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Soumah AM, Camara M, Kaboré JW, Sadissou I, Ilboudo H, Travaillé C, Camara O, Tichit M, Kaboré J, Boiro S, Crouzols A, Ngoune JMT, Hardy D, Camara A, Jamonneau V, MacLeod A, Bart JM, Camara M, Bucheton B, Rotureau B. Prevalence of dermal trypanosomes in suspected and confirmed cases of gambiense human African trypanosomiasis in Guinea. PLoS Negl Trop Dis 2024; 18:e0012436. [PMID: 39159265 PMCID: PMC11361743 DOI: 10.1371/journal.pntd.0012436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 08/29/2024] [Accepted: 08/05/2024] [Indexed: 08/21/2024] Open
Abstract
The skin is an anatomical reservoir for African trypanosomes, yet the prevalence of extravascular parasite carriage in the population at risk of gambiense Human African Trypanosomiasis (gHAT) remains unclear. Here, we conducted a prospective observational cohort study in the HAT foci of Forecariah and Boffa, Republic of Guinea. Of the 18,916 subjects serologically screened for gHAT, 96 were enrolled into our study. At enrolment and follow-up visits, participants underwent a dermatological examination and had blood samples and superficial skin snip biopsies taken for examination by molecular and immuno-histological methods. In seropositive individuals, dermatological symptoms were significantly more frequent as compared to seronegative controls. Trypanosoma brucei DNA was detected in the blood of 67% of confirmed cases (22/33) and 9% of unconfirmed seropositive individuals (3/32). However, parasites were detected in the extravascular dermis of up to 71% of confirmed cases (25/35) and 41% of unconfirmed seropositive individuals (13/32) by PCR and/or immuno-histochemistry. Six to twelve months after treatment, trypanosome detection in the skin dropped to 17% of confirmed cases (5/30), whereas up to 25% of unconfirmed, hence untreated, seropositive individuals (4/16) were still found positive. Dermal trypanosomes were observed in subjects from both transmission foci, however, the occurrence of pruritus and the PCR positivity rates were significantly higher in unconfirmed seropositive individuals in Forecariah. The lower sensitivity of superficial skin snip biopsies appeared critical for detecting trypanosomes in the basal dermis. These results are discussed in the context of the planned elimination of gHAT.
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Affiliation(s)
- Alseny M’mah Soumah
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
| | - Mariame Camara
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
| | - Justin Windingoudi Kaboré
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
| | - Ibrahim Sadissou
- INTERTRYP, Université de Montpellier, CIRAD, IRD, Montpellier, France
| | - Hamidou Ilboudo
- INTERTRYP, Université de Montpellier, CIRAD, IRD, Montpellier, France
- Institut de Recherche en Sciences de la Santé - Unité de Recherche Clinique de Nanoro, Nanoro, Burkina-Faso
| | - Christelle Travaillé
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - Oumou Camara
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
| | - Magali Tichit
- Histopathology Core Facility, Institut Pasteur, Université Paris Cité, Paris, France
| | - Jacques Kaboré
- Unité de recherches sur les bases biologiques de la lutte intégrée, Centre International de Recherche-Développement sur l’Elevage en zone Subhumide, Bobo-Dioulasso, Burkina Faso
| | - Salimatou Boiro
- Parasitology Unit, Institut Pasteur of Guinea, Conakry, Guinea
| | - Aline Crouzols
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - Jean Marc Tsagmo Ngoune
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - David Hardy
- Histopathology Core Facility, Institut Pasteur, Université Paris Cité, Paris, France
| | - Aïssata Camara
- Parasitology Unit, Institut Pasteur of Guinea, Conakry, Guinea
| | - Vincent Jamonneau
- INTERTRYP, Université de Montpellier, CIRAD, IRD, Montpellier, France
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Jean-Mathieu Bart
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
- INTERTRYP, Université de Montpellier, CIRAD, IRD, Montpellier, France
| | - Mamadou Camara
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
| | - Bruno Bucheton
- Programme National de Lutte contre les Maladies Tropicales Négligées, Ministère de la Santé, Conakry, Guinea
- INTERTRYP, Université de Montpellier, CIRAD, IRD, Montpellier, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
- Parasitology Unit, Institut Pasteur of Guinea, Conakry, Guinea
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Saldanha I, Lea R, Manangwa O, Garrod G, Haines LR, Acosta-Serrano Á, Auty H, Betson M, Lord JS, Morrison LJ, Mramba F, Torr SJ, Cunningham LJ. Caught in a trap: DNA contamination in tsetse xenomonitoring can lead to over-estimates of Trypanosoma brucei infection. PLoS Negl Trop Dis 2024; 18:e0012095. [PMID: 39133740 PMCID: PMC11341098 DOI: 10.1371/journal.pntd.0012095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 08/22/2024] [Accepted: 07/26/2024] [Indexed: 08/24/2024] Open
Abstract
BACKGROUND Tsetse flies (Glossina sp.) are vectors of Trypanosoma brucei subspecies that cause human African trypanosomiasis (HAT). Capturing and screening tsetse is critical for HAT surveillance. Classically, tsetse have been microscopically analysed to identify trypanosomes, but this is increasingly replaced with molecular xenomonitoring. Nonetheless, sensitive T. brucei-detection assays, such as TBR-PCR, are vulnerable to DNA cross-contamination. This may occur at capture, when often multiple live tsetse are retained temporarily in the cage of a trap. This study set out to determine whether infected tsetse can contaminate naïve tsetse with T. brucei DNA via faeces when co-housed. METHODOLOGY/PRINCIPLE FINDINGS Insectary-reared teneral G. morsitans morsitans were fed an infectious T. b. brucei-spiked bloodmeal. At 19 days post-infection, infected and naïve tsetse were caged together in the following ratios: (T1) 9:3, (T2) 6:6 (T3) 1:11 and a control (C0) 0:12 in triplicate. Following 24-hour incubation, DNA was extracted from each fly and screened for parasite DNA presence using PCR and qPCR. All insectary-reared infected flies were positive for T. brucei DNA using TBR-qPCR. However, naïve tsetse also tested positive. Even at a ratio of 1 infected to 11 naïve flies, 91% of naïve tsetse gave positive TBR-qPCR results. Furthermore, the quantity of T. brucei DNA detected in naïve tsetse was significantly correlated with cage infection ratio. With evidence of cross-contamination, field-caught tsetse from Tanzania were then assessed using the same screening protocol. End-point TBR-PCR predicted a sample population prevalence of 24.8%. Using qPCR and Cq cut-offs optimised on insectary-reared flies, we estimated that prevalence was 0.5% (95% confidence interval [0.36, 0.73]). CONCLUSIONS/SIGNIFICANCE Our results show that infected tsetse can contaminate naïve flies with T. brucei DNA when co-caged, and that the level of contamination can be extensive. Whilst simple PCR may overestimate infection prevalence, quantitative PCR offers a means of eliminating false positives.
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Affiliation(s)
- Isabel Saldanha
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Rachel Lea
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Oliver Manangwa
- Vector and Vector-borne Diseases Research Institute, Tanga, Tanzania
| | - Gala Garrod
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lee R. Haines
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Álvaro Acosta-Serrano
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Harriet Auty
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Martha Betson
- School of Veterinary Medicine, University of Surrey, Guildford, United Kingdom
| | - Jennifer S. Lord
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Liam J. Morrison
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Furaha Mramba
- Vector and Vector-borne Diseases Research Institute, Tanga, Tanzania
| | - Stephen J. Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lucas J. Cunningham
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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3
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Saldanha I, Betson M, Vrettou C, Paxton E, Nixon J, Tennant P, Ritchie A, Matthews KR, Morrison LJ, Torr SJ, Cunningham LJ. Consistent detection of Trypanosoma brucei but not T. congolense DNA in faeces of experimentally infected cattle. Sci Rep 2024; 14:4158. [PMID: 38378867 PMCID: PMC10879203 DOI: 10.1038/s41598-024-54857-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/17/2024] [Indexed: 02/22/2024] Open
Abstract
Animal African trypanosomiasis (AAT) is a significant food security and economic burden in sub-Saharan Africa. Current AAT empirical and immunodiagnostic surveillance tools suffer from poor sensitivity and specificity, with blood sampling requiring animal restraint and trained personnel. Faecal sampling could increase sampling accessibility, scale, and species range. Therefore, this study assessed feasibility of detecting Trypanosoma DNA in the faeces of experimentally-infected cattle. Holstein-Friesian calves were inoculated with Trypanosoma brucei brucei AnTat 1.1 (n = 5) or T. congolense Savannah IL3000 (n = 6) in separate studies. Faecal and blood samples were collected concurrently over 10 weeks and screened using species-specific PCR and qPCR assays. T. brucei DNA was detected in 85% of post-inoculation (PI) faecal samples (n = 114/134) by qPCR and 50% by PCR between 4 and 66 days PI. However, T. congolense DNA was detected in just 3.4% (n = 5/145) of PI faecal samples by qPCR, and none by PCR. These results confirm the ability to consistently detect T. brucei DNA, but not T. congolense DNA, in infected cattle faeces. This disparity may derive from the differences in Trypanosoma species tissue distribution and/or extravasation. Therefore, whilst faeces are a promising substrate to screen for T. brucei infection, blood sampling is required to detect T. congolense in cattle.
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Affiliation(s)
- Isabel Saldanha
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Martha Betson
- School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | - Edith Paxton
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - James Nixon
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Peter Tennant
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Adrian Ritchie
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute of Immunology and Infection, University of Edinburgh, Edinburgh, UK
| | | | - Stephen J Torr
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Lucas J Cunningham
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Sereno D, Oury B, Geiger A, Vela A, Karmaoui A, Desquesnes M. Isothermal Nucleic Acid Amplification to Detect Infection Caused by Parasites of the Trypanosomatidae Family: A Literature Review and Opinion on the Laboratory to Field Applicability. Int J Mol Sci 2022; 23:7543. [PMID: 35886895 PMCID: PMC9322063 DOI: 10.3390/ijms23147543] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 12/13/2022] Open
Abstract
Isothermal amplification of nucleic acids has the potential to be applied in resource-limited areas for the detection of infectious agents, as it does not require complex nucleic purification steps or specific and expensive equipment and reagents to perform the reaction and read the result. Since human and animal infections by pathogens of the Tryponasomatidae family occur mainly in resource-limited areas with scant health infrastructures and personnel, detecting infections by these methodologies would hold great promise. Here, we conduct a narrative review of the literature on the application of isothermal nucleic acid amplification for Trypanosoma and Leishmania infections, which are a scourge for human health and food security. We highlight gaps and propose ways to improve them to translate these powerful technologies into real-world field applications for neglected human and animal diseases caused by Trypanosomatidae.
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Affiliation(s)
- Denis Sereno
- Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, Parasite Infectiology and Public Health Group, 34032 Montpellier, France
| | - Bruno Oury
- Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, Parasite Infectiology and Public Health Group, 34032 Montpellier, France
| | - Anne Geiger
- Centre International de Recherche en Agronomie pour le Développement, Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, 34032 Montpellier, France
| | - Andrea Vela
- One Health Research Group, Facultad de Ciencias de la Salud, Universidad de las Américas-Quito, Calle de los Colimes y Avenida De los Granados, Quito 170513, Ecuador
| | - Ahmed Karmaoui
- Bioactives (Health and Environmental, Epigenetics Team), Faculty of Sciences and Techniques, Errachidia (UMI), Moroccan Center for Culture and Sciences, University Moulay Ismail, Meknes 50000, Morocco
| | - Marc Desquesnes
- CIRAD, UMR INTERTRYP, 31076 Toulouse, France
- INTERTRYP, Université de Montpellier, CIRAD, IRD, 34032 Montpellier, France
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5
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Vasuki V, Hoti SL, Subramanian S, Khan AM, Thenmozhi V, Ananganallur NS, Mahapatra N, Balasubramaniyan R. Multi-centric evaluation of a stage-specific reverse transcriptase-polymerase chain reaction assay as a xenomonitoring tool for the detection of infective (L 3) stage Wuchereria bancrofti in vectors. Indian J Med Res 2021; 154:132-140. [PMID: 34782539 PMCID: PMC8715687 DOI: 10.4103/ijmr.ijmr_713_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background & objectives: An infective stage specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay utilizing the abundant larval transcript-3 (Alt-3) gene of Wuchereria bancrofti was developed at ICMR-VCRC, Puducherry and found to be stage specific, and sensitive upon validation in the laboratory. This study was aimed at independently evaluating this assay for its utility as a monitoring/surveillance tool in the operational programme for elimination of lymphatic filariasis (LF) by four national research laboratories. Methods: Evaluation of the assay was carried out in a multi-centric mode in three phases. In phase I, a workshop was conducted to impart hands-on training to the scientists from the collaborating centres on the RT-PCR assay and in Phase II the assay was evaluated for specificity and sensitivity in detecting the infective (L3) stage larvae of W. bancrofti in its vector, Culex quinquefasciatus, using 50 coded pooled samples. Phase III evaluation was done on wild-caught mosquito vectors from selected endemic areas of Assam and Bhubaneswar States and Andaman Nicobar islands. Results: Phase I data indicated that the assay was able to detect all the pools of mosquito samples contaning L3 stage larvae of W. bancrofti as positive, even in the presence of other vector stages of the parasite indicating its stage specificity (100%). The assay was found highly sensitive (100%), detecting all the infected pools as positive and specific detecting all uninfected pools as negative. The results of phase II showed inter-laboratory variation. Phase III evaluation from all the centres suggested that the infectivity rate determined for pooled mosquitoes by the RT-PCR assay (0.5%) was comparable to that by dissection method (1.2%) (95% confidence interval overlaps). Interpretation & conclusions: Overall, the results from three of the four participating centres indicated that the assay is at least as sensitive and stage specific as the conventional mosquito dissection technique, and hence, may be useful as a xenomonitoring tool for Transmission Assessment Survey in Mass Drug Administration programmes for LF.
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Affiliation(s)
| | | | | | | | | | | | - Namita Mahapatra
- ICMR-Regional Medical Research Centre, Bhubaneswar, Odisha, India
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Single nucleotide polymorphisms and copy-number variations in the Trypanosoma brucei repeat (TBR) sequence can be used to enhance amplification and genotyping of Trypanozoon strains. PLoS One 2021; 16:e0258711. [PMID: 34695154 PMCID: PMC8544829 DOI: 10.1371/journal.pone.0258711] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
The Trypanosoma brucei repeat (TBR) is a tandem repeat sequence present on the Trypanozoon minichromosomes. Here, we report that the TBR sequence is not as homogenous as previously believed. BLAST analysis of the available T. brucei genomes reveals various TBR sequences of 177 bp and 176 bp in length, which can be sorted into two TBR groups based on a few key single nucleotide polymorphisms. Conventional and quantitative PCR with primers matched to consensus sequences that target either TBR group show substantial copy-number variations in the TBR repertoire within a collection of 77 Trypanozoon strains. We developed the qTBR, a novel PCR consisting of three primers and two probes, to simultaneously amplify target sequences from each of the two TBR groups into one single qPCR reaction. This dual probe setup offers increased analytical sensitivity for the molecular detection of all Trypanozoon taxa, in particular for T.b. gambiense and T. evansi, when compared to existing TBR PCRs. By combining the qTBR with 18S rDNA amplification as an internal standard, the relative copy-number of each TBR target sequence can be calculated and plotted, allowing for further classification of strains into TBR genotypes associated with East, West or Central Africa. Thus, the qTBR takes advantage of the single-nucleotide polymorphisms and copy number variations in the TBR sequences to enhance amplification and genotyping of all Trypanozoon strains, making it a promising tool for prevalence studies of African trypanosomiasis in both humans and animals.
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Camara M, Soumah AM, Ilboudo H, Travaillé C, Clucas C, Cooper A, Kuispond Swar NR, Camara O, Sadissou I, Calvo Alvarez E, Crouzols A, Bart JM, Jamonneau V, Camara M, MacLeod A, Bucheton B, Rotureau B. Extravascular Dermal Trypanosomes in Suspected and Confirmed Cases of gambiense Human African Trypanosomiasis. Clin Infect Dis 2021; 73:12-20. [PMID: 32638003 PMCID: PMC8246823 DOI: 10.1093/cid/ciaa897] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/25/2020] [Indexed: 11/18/2022] Open
Abstract
Background The diagnosis of gambiense human African trypanosomiasis (gHAT) typically involves 2 steps: a serological screen, followed by the detection of living trypanosome parasites in the blood or lymph node aspirate. Live parasites can, however, remain undetected in some seropositive individuals, who, we hypothesize, are infected with Trypanosoma brucei gambiense parasites in their extravascular dermis. Methods To test this hypothesis, we conducted a prospective observational cohort study in the gHAT focus of Forecariah, Republic of Guinea. Of the 5417 subjects serologically screened for gHAT, 66 were enrolled into our study and underwent a dermatological examination. At enrollment, 11 seronegative, 8 unconfirmed seropositive, and 18 confirmed seropositive individuals had blood samples and skin biopsies taken and examined for trypanosomes by molecular and immunohistological methods. Results In seropositive individuals, dermatological symptoms were significantly more frequent, relative to seronegative controls. T.b. gambiense parasites were present in the blood of all confirmed cases (n = 18) but not in unconfirmed seropositive individuals (n = 8). However, T. brucei parasites were detected in the extravascular dermis of all unconfirmed seropositive individuals and all confirmed cases. Skin biopsies of all treated cases and most seropositive untreated individuals progressively became negative for trypanosomes 6 and 20 months later. Conclusions Our results highlight the skin as a potential reservoir for African trypanosomes, with implications for our understanding of this disease’s epidemiology in the context of its planned elimination and underlining the skin as a novel target for gHAT diagnostics.
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Affiliation(s)
- Mariame Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Alseny M'mah Soumah
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Service de Dermatologie, Hôpital de Donka,Conakry, Guinea
| | - Hamidou Ilboudo
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Institut de Recherche en Sciences de la Santé (IRSS)-Unité de Recherche Clinique de Nanoro (URCN), Nanoro, Burkina-Faso.,Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Christelle Travaillé
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Caroline Clucas
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Anneli Cooper
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Nono-Raymond Kuispond Swar
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom.,Department of Parasitology, National Institute of Biomedical Research (INRB), Kinshasa, Democratic Republic of the Congo
| | - Oumou Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Ibrahim Sadissou
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Estefania Calvo Alvarez
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Aline Crouzols
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Jean-Mathieu Bart
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Vincent Jamonneau
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Mamadou Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Bruno Bucheton
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
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Solano P. Need of entomological criteria to assess zero transmission of gambiense HAT. PLoS Negl Trop Dis 2021; 15:e0009235. [PMID: 33765067 PMCID: PMC7993614 DOI: 10.1371/journal.pntd.0009235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Philippe Solano
- Institut de Recherche pour le Développement, UMR INTERTRYP IRD-CIRAD, Université de Montpellier, Montpellier, France
- * E-mail:
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9
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Pennance T, Archer J, Lugli EB, Rostron P, Llanwarne F, Ali SM, Amour AK, Suleiman KR, Li S, Rollinson D, Cable J, Knopp S, Allan F, Ame SM, Webster BL. Development of a Molecular Snail Xenomonitoring Assay to Detect Schistosoma haematobium and Schistosoma bovis Infections in their Bulinus Snail Hosts. Molecules 2020; 25:E4011. [PMID: 32887445 PMCID: PMC7116084 DOI: 10.3390/molecules25174011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 12/20/2022] Open
Abstract
Schistosomiasis, a neglected tropical disease of medical and veterinary importance, transmitted through specific freshwater snail intermediate hosts, is targeted for elimination in several endemic regions in sub-Saharan Africa. Multi-disciplinary methods are required for both human and environmental diagnostics to certify schistosomiasis elimination when eventually reached. Molecular xenomonitoring protocols, a DNA-based detection method for screening disease vectors, have been developed and trialed for parasites transmitted by hematophagous insects, such as filarial worms and trypanosomes, yet few have been extensively trialed or proven reliable for the intermediate host snails transmitting schistosomes. Here, previously published universal and Schistosoma-specific internal transcribed spacer (ITS) rDNA primers were adapted into a triplex PCR primer assay that allowed for simple, robust, and rapid detection of Schistosoma haematobium and Schistosoma bovis in Bulinus snails. We showed this two-step protocol could sensitively detect DNA of a single larval schistosome from experimentally infected snails and demonstrate its functionality for detecting S. haematobium infections in wild-caught snails from Zanzibar. Such surveillance tools are a necessity for succeeding in and certifying the 2030 control and elimination goals set by the World Health Organization.
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Affiliation(s)
- Tom Pennance
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK;
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
| | - John Archer
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
| | - Elena Birgitta Lugli
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
| | - Penny Rostron
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
| | - Felix Llanwarne
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Said Mohammed Ali
- Public Health Laboratory–Ivo de Carneri, P.O. Box 122 Chake-Chake, Pemba, Tanzania; (S.M.A.); (A.K.A.); (K.R.S.); (S.M.A.)
| | - Amour Khamis Amour
- Public Health Laboratory–Ivo de Carneri, P.O. Box 122 Chake-Chake, Pemba, Tanzania; (S.M.A.); (A.K.A.); (K.R.S.); (S.M.A.)
| | - Khamis Rashid Suleiman
- Public Health Laboratory–Ivo de Carneri, P.O. Box 122 Chake-Chake, Pemba, Tanzania; (S.M.A.); (A.K.A.); (K.R.S.); (S.M.A.)
| | - Sarah Li
- Schistosomiasis Resource Centre, Biomedical Research Institute, 9410 Key West, Rockville, MD 20850, USA;
| | - David Rollinson
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
| | - Jo Cable
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK;
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland;
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Fiona Allan
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
| | - Shaali Makame Ame
- Public Health Laboratory–Ivo de Carneri, P.O. Box 122 Chake-Chake, Pemba, Tanzania; (S.M.A.); (A.K.A.); (K.R.S.); (S.M.A.)
| | - Bonnie Lee Webster
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (E.B.L.); (P.R.); (F.L.); (D.R.); (F.A.); (B.L.W.)
- London Centre for Neglected Tropical Disease Research (LCNTDR), London W2 1PG, UK
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Pilotte N, Cook DA, Pryce J, Zulch MF, Minetti C, Reimer LJ, Williams SA. Laboratory evaluation of molecular xenomonitoring using mosquito and tsetse fly excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA. Gates Open Res 2020; 3:1734. [PMID: 32596646 PMCID: PMC7308644 DOI: 10.12688/gatesopenres.13093.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods: Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent and incompetent vector species, and effects of additional blood feedings post parasite-exposure were evaluated. Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR (dPCR)) were also compared, with strengths and weaknesses examined for each. Results: Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent and incompetent vector mosquito species. Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible. However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei. Testing also suggested that dPCR may facilitate detection through its increased sensitivity. Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions: By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible. However, translation of this methodology from the lab to the field will first require field-based pilot studies aimed at assessing the efficacy of E/F screening.
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Affiliation(s)
- Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Darren A.N. Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Joseph Pryce
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Michael F. Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
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11
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Cunningham LJ, Lingley JK, Tirados I, Esterhuizen J, Opiyo M, Mangwiro CTN, Lehane MJ, Torr SJ. Evidence of the absence of human African trypanosomiasis in two northern districts of Uganda: Analyses of cattle, pigs and tsetse flies for the presence of Trypanosoma brucei gambiense. PLoS Negl Trop Dis 2020; 14:e0007737. [PMID: 32255793 PMCID: PMC7164673 DOI: 10.1371/journal.pntd.0007737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 04/17/2020] [Accepted: 02/20/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Large-scale control of sleeping sickness has led to a decline in the number of cases of Gambian human African trypanosomiasis (g-HAT) to <2000/year. However, achieving complete and lasting interruption of transmission may be difficult because animals may act as reservoir hosts for T. b. gambiense. Our study aims to update our understanding of T. b. gambiense in local vectors and domestic animals of N.W. Uganda. METHODS We collected blood from 2896 cattle and 400 pigs and In addition, 6664 tsetse underwent microscopical examination for the presence of trypanosomes. Trypanosoma species were identified in tsetse from a subsample of 2184 using PCR. Primers specific for T. brucei s.l. and for T. brucei sub-species were used to screen cattle, pig and tsetse samples. RESULTS In total, 39/2,088 (1.9%; 95% CI = 1.9-2.5) cattle, 25/400 (6.3%; 95% CI = 4.1-9.1) pigs and 40/2,184 (1.8%; 95% CI = 1.3-2.5) tsetse, were positive for T. brucei s.l.. Of these samples 24 cattle (61.5%), 15 pig (60%) and 25 tsetse (62.5%) samples had sufficient DNA to be screened using the T. brucei sub-species PCR. Further analysis found no cattle or pigs positive for T. b. gambiense, however, 17/40 of the tsetse samples produced a band suggestive of T. b. gambiense. When three of these 17 PCR products were sequenced the sequences were markedly different to T. b. gambiense, indicating that these flies were not infected with T. b. gambiense. CONCLUSION The lack of T. b. gambiense positives in cattle, pigs and tsetse accords with the low prevalence of g-HAT in the human population. We found no evidence that livestock are acting as reservoir hosts. However, this study highlights the limitations of current methods of detecting and identifying T. b. gambiense which relies on a single copy-gene to discriminate between the different sub-species of T. brucei s.l.
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Affiliation(s)
- Lucas J. Cunningham
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jessica K. Lingley
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Iñaki Tirados
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Johan Esterhuizen
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Mercy Opiyo
- Institute for Global Health, University of Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Clement T. N. Mangwiro
- Department of Animal Science, Bindura University of Science Education, Bindura, Zimbabwe
| | - Mike J. Lehane
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen J. Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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12
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Pilotte N, Cook DA, Pryce J, Zulch MF, Minetti C, Reimer LJ, Williams SA. Laboratory evaluation of molecular xenomonitoring using mosquito excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA. Gates Open Res 2019; 3:1734. [PMID: 32596646 PMCID: PMC7308644 DOI: 10.12688/gatesopenres.13093.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2019] [Indexed: 03/30/2024] Open
Abstract
Background: Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods: Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent- and incompetent-vector species, and effects of additional blood feedings post parasite-exposure were evaluated. Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR [dPCR]) were also compared, with strengths and weaknesses examined for each. Results: Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent- and incompetent-vector mosquito species. Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible. However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei. Testing also suggested that dPCR may facilitate detection through its increased sensitivity. Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions: By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible. However, translation of this methodology from the lab to the field will first require the completion of field-based pilot studies aimed at assessing the efficacy of E/F screening.
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Affiliation(s)
- Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Darren A.N. Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Joseph Pryce
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Michael F. Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
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13
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Nambala P, Musaya J, Hayashida K, Maganga E, Senga E, Kamoto K, Chisi J, Sugimoto C. Comparative evaluation of dry and liquid RIME LAMP in detecting trypanosomes in dead tsetse flies. ACTA ACUST UNITED AC 2018; 85:e1-e6. [PMID: 30326717 PMCID: PMC6324077 DOI: 10.4102/ojvr.v85i1.1543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 07/23/2018] [Accepted: 07/25/2018] [Indexed: 11/06/2022]
Abstract
Xenomonitoring is an important approach in assessing the progress of trypanosomiasis control as well as in estimating the endemicity of trypanosomes in affected areas. One of the major challenges in this approach is the unavailability of sensitive and easy to use xenomonitoring tools that can be used in the remote areas where the disease occurs. One tool that has been used successfully in detecting the parasites in tsetse flies is the repetitive insertion mobile element loop-mediated isothermal amplification (RIME LAMP). This tool has recently been modified from the liquid form to dry form for use in remote areas; however, uptake for use in the field has been slow. Field-collected tsetse flies were used to evaluate the performance of dry RIME LAMP over the conventional liquid RIME LAMP. All the samples were also subjected to internal transcribed spacer 1 (ITS1) ribosomal deoxyribonucleic acid (DNA) polymerase chain reaction (PCR) as a standard. ITS1-PCR-positive samples were further sequenced for confirmation of the species. A total of 86 wild tsetse flies were left to dry at room temperature for 3 months and DNA was extracted subsequently. All 86 flies were Glossina morsitans morsitans. From these, dry RIME LAMP detected 16.3% while liquid RIME LAMP detected 11.6% as infected with trypanosomes. Ten positive samples on ITS1-PCR were sequenced and all were shown to be trypanosomes. The use of dry RIME LAMP in the field for xenomonitoring of trypanosomes in tsetse flies will greatly contribute towards control of this neglected tropical disease as it provides the cheapest, fastest and simplest way to estimate possible human infective trypanosome infection rates in the tsetse fly vectors.
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Affiliation(s)
- Peter Nambala
- Department of Basic Medical Sciences, University of Malawi.
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14
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Lord JS, Hargrove JW, Torr SJ, Vale GA. Climate change and African trypanosomiasis vector populations in Zimbabwe's Zambezi Valley: A mathematical modelling study. PLoS Med 2018; 15:e1002675. [PMID: 30346952 PMCID: PMC6197628 DOI: 10.1371/journal.pmed.1002675] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 09/14/2018] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Quantifying the effects of climate change on the entomological and epidemiological components of vector-borne diseases is an essential part of climate change research, but evidence for such effects remains scant, and predictions rely largely on extrapolation of statistical correlations. We aimed to develop a mechanistic model to test whether recent increases in temperature in the Mana Pools National Park of the Zambezi Valley of Zimbabwe could account for the simultaneous decline of tsetse flies, the vectors of human and animal trypanosomiasis. METHODS AND FINDINGS The model we developed incorporates the effects of temperature on mortality, larviposition, and emergence rates and is fitted to a 27-year time series of tsetse caught from cattle. These catches declined from an average of c. 50 flies per animal per afternoon in 1990 to c. 0.1 in 2017. Since 1975, mean daily temperatures have risen by c. 0.9°C and temperatures in the hottest month of November by c. 2°C. Although our model provided a good fit to the data, it cannot predict whether or when extinction will occur. CONCLUSIONS The model suggests that the increase in temperature may explain the observed collapse in tsetse abundance and provides a first step in linking temperature to trypanosomiasis risk. If the effect at Mana Pools extends across the whole of the Zambezi Valley, then transmission of trypanosomes is likely to have been greatly reduced in this warm low-lying region. Conversely, rising temperatures may have made some higher, cooler, parts of Zimbabwe more suitable for tsetse and led to the emergence of new disease foci.
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Affiliation(s)
- Jennifer S. Lord
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | | | - Stephen J. Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Glyn A. Vale
- SACEMA, University of Stellenbosch, Stellenbosch, South Africa
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
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15
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Occurrence of Schistosoma bovis on Pemba Island, Zanzibar: implications for urogenital schistosomiasis transmission monitoring. Parasitology 2018; 145:1727-1731. [PMID: 30086805 PMCID: PMC7116046 DOI: 10.1017/s0031182018001154] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The causative agent of urogenital schistosomiasis, Schistosoma haematobium, was thought to be the only schistosome species transmitted through Bulinus snails on Unguja and Pemba Island (Zanzibar, United Republic of Tanzania). For insights into the environmental risk of S. haematobium transmission on Pemba Island, malacological surveys collecting Bulinus globosus and B. nasutus, two closely related potential intermediate hosts of S. haematobium were conducted across the island in November 2016. Of 1317 B. globosus/B. nasutus collected, seven B. globosus, identified through sequencing a DNA region of the mitochondrial cytochrome oxidase subunit 1 (cox1), were observed with patent infections assumed to be S. haematobium. However, when the collected cercariae were identified through sequencing a region of the cox1 and the nuclear internal transcribed spacer (ITS1 + 2), schistosomes from five of these B. globosus collected from a single locality were in fact S. bovis. The identified presence of S. bovis raises concerns for animal health on Pemba, and complicates future transmission monitoring of S. haematobium. These results show the pertinence for not only sensitive, but also species-specific markers to be used when identifying cercariae during transmission monitoring, and also provide the first molecular confirmation for B. globosus transmitting S. bovis in East Africa.
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16
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Cook DAN, Pilotte N, Minetti C, Williams SA, Reimer LJ. A superhydrophobic cone to facilitate the xenomonitoring of filarial parasites, malaria, and trypanosomes using mosquito excreta/feces. Gates Open Res 2018; 1:7. [PMID: 29377042 DOI: 10.12688/gatesopenres.12749.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2018] [Indexed: 11/20/2022] Open
Abstract
Background: Molecular xenomonitoring (MX), the testing of insect vectors for the presence of human pathogens, has the potential to provide a non-invasive and cost-effective method for monitoring the prevalence of disease within a community. Current MX methods require the capture and processing of large numbers of mosquitoes, particularly in areas of low endemicity, increasing the time, cost and labour required. Screening the excreta/feces (E/F) released from mosquitoes, rather than whole carcasses, improves the throughput by removing the need to discriminate vector species since non-vectors release ingested pathogens in E/F. It also enables larger numbers of mosquitoes to be processed per pool. However, this new screening approach requires a method of efficiently collecting E/F. Methods: We developed a cone with a superhydrophobic surface to allow for the efficient collection of E/F. Using mosquitoes exposed to either Plasmodium falciparum, Brugia malayi or Trypanosoma brucei brucei, we tested the performance of the superhydrophobic cone alongside two other collection methods. Results: All collection methods enabled the detection of DNA from the three parasites. Using the superhydrophobic cone to deposit E/F into a small tube provided the highest number of positive samples (16 out of 18) and facilitated detection of parasite DNA in E/F from individual mosquitoes. Further tests showed that following a simple washing step, the cone can be reused multiple times, further improving its cost-effectiveness. Conclusions: Incorporating the superhydrophobic cone into mosquito traps or holding containers could provide a simple and efficient method for collecting E/F. Where this is not possible, swabbing the container or using the washing method facilitates the detection of the three parasites used in this study.
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Affiliation(s)
- Darren A N Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.,Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.,Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Lisa J Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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17
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Cook DAN, Pilotte N, Minetti C, Williams SA, Reimer LJ. A superhydrophobic cone to facilitate the xenomonitoring of filarial parasites, malaria, and trypanosomes using mosquito excreta/feces. Gates Open Res 2018; 1:7. [PMID: 29377042 PMCID: PMC5781187 DOI: 10.12688/gatesopenres.12749.2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2018] [Indexed: 11/20/2022] Open
Abstract
Background: Molecular xenomonitoring (MX), the testing of insect vectors for the presence of human pathogens, has the potential to provide a non-invasive and cost-effective method for monitoring the prevalence of disease within a community. Current MX methods require the capture and processing of large numbers of mosquitoes, particularly in areas of low endemicity, increasing the time, cost and labour required. Screening the excreta/feces (E/F) released from mosquitoes, rather than whole carcasses, improves the throughput by removing the need to discriminate vector species since non-vectors release ingested pathogens in E/F. It also enables larger numbers of mosquitoes to be processed per pool. However, this new screening approach requires a method of efficiently collecting E/F. Methods: We developed a cone with a superhydrophobic surface to allow for the efficient collection of E/F. Using mosquitoes exposed to either Plasmodium falciparum, Brugia malayi or Trypanosoma brucei brucei, we tested the performance of the superhydrophobic cone alongside two other collection methods. Results: All collection methods enabled the detection of DNA from the three parasites. Using the superhydrophobic cone to deposit E/F into a small tube provided the highest number of positive samples (16 out of 18) and facilitated detection of parasite DNA in E/F from individual mosquitoes. Further tests showed that following a simple washing step, the cone can be reused multiple times, further improving its cost-effectiveness. Conclusions: Incorporating the superhydrophobic cone into mosquito traps or holding containers could provide a simple and efficient method for collecting E/F. Where this is not possible, swabbing the container or using the washing method facilitates the detection of the three parasites used in this study.
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Affiliation(s)
- Darren A N Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.,Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.,Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Lisa J Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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18
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Noden BH, Martin J, Carrillo Y, Talley JL, Ochoa-Corona FM. Development of a loop-mediated isothermal amplification (LAMP) assay for rapid screening of ticks and fleas for spotted fever group rickettsia. PLoS One 2018; 13:e0192331. [PMID: 29390021 PMCID: PMC5794167 DOI: 10.1371/journal.pone.0192331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 01/20/2018] [Indexed: 11/18/2022] Open
Abstract
Background The importance of tick and flea-borne rickettsia infections is increasingly recognized worldwide. While increased focus has shifted in recent years to the development of point-of-care diagnostics for various vector-borne diseases in humans and animals, little research effort has been devoted to their integration into vector surveillance and control programs, particularly in resource-challenged countries. One technology which may be helpful for large scale vector surveillance initiatives is loop-mediated isothermal amplification (LAMP). The aim of this study was to develop a LAMP assay to detect spotted fever group (SFG) rickettsia DNA from field-collected ticks and fleas and compare with published end-point PCR results. Methodology/Principal findings A Spotted Fever Group rickettsia-specific loop-mediated isothermal amplification (SFGR-LAMP) assay was developed using primers based on a region of the R. rickettsii 17kDa protein gene. The sensitivity, specificity, and reproducibility of the assay were evaluated. The assay was then compared with the results of end-point PCR assays for pooled tick and flea samples obtained from field-based surveillance studies. The sensitivity of the SFGR-LAMP assay was 0.00001 ng/μl (25μl volume) which was 10 times more sensitive than the 17kDa protein gene end-point PCR used as the reference method. The assay only recognized gDNA from SFG and transitional group (TRG) rickettsia species tested but did not detect gDNA from typhus group (TG) rickettsia species or closely or distantly related bacterial species. The SFGR-LAMP assay detected the same positives from a set of pooled tick and flea samples detected by end-point PCR in addition to two pooled flea samples not detected by end-point PCR. Conclusions/significance To our knowledge, this is the first study to develop a functional LAMP assay to initially screen for SFG and TRG rickettsia pathogens in field-collected ticks and fleas. With a high sensitivity and specificity, the results indicate the potential use as a field-based surveillance tool for tick and flea-borne rickettsial pathogens in resource-challenged countries.
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Affiliation(s)
- Bruce H. Noden
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma, United States of America
- * E-mail:
| | - Jaclyn Martin
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Yisel Carrillo
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Justin L. Talley
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Francisco M. Ochoa-Corona
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma, United States of America
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Abstract
Many pathogens evade host immunity by periodically changing the proteins they express on their surface - a phenomenon termed antigenic variation. An extreme form of antigenic variation, based around switching the composition of a Variant Surface Glycoprotein (VSG) coat, is exhibited by the African trypanosome Trypanosoma brucei, which causes human disease. The molecular details of VSG switching in T. brucei have been extensively studied over the last three decades, revealing in increasing detail the machinery and mechanisms by which VSG expression is controlled and altered. However, several key components of the models of T. brucei antigenic variation that have emerged have been challenged through recent discoveries. These discoveries include new appreciation of the importance of gene mosaics in generating huge levels of new VSG variants, the contributions of parasite development and body compartmentation in the host to the infection dynamics and, finally, potential differences in the strategies of antigenic variation and host infection used by the crucial livestock trypanosomes T. congolense and T. vivax. This review will discuss all these observations, which raise questions regarding how secure the existing models of trypanosome antigenic variation are. In addition, we will discuss the importance of continued mathematical modelling to understand the purpose of this widespread immune survival process.
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Garcia HA, Rodrigues CMF, Rodrigues AC, Pereira DL, Pereira CL, Camargo EP, Hamilton PB, Teixeira MMG. Remarkable richness of trypanosomes in tsetse flies (Glossina morsitans morsitans and Glossina pallidipes) from the Gorongosa National Park and Niassa National Reserve of Mozambique revealed by fluorescent fragment length barcoding (FFLB). INFECTION GENETICS AND EVOLUTION 2017; 63:370-379. [PMID: 28688979 DOI: 10.1016/j.meegid.2017.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 07/03/2017] [Accepted: 07/04/2017] [Indexed: 11/25/2022]
Abstract
Trypanosomes of African wild ungulates transmitted by tsetse flies can cause human and livestock diseases. However, trypanosome diversity in wild tsetse flies remains greatly underestimated. We employed FFLB (fluorescent fragment length barcoding) for surveys of trypanosomes in tsetse flies (3086) from the Gorongosa National Park (GNP) and Niassa National Reserve (NNR) in Mozambique (MZ), identified as Glossina morsitans morsitans (GNP/NNR=77.6%/90.5%) and Glossina pallidipes (22.4%/9.5%). Trypanosomes were microscopically detected in 8.3% of tsetse guts. FFLB of gut samples revealed (GNP/NNR): Trypanosoma congolense of Savannah (27%/63%), Kilifi (16.7%/29.7%) and Forest (1.0%/0.3%) genetic groups; T. simiae Tsavo (36.5%/6.1%); T. simiae (22.2%/17.7%); T. godfreyi (18.2%/7.0%); subgenus Trypanozoon (20.2%/25.7%); T. vivax/T. vivax-like (1.5%/5.2%); T. suis/T. suis-like (9.4%/11.9%). Tsetse proboscises exhibited similar species composition, but most prevalent species were (GNP/NNR): T. simiae (21.9%/28%), T. b. brucei (19.2%/31.7%), and T. vivax/T. vivax-like (19.2%/28.6%). Flies harboring mixtures of trypanosomes were common (~ 64%), and combinations of more than four trypanosomes were especially abundant in the pristine NNR. The non-pathogenic T. theileri was found in 2.5% while FFLB profiles of unknown species were detected in 19% of flies examined. This is the first report on molecular diversity of tsetse flies and their trypanosomes in MZ; all trypanosomes pathogenic for ungulates were detected, but no human pathogens were detected. Overall, two species of tsetse flies harbor 12 species/genotypes of trypanosomes. This notable species richness was likely uncovered because flies were captured in wildlife reserves and surveyed using the method of FFLB able to identify, with high sensitivity and accuracy, known and novel trypanosomes. Our findings importantly improve the knowledge on trypanosome diversity in tsetse flies, revealed the greatest species richness so far reported in tsetse fly of any African country, and indicate the existence of a hidden trypanosome diversity to be discovered in African wildlife protected areas.
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Affiliation(s)
- Herakles A Garcia
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Carla M F Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Adriana C Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | - Carlos L Pereira
- Ministry of Tourism of Mozambique, Wildlife Conservation Society, Mozambique
| | - Erney P Camargo
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - P B Hamilton
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Marta M G Teixeira
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil.
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Aksoy S, Buscher P, Lehane M, Solano P, Van Den Abbeele J. Human African trypanosomiasis control: Achievements and challenges. PLoS Negl Trop Dis 2017; 11:e0005454. [PMID: 28426685 PMCID: PMC5398477 DOI: 10.1371/journal.pntd.0005454] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Sleeping sickness, also known as human African trypanosomiasis (HAT), is a neglected disease that impacts 70 million people living in 1.55 million km2 in sub-Saharan Africa. Since the beginning of the 20th century, there have been multiple HAT epidemics in sub-Saharan Africa, with the most recent epidemic in the 1990s resulting in about half a million HAT cases reported between 1990 and 2015. Here we review the status of HAT disease at the current time and the toolbox available for its control. We also highlight future opportunities under development towards novel or improved interventions.
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Affiliation(s)
- Serap Aksoy
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| | - Phillipe Buscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Mike Lehane
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Philippe Solano
- Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Jan Van Den Abbeele
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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Loop-Mediated Isothermal Amplification Test for Trypanosoma gambiense Group 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness. J Trop Med 2017; 2017:8630708. [PMID: 28321260 PMCID: PMC5339478 DOI: 10.1155/2017/8630708] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/06/2017] [Indexed: 11/18/2022] Open
Abstract
The World Health Organization has targeted Human African Trypanosomiasis (HAT) for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring) since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers) to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min), were 10–100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.
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