other datasets. Our results highlight the importance of reducing times from onset of symptoms to diagnosis and treatment to reduce opportunities for transmission. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1136-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lloyd A C Chapman
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK.
| | - Louise Dyson
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK
| | - Orin Courtenay
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK
| | - Rajib Chowdhury
- Country Programme Manager - Bangladesh, KalaCORE Programme, Dhaka, Bangladesh.,Department of Medical Entomology, National Institute of Preventive and Social Medicine (NIPSOM), Mohakhali, Dhaka, Bangladesh
| | - Caryn Bern
- UCSF School of Medicine, 550 16th Street, San Francisco, CA, 94158, USA
| | - Graham F Medley
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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