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Mudji J, Ackam N, Amoako YA, Madinga B, Mumbere P, Agbanyo A, Blum J, Phillips RO, Molyneux DH. Mental distress and health-related quality of life in gambiense human African trypanosomiasis: a case-control study in the Democratic Republic of Congo. Trans R Soc Trop Med Hyg 2022; 116:1022-1031. [PMID: 35474014 DOI: 10.1093/trstmh/trac035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/17/2022] [Accepted: 04/01/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The extent to which neuropsychiatric sequelae affects the mental health status and quality of life of former gambiense human African trypanosomiasis (gHAT) patients is not known. METHODS We assessed anxiety, depression and health-related quality of life (HRQoL) in 93 patients and their age- and sex-matched controls using the Hospital Anxiety and Depression Scale, Becks Depression Inventory and the 36-item Short Form Health Survey in structured interviews in the Vanga health zone in the Democratic Republic of Congo. Data were analysed using Stata version 14.0. The degree of association between neurologic sequelae and mental distress was evaluated using the Student's t-test and χ2 or Fisher's exact tests, where appropriate, with a p-value <0.05 deemed to be statistically significant. RESULTS We found that neurological sequelae persisted in former patients at least 15 y after treatment. Depression (p<0.001) and anxiety (p=0.001) were significantly higher in former patients with neurologic sequelae. The mean quality-of-life (QoL) scores were significantly lower for patients than in controls in the physical, emotional and mental health domains. CONCLUSIONS The presence of neurological sequelae leads to mental distress and a diminished QoL in former gHAT patients. Minimising neurologic sequelae and incorporating psychosocial interventions should be essential management goals for gHAT.
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Affiliation(s)
- Junior Mudji
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Department of Family Medicine and Primary Care, Protestant University of Congo, B.P. 4745, Kinshasa 2, Democratic Republic of the Congo
| | - Nancy Ackam
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Yaw Ampem Amoako
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Blaise Madinga
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Department of Family Medicine and Primary Care, Protestant University of Congo, B.P. 4745, Kinshasa 2, Democratic Republic of the Congo
| | - Pépé Mumbere
- Universite de Kinshasa, Centre Neuro-psycho-pathologie, Kinshasa, Democratic Republic of the Congo
| | - Abigail Agbanyo
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Johannes Blum
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland.,University of Basel, 4001 Basel, Switzerland
| | - Richard Odame Phillips
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - David Hurst Molyneux
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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Alumasa L, Thomas LF, Amanya F, Njoroge SM, Moriyón I, Makhandia J, Rushton J, Fèvre EM, Falzon LC. Hospital-based evidence on cost-effectiveness of brucellosis diagnostic tests and treatment in Kenyan hospitals. PLoS Negl Trop Dis 2021; 15:e0008977. [PMID: 33411798 PMCID: PMC7833147 DOI: 10.1371/journal.pntd.0008977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 01/25/2021] [Accepted: 11/10/2020] [Indexed: 12/19/2022] Open
Abstract
Hospitals in Kenya continue to use the Febrile Antigen Brucella Agglutination Test (FBAT) to diagnose brucellosis, despite reports showing its inadequacy. This study generated hospital-based evidence on the performance and cost-effectiveness of the FBAT, compared to the Rose Bengal Test (RBT).Twelve hospitals in western Kenya stored patient serum samples that were tested for brucellosis using the FBAT, and these were later re-tested using the RBT. Data on the running time and cost of the FBAT, and the treatment prescribed for brucellosis, were collected. The cost-effectiveness of the two tests, defined as the cost in US Dollars ($) per Disability Adjusted Life Year (DALY) averted, was determined, and a basic sensitivity analysis was run to identify the most influential parameters. Over a 6-month period, 180 patient serum samples that were tested with FBAT at the hospitals were later re-tested with RBT at the field laboratory. Of these 24 (13.3%) and 3 (1.7%) tested positive with FBAT and RBT, respectively. The agreement between the FBAT and RBT was slight (Kappa = 0.12). Treatment prescribed following FBAT positivity varied between hospitals, and only one hospital prescribed a standardized therapy regimen. The mean $/DALY averted when using the FBAT and RBT were $2,065 (95% CI $481-$6,736) and $304 (95% CI $126-$604), respectively. Brucellosis prevalence was the most influential parameter in the cost-effectiveness of both tests. Extrapolation to the national level suggested that an estimated $338,891 (95% CI $47,000-$1,149,000) per year is currently spent unnecessarily treating those falsely testing positive by FBAT. These findings highlight the potential for misdiagnosis using the FBAT. Furthermore, the RBT is cost-effective, and could be considered as the mainstay screening test for human brucellosis in this setting. Lastly, the treatment regimens must be harmonized to ensure the appropriate use of antibiotics for treatment. Brucellosis is the most common bacterial zoonosis globally, with a higher burden in low-resource settings. In humans, the disease manifests itself with non-specific clinical signs, and current international guidelines recommend the use of two serological diagnostic tests to make a confirmatory diagnosis. Many hospitals in Kenya and some neighbouring countries have been using the Febrile Antigen Brucella Agglutination Test (FBAT) for diagnosis, despite reports showing its poor performance. In this study we compared the diagnostic performance and cost-effectiveness of the FBAT with that of the Rose Bengal Test (RBT), a serological assay recommended by international guidelines. Our results showed that, compared to the RBT, the FBAT incorrectly diagnosed a number of patients. This is of concern as it leads to unnecessary antibiotic treatments, increasing the economic burden of the disease and exacerbating the risk of antibiotic resistance. We also highlight the discrepancies in brucellosis treatment regimens currently being prescribed by various hospitals. Finally, we showed that the RBT is a more cost-effective diagnostic test. Our recommendation, therefore, is for the RBT to be considered as the mainstay diagnostic test for human brucellosis in all Kenyan hospitals, and for the harmonization of treatment guidelines.
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Affiliation(s)
- Lorren Alumasa
- International Livestock Research Institute, Nairobi, Kenya
| | - Lian F. Thomas
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | | | - Samuel M. Njoroge
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Ignacio Moriyón
- Departamento de Microbiología y Parasitología, Facultad de Medicina, and Institute for Tropical Health, Universidad de Navarra, Pamplona, Spain
| | | | - Jonathan Rushton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Eric M. Fèvre
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- * E-mail: (EMF); (LCF)
| | - Laura C. Falzon
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- * E-mail: (EMF); (LCF)
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Koné M, N’Gouan EK, Kaba D, Koffi M, Kouakou L, N’Dri L, Kouamé CM, Nanan VK, Tapé GA, Coulibaly B, Courtin F, Ahouty B, Djohan V, Bucheton B, Solano P, Büscher P, Lejon V, Jamonneau V. The complex health seeking pathway of a human African trypanosomiasis patient in Côte d'Ivoire underlines the need of setting up passive surveillance systems. PLoS Negl Trop Dis 2020; 14:e0008588. [PMID: 32925917 PMCID: PMC7515183 DOI: 10.1371/journal.pntd.0008588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/24/2020] [Accepted: 07/13/2020] [Indexed: 11/25/2022] Open
Abstract
Background Significant efforts to control human African trypanosomiasis (HAT) over the two past decades have resulted in drastic decrease of its prevalence in Côte d’Ivoire. In this context, passive surveillance, integrated in the national health system and based on clinical suspicion, was reinforced. We describe here the health-seeking pathway of a girl who was the first HAT patient diagnosed through this strategy in August 2017. Methods After definitive diagnosis of this patient, epidemiological investigations were carried out into the clinical evolution and the health and therapeutic itinerary of the patient before diagnosis. Results At the time of diagnosis, the patient was positive in both serological and molecular tests and trypanosomes were detected in blood and cerebrospinal fluid. She suffered from important neurological disorders. The first disease symptoms had appeared three years earlier, and the patient had visited several public and private peripheral health care centres and hospitals in different cities. The failure to diagnose HAT for such a long time caused significant health deterioration and was an important financial burden for the family. Conclusion This description illustrates the complexity of detecting the last HAT cases due to complex diagnosis and the progressive disinterest and unawareness by both health professionals and the population. It confirms the need of implementing passive surveillance in combination with continued sensitization and health staff training. Human African trypanosomiasis (HAT) or sleeping sickness is a parasitic disease caused by Trypanosoma brucei that is transmitted by tsetse flies. In 2012, HAT was included in the World Health Organization roadmap for the control of neglected tropical diseases with the objective of elimination as a public health problem by 2020. In Côte d’Ivoire, HAT prevalence has dropped sharply the last decade. A passive HAT surveillance was therefore integrated in the national health system, which allowed to detect a first patient in 2017. This article describes the complex health seeking pathway and suffering before diagnosis of this patient, an 11 years old girl, and illustrates the challenge when health agents and population no longer consider HAT as a threat in an elimination context. Our results show the need to install a solid surveillance system, in combination with continued sensitization and repeated health staff training.
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Affiliation(s)
- Minayégninrin Koné
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | | | - Dramane Kaba
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Mathurin Koffi
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | - Lingué Kouakou
- Programme National d’Élimination de la Trypanosomose Humaine Africaine, Abidjan, Côte d’Ivoire
| | - Louis N’Dri
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Cyrille Mambo Kouamé
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Valentin Kouassi Nanan
- Direction Départementale de la Marahoué, District sanitaire de Sinfra, Ministère de la Santé et de l’Hygiène Publique, Abidjan, Côte d’Ivoire
| | - Gossé Apollinaire Tapé
- Direction départementale de la santé de la Marahoué, Centre de Santé Urbain de Bonon, Ministère de la Santé et de l’Hygiène Publique, Abidjan Côte d’Ivoire
| | - Bamoro Coulibaly
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Fabrice Courtin
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Bernardin Ahouty
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | - Vincent Djohan
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Bruno Bucheton
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Philippe Solano
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Veerle Lejon
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Vincent Jamonneau
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
- * E-mail:
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Vahekeni N, Neto PM, Kayimbo MK, Mäser P, Josenando T, da Costa E, Falquet J, van Eeuwijk P. Use of herbal remedies in the management of sleeping sickness in four northern provinces of Angola. JOURNAL OF ETHNOPHARMACOLOGY 2020; 256:112382. [PMID: 31743767 DOI: 10.1016/j.jep.2019.112382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 11/02/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE This study reports for the first time on the use of folk medicine to treat sleeping sickness and its symptoms in four endemic provinces in northern Angola. By interviewing both traditional practitioners and confirmed patients, it highlights reasons to recourse to folk medicine, the plant species used for this affection as well as arises awareness about the use of particular plants showing potential risks. AIM OF THE STUDY The aims of this explorative study were three-fold. Firstly, it informed on access to, and use of plant-based medicine as first-choice treatment by infected persons. Secondly, it aimed at collecting comprehensive data from patients and traditional healers on herbal remedies in order to identify plant species used in the management of the disease. Thirdly, it served as contribution for primary indication of potential risk of use associated with the studied plants and their preparation. MATERIALS AND METHODS The study was conducted in 4 endemic provinces of Angola, namely Bengo, Zaire, Kwanza Norte and Uíge. We explored the use of herbal remedies by conducting structured and semi-structured interviews within two distinct study populations. The first group comprises 30 patients who had been diagnosed for trypanosomiasis and treated by the reference treatment. The second group included 9 traditional practitioners who had already treated sleeping sickness. The plants that were cited during the interviews were collected during field walks under supervision of a traditional healer, then authenticated and deposited at the National Herbarium in Luanda. RESULTS Of the 30 included patients, 12 (40%) had turned to folk medicine in the management of trypanosomiasis and related symptoms. 7 medicinal plants were reported by this group. Considering the key motivation to consult a traditional practitioner, two main factors accounted for half of the cases: "past experience with folk medicine" and "family habit". Out of 9 traditional practitioners' interviewees, 26 medicinal plants were cited. Roots and leaves were the most used plant parts, and decoction was the common mode of preparation. Evidence for antitrypanosomal activity in the scientific literature was found for 56% (17 of 30) of the identified plant species. The most cited plant was Crossopteryx febrifuga (UR = 6). Some of the cited plants, as for example Aristolochia gigantea, raised concern about potential toxicity. CONCLUSIONS With 40% of infected persons having turned first to folk medicine before consulting a medical doctor, this explorative study points out that plant-based medicines play an important role in local dynamics of health care. It highlights the need for primary assessment of potential risk of use related to the herbal recipes, and for reporting it to the concerned population. This first ethnobotanical study on trypanosomiasis in endemic provinces of Angola provides information on 30 plants, of which some had been identified as promising for further pharmacological research. Our results provide a first step towards the validation and valorization of Angolan herbal remedies for sleeping sickness.
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Affiliation(s)
- Nina Vahekeni
- Swiss Tropical and Public Health Institute (Swiss TPH), Socinstr. 53, 4051, Basel, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland; Nacional Center of Scientific Investigation (CNIC), Luanda, Angola.
| | - Pedro Menezes Neto
- Centro de Estudos e Investigação Científica de Botânica, Universidade Agostinho Neto, Luanda, Angola.
| | | | - Pascal Mäser
- Swiss Tropical and Public Health Institute (Swiss TPH), Socinstr. 53, 4051, Basel, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
| | - Théophile Josenando
- Instituto de Combate e Controlo das Tripanossomíasses (ICCT), Luanda, Angola.
| | - Esperança da Costa
- Centro de Estudos e Investigação Científica de Botânica, Universidade Agostinho Neto, Luanda, Angola.
| | | | - Peter van Eeuwijk
- Swiss Tropical and Public Health Institute (Swiss TPH), Socinstr. 53, 4051, Basel, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland; Institute of Social Anthropology, University of Basel, Münsterplatz 19, 4051, Basel, Switzerland.
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Bukachi SA, Mumbo AA, Alak ACD, Sebit W, Rumunu J, Biéler S, Ndung'u JM. Knowledge, attitudes and practices about human African trypanosomiasis and their implications in designing intervention strategies for Yei county, South Sudan. PLoS Negl Trop Dis 2018; 12:e0006826. [PMID: 30273342 PMCID: PMC6181432 DOI: 10.1371/journal.pntd.0006826] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 10/11/2018] [Accepted: 09/11/2018] [Indexed: 02/01/2023] Open
Abstract
Background A clear understanding of the knowledge, attitudes and practices (KAP) of a particular community is necessary in order to improve control of human African trypanosomiasis (HAT).New screening and diagnostic tools and strategies were introduced into South Sudan, as part of integrated delivery of primary healthcare. Knowledge and awareness on HAT, its new/improved screening and diagnostic tools, the places and processes of getting a confirmatory diagnosis and treatment are crucial to the success of this strategy. Methodology A KAP survey was carried out in Yei County, South Sudan, to identify gaps in community KAP and determine the preferred channels and sources of information on the disease. The cross-sectional KAP survey utilized questionnaires, complemented with key informant interviews and a focus group discussion to elicit communal as well as individual KAP on HAT. Findings Most (90%) of the respondents had general knowledge on HAT. Lower levels of education, gender and geographic locations without a history of HAT interventions were associated with incorrect knowledge and/or negative perceptions about the treatability of HAT. Symptoms appearing in the late stage were best known. A majority (97.2%) would seek treatment for HAT only in a health centre. However, qualitative data indicates that existing myths circulating in the popular imagination could influence people’s practices. Seventy-one percent of the respondents said they would offer social support to patients with HAT but qualitative data highlights that stigma still exists. Misconceptions and stigma can negatively influence the health seeking behaviour of HAT cases. In relation to communication, the top preferred and effective source of communication was radio (24%). Conclusion Gaps in relation to KAP on HAT still exist in the community. Perceptions on HAT, specifically myths and stigma, were key gaps that need to be bridged through effective education and communication strategies for HAT control alongside other interventions. Misconceptions about sleeping sickness, a neglected tropical disease transmitted by tsetse flies, can be a hindrance to effective implementation of control interventions especially in the face of accelerating work to eliminate the disease. Understanding community knowledge, attitudes and practices about sleeping sickness is important in developing appropriate material for educating and sensitizing communities at risk of the disease. We conducted a study to establish community knowledge, attitudes and practices, including preferred channels of disseminating sleeping sickness information. Despite the fact that the community in Yei County knew about the disease, existing myths and stigma have the potential of influencing their health seeking behaviour. The radio, community health workers and village elders were the most preferred sources of sharing information with the community. There is need to develop education and awareness material to address issues of existing myths, potential stigma, treat ability of HAT, importance of testing and treatment, as well as provide information on the new/improved testing and treatment approaches for HAT. In addition, this should be provided through use of preferred and trusted sources of information dissemination, which is critical in uptake of HAT control, management and prevention activities.
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Affiliation(s)
- Salome A. Bukachi
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
- Research and Development, Passion Africa Limited, Nairobi, Kenya
- * E-mail:
| | - Angeline A. Mumbo
- South Sudan Coordination Office, Malteser International, Juba, Republic of South Sudan
| | - Ayak C. D. Alak
- Preventive Health Services, Ministry of Health, Juba, Republic of South Sudan
| | - Wilson Sebit
- Preventive Health Services, Ministry of Health, Juba, Republic of South Sudan
| | - John Rumunu
- Preventive Health Services, Ministry of Health, Juba, Republic of South Sudan
| | - Sylvain Biéler
- Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Joseph M. Ndung'u
- Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland
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Holzmuller P, Geiger A, Nzoumbou-Boko R, Pissarra J, Hamrouni S, Rodrigues V, Dauchy FA, Lemesre JL, Vincendeau P, Bras-Gonçalves R. Trypanosomatid Infections: How Do Parasites and Their Excreted-Secreted Factors Modulate the Inducible Metabolism of l-Arginine in Macrophages? Front Immunol 2018; 9:778. [PMID: 29731753 PMCID: PMC5921530 DOI: 10.3389/fimmu.2018.00778] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 03/28/2018] [Indexed: 12/20/2022] Open
Abstract
Mononuclear phagocytes (monocytes, dendritic cells, and macrophages) are among the first host cells to face intra- and extracellular protozoan parasites such as trypanosomatids, and significant expansion of macrophages has been observed in infected hosts. They play essential roles in the outcome of infections caused by trypanosomatids, as they can not only exert a powerful antimicrobial activity but also promote parasite proliferation. These varied functions, linked to their phenotypic and metabolic plasticity, are exerted via distinct activation states, in which l-arginine metabolism plays a pivotal role. Depending on the environmental factors and immune response elements, l-arginine metabolites contribute to parasite elimination, mainly through nitric oxide (NO) synthesis, or to parasite proliferation, through l-ornithine and polyamine production. To survive and adapt to their hosts, parasites such as trypanosomatids developed mechanisms of interaction to modulate macrophage activation in their favor, by manipulating several cellular metabolic pathways. Recent reports emphasize that some excreted-secreted (ES) molecules from parasites and sugar-binding host receptors play a major role in this dialog, particularly in the modulation of the macrophage's inducible l-arginine metabolism. Preventing l-arginine dysregulation by drugs or by immunization against trypanosomatid ES molecules or by blocking partner host molecules may control early infection and is a promising way to tackle neglected diseases including Chagas disease, leishmaniases, and African trypanosomiases. The present review summarizes recent knowledge on trypanosomatids and their ES factors with regard to their influence on macrophage activation pathways, mainly the NO synthase/arginase balance. The review ends with prospects for the use of biological knowledge to develop new strategies of interference in the infectious processes used by trypanosomatids, in particular for the development of vaccines or immunotherapeutic approaches.
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Affiliation(s)
- Philippe Holzmuller
- CIRAD, Montpellier, France.,UMR 117 ASTRE "Animal, Santé, Territoire, Risques et Ecosystèmes", Univ. Montpellier (I-MUSE), CIRAD, INRA, Montpellier, France
| | - Anne Geiger
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France
| | - Romaric Nzoumbou-Boko
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France.,Univ. Bordeaux, UMR 177 INTERTRYP, Bordeaux, France.,CHU Bordeaux, Laboratoire de Parasitologie-Mycologie, Bordeaux, France
| | - Joana Pissarra
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France
| | - Sarra Hamrouni
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France
| | - Valérie Rodrigues
- CIRAD, Montpellier, France.,UMR 117 ASTRE "Animal, Santé, Territoire, Risques et Ecosystèmes", Univ. Montpellier (I-MUSE), CIRAD, INRA, Montpellier, France
| | - Frédéric-Antoine Dauchy
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France.,Univ. Bordeaux, UMR 177 INTERTRYP, Bordeaux, France.,CHU Bordeaux, Département des Maladies Infectieuses et Tropicales, Bordeaux, France
| | - Jean-Loup Lemesre
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France
| | - Philippe Vincendeau
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France.,Univ. Bordeaux, UMR 177 INTERTRYP, Bordeaux, France.,CHU Bordeaux, Laboratoire de Parasitologie-Mycologie, Bordeaux, France
| | - Rachel Bras-Gonçalves
- UMR 177 INTERTRYP "Interactions Hôte-Vecteur-Parasite-Environnement dans les maladies tropicales négligées dues aux Trypanosomatidae", Univ. Montpellier (I-MUSE), CIRAD, IRD, Univ. Bordeaux 2, Univ. Lyon 1, Montpellier, France
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Checchi F, Funk S, Chandramohan D, Chappuis F, Haydon DT. The impact of passive case detection on the transmission dynamics of gambiense Human African Trypanosomiasis. PLoS Negl Trop Dis 2018; 12:e0006276. [PMID: 29624584 PMCID: PMC5906023 DOI: 10.1371/journal.pntd.0006276] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 04/18/2018] [Accepted: 01/26/2018] [Indexed: 12/02/2022] Open
Abstract
Gambiense Human African Trypanosomiasis (HAT), or sleeping sickness, is a vector-borne disease affecting largely rural populations in Western and Central Africa. The main method for detecting and treating cases of gambiense HAT are active screening through mobile teams and passive detection through self-referral of patients to dedicated treatment centres or hospitals. Strategies based on active case finding and treatment have drastically reduced the global incidence of the disease over recent decades. However, little is known about the coverage and transmission impact of passive case detection. We used a mathematical model to analyse data from the period between active screening sessions in hundreds of villages that were monitored as part of three HAT control projects run by Médecins Sans Frontières in Southern Sudan and Uganda in the late 1990s and early 2000s. We found heterogeneity in incidence across villages, with a small minority of villages found to have much higher transmission rates and burdens than the majority. We further found that only a minority of prevalent cases in the first, haemo-lymphatic stage of the disease were detected passively (maximum likelihood estimate <30% in all three settings), whereas around 50% of patients in the second, meningo-encephalitic were detected. We estimated that passive case detection reduced transmission in affected areas by between 30 and 50%, suggesting that there is great potential value in improving rates of passive case detection. As gambiense HAT is driven towards elimination, it will be important to establish good systems of passive screening, and estimates such as the ones here will be of value in assessing the expected impact of moving from a primarily active to a more passive screening regime. Gambiense Human African Trypanosomiasis, or sleeping sickness, is transmitted by the tsetse fly and affects rural populations in Western and Central Africa. It is a deadly disease if untreated, and it is therefore important to find people in the early stages of disease so that appropriate care and medication can be provided. Because of this, much emphasis is put on mobile teams going from village to village and actively finding as many potential patients as possible. This does not reach all infected people, though, and some are only detected passively, that is they report themselves to a health provider, often in advanced stages of disease. It is not clear what proportion of cases of sleeping sickness are detected in this way, or how much onwards transmission is prevented. Here we used a mathematical model to analyse data from a sleeping sickness control programme in Uganda and South Sudan, in order to identify which proportion of people infected with the disease are identified through passive case detection. We found that only a minority of patients are identified in this way in the early stages of disease, but around half are identified if they are in the later stages. We further found that passive screening reduced transmission in affected areas by between 30 and 50%. This suggests that there is great potential value in improving the rates of passive case detection, and we recommend that more emphasis is put on tackling potential barriers that prevent people being detected.
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Affiliation(s)
- Francesco Checchi
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Sebastian Funk
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Daniel Chandramohan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - François Chappuis
- Division of Tropical and Humanitarian Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Daniel T. Haydon
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Bukachi SA, Wandibba S, Nyamongo IK. The socio-economic burden of human African trypanosomiasis and the coping strategies of households in the South Western Kenya foci. PLoS Negl Trop Dis 2017; 11:e0006002. [PMID: 29073144 PMCID: PMC5675461 DOI: 10.1371/journal.pntd.0006002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 11/07/2017] [Accepted: 09/30/2017] [Indexed: 12/03/2022] Open
Abstract
Introduction Human African Trypanosomiasis (HAT), a disease caused by protozoan parasites transmitted by tsetse flies, is an important neglected tropical disease endemic in remote regions of sub-Saharan Africa. Although the determination of the burden of HAT has been based on incidence, mortality and morbidity rates, the true burden of HAT goes beyond these metrics. This study sought to establish the socio-economic burden that households with HAT faced and the coping strategies they employed to deal with the increased burden. Materials and methods A mixed methods approach was used and data were obtained through: review of hospital records; structured interviews (152); key informant interviews (11); case narratives (12) and focus group discussions (15) with participants drawn from sleeping sickness patients in the south western HAT foci in Kenya. Quantitative data were analysed using descriptive statistics while qualitative data was analysed based on emerging themes. Results Socio-economic impacts included, disruption of daily activities, food insecurity, neglect of homestead, poor academic performance/school drop-outs and death. Delayed diagnosis of HAT caused 93% of the affected households to experience an increase in financial expenditure (ranging from US$ 60–170) in seeking treatment. Out of these, 81.5% experienced difficulties in raising money for treatment resorting to various ways of raising it. The coping strategies employed to deal with the increased financial expenditure included: sale of agricultural produce (64%); seeking assistance from family and friends (54%); sale/lease of family assets (22%); seeking credit (22%) and use of personal savings (17%). Conclusion and recommendation Coping strategies outlined in this study impacted negatively on the affected households leading to further food insecurity and impoverishment. Calculation of the true burden of disease needs to go beyond incidence, mortality and morbidity rates to capture socio-economic variables entailed in seeking treatment and coping strategies of HAT affected households. Sleeping sickness affects people often living in remote rural areas and those who mainly depend on subsistence agriculture. We carried out a study among former sleeping sickness patients in Kenya to find out the socio-economic challenges they faced in seeking treatment and the coping strategies they used to deal with them. This is important because the socio-economic effects of sleeping sickness and its coping strategies have not been adequately researched on yet it is on the strength of these impacts that policies and control programmes are formulated. If the real burden of sleeping sickness is not known, then it will continue to be neglected in terms of the attention it receives world-wide. Sleeping sickness patients and their households spent a lot of money seeking treatment besides facing challenges of disruption of daily activities, food insecurity, neglect of homesteads, poor academic performance/school drop-outs and death. Majority of them faced difficulties in raising the money required for seeking treatment hence resorted to various coping strategies. These negatively impacted on them and their households, already living on less than a dollar per day. There is need to pay attention to these effects of sleeping sickness in establishing the real burden of the disease.
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Affiliation(s)
- Salome A. Bukachi
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
- * E-mail:
| | - Simiyu Wandibba
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
| | - Isaac K. Nyamongo
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
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Wamboga C, Matovu E, Bessell PR, Picado A, Biéler S, Ndung’u JM. Enhanced passive screening and diagnosis for gambiense human African trypanosomiasis in north-western Uganda - Moving towards elimination. PLoS One 2017; 12:e0186429. [PMID: 29023573 PMCID: PMC5638538 DOI: 10.1371/journal.pone.0186429] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/29/2017] [Indexed: 11/18/2022] Open
Abstract
Introduction The incidence of gambiense human African trypanosomiasis (gHAT) in Uganda has been declining, from 198 cases in 2008, to only 20 in 2012. Interruption of transmission of the disease by early diagnosis and treatment is core to the control and eventual elimination of gHAT. Until recently, the format of available screening tests had restricted screening and diagnosis to central health facilities (passive screening). We describe a novel strategy that is contributing to elimination of gHAT in Uganda through expansion of passive screening to the entire population at risk. Methodology / Principal findings In this strategy, patients who are clinically suspected of having gHAT at primary health facilities are screened using a rapid diagnostic test (RDT), followed by parasitological confirmation at strategically located microscopy centres. For patients who are positive with the RDT and negative by microscopy, blood samples undergo further testing using loop-mediated isothermal amplification (LAMP), a molecular test that detects parasite DNA. LAMP positive patients are considered strong suspects, and are re-evaluated by microscopy. Location and upgrading of facilities to perform microscopy and LAMP was informed by results of georeferencing and characterization of all public healthcare facilities in the 7 gHAT endemic districts in Uganda. Three facilities were upgraded to perform RDTs, microscopy and LAMP, 9 to perform RDTs and microscopy, and 200 to screen patients with RDTs. This reduced the distance that a sick person must travel to be screened for gHAT to a median distance of 2.5km compared to 23km previously. In this strategy, 9 gHAT cases were diagnosed in 2014, and 4 in 2015. Conclusions This enhanced passive screening strategy for gHAT has enabled full coverage of the population at risk, and is being replicated in other gHAT endemic countries. The improvement in case detection is making elimination of the disease in Uganda an imminent possibility.
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Affiliation(s)
| | - Enock Matovu
- College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | | | - Albert Picado
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Sylvain Biéler
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
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Mwiinde AM, Simuunza M, Namangala B, Chama-Chiliba CM, Machila N, Anderson N, Shaw A, Welburn SC. Estimating the economic and social consequences for patients diagnosed with human African trypanosomiasis in Muchinga, Lusaka and Eastern Provinces of Zambia (2004-2014). Infect Dis Poverty 2017; 6:150. [PMID: 29017597 PMCID: PMC5634962 DOI: 10.1186/s40249-017-0363-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 09/19/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acute human African trypanosomiasis (rHAT) caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated. Only a few studies have examined the psychological, social and economic impacts of rHAT. In this study, mixed qualitative and quantitative research methods were used to evaluate the socio-economic impacts of rHAT in Mambwe, Rufunsa, Mpika and Chama Districts of Zambia. METHODS Individuals diagnosed with rHAT from 2004 to 2014 were traced using hospital records and discussions with communities. Either they, or their families, were interviewed using a structured questionnaire and focus group discussions were conducted with affected communities. The burden of the disease was investigated using disability adjusted life years (DALYs), with and without discounting and age-weighting. The impact of long-term disabilities on the rHAT burden was also investigated. RESULTS Sixty four cases were identified in the study. The majority were identified in second stage, and the mortality rate was high (12.5%). The total number of DALYs was 285 without discounting or age-weighting. When long-term disabilities were included this estimate increased by 50% to 462. The proportion of years lived with disability (YLD) increased from 6.4% to 37% of the undiscounted and un-age-weighted DALY total. When a more active surveillance method was applied in 2013-2014 the cases identified increased dramatically, suggesting a high level of under-reporting. Similarly, the proportion of females increased substantially, indicating that passive surveillance may be especially failing this group. An average of 4.9 months of productive time was lost per patient as a consequence of infection. The health consequences included pain, amnesia and physical disability. The social consequences included stigma, dropping out of education, loss of friends and self-esteem. Results obtained from focus group discussions revealed misconceptions among community members which could be attributed to lack of knowledge about rHAT. CONCLUSIONS The social and economic impact of rHAT on rural households and communities is substantial. Improved surveillance and strengthening of local medical services are needed for early and accurate diagnosis. Disease prevention should be prioritised in communities at risk of rHAT, and interventions put in place to prevent zoonotic disease spill over from domestic animals and wildlife. Supportive measures to mitigate the long-term effects of disability due to rHAT are needed.
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Affiliation(s)
- Allan Mayaba Mwiinde
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia. .,School of Veterinary Medicine Department of Disease Control, University of Zambia, P.O Box 32379, Lusaka, Zambia.
| | - Martin Simuunza
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | | | | | - Noreen Machila
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.,Division of Infection and Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, Scotland, EH16 4SB, UK
| | - Neil Anderson
- The Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh, Roslin, EH25 9RG, UK
| | - Alexandra Shaw
- Division of Infection and Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, Scotland, EH16 4SB, UK.,AP Consultants, Walworth Enterprise Centre, Andover, SP10 5AP, UK
| | - Susan C Welburn
- Division of Infection and Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, Scotland, EH16 4SB, UK
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Cleaveland S, Sharp J, Abela-Ridder B, Allan KJ, Buza J, Crump JA, Davis A, Del Rio Vilas VJ, de Glanville WA, Kazwala RR, Kibona T, Lankester FJ, Lugelo A, Mmbaga BT, Rubach MP, Swai ES, Waldman L, Haydon DT, Hampson K, Halliday JEB. One Health contributions towards more effective and equitable approaches to health in low- and middle-income countries. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160168. [PMID: 28584176 PMCID: PMC5468693 DOI: 10.1098/rstb.2016.0168] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/31/2016] [Indexed: 02/06/2023] Open
Abstract
Emerging zoonoses with pandemic potential are a stated priority for the global health security agenda, but endemic zoonoses also have a major societal impact in low-resource settings. Although many endemic zoonoses can be treated, timely diagnosis and appropriate clinical management of human cases is often challenging. Preventive 'One Health' interventions, e.g. interventions in animal populations that generate human health benefits, may provide a useful approach to overcoming some of these challenges. Effective strategies, such as animal vaccination, already exist for the prevention, control and elimination of many endemic zoonoses, including rabies, and several livestock zoonoses (e.g. brucellosis, leptospirosis, Q fever) that are important causes of human febrile illness and livestock productivity losses in low- and middle-income countries. We make the case that, for these diseases, One Health interventions have the potential to be more effective and generate more equitable benefits for human health and livelihoods, particularly in rural areas, than approaches that rely exclusively on treatment of human cases. We hypothesize that applying One Health interventions to tackle these health challenges will help to build trust, community engagement and cross-sectoral collaboration, which will in turn strengthen the capacity of fragile health systems to respond to the threat of emerging zoonoses and other future health challenges. One Health interventions thus have the potential to align the ongoing needs of disadvantaged communities with the concerns of the broader global community, providing a pragmatic and equitable approach to meeting the global goals for sustainable development and supporting the global health security agenda.This article is part of the themed issue 'One Health for a changing world: zoonoses, ecosystems and human well-being'.
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Affiliation(s)
- S Cleaveland
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
| | - J Sharp
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - B Abela-Ridder
- Department for the Control of Neglected Tropical Diseases, World Health Organization, Avenue Appia 20, 1211 Geneva 27, Switzerland
| | - K J Allan
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
| | - J Buza
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, PO Box 447, Arusha, Tanzania
| | - J A Crump
- Centre for International Health, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A Davis
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - V J Del Rio Vilas
- School of Veterinary Medicine, University of Surrey, Guildford GU2 7XH, UK
| | - W A de Glanville
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
| | - R R Kazwala
- College of Veterinary Medicine and Medical Sciences, Sokoine University of Agriculture, PO Box 3105, Morogoro, Tanzania
| | - T Kibona
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, PO Box 447, Arusha, Tanzania
| | - F J Lankester
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - A Lugelo
- College of Veterinary Medicine and Medical Sciences, Sokoine University of Agriculture, PO Box 3105, Morogoro, Tanzania
| | - B T Mmbaga
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical Centre, PO Box 2236, Moshi, Tanzania
| | - M P Rubach
- Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA
| | - E S Swai
- Ministry of Agriculture, Livestock and Fisheries, PO Box 9152, Dar es Salaam, Tanzania
| | - L Waldman
- Institute for Development Studies, Library Road, Brighton BN1 9RE, UK
| | - D T Haydon
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
| | - K Hampson
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
| | - J E B Halliday
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, and
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12
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Acup C, Bardosh KL, Picozzi K, Waiswa C, Welburn SC. Factors influencing passive surveillance for T. b. rhodesiense human african trypanosomiasis in Uganda. Acta Trop 2017; 165:230-239. [PMID: 27212706 DOI: 10.1016/j.actatropica.2016.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 05/14/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Sleeping sickness or Human African Trypanosomiasis (HAT) is a neglected tropical disease of public health importance across much of Sub-Saharan Africa. In Uganda, chronic T. b. gambiense HAT (gHAT) and acute T. b. rhodesiense HAT (rHAT) occur in two large but discrete geographical foci. Both forms are difficult to diagnose, expensive to treat and ultimately fatal in the absence of treatment. The area affected by zoonotic rHAT has been steadily expanding, placing a high burden on local health systems. HAT is a disease of neglected populations and is notorious for being under-reported. Here we examine the factors that influence passive rHAT surveillance within the district health system in four Ugandan districts into which the disease had recently been introduced, focusing on staff knowledge, infrastructure and data management. METHODS A mixed methods study was undertaken between 2011 and 2013 in Dokolo, Kaberamaido, Soroti and Serere districts to explore health facility capacity and clinical service provision, diagnostic capacity, HAT knowledge and case reporting. Structured interviews were undertaken with 86 medical personnel, including clinicians, nurses, midwives and technicians across 65 HC-II and HC-III medical facilities, where the health infrastructure was also directly observed. Eleven semi-structured interviews were undertaken with medical staff in each of the three designated HAT treatment facilities (Dokolo, Lwala and Serere HC-IV) in the area. HAT treatment centre case records, collected between 2009 and 2012, were analyzed. RESULTS Most medical staff in HC-II and HC-III facilities had been made aware of HAT from radio broadcasts, newspapers and by word of mouth, suggestive of a lack of formal training. Key knowledge as regards the causative agent, clinical signs and that HAT drugs are provided free of charge was lower amongst HC-II than HC-III staff. Many respondents did not know whether HAT was endemic in their district. In rHAT specialist treatment centres, staff were knowledgeable of HAT and were confident in their ability to diagnose and manage cases. Between 2009-2012, 342 people were diagnosed in the area, 54% in the late stage of the disease. Over the period of this study the proportion of rHAT cases identified in early stage fell and by 2012 the majority of cases identified were diagnosed in the late stage. CONCLUSION This study illustrates the critical role of the district health system in HAT management. The increasing proportion of cases identified at a late stage in this study indicates a major gap in lower tier levels in patient referral, diagnosis and reporting that urgently needs to be addressed. Integrating HAT diagnosis into national primary healthcare programs and providing training to medical workers at all levels is central to the new 2030 WHO HAT elimination goal. Given the zoonotic nature of rHAT, joined up active surveillance in human and animal populations in Uganda is also needed. The role of the Coordinating Office for Control of Trypanosomiasis in Uganda in implementing a One Health approach will be key to sustainable management of zoonotic HAT.
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Geiger A, Bossard G, Sereno D, Pissarra J, Lemesre JL, Vincendeau P, Holzmuller P. Escaping Deleterious Immune Response in Their Hosts: Lessons from Trypanosomatids. Front Immunol 2016; 7:212. [PMID: 27303406 PMCID: PMC4885876 DOI: 10.3389/fimmu.2016.00212] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/17/2016] [Indexed: 12/21/2022] Open
Abstract
The Trypanosomatidae family includes the genera Trypanosoma and Leishmania, protozoan parasites displaying complex digenetic life cycles requiring a vertebrate host and an insect vector. Trypanosoma brucei gambiense, Trypanosoma cruzi, and Leishmania spp. are important human pathogens causing human African trypanosomiasis (HAT or sleeping sickness), Chagas' disease, and various clinical forms of Leishmaniasis, respectively. They are transmitted to humans by tsetse flies, triatomine bugs, or sandflies, and affect millions of people worldwide. In humans, extracellular African trypanosomes (T. brucei) evade the hosts' immune defenses, allowing their transmission to the next host, via the tsetse vector. By contrast, T. cruzi and Leishmania sp. have developed a complex intracellular lifestyle, also preventing several mechanisms to circumvent the host's immune response. This review seeks to set out the immune evasion strategies developed by the different trypanosomatids resulting from parasite-host interactions and will focus on: clinical and epidemiological importance of diseases; life cycles: parasites-hosts-vectors; innate immunity: key steps for trypanosomatids in invading hosts; deregulation of antigen-presenting cells; disruption of efficient specific immunity; and the immune responses used for parasite proliferation.
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Affiliation(s)
- Anne Geiger
- UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G, Montpellier, France
| | | | - Denis Sereno
- UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G, Montpellier, France
| | - Joana Pissarra
- UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G, Montpellier, France
| | | | - Philippe Vincendeau
- UMR 177, IRD-CIRAD Université de Bordeaux Laboratoire de Parasitologie, Bordeaux, France
| | - Philippe Holzmuller
- UMRCMAEE CIRAD-INRA TA-A15/G “Contrôle des maladies animales exotiques et émergentes”, Montpellier, France
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Abstract
OBJECTIVES Human migration and concomitant HIV infections are likely to bring about major changes in the epidemiology of zoonotic parasitic infections. Human African trypanosomiasis (HAT) control is particularly fraught with intricacies. The primarily zoonotic form, T.b. rhodesiense, and the non-zoonotic T.b. gambiense co-exist in Northern Uganda, leading to a potential geographic and genetic overlap of the two foci. This region also has the highest HIV prevalence in Uganda plus poor food security. We examine the bottlenecks facing the control program in a changed political and economic context. METHOD We searched the literature in July 2015 using three databases: MEDLINE, Google Scholar, and Web of Science. FINDINGS Decentralized zoonotic HAT control for animal reservoirs and vectors compromise sustainability of the control programs. Human transmission potential may be underestimated in a region with other endemic diseases and where an HIV-HAT epidemic, could merge two strains. CONCLUSION Our comprehensive literature review concludes that enhanced collaboration is imperative not only between human and animal health specialists, but also with political science. Multi-sectorial collaborations may need to be nurtured within existing operational national HIV prevention frameworks, with an integrated surveillance framework.
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Keating J, Yukich JO, Sutherland CS, Woods G, Tediosi F. Human African trypanosomiasis prevention, treatment and control costs: a systematic review. Acta Trop 2015; 150:4-13. [PMID: 26056739 DOI: 10.1016/j.actatropica.2015.06.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/18/2022]
Abstract
The control and eventual elimination of human African trypanosomiasis (HAT) requires the expansion of current control and surveillance activities. A systematic review of the published literature on the costs of HAT prevention, treatment, and control, in addition to the economic burden, was conducted. All studies that contained primary or secondary data on costs of prevention, treatment and control were considered, resulting in the inclusion of 42 papers. The geographically focal nature of the disease and a lack of standardization in the cost data limit the usefulness of the available information for making generalizations across diverse settings. More recent information on the costs of treatment and control interventions for HAT is needed to provide accurate information for analyses and planning. The cost information contained herein can be used to inform rational decision making in control and elimination programs, and to assess potential synergies with existing vector-borne disease control programs, but programs would benefit significantly from new cost data collection.
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Affiliation(s)
- Joseph Keating
- Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2200, New Orleans, LA 70112, USA; Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2309, New Orleans, LA 70112, USA.
| | - Joshua O Yukich
- Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2200, New Orleans, LA 70112, USA; Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2309, New Orleans, LA 70112, USA.
| | - C Simone Sutherland
- Department of Epidemiologyand Public Health, Swiss Tropicaland Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Switzerland.
| | - Geordie Woods
- Sightsavers, 35 Perrymount Road, Haywards Heath, West Sussex, RH16 3BW, UK.
| | - Fabrizio Tediosi
- Department of Epidemiologyand Public Health, Swiss Tropicaland Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Switzerland; Centre for Research on Health and Social Care Management (CERGAS), UniversitàBocconi, Milan, Italy.
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Assessing the capacity to diagnose human African trypanosomiasis among health care personnel from Chama and Mambwe districts of eastern Zambia. BMC Res Notes 2015; 8:433. [PMID: 26362937 PMCID: PMC4567820 DOI: 10.1186/s13104-015-1403-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 08/31/2015] [Indexed: 11/10/2022] Open
Abstract
Background Human African Trypanosomiasis (HAT) is a neglected tropical disease affecting poor rural communities living in tsetse-infested regions of sub-Saharan Africa. In Zambia, sporadic cases of HAT have been reported mainly in the old foci along the tsetse-infested Luangwa river valley in north-eastern part of the country. In such places where malaria is the major endemic febrile disease, with possibilities of co-infections of HAT and malaria and where the levels of alertness to the presence of HAT among health care personnel (HCP) is low, there is a high chance of misdiagnosing HAT for malaria because of their similarities in clinical presentation. This study, conducted in Zambia’s tsetse-infested rural health centres (RHCs) of Chama and Mambwe districts, was designed to investigate the staffing levels, the HCP levels of alertness to the occurrence of HAT and their capacity to detect the disease. Methods Structured questionnaires were used to collect information pertaining to HAT alertness and the capacity to detect the disease from 101 HCP in a cross sectional study of 23 RHCs drawn from Zambia’s Chama and Mambwe districts between April and July 2013. The data collected were analyzed using Stata/SE version 11.0. Results Participants from both Chama and Mambwe district RHCs reported similar very low levels of qualified HCP and laboratory technicians, and that they had similar basic tools for HAT diagnosis. Although not statistically significant, respondents from Chama (~89 %) tended to be more aware about the occurrence of HAT compared to their Mambwe counterparts (~78 %). Whereas ~40 % of the HCP from Chama district (n = 52) claimed to have encountered at least one case of HAT, only ~4 % of their Mambwe counterparts (n = 49) had similar experiences (P = 0.000). Conclusion Health care personnel in RHCs from Chama tended to be more alert to the occurrence of HAT than the HCP from Mambwe district. The extremely low levels of categorized HCP, general absence of functional laboratories, coupled with absence of national HAT surveillance and control programs, are among some of the serious challenges that Zambia’s Chama and Mambwe districts face to control/eliminate HAT.
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Kato CD, Nanteza A, Mugasa C, Edyelu A, Matovu E, Alibu VP. Clinical profiles, disease outcome and co-morbidities among T. b. rhodesiense sleeping sickness patients in Uganda. PLoS One 2015; 10:e0118370. [PMID: 25719539 PMCID: PMC4342333 DOI: 10.1371/journal.pone.0118370] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/15/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The acute form of Human African Trypanosomiasis (HAT, also known as Sleeping sickness) caused by Trypanosoma brucei rhodesiense has been shown to have a wide spectrum of focus specific clinical presentation and severity in East and Southern Africa. Indeed HAT occurs in regions endemic for other tropical diseases, however data on how these co-morbidities might complicate the clinical picture and affect disease outcome remains largely scanty. We here describe the clinical presentation, presence of co-infections, and how the latter impact on HAT prognosis. METHODS AND FINDINGS We carried out a retrospective analysis of clinical data from 258 sleeping sickness patients reporting to Lwala hospital between 2005 and 2012. The mean patient age was 28.6 years with a significant number of cases below 18 years (p< 0.0001). About 93.4% of the cases were diagnosed as late stage (p< 0.0001). The case fatality rate was 10.5% with post treatment reactive encephalopathys reported in 7.9% of the cases, of whom 36.8% eventually died. Fever was significantly (p = 0.045) higher in patients under 18 years. Of the early stage patients, 26.7% and 6.7% presented with late stage signs of sleep disorder and mental confusion respectively. Among the co-infections, malaria was significantly more prevalent (28.9%; p< 0.0001) followed by urinary tract infections (4.2%). Co-infections were present in 14.3% of in-hospital deaths, 38.5% of which were recorded as Malaria. Malaria was significantly more common in patients under 18 years (45.5%; p< 0.02), and was reported in 60% of the fatal cases in this age group. CONCLUSIONS We show a wide spectrum of sleeping sickness clinical presentation and disease outcome that was apparently not significantly influenced by concurrent infections. It would thus be interesting to determine the host and/or parasite factors that might be responsible for the observed diverse clinical presentation.
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Affiliation(s)
- Charles D. Kato
- School of Bio-security, Biotechnical & Laboratory Sciences, College of Veterinary Medicine, Animal Resources & Bio-security, Makerere University, Kampala Uganda
| | - Ann Nanteza
- School of Bio-security, Biotechnical & Laboratory Sciences, College of Veterinary Medicine, Animal Resources & Bio-security, Makerere University, Kampala Uganda
| | - Claire Mugasa
- School of Bio-security, Biotechnical & Laboratory Sciences, College of Veterinary Medicine, Animal Resources & Bio-security, Makerere University, Kampala Uganda
| | | | - Enock Matovu
- School of Bio-security, Biotechnical & Laboratory Sciences, College of Veterinary Medicine, Animal Resources & Bio-security, Makerere University, Kampala Uganda
| | - Vincent P. Alibu
- College of Natural Sciences, Makerere University, Kampala Uganda
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Geiger A, Ponton F, Simo G. Adult blood-feeding tsetse flies, trypanosomes, microbiota and the fluctuating environment in sub-Saharan Africa. ISME JOURNAL 2014; 9:1496-507. [PMID: 25500509 DOI: 10.1038/ismej.2014.236] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 11/03/2014] [Accepted: 11/06/2014] [Indexed: 01/01/2023]
Abstract
The tsetse fly vector transmits the protozoan Trypanosoma brucei, responsible for Human African Trypanosomiasis, one of the most neglected tropical diseases. Despite a recent decline in new cases, it is still crucial to develop alternative strategies to combat this disease. Here, we review the literature on the factors that influence trypanosome transmission from the fly vector to its vertebrate host (particularly humans). These factors include climate change effects to pathogen and vector development (in particular climate warming), as well as the distribution of host reservoirs. Finally, we present reports on the relationships between insect vector nutrition, immune function, microbiota and infection, to demonstrate how continuing research on the evolving ecology of these complex systems will help improve control strategies. In the future, such studies will be of increasing importance to understand how vector-borne diseases are spread in a changing world.
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Affiliation(s)
- Anne Geiger
- UMR 177, IRD-CIRAD, CIRAD TA A-17/G, Campus International de Baillarguet, Montpellier Cedex 5, France
| | - Fleur Ponton
- 1] School of Biological Sciences, The University of Sydney, Sydney, New South Wales, Australia [2] The Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
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Sullivan L, Fleming J, Sastry L, Mehlert A, Wall SJ, Ferguson MAJ. Identification of sVSG117 as an immunodiagnostic antigen and evaluation of a dual-antigen lateral flow test for the diagnosis of human African trypanosomiasis. PLoS Negl Trop Dis 2014; 8:e2976. [PMID: 25033401 PMCID: PMC4102454 DOI: 10.1371/journal.pntd.0002976] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 05/12/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The diagnosis of human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense relies mainly on the Card Agglutination Test for Trypanosomiasis (CATT). There is no immunodiagnostic for HAT caused by T. b. rhodesiense. Our principle aim was to develop a prototype lateral flow test that might be an improvement on CATT. METHODOLOGY/PRINCIPLE FINDINGS Pools of infection and control sera were screened against four different soluble form variant surface glycoproteins (sVSGs) by ELISA and one, sVSG117, showed particularly strong immunoreactivity to pooled infection sera. Using individual sera, sVSG117 was shown to be able to discriminate between T. b. gambiense infection and control sera by both ELISA and lateral flow test. The sVSG117 antigen was subsequently used with a previously described recombinant diagnostic antigen, rISG65, to create a dual-antigen lateral flow test prototype. The latter was used blind in a virtual field trial of 431 randomized infection and control sera from the WHO HAT Specimen Biobank. CONCLUSION/SIGNIFICANCE In the virtual field trial, using two positive antigen bands as the criterion for infection, the sVSG117 and rISG65 dual-antigen lateral flow test prototype showed a sensitivity of 97.3% (95% CI: 93.3 to 99.2) and a specificity of 83.3% (95% CI: 76.4 to 88.9) for the detection of T. b. gambiense infections. The device was not as good for detecting T. b. rhodesiense infections using two positive antigen bands as the criterion for infection, with a sensitivity of 58.9% (95% CI: 44.9 to 71.9) and specificity of 97.3% (95% CI: 90.7 to 99.7). However, using one or both positive antigen band(s) as the criterion for T. b. rhodesiense infection improved the sensitivity to 83.9% (95% CI: 71.7 to 92.4) with a specificity of 85.3% (95% CI: 75.3 to 92.4). These results encourage further development of the dual-antigen device for clinical use.
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Affiliation(s)
- Lauren Sullivan
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jennifer Fleming
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Lalitha Sastry
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angela Mehlert
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | - Michael A. J. Ferguson
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail:
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A mixed methods study of a health worker training intervention to increase syndromic referral for gambiense human African trypanosomiasis in South Sudan. PLoS Negl Trop Dis 2014; 8:e2742. [PMID: 24651696 PMCID: PMC3961197 DOI: 10.1371/journal.pntd.0002742] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 01/31/2014] [Indexed: 11/19/2022] Open
Abstract
Background Active screening by mobile teams is considered the most effective method for detecting gambiense-type human African trypanosomiasis (HAT) but constrained funding in many post-conflict countries limits this approach. Non-specialist health care workers (HCWs) in peripheral health facilities could be trained to identify potential cases for testing based on symptoms. We tested a training intervention for HCWs in peripheral facilities in Nimule, South Sudan to increase knowledge of HAT symptomatology and the rate of syndromic referrals to a central screening and treatment centre. Methodology/Principal Findings We trained 108 HCWs from 61/74 of the public, private and military peripheral health facilities in the county during six one-day workshops and assessed behaviour change using quantitative and qualitative methods. In four months prior to training, only 2/562 people passively screened for HAT were referred from a peripheral HCW (0 cases detected) compared to 13/352 (2 cases detected) in the four months after, a 6.5-fold increase in the referral rate observed by the hospital. Modest increases in absolute referrals received, however, concealed higher levels of referral activity in the periphery. HCWs in 71.4% of facilities followed-up had made referrals, incorporating new and pre-existing ideas about HAT case detection into referral practice. HCW knowledge scores of HAT symptoms improved across all demographic sub-groups. Of 71 HAT referrals made, two-thirds were from new referrers. Only 11 patients completed the referral, largely because of difficulties patients in remote areas faced accessing transportation. Conclusions/Significance The training increased knowledge and this led to more widespread appropriate HAT referrals from a low base. Many referrals were not completed, however. Increasing access to screening and/or diagnostic tests in the periphery will be needed for greater impact on case-detection in this context. These data suggest it may be possible for peripheral HCWs to target the use of rapid diagnostic tests for HAT. Human African trypanosomiasis (HAT or sleeping sickness) is a fatal but treatable disease affecting poor people in sub-Saharan Africa. Most HAT diagnostic equipment, infrastructure and expertise is located in hospitals. The expense of expanding testing services to remote areas using mobile teams severely restricts their use. Non-specialist healthcare workers (HCWs) in first-line (primary) health care facilities can contribute to control by identifying patients in need of testing based on their symptoms. We therefore trained first-line HCWs to recognise potential syndromic cases of HAT and refer them to a hospital screening service. Against a low baseline of HCW HAT referral experience, four months after the intervention, HCW knowledge of HAT symptoms increased and HCWs in 71.4% of facilities across the county had made referrals, incorporating new and pre-existing ideas about HAT case detection into referral practice. There was only a modest increase in numbers of referred patients received at the hospital for screening, however, largely because of distance. In an era where approaches to HAT case detection and control must increasingly be integrated into health referral systems, it is vital to understand the opportunities and challenges associated with syndromic case detection in first line facilities to design effective interventions.
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Palmer JJ, Kelly AH, Surur EI, Checchi F, Jones C. Changing landscapes, changing practice: negotiating access to sleeping sickness services in a post-conflict society. Soc Sci Med 2014; 120:396-404. [PMID: 24679924 DOI: 10.1016/j.socscimed.2014.03.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 03/10/2014] [Accepted: 03/13/2014] [Indexed: 11/29/2022]
Abstract
For several decades, control programmes for human African trypanosomiasis (HAT, or sleeping sickness) in South Sudan have been delivered almost entirely as humanitarian interventions: large, well-organised, externally-funded but short-term programmes with a strategic focus on active screening. When attempts to hand over these programmes to local partners fail, resident populations must actively seek and negotiate access to tests at hospitals via passive screening. However, little is known about the social impact of such humanitarian interventions or the consequences of withdrawal on access to and utilisation of remaining services by local populations. Based on qualitative and quantitative fieldwork in Nimule, South Sudan (2008-2010), where passive screening necessarily became the predominant strategy, this paper investigates the reasons why, among two ethnic groups (Madi returnees and Dinka displaced populations), service uptake was so much higher among the latter. HAT tests were the only form of clinical care for which displaced Dinka populations could self-refer; access to all other services was negotiated through indigenous area workers. Because of the long history of conflict, these encounters were often morally and politically fraught. An open-door policy to screening supported Dinka people to 'try' HAT tests in the normal course of treatment-seeking, thereby empowering them to use HAT services more actively. This paper argues that in a context like South Sudan, where HAT control increasingly depends upon patient-led approaches to case-detection, it is imperative to understand the cultural values and political histories associated with the practice of testing and how medical humanitarian programmes shape this landscape of care, even after they have been scaled down.
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Affiliation(s)
- Jennifer J Palmer
- Clinical Research Department, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel St., London WC1B 7HT, UK.
| | - Ann H Kelly
- Faculty of Public Health & Policy, London School of Hygiene & Tropical Medicine, London, UK; Department of Philosophy, Sociology & Anthropology, University of Exeter, UK
| | - Elizeous I Surur
- Medical Emergency Relief International (Merlin), Nimule, South Sudan
| | - Francesco Checchi
- Clinical Research Department, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel St., London WC1B 7HT, UK
| | - Caroline Jones
- Clinical Research Department, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel St., London WC1B 7HT, UK; KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, UK
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Deborggraeve S, Büscher P. Recent progress in molecular diagnosis of sleeping sickness. Expert Rev Mol Diagn 2014; 12:719-30. [DOI: 10.1586/erm.12.72] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bukachi SA, Wandibba S, Nyamongo IK. The treatment pathways followed by cases of human African trypanosomiasis in western Kenya and eastern Uganda. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2013; 103:211-20. [DOI: 10.1179/136485909x398230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Bardosh K, Waiswa C, Welburn SC. Conflict of interest: use of pyrethroids and amidines against tsetse and ticks in zoonotic sleeping sickness endemic areas of Uganda. Parasit Vectors 2013; 6:204. [PMID: 23841963 PMCID: PMC3711891 DOI: 10.1186/1756-3305-6-204] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 07/08/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Caused by trypanosomes and transmitted by tsetse flies, Human African Trypanosomiasis and bovine trypanosomiasis remain endemic across much of rural Uganda where the major reservoir of acute human infection is cattle. Following elimination of trypanosomes by mass trypanocidal treatment, it is crucial that farmers regularly apply pyrethroid-based insecticides to cattle to sustain parasite reductions, which also protect against tick-borne diseases. The private veterinary market is divided between products only effective against ticks (amidines) and those effective against both ticks and tsetse (pyrethroids). This study explored insecticide sales, demand and use in four districts of Uganda where mass cattle treatments have been undertaken by the 'Stamp Out Sleeping Sickness' programme. METHODS A mixed-methods study was undertaken in Dokolo, Kaberamaido, Serere and Soroti districts of Uganda between September 2011 and February 2012. This included: focus groups in 40 villages, a livestock keeper survey (n = 495), a veterinary drug shop questionnaire (n = 74), participatory methods in six villages and numerous semi-structured interviews. RESULTS Although 70.5% of livestock keepers reportedly used insecticide each month during the rainy season, due to a variety of perceptions and practices nearly half used products only effective against ticks and not tsetse. Between 640 and 740 litres of insecticide were being sold monthly, covering an average of 53.7 cattle/km(2). Sales were roughly divided between seven pyrethroid-based products and five products only effective against ticks. In the high-risk HAT district of Kaberamaido, almost double the volume of non-tsetse effective insecticide was being sold. Factors influencing insecticide choice included: disease knowledge, brand recognition, product price, half-life and mode of product action, product availability, and dissemination of information. Stakeholders considered market restriction of non-tsetse effective products the most effective way to increase pyrethroid use. CONCLUSIONS Conflicts of interest between veterinary business and vector control were found to constrain sleeping sickness control. While a variety of strategies could increase pyrethroid use, regulation of the insecticide market could effectively double the number of treated cattle with little cost to government, donors or farmers. Such regulation is entirely consistent with the role of the state in a privatised veterinary system and should include a mitigation strategy against the potential development of tick resistance.
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Affiliation(s)
- Kevin Bardosh
- Centre of African Studies, School of Social and Political Science, College of Humanities and Social Science, The University of Edinburgh, 58 George Square, Edinburgh EH8 9LD, UK
| | - Charles Waiswa
- Department of Pharmacy, Clinical and Comparative Studies, School of Veterinary Medicine and Animal Resources, Makerere University, P.O Box 7062, Kampala, Uganda
| | - Susan C Welburn
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
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Sullivan L, Wall SJ, Carrington M, Ferguson MAJ. Proteomic selection of immunodiagnostic antigens for human African trypanosomiasis and generation of a prototype lateral flow immunodiagnostic device. PLoS Negl Trop Dis 2013; 7:e2087. [PMID: 23469310 PMCID: PMC3584999 DOI: 10.1371/journal.pntd.0002087] [Citation(s) in RCA: 38] [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: 11/16/2012] [Accepted: 01/17/2013] [Indexed: 11/30/2022] Open
Abstract
Background The diagnosis of Human African Trypanosomiasis relies mainly on the Card Agglutination Test for Trypanosomiasis (CATT). While this test is successful, it is acknowledged that there may be room for improvement. Our aim was to develop a prototype lateral flow test based on the detection of antibodies to trypanosome antigens. Methodology/Principal Findings We took a non-biased approach to identify potential immunodiagnostic parasite protein antigens. The IgG fractions from the sera from Trypanosoma brucei gambiense infected and control patients were isolated using protein-G affinity chromatography and then immobilized on Sepharose beads. The IgG-beads were incubated with detergent lysates of trypanosomes and those proteins that bound were identified by mass spectrometry-based proteomic methods. This approach provided a list of twenty-four trypanosome proteins that selectively bound to the infection IgG fraction and that might, therefore, be considered as immunodiagnostic antigens. We selected four antigens from this list (ISG64, ISG65, ISG75 and GRESAG4) and performed protein expression trials in E. coli with twelve constructs. Seven soluble recombinant protein products (three for ISG64, two for ISG65 and one each for ISG75 and GRESAG4) were obtained and assessed for their immunodiagnostic potential by ELISA using individual and/or pooled patient sera. The ISG65 and ISG64 construct ELISAs performed well with respect to detecting T. b. gambiense infections, though less well for detecting T. b. rhodesiense infections, and the best performing ISG65 construct was used to develop a prototype lateral flow diagnostic device. Conclusions/Significance Using a panel of eighty randomized T. b. gambiense infection and control sera, the prototype showed reasonable sensitivity (88%) and specificity (93%) using visual readout in detecting T. b. gambiense infections. These results provide encouragement to further develop and optimize the lateral flow device for clinical use. Human African Trypanosomiasis is caused by infection with Trypanosoma brucei gambiense or T. b. rhodesiense. Preliminary diagnosis of T. b. gambiense infection relies mainly on a Card Agglutination Test for Trypanosomiasis (CATT), which has acknowledged limitations. New approaches are needed, first to identify new diagnostic antigens and, second, to find a more suitable platform for field-based immunodiagnostic tests. We took an unbiased approach to identify candidate diagnostic antigens by asking which parasite proteins bind to the antibodies of infected patients and not to the antibodies of uninfected patients. From this list of twenty-four candidate antigens, we selected four and from these we selected the one that worked the best in conventional immunodiagnostic tests. This antigen, ISG65, was used to make lateral flow devices, where a small sample of patient serum is added to a pad and thirty minutes later infection can be inferred by simple optical read out. This simple prototype device works as well as the CATT test and may be developed and optimized for clinical use in the field.
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Affiliation(s)
- Lauren Sullivan
- College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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Palmer JJ, Surur EI, Goch GW, Mayen MA, Lindner AK, Pittet A, Kasparian S, Checchi F, Whitty CJM. Syndromic algorithms for detection of gambiense human African trypanosomiasis in South Sudan. PLoS Negl Trop Dis 2013; 7:e2003. [PMID: 23350005 PMCID: PMC3547858 DOI: 10.1371/journal.pntd.0002003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 11/28/2012] [Indexed: 11/20/2022] Open
Abstract
Background Active screening by mobile teams is considered the best method for detecting human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense but the current funding context in many post-conflict countries limits this approach. As an alternative, non-specialist health care workers (HCWs) in peripheral health facilities could be trained to identify potential cases who need testing based on their symptoms. We explored the predictive value of syndromic referral algorithms to identify symptomatic cases of HAT among a treatment-seeking population in Nimule, South Sudan. Methodology/Principal Findings Symptom data from 462 patients (27 cases) presenting for a HAT test via passive screening over a 7 month period were collected to construct and evaluate over 14,000 four item syndromic algorithms considered simple enough to be used by peripheral HCWs. For comparison, algorithms developed in other settings were also tested on our data, and a panel of expert HAT clinicians were asked to make referral decisions based on the symptom dataset. The best performing algorithms consisted of three core symptoms (sleep problems, neurological problems and weight loss), with or without a history of oedema, cervical adenopathy or proximity to livestock. They had a sensitivity of 88.9–92.6%, a negative predictive value of up to 98.8% and a positive predictive value in this context of 8.4–8.7%. In terms of sensitivity, these out-performed more complex algorithms identified in other studies, as well as the expert panel. The best-performing algorithm is predicted to identify about 9/10 treatment-seeking HAT cases, though only 1/10 patients referred would test positive. Conclusions/Significance In the absence of regular active screening, improving referrals of HAT patients through other means is essential. Systematic use of syndromic algorithms by peripheral HCWs has the potential to increase case detection and would increase their participation in HAT programmes. The algorithms proposed here, though promising, should be validated elsewhere. Human African trypanosomiasis (HAT or sleeping sickness) is an almost always fatal disease affecting poor people in rural, conflict-affected areas of sub-Saharan Africa. It is difficult to diagnose. Effective treatment exists, but because diagnostic and treatment services are usually based only in hospitals, many HAT patients in rural areas are never detected. Control programmes aim periodically to extend testing services via mobile teams (active screening) but their expense and operational issues severely restrict their use. We explored the predictive value of different combinations of symptoms that were present in a treatment-seeking population to identify people infected with HAT. Through this approach, we identified a simple four-symptom referral algorithm that, if replicable, has the potential to identify one HAT patient for every ten patients referred through subsequent testing. It would identify most symptomatic HAT patients who seek treatment, if systematically applied by non-specialist healthcare workers already working in these areas. As these types of health workers are rarely included in formal HAT control efforts, teaching this algorithm also represents an opportunity to decentralise life-saving knowledge, and contribute to endemic populations' long-term empowerment and ability to help control this disease.
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Affiliation(s)
- Jennifer J Palmer
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
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Hasker E, Lumbala C, Mbo F, Mpanya A, Kande V, Lutumba P, Boelaert M. Health care-seeking behaviour and diagnostic delays for Human African Trypanosomiasis in the Democratic Republic of the Congo. Trop Med Int Health 2011; 16:869-74. [PMID: 21447063 DOI: 10.1111/j.1365-3156.2011.02772.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE About half of the patients with Human African trypanosomiasis (HAT) reported in the Democratic Republic of the Congo (DRC) are currently detected by fixed health facilities and not by mobile teams. Given the recent policy to integrate HAT control into general health services, we studied health seeking behaviour in these spontaneously presenting patients. METHODS We took a random sample from all patients diagnosed with a first-time HAT episode through passive case finding between 1 October 2008 and 30 September 2009 in the two most endemic provinces of the DRC. Patients were approached at their homes for a structured interview. We documented patient delay (i.e. time between onset of symptoms and contacting a health centre) and health system delay (i.e. time between first contact and correct diagnosis of HAT). RESULTS Median patient delay was 4 months (IQR 1-10 months, n = 66); median health system delay was 3 months (IQR 0.5-11 months). Those first presenting to public health centres had a median systems delay of 7 months (IQR 2-14 months, n = 23). On median, patients were diagnosed upon the forth visit to a health facility (IQR 3rd-7th visit). CONCLUSIONS Substantial patient as well as health system delays are incurred in HAT cases detected passively. Public health centres are performing poorly in the diagnostic work-up for HAT, mainly because HAT is a relatively rare disease with few and non-specific early symptoms. Integration of HAT diagnosis and treatment into general health services requires strong technical support and well-organized supervision and referral mechanisms.
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Affiliation(s)
- E Hasker
- Epidemiology and Disease Control Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.
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Transcriptomics and proteomics in human African trypanosomiasis: current status and perspectives. J Proteomics 2011; 74:1625-43. [PMID: 21316496 DOI: 10.1016/j.jprot.2011.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 01/23/2011] [Accepted: 01/27/2011] [Indexed: 01/21/2023]
Abstract
Human African trypanosomiasis, or sleeping sickness, is a neglected vector-borne parasitic disease caused by protozoa of the species Trypanosoma brucei sensu lato. Within this complex species, T. b. gambiense is responsible for the chronic form of sleeping sickness in Western and Central Africa, whereas T. b. rhodesiense causes the acute form of the disease in East Africa. Presently, 1.5 million disability-adjusted life years (DALYs) per year are lost due to sleeping sickness. In addition, on the basis of the mortality, the disease is ranked ninth out of 25 human infectious and parasitic diseases in Africa. Diagnosis is complex and needs the intervention of a specialized skilled staff; treatment is difficult and expensive and has potentially life-threatening side effects. The use of transcriptomic and proteomic technologies, currently in rapid development and increasing in sensitivity and discriminating power, is already generating a large panel of promising results. The objective of these technologies is to significantly increase our knowledge of the molecular mechanisms governing the parasite establishment in its vector, the development cycle of the parasite during the parasite's intra-vector life, its interactions with the fly and the other microbial inhabitants of the gut, and finally human host-trypanosome interactions. Such fundamental investigations are expected to provide opportunities to identify key molecular events that would constitute accurate targets for further development of tools dedicated to field work for early, sensitive, and stage-discriminant diagnosis, epidemiology, new chemotherapy, and potentially vaccine development, all of which will contribute to fighting the disease. The present review highlights the contributions of the transcriptomic and proteomic analyses developed thus far in order to identify potential targets (genes or proteins) and biological pathways that may constitute a critical step in the identification of new targets for the development of new tools for diagnostic and therapeutic purposes.
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Mwanakasale V, Songolo P. Disappearance of some human African trypanosomiasis transmission foci in Zambia in the absence of a tsetse fly and trypanosomiasis control program over a period of forty years. Trans R Soc Trop Med Hyg 2011; 105:167-72. [PMID: 21276598 DOI: 10.1016/j.trstmh.2010.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 12/07/2010] [Accepted: 12/07/2010] [Indexed: 11/26/2022] Open
Abstract
We conducted a situation analysis of human African trypanosomiasis (HAT) in Zambia from January 2000 to April 2007. The aim of this survey was to identify districts in Zambia that were still recording cases of HAT. Three districts namely, Mpika, Chama, and Chipata were found to be still reporting cases of HAT and thus lay in HAT transmission foci in North Eastern Zambia. During the period under review, 24 cases of HAT were reported from these three districts. We thereafter reviewed literature on the occurrence of HAT in Zambia from the early 1960s to mid 1990s. This revealed that HAT transmission foci were widespread in Western, North Western, Lusaka, Eastern, Luapula, and Northern Provinces of Zambia during this period. In this article we have tried to give possible reasons as to why the distribution of HAT transmission foci is so different between before and after 2000 when there has been no active national tsetse fly and trypanosomiasis control program in Zambia.
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Wardrop NA, Atkinson PM, Gething PW, Fèvre EM, Picozzi K, Kakembo ASL, Welburn SC. Bayesian geostatistical analysis and prediction of Rhodesian human African trypanosomiasis. PLoS Negl Trop Dis 2010; 4:e914. [PMID: 21200429 PMCID: PMC3006141 DOI: 10.1371/journal.pntd.0000914] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 11/15/2010] [Indexed: 11/18/2022] Open
Abstract
Background The persistent spread of Rhodesian human African trypanosomiasis (HAT) in Uganda in recent years has increased concerns of a potential overlap with the Gambian form of the disease. Recent research has aimed to increase the evidence base for targeting control measures by focusing on the environmental and climatic factors that control the spatial distribution of the disease. Objectives One recent study used simple logistic regression methods to explore the relationship between prevalence of Rhodesian HAT and several social, environmental and climatic variables in two of the most recently affected districts of Uganda, and suggested the disease had spread into the study area due to the movement of infected, untreated livestock. Here we extend this study to account for spatial autocorrelation, incorporate uncertainty in input data and model parameters and undertake predictive mapping for risk of high HAT prevalence in future. Materials and Methods Using a spatial analysis in which a generalised linear geostatistical model is used in a Bayesian framework to account explicitly for spatial autocorrelation and incorporate uncertainty in input data and model parameters we are able to demonstrate a more rigorous analytical approach, potentially resulting in more accurate parameter and significance estimates and increased predictive accuracy, thereby allowing an assessment of the validity of the livestock movement hypothesis given more robust parameter estimation and appropriate assessment of covariate effects. Results Analysis strongly supports the theory that Rhodesian HAT was imported to the study area via the movement of untreated, infected livestock from endemic areas. The confounding effect of health care accessibility on the spatial distribution of Rhodesian HAT and the linkages between the disease's distribution and minimum land surface temperature have also been confirmed via the application of these methods. Conclusions Predictive mapping indicates an increased risk of high HAT prevalence in the future in areas surrounding livestock markets, demonstrating the importance of livestock trading for continuing disease spread. Adherence to government policy to treat livestock at the point of sale is essential to prevent the spread of sleeping sickness in Uganda. The tsetse transmitted parasites, Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense, cause the fatal disease human African trypanosomiasis (HAT); the clinical progression, as well as the preferred diagnostic and treatment methods differ between the two types. Currently, the two do not overlap, although recent spread of Rhodesian HAT in Uganda has raised concerns over a potential future overlap. A recent study using geo-referenced HAT case records suggested that the most recent spread of Rhodesian HAT may have been due to movements of infected, untreated livestock (the main reservoir of the parasite). Here, the initial analysis has been extended by explicitly accounting for spatial locations and their proximity to one another, providing improved accuracy. The results provide strengthened evidence of the significance of livestock movements for the continued spread of Rhodesian HAT within Uganda, despite the introduction of cattle treatment regulations which were implemented in an effort to curb the disease's spread. The application of predictive mapping indicates an increased risk of HAT in areas surrounding livestock markets, demonstrating the importance of livestock trading for continuing disease spread. This robust evidence can be used for the targeting of disease control efforts within Uganda to prevent further spread of Rhodesian HAT.
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Affiliation(s)
- Nicola A. Wardrop
- Centre for Infectious Diseases, Division of Pathway Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
- School of Geography, University of Southampton, Southampton, United Kingdom
| | - Peter M. Atkinson
- School of Geography, University of Southampton, Southampton, United Kingdom
| | - Peter W. Gething
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Eric M. Fèvre
- Centre for Infectious Diseases, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Kim Picozzi
- Centre for Infectious Diseases, Division of Pathway Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Susan C. Welburn
- Centre for Infectious Diseases, Division of Pathway Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Berrang-Ford L, Berke O, Sweeney S, Abdelrahman L. Sleeping Sickness in Southeastern Uganda: A Spatio-Temporal Analysis of Disease Risk, 1970–2003. Vector Borne Zoonotic Dis 2010; 10:977-88. [DOI: 10.1089/vbz.2008.0196] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Lea Berrang-Ford
- Department of Geography, McGill University, Montreal, Quebec, Canada
| | - Olaf Berke
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada
| | - Sean Sweeney
- Centre for the Study of Institutions, Populations and Environmental Change (CIPEC), Indiana University, Bloomington, Indiana
| | - Lubowa Abdelrahman
- Department of Food Science and Technology, Makerere University, Kampala, Uganda
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Matemba LE, Fèvre EM, Kibona SN, Picozzi K, Cleaveland S, Shaw AP, Welburn SC. Quantifying the burden of rhodesiense sleeping sickness in Urambo District, Tanzania. PLoS Negl Trop Dis 2010; 4:e868. [PMID: 21072230 PMCID: PMC2970539 DOI: 10.1371/journal.pntd.0000868] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/01/2010] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Human African trypanosomiasis is a severely neglected vector-borne disease that is always fatal if untreated. In Tanzania it is highly focalised and of major socio-economic and public health importance in affected communities. OBJECTIVES This study aimed to estimate the public health burden of rhodesiense HAT in terms of DALYs and financial costs in a highly disease endemic area of Tanzania using hospital records. MATERIALS AND METHODS Data was obtained from 143 patients admitted in 2004 for treatment for HAT at Kaliua Health Centre, Urambo District. The direct medical and other indirect costs incurred by individual patients and by the health services were calculated. DALYs were estimated using methods recommended by the Global Burden of Disease Project as well as those used in previous rhodesiense HAT estimates assuming HAT under reporting of 45%, a figure specific for Tanzania. RESULTS The DALY estimate for HAT in Urambo District with and without age-weighting were 215.7 (95% CI: 155.3-287.5) and 281.6 (95% CI: 209.1-362.6) respectively. When 45% under-reporting was included, the results were 622.5 (95% CI: 155.3-1098.9) and 978.9 (95% CI: 201.1-1870.8) respectively. The costs of treating 143 patients in terms of admission costs, diagnosis, hospitalization and sleeping sickness drugs were estimated at US$ 15,514, of which patients themselves paid US$ 3,673 and the health services US$ 11,841. The burden in terms of indirect non-medical costs for the 143 patients was estimated at US$ 9,781. CONCLUSIONS This study shows that HAT imposes a considerable burden on affected rural communities in Tanzania and stresses the urgent need for location- and disease-specific burden estimates tailored to particular rural settings in countries like Tanzania where a considerable number of infectious diseases are prevalent and, due to their focal nature, are often concentrated in certain locations where they impose an especially high burden.
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Affiliation(s)
- Lucas E. Matemba
- Tabora Research Centre, National Institute for Medical Research, Tabora, Tanzania
- Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Eric M. Fèvre
- Ashworth Laboratories, Centre for Infectious Diseases, School of Biological Sciences, College of Science and Engineering, University of Edinburgh, Edinburgh, United Kingdom
| | - Stafford N. Kibona
- Tabora Research Centre, National Institute for Medical Research, Tabora, Tanzania
| | - Kim Picozzi
- Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Sarah Cleaveland
- Division of Ecology and Evolutionary Biology, University of Glasgow, Glasgow, United Kingdom
| | | | - Susan C. Welburn
- Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
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Hasker E, Lutumba P, Mumba D, Lejon V, Büscher P, Kande V, Muyembe JJ, Menten J, Robays J, Boelaert M. Diagnostic accuracy and feasibility of serological tests on filter paper samples for outbreak detection of T.b. gambiense human African trypanosomiasis. Am J Trop Med Hyg 2010; 83:374-9. [PMID: 20682885 DOI: 10.4269/ajtmh.2010.09-0735] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Control of human African trypanosomiasis (HAT) in the Democratic Republic of Congo is based on mass population screening by mobile teams; a costly and labor-intensive approach. We hypothesized that blood samples collected on filter paper by village health workers and processed in a central laboratory might be a cost-effective alternative. We estimated sensitivity and specificity of micro-card agglutination test for trypanosomiasis (micro-CATT) and enzyme-linked immunosorbent assay (ELISA)/T.b. gambiense on filter paper samples compared with parasitology-based case classification and used the results in a Monte Carlo simulation of a lot quality assurance sampling (LQAS) approach. Micro-CATT and ELISA/T.b. gambiense showed acceptable sensitivity (92.7% [95% CI 87.4-98.0%] and 82.2% [95% CI 75.3-90.4%]) and very high specificity (99.4% [95% CI 99.0-99.9%] and 99.8% [95% CI 99.5-100%]), respectively. Conditional on high sample size per lot (> or = 60%), both tests could reliably distinguish a 2% from a zero prevalence at village level. Alternatively, these tests could be used to identify individual HAT suspects for subsequent confirmation.
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Affiliation(s)
- Epco Hasker
- Institute of Tropical Medicine Antwerp, Belgium.
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Cecchi G, Paone M, Franco JR, Fèvre EM, Diarra A, Ruiz JA, Mattioli RC, Simarro PP. Towards the Atlas of human African trypanosomiasis. Int J Health Geogr 2009; 8:15. [PMID: 19296837 PMCID: PMC2661317 DOI: 10.1186/1476-072x-8-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 03/18/2009] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Updated, accurate and comprehensive information on the distribution of human African trypanosomiasis (HAT), also known as sleeping sickness, is critically important to plan and monitor control activities. We describe input data, methodology, preliminary results and future prospects of the HAT Atlas initiative, which will allow major improvements in the understanding of the spatial distribution of the disease. METHODS Up-to-date as well as historical data collected by national sleeping sickness control programmes, non-governmental organizations and research institutes have been collated over many years by the HAT Control and Surveillance Programme of the World Health Organization. This body of information, unpublished for the most part, is now being screened, harmonized, and analysed by means of database management systems and geographical information systems (GIS). The number of new HAT cases and the number of people screened within a defined geographical entity were chosen as the key variables to map disease distribution in sub-Saharan Africa. RESULTS At the time of writing, over 600 epidemiological reports and files from seventeen countries were collated and included in the data repository. The reports contain information on approximately 20,000 HAT cases, associated to over 7,000 different geographical entities. The oldest epidemiological records considered so far date back to 1985, the most recent having been gathered in 2008. Data from Cameroon, Central African Republic, Chad, Congo, Equatorial Guinea and Gabon from the year 2000 onwards were fully processed and the preliminary regional map of HAT distribution is presented. CONCLUSION The use of GIS tools and geo-referenced, village-level epidemiological data allow the production of maps that substantially improve on the spatial quality of previous cartographic products of similar scope. The significant differences between our preliminary outputs and earlier maps of HAT transmission areas demonstrate the strong need for this systematic approach to mapping sleeping sickness and point to the inaccuracy of any calculation of population at risk based on previous maps of HAT transmission areas. The Atlas of HAT will lay the basis for novel, evidence-based methodologies to estimate the population at risk and the burden of disease, ultimately leading to more efficient targeting of interventions. Also, the Atlas will help streamline future field data collection in those parts of Africa that still require it.
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Affiliation(s)
- Giuliano Cecchi
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy.
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Abstract
Human African trypanosomiasis (HAT, or sleeping sickness) is a protozoan parasitic infection caused by Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense. These are neglected tropical diseases, and T.b. rhodesiense HAT is a zoonosis. We review current knowledge on the burden of HAT in sub-Saharan Africa, with an emphasis on the disability-adjusted life year (DALY), data sources, and methodological issues relating to the use of this metric for assessing the burden of this disease. We highlight areas where data are lacking to properly quantify the impact of these diseases, mainly relating to quantifying under-reporting and disability associated with infection, and challenge the HAT research community to tackle the neglect in data gathering to enable better evidence-based assessments of burden using DALYs or other appropriate measures.
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Affiliation(s)
- Eric M. Fèvre
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - Beatrix v. Wissmann
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, University of Edinburgh, Summerhall, Edinburgh, United Kingdom
| | - Susan C. Welburn
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, University of Edinburgh, Summerhall, Edinburgh, United Kingdom
| | - Pascal Lutumba
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of Congo
- Institute of Tropical Medicine, Antwerp, Belgium
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John K, Kazwala R, Mfinanga GS. Knowledge of causes, clinical features and diagnosis of common zoonoses among medical practitioners in Tanzania. BMC Infect Dis 2008; 8:162. [PMID: 19046464 PMCID: PMC2611996 DOI: 10.1186/1471-2334-8-162] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 12/02/2008] [Indexed: 11/26/2022] Open
Abstract
Background Many factors have been mentioned as contributing to under-diagnosis and under-reporting of zoonotic diseases particularly in the sub-Sahara African region. These include poor disease surveillance coverage, poor diagnostic capacity, the geographical distribution of those most affected and lack of clear strategies to address the plight of zoonotic diseases. The current study investigates the knowledge of medical practitioners of zoonotic diseases as a potential contributing factor to their under-diagnosis and hence under-reporting. Methods The study was designed as a cross-sectional survey. Semi-structured open-ended questionnaire was administered to medical practitioners to establish the knowledge of anthrax, rabies, brucellosis, trypanosomiasis, echinococcosis and bovine tuberculosis in selected health facilities within urban and rural settings in Tanzania between April and May 2005. Frequency data were analyzed using likelihood ratio chi-square in Minitab version 14 to compare practitioners' knowledge of transmission, clinical features and diagnosis of the zoonoses in the two settings. For each analysis, likelihood ratio chi-square p-value of less than 0.05 was considered to be significant. Fisher's exact test was used where expected results were less than five. Results Medical practitioners in rural health facilities had poor knowledge of transmission of sleeping sickness and clinical features of anthrax and rabies in humans compared to their urban counterparts. In both areas the practitioners had poor knowledge of how echinococcosis is transmitted to humans, clinical features of echinococcosis in humans, and diagnosis of bovine tuberculosis in humans. Conclusion Knowledge of medical practitioners of zoonotic diseases could be a contributing factor to their under-diagnosis and under-reporting in Tanzania. Refresher courses on zoonotic diseases should be conducted particularly to practitioners in rural areas. More emphasis should be put on zoonotic diseases in teaching curricula of medical practitioners' training institutions in Tanzania to improve the diagnosis, reporting and control of zoonotic diseases. Veterinary and medical collaboration should be strengthened to enable more effective control of zoonotic diseases in Tanzania.
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Affiliation(s)
- Kunda John
- National Institute for Medical Research, Muhimbili Medical Research Centre, Dar es Salaam, Tanzania.
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Fèvre EM, Odiit M, Coleman PG, Woolhouse MEJ, Welburn SC. Estimating the burden of rhodesiense sleeping sickness during an outbreak in Serere, eastern Uganda. BMC Public Health 2008; 8:96. [PMID: 18366755 PMCID: PMC2322978 DOI: 10.1186/1471-2458-8-96] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Accepted: 03/26/2008] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Zoonotic sleeping sickness, or HAT (Human African Trypanosomiasis), caused by infection with Trypanosoma brucei rhodesiense, is an under-reported and neglected tropical disease. Previous assessments of the disease burden expressed as Disability-Adjusted Life Years (DALYs) for this infection have not distinguished T.b. rhodesiense from infection with the related, but clinically distinct Trypanosoma brucei gambiense form. T.b. rhodesiense occurs focally, and it is important to assess the burden at the scale at which resource-allocation decisions are made. METHODS The burden of T.b. rhodesiense was estimated during an outbreak of HAT in Serere, Uganda. We identified the unique characteristics affecting the burden of rhodesiense HAT such as age, severity, level of under-reporting and duration of hospitalisation, and use field data and empirical estimates of these to model the burden imposed by this and other important diseases in this study population. While we modelled DALYs using standard methods, we also modelled uncertainty of our parameter estimates through a simulation approach. We distinguish between early and late stage HAT morbidity, and used disability weightings appropriate for the T.b. rhodesiense form of HAT. We also use a model of under-reporting of HAT to estimate the contribution of un-reported mortality to the overall disease burden in this community, and estimate the cost-effectiveness of hospital-based HAT control. RESULTS Under-reporting accounts for 93% of the DALY estimate of rhodesiense HAT. The ratio of reported malaria cases to reported HAT cases in the same health unit was 133:1, however, the ratio of DALYs was 3:1. The age productive function curve had a close correspondence with the HAT case distribution, and HAT cases occupied more patient admission time in Serere during 1999 than all other infectious diseases other than malaria. The DALY estimate for HAT in Serere shows that the burden is much greater than might be expected from its relative incidence. Hospital based control in this setting appears to be highly cost-effective, highlighting the value of increasing coverage of therapy and reducing under-reporting. CONCLUSION We show the utility of calculating DALYs for neglected diseases at the local decision making level, and emphasise the importance of improved reporting systems for acquiring a better understanding of the burden of neglected zoonotic diseases.
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Affiliation(s)
- Eric M Fèvre
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh, EH9 3JT, UK
| | - Martin Odiit
- Centre for Tropical Veterinary Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
- Uganda AIDS Control Project, P.O. Box 25589, Kampala, Uganda; formerly Sleeping Sickness Programme, Livestock Health Research Institute, P. O. Box 96 Tororo, Uganda
| | - Paul G Coleman
- London School of Hygiene and Tropical Medicine, University of London, Keppel Street, WC1 7HT, UK
| | - Mark EJ Woolhouse
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh, EH9 3JT, UK
| | - Susan C Welburn
- Centre for Tropical Veterinary Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
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Kunda J, Fitzpatrick J, Kazwala R, French NP, Shirima G, Macmillan A, Kambarage D, Bronsvoort M, Cleaveland S. Health-seeking behaviour of human brucellosis cases in rural Tanzania. BMC Public Health 2007; 7:315. [PMID: 17980046 PMCID: PMC2186323 DOI: 10.1186/1471-2458-7-315] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 11/03/2007] [Indexed: 11/13/2022] Open
Abstract
Background Brucellosis is known to cause debilitating conditions if not promptly treated. In some rural areas of Tanzania however, practitioners give evidence of seeing brucellosis cases with symptoms of long duration. The purpose of this study was to establish health-seeking behaviour of human brucellosis cases in rural Tanzania and explore the most feasible ways to improve it. Methods This was designed as a longitudinal study. Socio-demographic, clinical and laboratory data were collected from patients who reported to selected hospitals in rural northern Tanzania between June 2002 and April 2003. All patients with conditions suspicious of brucellosis on the basis of preliminary clinical examination and history were enrolled into the study as brucellosis suspects. Blood samples were taken and tested for brucellosis using the Rose-Bengal Plate Test (RBPT) and other agglutination tests available at the health facilities and the competitive ELISA (c-ELISA) test at the Veterinary Laboratory Agencies (VLA) in the UK. All suspects who tested positive with the c-ELISA test were regarded as brucellosis cases. A follow-up of 49 cases was made to collect data on health-seeking behaviour of human brucellosis cases. Results The majority of cases 87.7% gave a history of going to hospital as the first point of care, 10.2% purchased drugs from a nearby drug shop before going to hospital and 2% went to a local traditional healer first. Brucellosis cases delayed going to hospital with a median delay time of 90 days, and with 20% of the cases presenting to hospitals more than a year after the onset of symptoms. Distance to the hospital, keeping animals and knowledge of brucellosis were significantly associated with patient delay to present to hospital. Conclusion More efforts need to be put on improving the accessibility of health facilities to the rural poor people who succumb to most of the diseases including zoonoses. Health education on brucellosis in Tanzania should also stress the importance of early presentation to hospitals for prompt treatment.
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Affiliation(s)
- John Kunda
- National Institute for Medical Research, Muhimbili Centre, Tanzania.
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Berrang Ford L. Civil conflict and sleeping sickness in Africa in general and Uganda in particular. Confl Health 2007; 1:6. [PMID: 17411421 PMCID: PMC1851948 DOI: 10.1186/1752-1505-1-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 03/29/2007] [Indexed: 11/20/2022] Open
Abstract
Conflict and war have long been recognized as determinants of infectious disease risk. Re-emergence of epidemic sleeping sickness in sub-Saharan Africa since the 1970s has coincided with extensive civil conflict in affected regions. Sleeping sickness incidence has placed increasing pressure on the health resources of countries already burdened by malaria, HIV/AIDS, and tuberculosis. In areas of Sudan, the Democratic Republic of the Congo, and Angola, sleeping sickness occurs in epidemic proportions, and is the first or second greatest cause of mortality in some areas, ahead of HIV/AIDS. In Uganda, there is evidence of increasing spread and establishment of new foci in central districts. Conflict is an important determinant of sleeping sickness outbreaks, and has contributed to disease resurgence. This paper presents a review and characterization of the processes by which conflict has contributed to the occurrence of sleeping sickness in Africa. Conflict contributes to disease risk by affecting the transmission potential of sleeping sickness via economic impacts, degradation of health systems and services, internal displacement of populations, regional insecurity, and reduced access for humanitarian support. Particular focus is given to the case of sleeping sickness in south-eastern Uganda, where incidence increase is expected to continue. Disease intervention is constrained in regions with high insecurity; in these areas, political stabilization, localized deployment of health resources, increased administrative integration and national capacity are required to mitigate incidence. Conflict-related variables should be explicitly integrated into risk mapping and prioritization of targeted sleeping sickness research and mitigation initiatives.
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Affiliation(s)
- Lea Berrang Ford
- Department of Population Medicine, University of Guelph, Canada.
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Robays J, Lefèvre P, Lutumba P, Lubanza S, Kande Betu Ku Mesu V, Van der Stuyft P, Boelaert M. Drug toxicity and cost as barriers to community participation in HAT control in the Democratic Republic of Congo. Trop Med Int Health 2007; 12:290-8. [PMID: 17300638 DOI: 10.1111/j.1365-3156.2006.01768.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Active case-finding programmes by mobile teams are the cornerstone of West African Human African Trypanosomiasis (HAT) control. Low attendance rates of screening and low uptake of treatment after diagnosis are major problems. The objectives of this survey were to explore community perception of HAT, to assess acceptability of control activities and to identify barriers amenable to intervention. METHODS In September 2004, we conducted 33 focus group discussions with beneficiaries of the HAT control programme among various ethnic groups in two ecological settings (savannah and fluvial) of the Democratic Republic of Congo. RESULTS The population had a very detailed knowledge and understanding of HAT transmission, utility of screening, symptoms and treatment. Melarsoprol treatment was feared for its side effects. The sudden death of previously asymptomatic people during treatment was attributed to witchcraft, to which one becomes more vulnerable when the diagnosis is disclosed in public. Lack of confidentiality was also a problem because HAT carries a stigma as a mental disease. Lumbar punctures, especially when performed in public, were disliked but less feared. Financial barriers were a major obstacle for many patients. CONCLUSION Less toxic drugs, lowering financial barriers and improving confidentiality would have considerable impact on the participation in population screening for HAT.
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Affiliation(s)
- J Robays
- Institute of Tropical Medicine, Epidemiology and Disease Control Unit, Antwerp, Belgium.
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Lutumba P, Makieya E, Shaw A, Meheus F, Boelaert M. Human African trypanosomiasis in a rural community, Democratic Republic of Congo. Emerg Infect Dis 2007; 13:248-54. [PMID: 17479887 PMCID: PMC2725878 DOI: 10.3201/eid1302.060075] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
According to the World Health Organization, human African trypanosomiasis (HAT) (sleeping sickness) caused the loss of approximately 1.5 million disability-adjusted life years (DALYs) in 2002. We describe the effect of HAT during 2000-2002 in Buma, a rural community near Kinshasa in the Democratic Republic of Congo. We used retrospective questionnaire surveys to estimate HAT-related household costs and DALYs. The HAT outbreak in Buma involved 57 patients and affected 47 (21%) households. The cost to each household was equivalent to 5 months' income for that household. The total number of HAT-related DALYs was 2,145, and interventions to control HAT averted 1,408 DALYs. The cost per DALY averted was US $17. Because HAT has a serious economic effect on households and control interventions are cost-effective, considering only global burden of disease rankings for resource allocation could lead to misguided priority setting if applied without caution in HAT-affected countries.
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Affiliation(s)
- Pascal Lutumba
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of Congo
- Institute of Tropical Medicine, Antwerp, Belgium
| | - Eric Makieya
- University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | | | - Filip Meheus
- Royal Tropical Institute, Amsterdam, the Netherlands
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Berrang-Ford L, Berke O, Abdelrahman L, Waltner-Toews D, McDermott J. Spatial analysis of sleeping sickness, southeastern Uganda, 1970-2003. Emerg Infect Dis 2006; 12:813-20. [PMID: 16704843 PMCID: PMC3293436 DOI: 10.3201/eid1205.051284] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Disease will likely spread into central Uganda. Sleeping sickness reemerged in southeastern Uganda in the 1970s and remains a public health problem. It has continued to spread north into new districts, and gaps remain in the understanding of the causes of its spread and distribution. We report the distribution and magnitude of sleeping sickness in southeastern Uganda from 1970 to 2003. Data were collected from records of the Ugandan Ministry of Health, individual sleeping sickness treatment centers, and interviews with public health officials. Data were used to develop incidence maps over time, conduct space-time cluster detection analyses, and develop a velocity vector map to visualize spread of sleeping sickness over time in southeastern Uganda. Results show rapid propagation of sleeping sickness from its epicenter in southern Iganga District and its spread north into new districts and foci.
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Affiliation(s)
- Lea Berrang-Ford
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada.
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Inojosa WO, Augusto I, Bisoffi Z, Josenado T, Abel PM, Stich A, Whitty CJM. Diagnosing human African trypanosomiasis in Angola using a card agglutination test: observational study of active and passive case finding strategies. BMJ 2006; 332:1479. [PMID: 16777858 PMCID: PMC1482336 DOI: 10.1136/bmj.38859.531354.7c] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To assess the operational feasibility of detecting human African trypanosomiasis by active and passive case finding using the card agglutination test with serial dilution of serum to guide treatment. SETTING Trypanosomiasis control programme in the Negage focus, northern Angola, during a period of civil war. DESIGN Observational study. PARTICIPANTS 359 patients presenting themselves to health centres with symptoms (passive case finding) and 14,446 people actively screened in villages. MAIN OUTCOME MEASURES Whole blood and serological tests at different dilutions using the card agglutination test, and detection of parasites by microscopy. RESULTS Active case finding identified 251 people with a positive card agglutination test result, 10 of whom had confirmed parasites. In those presenting for investigation 34 of 51 with a positive card agglutination test result at the dilution of 1:8 or more used to guide treatment had parasites in blood, lymph node fluid, or cerebrospinal fluid, compared with 10 of 76 in those detected by active case finding: positive predictive values of 67% for passive case detection and 13% for active case detection. Only at a cut-off dilution more than 1:32 was the positive predictive value in active case detection reasonable (46%) and at this dilution 40% of microscopically proved cases were missed. CONCLUSIONS The card agglutination test is useful for initial screening in active detection of cases with human African trypanosomiasis but, given the toxicity of the drugs, serology using the card agglutination test should be not used alone to guide treatment after active case finding. A second confirmatory test is needed.
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Kaare MT, Picozzi K, Mlengeya T, Fèvre EM, Mellau LS, Mtambo MM, Cleaveland S, Welburn SC. Sleeping sickness--a re-emerging disease in the Serengeti? Travel Med Infect Dis 2006; 5:117-24. [PMID: 17298919 DOI: 10.1016/j.tmaid.2006.01.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 01/16/2006] [Indexed: 11/30/2022]
Abstract
Sleeping sickness is a re-emerging disease in the Serengeti ecosystem affecting both local people and tourists. Here we report the results of a survey to assess the prevalence of trypanosomiasis in both domestic and wild animals from this area. Five hundred and eighteen cattle samples were collected from 12 villages that bordered the Serengeti National Park and 220 samples from 15 different wild animal species were collected from within the park. PCR analysis, directed against the human serum resistance associated gene SRA, identified human infective Trypanosoma brucei rhodesiense parasites in both cattle and warthogs.
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Affiliation(s)
- Magai T Kaare
- Department of Veterinary Medicine and Public Health, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, Tanzania
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Odiit M, Bessell PR, Fèvre EM, Robinson T, Kinoti J, Coleman PG, Welburn SC, McDermott J, Woolhouse MEJ. Using remote sensing and geographic information systems to identify villages at high risk for rhodesiense sleeping sickness in Uganda. Trans R Soc Trop Med Hyg 2006; 100:354-62. [PMID: 16246384 DOI: 10.1016/j.trstmh.2005.04.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Revised: 04/01/2005] [Accepted: 04/12/2005] [Indexed: 11/25/2022] Open
Abstract
Geographic information systems (GIS) and remote sensing were used to identify villages at high risk for sleeping sickness, as defined by reported incidence. Landsat Enhanced Thematic Mapper (ETM) satellite data were classified to obtain a map of land cover, and the Normalised Difference Vegetation Index (NDVI) and Landsat band 5 were derived as unclassified measures of vegetation density and soil moisture, respectively. GIS functions were used to determine the areas of land cover types and mean NDVI and band 5 values within 1.5 km radii of 389 villages where sleeping sickness incidence had been estimated. Analysis using backward binary logistic regression found proximity to swampland and low population density to be predictive of reported sleeping sickness presence, with distance to the sleeping sickness hospital as an important confounding variable. These findings demonstrate the potential of remote sensing and GIS to characterize village-level risk of sleeping sickness in endemic regions.
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Affiliation(s)
- Martin Odiit
- Sleeping Sickness Programme, National Agricultural Research Organization, LIRI Hospital, P.O. Box 96, Tororo, Uganda
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46
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Fèvre EM, Tilley A, Picozzi K, Fyfe J, Anderson I, Magona JW, Shaw DJ, Eisler MC, Welburn SC. Central point sampling from cattle in livestock markets in areas of human sleeping sickness. Acta Trop 2006; 97:229-32. [PMID: 16387279 DOI: 10.1016/j.actatropica.2005.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 11/16/2005] [Accepted: 11/29/2005] [Indexed: 12/01/2022]
Abstract
We present the results of a study to determine the value of central point sampling in cattle markets as a means of estimating the trypanosomiasis (T. brucei s.l.) prevalence in the surrounding landscape in Uganda. We find that in the epidemic area studied, central point sampling is a good predictor of prevalence in surrounding villages, but not in endemic areas. We also find that animals infected with trypanosomiasis are more likely to be brought for sale in livestock markets in endemic areas; we discuss these results in relation to the prevention of the spread of sleeping sickness.
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Affiliation(s)
- E M Fèvre
- Centre for Tropical Veterinary Medicine, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK.
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Fèvre EM, Picozzi K, Jannin J, Welburn SC, Maudlin I. Human African Trypanosomiasis: Epidemiology and Control. ADVANCES IN PARASITOLOGY 2006; 61:167-221. [PMID: 16735165 DOI: 10.1016/s0065-308x(05)61005-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Human African trypanosomiasis (HAT), or sleeping sickness, describes not one but two discrete diseases: that caused by Trypanosoma brucei rhodesiense and that caused by T. b. gambiense. The Gambian form is currently a major public health problem over vast areas of central and western Africa, while the zoonotic, Rhodesian form continues to present a serious health risk in eastern and southern Africa. The two parasites cause distinct clinical manifestations, and there are significant differences in the epidemiology of the diseases caused. We discuss the differences between the diseases caused by the two parasites, with an emphasis on disease burden, reservoir hosts, transmission, diagnosis, treatment and control. We analyse how these differences impacted on historical disease control trends and how they can inform contemporary treatment and control options. We consider the optimal ways in which to devise HAT control policies in light of the differing biology and epidemiology of the parasites, and emphasise, in particular, the wider aspects of control policy, outlining the responsibilities of individuals, governments and international organisations in control programmes.
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Affiliation(s)
- E M Fèvre
- Centre for Infectious Diseases, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
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Odiit M, Coleman PG, Liu WC, McDermott JJ, Fèvre EM, Welburn SC, Woolhouse MEJ. Quantifying the level of under-detection of Trypanosoma brucei rhodesiense sleeping sickness cases. Trop Med Int Health 2005; 10:840-9. [PMID: 16135190 DOI: 10.1111/j.1365-3156.2005.01470.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To formally quantify the level of under-detection of Trypanosoma brucei rhodesiense sleeping sickness (SS) during an epidemic in Uganda, a decision tree (under-detection) model was developed; concurrently, to quantify the subset of undetected cases that sought health care but were not diagnosed, a deterministic (subset) model was developed. The values of the under-detection model parameters were estimated from previously published records of the duration of symptoms prior to presentation and the ratio of early to late stage cases in 760 SS patients presenting at LIRI hospital, Tororo, Uganda during the 1988--1990 epidemic of SS. For the observed early to late stage ratio of 0.47, we estimate that the proportion of under-detection in the catchment area of LIRI hospital was 0.39 (95% CI 0.37--0.41) i.e. 39% of cases are not reported. Based on this value, it is calculated that for every one reported death of SS, 12.0 (95% CI 11.0--13.0) deaths went undetected in the LIRI hospital catchment area - i.e. 92% of deaths are not reported. The deterministic (subset) model structured on the possible routes of a SS infection to either diagnosis or death through the health system or out of it, showed that of a total of 73 undetected deaths, 62 (CI 60-64) (85%) entered the healthcare system but were not diagnosed, and 11 (CI 11--12) died without seeking health care from a recognized health unit. The measure of early to late stage presentation provides a tractable measure to determine the level of rhodesiense SS under-detection and to gauge the effects of interventions aimed at increasing treatment coverage.
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