1
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Lymbery AJ, Smit NJ. Conservation of parasites: A primer. Int J Parasitol Parasites Wildl 2023; 21:255-263. [PMID: 37483309 PMCID: PMC10359719 DOI: 10.1016/j.ijppaw.2023.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/25/2023]
Abstract
Although parasites make up a substantial proportion of the biotic component of ecosystems, in terms of both biomass and number of species, they are rarely considered in conservation planning, except where they are thought to pose a threat to the conservation of their hosts. In this review, we address a number of unresolved questions concerning parasite conservation. Arguments for conserving parasite species refer to the intrinsic value conferred by their evolutionary heritage and potential, their functional role in the provision of ecosystem services, and their value as indicators of ecosystem quality. We propose that proper consideration of these arguments mean that it is not logically defensible to automatically exclude parasite species from conservation decisions; rather, endangered hosts and parasites should be considered together as a threatened ecological community. The extent to which parasites are threatened with extinction is difficult to estimate with any degree of confidence, because so many parasite species have yet to be identified and, even for those which have been formally described, we have limited information on the factors affecting their distribution and abundance. This lack of ecological information may partially explain the under-representation of parasites on threatened species lists. Effective conservation of parasites requires maintaining access to suitable hosts and the ecological conditions that permit successful transmission between hosts. When implementing recovery plans for threatened host species, this may be best achieved by attempting to restore the ecological conditions that maintain the host and its parasite fauna in dynamic equilibrium. Ecosystem-centred conservation may be a more effective strategy than species-centred (or host-parasite community-centred) approaches for preventing extinction of parasites, but the criteria which are typically used to identify protected areas do not provide information on the ecological conditions required for effective transmission. We propose a simple decision tree to aid the identification of appropriate conservation actions for threatened parasites.
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Affiliation(s)
- Alan J. Lymbery
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, 6150, Western Australia, Australia
| | - Nico J. Smit
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa
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2
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Dunstand-Guzmán E, Hallal-Calleros C, Hernández-Velázquez VM, Dominguez-Roldan R, Peña-Chora G, Flores-Pérez I. Potential control of the infective stage of Taenia pisiformis using Bacillus thuringiensis GP526 strain. Exp Parasitol 2023; 249:108522. [PMID: 37011803 DOI: 10.1016/j.exppara.2023.108522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023]
Abstract
The GP526 strain of Bacillus thuringiensis has been referred as an in vitro helminthicide on various stages of Dipylidium caninum and Centrocestus formosanus. Our study addresses the in vitro ovicidal activity of GP526 strain spore-crystal complex on Taenia pisiformis eggs, evaluating induced damage microscopically. The eggs exposed to the total extract containing spores and crystals show damage after 24 hours, with loss of integrity on the eggshell, and an ovicidal activity of 33% at 1mg/ml. The destruction of the embryophore was observed after 120 h with a 72% of ovicidal activity at 1 mg/ml. The LC50 was 609.6 μg/ml, dose that causes a 50% of lethality on the hexacanth embryo, altering the oncosphere membrane. The spore-crystal proteins were extracted, and the protein profile was obtained by electrophoresis, finding a major band of 100 kDa suggestive of an S-layer protein, since an S-layer was immunodetected in both, spores and extracted proteins. The protein fraction containing the S-layer protein presents adhesion to the T. pisiformis eggs, and 0.4 mg/ml of the protein induces a lethality of 21.08% at 24 h. The characterization of molecular mechanisms of ovicidal activity will be an important contribution, so the characterization of the proteins that make up the extract of the GP526 strain, would be useful to support the biological potential for control of this cestodiasis and other parasitosis. B. thuringiensis is shown as a potent helminthicide on eggs, with useful potential for biological control of this cestodiasis.
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3
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Ellwanger JH, Fearnside PM, Ziliotto M, Valverde-Villegas JM, Veiga ABGDA, Vieira GF, Bach E, Cardoso JC, Müller NFD, Lopes G, Caesar L, Kulmann-Leal B, Kaminski VL, Silveira ES, Spilki FR, Weber MN, Almeida SEDEM, Hora VPDA, Chies JAB. Synthesizing the connections between environmental disturbances and zoonotic spillover. AN ACAD BRAS CIENC 2022; 94:e20211530. [PMID: 36169531 DOI: 10.1590/0001-3765202220211530] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/03/2022] [Indexed: 11/22/2022] Open
Abstract
Zoonotic spillover is a phenomenon characterized by the transfer of pathogens between different animal species. Most human emerging infectious diseases originate from non-human animals, and human-related environmental disturbances are the driving forces of the emergence of new human pathogens. Synthesizing the sequence of basic events involved in the emergence of new human pathogens is important for guiding the understanding, identification, and description of key aspects of human activities that can be changed to prevent new outbreaks, epidemics, and pandemics. This review synthesizes the connections between environmental disturbances and increased risk of spillover events based on the One Health perspective. Anthropogenic disturbances in the environment (e.g., deforestation, habitat fragmentation, biodiversity loss, wildlife exploitation) lead to changes in ecological niches, reduction of the dilution effect, increased contact between humans and other animals, changes in the incidence and load of pathogens in animal populations, and alterations in the abiotic factors of landscapes. These phenomena can increase the risk of spillover events and, potentially, facilitate new infectious disease outbreaks. Using Brazil as a study model, this review brings a discussion concerning anthropogenic activities in the Amazon region and their potential impacts on spillover risk and spread of emerging diseases in this region.
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Affiliation(s)
- Joel Henrique Ellwanger
- Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunobiologia e Imunogenética, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Philip Martin Fearnside
- Instituto Nacional de Pesquisas da Amazônia/INPA, Avenida André Araújo, 2936, Aleixo, 69067-375 Manaus, AM, Brazil
| | - Marina Ziliotto
- Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunobiologia e Imunogenética, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Jacqueline María Valverde-Villegas
- Institut de Génétique Moléculaire de Montpellier/IGMM, Centre National de la Recherche Scientifique/CNRS, Laboratoire coopératif IGMM/ABIVAX, 1919, route de Mende, 34090 Montpellier, Montpellier, France
| | - Ana Beatriz G DA Veiga
- Universidade Federal de Ciências da Saúde de Porto Alegre/UFCSPA, Departamento de Ciências Básicas de Saúde, Rua Sarmento Leite, 245, Centro Histórico, 90050-170 Porto Alegre, RS, Brazil
| | - Gustavo F Vieira
- Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunoinformática, Núcleo de Bioinformática do Laboratório de Imunogenética/NBLI, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Saúde e Desenvolvimento Humano, Universidade La Salle, Laboratório de Saúde Humana in silico, Avenida Victor Barreto, 2288, Centro, 92010-000 Canoas, RS, Brazil
| | - Evelise Bach
- Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunobiologia e Imunogenética, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Jáder C Cardoso
- Centro Estadual de Vigilância em Saúde/CEVS, Divisão de Vigilância Ambiental em Saúde, Secretaria da Saúde do Estado do Rio Grande do Sul, Avenida Ipiranga, 5400, Jardim Botânico, 90610-000 Porto Alegre, RS, Brazil
| | - Nícolas Felipe D Müller
- Centro Estadual de Vigilância em Saúde/CEVS, Divisão de Vigilância Ambiental em Saúde, Secretaria da Saúde do Estado do Rio Grande do Sul, Avenida Ipiranga, 5400, Jardim Botânico, 90610-000 Porto Alegre, RS, Brazil
| | - Gabriel Lopes
- Fundação Oswaldo Cruz/FIOCRUZ, Casa de Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, 21040-900 Rio de Janeiro, RJ, Brazil
| | - Lílian Caesar
- Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Indiana University/IU, Department of Biology, 915 East 3rd Street, Bloomington, IN 47405, USA
| | - Bruna Kulmann-Leal
- Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunobiologia e Imunogenética, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Valéria L Kaminski
- Programa de Pós-Graduação em Biotecnologia, Universidade Federal de São Paulo/UNIFESP, Instituto de Ciência e Tecnologia/ICT, Laboratório de Imunologia Aplicada, Rua Talim, 330, Vila Nair, 12231-280 São José dos Campos, SP, Brazil
| | - Etiele S Silveira
- Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunoinformática, Núcleo de Bioinformática do Laboratório de Imunogenética/NBLI, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Fernando R Spilki
- Universidade Feevale, Laboratório de Saúde Única, Instituto de Ciências da Saúde/ICS, Rodovia ERS-239, 2755, Vila Nova, 93525-075 Novo Hamburgo, RS, Brazil
| | - Matheus N Weber
- Universidade Feevale, Laboratório de Saúde Única, Instituto de Ciências da Saúde/ICS, Rodovia ERS-239, 2755, Vila Nova, 93525-075 Novo Hamburgo, RS, Brazil
| | - Sabrina E DE Matos Almeida
- Universidade Feevale, Laboratório de Saúde Única, Instituto de Ciências da Saúde/ICS, Rodovia ERS-239, 2755, Vila Nova, 93525-075 Novo Hamburgo, RS, Brazil
| | - Vanusa P DA Hora
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Rio Grande/FURG, Faculdade de Medicina, Rua Visconde de Paranaguá, 102, Centro, 96203-900, Rio Grande, RS, Brazil
| | - José Artur B Chies
- Universidade Federal do Rio Grande do Sul/UFRGS, Laboratório de Imunobiologia e Imunogenética, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular/PPGBM, Universidade Federal do Rio Grande do Sul/UFRGS, Departmento de Genética, Campus do Vale, Avenida Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
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4
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Ruiz-Castillo P, Rist C, Rabinovich R, Chaccour C. Insecticide-treated livestock: a potential One Health approach to malaria control in Africa. Trends Parasitol 2021; 38:112-123. [PMID: 34756820 DOI: 10.1016/j.pt.2021.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 12/20/2022]
Abstract
New vector-control tools are urgently needed to reduce malaria in areas where there is significant transmission after deployment of indoor residual spraying (IRS) and insecticide treated nets. Insecticide-treated livestock (ITL) is a potential novel strategy by which zoophagic mosquitos are killed after feeding upon animals treated with an insecticide. Although there are several insecticide candidates in the pipeline with a wide efficacy range against mosquitos, additional field studies with epidemiological outcomes are required to test the impact of this intervention on malaria transmission. Insecticides under consideration have long been used in livestock to improve animal health and productivity, but each has food and environmental safety considerations. Therefore, moving ITL from a concept to implementation will require a One Health framework.
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Affiliation(s)
| | - Cassidy Rist
- Virginia Maryland College of Veterinary Medicine at Virginia Tech, Blacksburg, VA, USA
| | - Regina Rabinovich
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Carlos Chaccour
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Facultad de Medicina, Universidad de Navarra, Pamplona, Spain
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5
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Chaccour C. Veterinary endectocides for malaria control and elimination: prospects and challenges. Philos Trans R Soc Lond B Biol Sci 2020; 376:20190810. [PMID: 33357062 DOI: 10.1098/rstb.2019.0810] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Residual transmission is the persistence of malaria transmission after scale-up of appropriate vector control tools and is one of the key challenges for malaria elimination today. Although long associated with outdoor biting, other mosquito behaviours such as partly feeding upon animals contribute greatly to sustaining transmission. Peri-domestic livestock can be used as decoy to protect humans from blood-seeking vectors but this approach often leads to an increased malaria risk in a phenomenon known as zoopotentiation. Treating the said livestock with drugs capable of killing intestinal parasites as well as mosquitoes that feed upon them has the potential to tackle malaria through a previously unexplored mechanism. The advantages and challenges associated with this approach are briefly discussed here. Numerous references are purposely provided. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Carlos Chaccour
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036 Barcelona, Spain.,Ifakara Health Institute, Off Mlabani Passage, PO Box 53, Ifakara, United Republic of Tanzania.,Faculty of Medicine, Universidad de Navarra, Calle de Irunlarrea 1, 31008 Pamplona, Spain
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6
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Capture-based enrichment of Theileria parva DNA enables full genome assembly of first buffalo-derived strain and reveals exceptional intra-specific genetic diversity. PLoS Negl Trop Dis 2020; 14:e0008781. [PMID: 33119590 PMCID: PMC7654785 DOI: 10.1371/journal.pntd.0008781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 11/10/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022] Open
Abstract
Theileria parva is an economically important, intracellular, tick-transmitted parasite of cattle. A live vaccine against the parasite is effective against challenge from cattle-transmissible T. parva but not against genotypes originating from the African Cape buffalo, a major wildlife reservoir, prompting the need to characterize genome-wide variation within and between cattle- and buffalo-associated T. parva populations. Here, we describe a capture-based target enrichment approach that enables, for the first time, de novo assembly of nearly complete T. parva genomes derived from infected host cell lines. This approach has exceptionally high specificity and sensitivity and is successful for both cattle- and buffalo-derived T. parva parasites. De novo genome assemblies generated for cattle genotypes differ from the reference by ~54K single nucleotide polymorphisms (SNPs) throughout the 8.31 Mb genome, an average of 6.5 SNPs/kb. We report the first buffalo-derived T. parva genome, which is ~20 kb larger than the genome from the reference, cattle-derived, Muguga strain, and contains 25 new potential genes. The average non-synonymous nucleotide diversity (πN) per gene, between buffalo-derived T. parva and the Muguga strain, was 1.3%. This remarkably high level of genetic divergence is supported by an average Wright’s fixation index (FST), genome-wide, of 0.44, reflecting a degree of genetic differentiation between cattle- and buffalo-derived T. parva parasites more commonly seen between, rather than within, species. These findings present clear implications for vaccine development, further demonstrated by the ability to assemble nearly all known antigens in the buffalo-derived strain, which will be critical in design of next generation vaccines. The DNA capture approach used provides a clear advantage in specificity over alternative T. parva DNA enrichment methods used previously, such as those that utilize schizont purification, is less labor intensive, and enables in-depth comparative genomics in this apicomplexan parasite. An estimated 50 million cattle in sub-Saharan Africa are at risk of the deadly livestock disease East coast fever (ECF), caused by the parasite Theileria parva, which imposes tremendous economic hardship on smallholder farmers. An existing ECF vaccine protects against strains circulating among cattle, but not against T. parva derived from African Cape buffalo, its main wildlife carrier. Understanding this difference in protective efficacy requires characterization of the genetic diversity in T. parva strains associated with each mammalian host, a goal that has been hindered by the proliferation of T. parva in nucleated host cells, with much larger genomes. Here we adapted a sequence capture approach to target the whole parasite genome, enabling enrichment of parasite DNA over that of the host. Choices in protocol development resulted in nearly 100% parasite genome specificity and sensitivity, making this approach the most successful yet to generate T. parva genome sequence data in a high-throughput manner. The analyses uncovered a degree of genetic differentiation between cattle- and buffalo-derived genotypes that is akin to levels more commonly seen between species. This approach, which will enable an in-depth T. parva population genomics study from cattle and buffalo in the endemic regions, can easily be adapted to other intracellular pathogens.
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7
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Peña-Espinoza M, Valente AH, Bornancin L, Simonsen HT, Thamsborg SM, Williams AR, López-Muñoz R. Anthelmintic and metabolomic analyses of chicory (Cichorium intybus) identify an industrial by-product with potent in vitro antinematodal activity. Vet Parasitol 2020; 280:109088. [PMID: 32278938 DOI: 10.1016/j.vetpar.2020.109088] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 01/20/2023]
Abstract
Chicory (Cichorium intybus) is a bioactive forage rich in sesquiterpene lactones (SLs) with reported in vitro and in vivo anthelmintic activity in livestock. However, the on-farm adoption of chicory as an anthelmintic crop is limited and may be facilitated by using standardised industrial chicory material. Chicory root pulp is a by-product obtained from industrial chicory roots after inulin extraction and can potentially retain SLs. However, SL content and associated anthelmintic activity of chicory root pulp have not been investigated. Here, we evaluated the anthelmintic activity of SL-enriched extracts from chicory root pulp and forage chicory, and used untargeted metabolomics and molecular networking to identify potential anthelmintic molecules. Six different sources of chicory material were used: fresh chicory root pulp (from industrial chicory roots C. intybus var. sativum; "Root Pulp"), fresh leaves from chicory cv. Spadona (sampled on four occasions) and fresh leaves from chicory cv. Choice. The resulting extracts were tested for anthelmintic activity against the free-living nematode Caenorhabditis elegans and the pig nematode Ascaris suum. The cytotoxicity of the chicory extracts was evaluated on mammalian (Vero) cells. In the C. elegans assays, the Root Pulp was the most potent extract and induced paralysis in >95% of worms exposed to >250 μg extract/mL (EC50 = 64.2 μg/mL). In the A. suum assays, the Root Pulp was also the most potent chicory extract to inhibit worm motility (EC50 = 87.6 μg/mL), followed closely by two of the Spadona leaf extracts (EC50 = 89.8 μg/mL and 112.2 μg/mL) The Root Pulp extract had the lowest cytotoxicity of all tested extracts towards mammalian cells, with a selectivity index of 5.37. Untargeted metabolomics revealed that chicory Root Pulp had a markedly different chemical profile in comparison with forage chicory extracts. Molecular networking confirmed several SLs and SL-derivatives mainly present in chicory root pulp, that may be responsible of its potent anti-parasitic activity. Bioactivity-based molecular networking of chicory root pulp and the most potent forage chicory extracts revealed a high predicted anthelmintic score for the guaianolide SL 11,13-dihydro-lactucopicrin. In conclusion, chicory root pulp showed potent and selective in vitro anthelmintic activity against C. elegans and A. suum, with low cytotoxicity in mammalian cells. The promising anthelmintic activity of chicory root pulp should be confirmed in vivo to further explore the potential of this agro-industrial by-product as a nutraceutical anthelmintic for livestock and as novel source of anti-parasitic compounds.
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Affiliation(s)
- Miguel Peña-Espinoza
- Instituto de Farmacologia y Morfofisiologia, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
| | - Angela H Valente
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870, Frederiksberg C, Denmark
| | - Louis Bornancin
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800, Kongens Lyngby, Denmark
| | - Henrik T Simonsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800, Kongens Lyngby, Denmark
| | - Stig M Thamsborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870, Frederiksberg C, Denmark
| | - Andrew R Williams
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870, Frederiksberg C, Denmark
| | - Rodrigo López-Muñoz
- Instituto de Farmacologia y Morfofisiologia, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
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8
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Hanks E, Todd H, Palarea-Albaladejo J, McNeilly TN, Britton C, Ballingall KT. A novel technique for retrospective genetic analysis of the response to vaccination or infection using cell-free DNA from archived sheep serum and plasma. Vet Res 2020; 51:9. [PMID: 32024546 PMCID: PMC7003321 DOI: 10.1186/s13567-020-0737-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 01/16/2020] [Indexed: 12/31/2022] Open
Abstract
Genetic variation is associated with differences in disease resistance and susceptibility among individuals within a population. To date, molecular genetic analyses of host responses have relied on extraction of genomic DNA from whole blood or tissue samples. However, such samples are not routinely collected during large-scale field studies. We demonstrate that cell-free genomic DNA (cfDNA) may be extracted and amplified from archived plasma samples, allowing retrospective analysis of host genetic diversity. This technique was also applicable to archived serum samples up to 35 years old and to different ruminant species. As proof of concept, we used this cfDNA approach to genotype the major histocompatibility complex (MHC) class II DRB1 locus of 224 Merino sheep which had participated in field trials of a commercial Haemonchus contortus vaccine, Barbervax®, in Australia. This identified a total of 51 different DRB1 alleles and their relative frequencies. This is the first study to examine host MHC diversity using DNA extracted from archived plasma samples, an approach that may be applied to retrospective analyses of genetic diversity and responses to vaccination or infection across different species and populations.
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Affiliation(s)
- Eve Hanks
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Road, Glasgow, G61 1QH, UK. .,SAC Consulting: Veterinary Services, SRUC Veterinary Services, Pentland Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK.
| | - Helen Todd
- Moredun Research Institute, Pentlands Science Park, Penicuik, Edinburgh, EH26 0PZ, UK
| | - Javier Palarea-Albaladejo
- Biomathematics and Statistics Scotland, JCMB, The King's Buildings, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Penicuik, Edinburgh, EH26 0PZ, UK
| | - Collette Britton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Road, Glasgow, G61 1QH, UK.
| | - Keith T Ballingall
- Moredun Research Institute, Pentlands Science Park, Penicuik, Edinburgh, EH26 0PZ, UK.
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9
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Abstract
AbstractNew technological methods, such as rapidly developing molecular approaches, often provide new tools for scientific advances. However, these new tools are often not utilized equally across different research areas, possibly leading to disparities in progress between these areas. Here, we use empirical evidence from the scientific literature to test for potential discrepancies in the use of genetic tools to study parasitic vs non-parasitic organisms across three distinguishable molecular periods, the allozyme, nucleotide and genomics periods. Publications on parasites constitute only a fraction (<5%) of the total research output across all molecular periods and are dominated by medically relevant parasites (especially protists), particularly during the early phase of each period. Our analysis suggests an increasing complexity of topics and research questions being addressed with the development of more sophisticated molecular tools, with the research focus between the periods shifting from predominantly species discovery to broader theory-focused questions. We conclude that both new and older molecular methods offer powerful tools for research on parasites, including their diverse roles in ecosystems and their relevance as human pathogens. While older methods, such as barcoding approaches, will continue to feature in the molecular toolbox of parasitologists for years to come, we encourage parasitologists to be more responsive to new approaches that provide the tools to address broader questions.
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10
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Imbahale SS, Montaña Lopez J, Brew J, Paaijmans K, Rist C, Chaccour C. Mapping the potential use of endectocide-treated cattle to reduce malaria transmission. Sci Rep 2019; 9:5826. [PMID: 30967606 PMCID: PMC6456610 DOI: 10.1038/s41598-019-42356-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 03/29/2019] [Indexed: 12/27/2022] Open
Abstract
Treating cattle with endectocide is a longstanding veterinary practice to reduce the load of endo and ectoparasites, but has the potential to be added to the malaria control and elimination toolbox, as it also kills malaria mosquitoes feeding on the animals. Here we used openly available data to map the areas of the African continent where high malaria prevalence in 2-10 year old children coincides with a high density of cattle and high density of the partly zoophilic malaria vector Anopheles arabiensis. That is, mapping the areas where treating cattle with endectocide would potentially have the greatest impact on reducing malaria transmission. In regions of Africa that are not dominated by rainforest nor desert, the map shows a scatter of areas in several countries where this intervention shows potential, including central and eastern sub-Saharan Africa. The savanna region underneath the Sahel in West Africa appears as the climatic block that would benefit to the largest extent from this intervention, encompassing several countries. West Africa currently presents the highest under-10 malaria prevalence and elimination within the next twenty years cannot be contemplated there with currently available interventions alone, making the use of endectocide treated cattle as a complementary intervention highly appealing.
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Affiliation(s)
- Susan S Imbahale
- Department of Applied and Technical Biology, The Technical University of Kenya, Nairobi, Kenya
| | - Julia Montaña Lopez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Joe Brew
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Krijn Paaijmans
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA.,The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
| | - Cassidy Rist
- Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Carlos Chaccour
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique. .,Ifakara Health Institute, Ifakara, United Republic of Tanzania. .,Facultad de Medicina, Universidad de Navarra, Pamplona, Spain.
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11
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Peña-Espinoza M, Valente AH, Thamsborg SM, Simonsen HT, Boas U, Enemark HL, López-Muñoz R, Williams AR. Antiparasitic activity of chicory (Cichorium intybus) and its natural bioactive compounds in livestock: a review. Parasit Vectors 2018; 11:475. [PMID: 30134991 PMCID: PMC6106872 DOI: 10.1186/s13071-018-3012-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/12/2018] [Indexed: 12/27/2022] Open
Abstract
Increasing drug resistance in gastrointestinal (GI) parasites of livestock and concerns about chemical residues in animal products and the environment are driving the development of alternative control strategies that are less reliant on the use of synthetic drugs. An increasingly investigated approach is the use of bioactive forages with antiparasitic properties as part of the animal's diet (nutraceuticals) or as potential sources of novel, natural parasiticides. Chicory (Cichorium intybus) is a multi-purpose crop and one of the most promising bioactive forages in temperate regions, and numerous in vivo trials have explored its potential against parasitic nematodes in livestock. However, it is unclear whether chicory can induce a direct and broad activity against various GI parasites in different livestock species, and the levels of chicory in the diet that are required to exert an efficient antiparasitic effect. Moreover, the mechanisms leading to the reported parasiticidal activity of chicory are still largely unknown, and its bioactive phytochemicals have only recently been investigated. In this review, we summarise the progress in the study of the antiparasitic activity of chicory and its natural bioactive compounds against GI parasites in livestock, through examination of the published literature. The available evidence indicates that feeding chicory can reduce faecal egg counts and/or worm burdens of abomasal nematodes, but not infections with intestinal worms, in ruminants. Highly chicory-rich diets (≥ 70% of chicory dry matter in the diet) may be necessary to directly affect abomasal parasitism. Chicory is known to synthesise several bioactive compounds with potential antiparasitic activity, but most research has been devoted to the role of sesquiterpene lactones (SL). Recent in vitro studies have confirmed direct and potent activity of SL-rich extracts from chicory against different GI helminths of livestock. Chicory SL have also been reported to exhibit antimalarial properties and its potential antiprotozoal activity in livestock remains to be evaluated. Furthermore, the detailed identification of the main antiparasitic metabolites of chicory and their pharmacokinetics need further confirmation. Research gaps and perspectives on the potential use of chicory as a nutraceutical forage and a source of bioactive compounds for parasite control in livestock are discussed.
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Affiliation(s)
- Miguel Peña-Espinoza
- Instituto de Farmacologia y Morfofisiologia, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Angela H. Valente
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
| | - Stig M. Thamsborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
| | - Henrik T. Simonsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kongens Lyngby, Denmark
| | - Ulrik Boas
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kongens Lyngby, Denmark
| | - Heidi L. Enemark
- Norwegian Veterinary Institute, Ullevålsveien 68, P.O. Box 750, N-0106 Oslo, Sentrum Norway
| | - Rodrigo López-Muñoz
- Instituto de Farmacologia y Morfofisiologia, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Andrew R. Williams
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
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12
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Targeting cattle for malaria elimination: marked reduction of Anopheles arabiensis survival for over six months using a slow-release ivermectin implant formulation. Parasit Vectors 2018; 11:287. [PMID: 29728135 PMCID: PMC5935946 DOI: 10.1186/s13071-018-2872-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/24/2018] [Indexed: 12/12/2022] Open
Abstract
Background Mosquitoes that feed on animals can survive and mediate residual transmission of malaria even after most humans have been protected with insecticidal bednets or indoor residual sprays. Ivermectin is a widely-used drug for treating parasites of humans and animals that is also insecticidal, killing mosquitoes that feed on treated subjects. Mass administration of ivermectin to livestock could be particularly useful for tackling residual malaria transmission by zoophagic vectors that evade human-centred approaches. Ivermectin comes from a different chemical class to active ingredients currently used to treat bednets or spray houses, so it also has potential for mitigating against emergence of insecticide resistance. However, the duration of insecticidal activity obtained with ivermectin is critical to its effectiveness and affordability. Results A slow-release formulation for ivermectin was implanted into cattle, causing 40 weeks of increased mortality among Anopheles arabiensis that fed on them. For this zoophagic vector of residual malaria transmission across much of Africa, the proportion surviving three days after feeding (typical mean duration of a gonotrophic cycle in field populations) was approximately halved for 25 weeks. Conclusions This implantable ivermectin formulation delivers stable and sustained insecticidal activity for approximately 6 months. Residual malaria transmission by zoophagic vectors could be suppressed by targeting livestock with this long-lasting formulation, which would be impractical or unacceptable for mass treatment of human populations. Electronic supplementary material The online version of this article (10.1186/s13071-018-2872-y) contains supplementary material, which is available to authorized users.
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13
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Sallé G, Laing R, Cotton JA, Maitland K, Martinelli A, Holroyd N, Tracey A, Berriman M, Smith WD, Newlands GFJ, Hanks E, Devaney E, Britton C. Transcriptomic profiling of nematode parasites surviving vaccine exposure. Int J Parasitol 2018. [PMID: 29534987 PMCID: PMC5909036 DOI: 10.1016/j.ijpara.2018.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Surviving Haemonchus contortus from vaccinated sheep were compared with control worms. There is no evidence for changes in expression of genes encoding Barbervax® antigens. There was increased expression of other proteases and regulators of lysosome trafficking. Surviving worms displayed up-regulated lipid storage and defecation abilities.
Some nematode species are economically important parasites of livestock, while others are important human pathogens causing some of the most important neglected tropical diseases. In both humans and animals, anthelmintic drug administration is the main control strategy, but the emergence of drug-resistant worms has stimulated the development of alternative control approaches. Among these, vaccination is considered to be a sustainable and cost effective strategy. Currently, Barbervax® for the ruminant strongylid Haemonchus contortus is the only registered subunit vaccine for a nematode parasite, although a vaccine for the human hookworm Necator americanus is undergoing clinical trials (HOOKVAC consortium). As both these vaccines comprise a limited number of proteins, there is potential for selection of nematodes with altered sequences or expression of the vaccine antigens. Here we compared the transcriptome of H. contortus populations from sheep vaccinated with Barbervax® with worms from control animals. Barbervax® antigens are native integral membrane proteins isolated from the brush border of the intestinal cells of the adult parasite and many of those are proteases. Our findings provide no evidence for changes in expression of genes encoding Barbervax® antigens in the surviving parasite populations. However, surviving parasites from vaccinated animals showed increased expression of other proteases and regulators of lysosome trafficking, and displayed up-regulated lipid storage and defecation abilities that may have circumvented the effect of the vaccine. Implications for other potential vaccines for human and veterinary nematodes are discussed.
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Affiliation(s)
- Guillaume Sallé
- INRA - U. Tours, UMR 1282 ISP Infectiologie et Santé Publique, Centre de Recherche Val de Loire, Nouzilly, France; Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom.
| | - Roz Laing
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow, United Kingdom
| | - James A Cotton
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Kirsty Maitland
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow, United Kingdom
| | - Axel Martinelli
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nancy Holroyd
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Alan Tracey
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - W David Smith
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, United Kingdom
| | - George F J Newlands
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, United Kingdom
| | - Eve Hanks
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow, United Kingdom
| | - Eileen Devaney
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow, United Kingdom
| | - Collette Britton
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow, United Kingdom
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14
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Jaeger LH, Carvalho-Costa FA. Status of benzimidazole resistance in intestinal nematode populations of livestock in Brazil: a systematic review. BMC Vet Res 2017; 13:358. [PMID: 29178952 PMCID: PMC5702221 DOI: 10.1186/s12917-017-1282-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/17/2017] [Indexed: 12/03/2022] Open
Abstract
Background Benzimidazoles (BZ) are a class of drugs widely used in veterinary and human medicine, creating a great selection pressure and the emergence of BZ resistance. We conducted a systematic review to assess the status of resistance and/or effectiveness reduction of BZ drugs in animal nematodes in Brazil, and make information accessible to the scientific community, as many studies are published in Portuguese. PubMed, SciELO Brasil, LILACS/Bireme, GNTD database, and Google Scholar were searched with no language restrictions. Results A total of 40 studies met our eligibility criteria (from the year 1989 forward). Sheep was the host most frequently analysed, and albendazole was the most frequently drug studied. The majority of studies (75.7%) showed that BZ drugs are insufficiently active (FECRT <80%) against nematode parasites of livestock. The mean FECRT for fenbendazole, thiabendazole, albendazole, mebendazole, oxfendazole, and ricobendazole were 71.8%, 71.8%, 58.6%, 53.9%, 46.9%, and 41.5%, respectively. It was observed through linear regression that FECRT is significantly reduced over time between 2007 and 2014 (R = −0.653 p = 0.021) for the treatment of cattle with BZ, suggesting progressive loss of effectiveness and increased resistance for these hosts. Conclusions The scenario of BZ resistance in nematode populations in Brazil is not favourable. Given the high cost of drug discovery and development, it is urgent to implement control measures and to monitor the effectiveness/resistance to nematodes in livestock in Brazil.
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Affiliation(s)
- Lauren Hubert Jaeger
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Pavilhão Leônidas Deane, sala 308, Avenida Brasil 4365, Manguinhos, Rio de Janeiro, RJ, 21040-900, Brazil.
| | - Filipe Anibal Carvalho-Costa
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Pavilhão Leônidas Deane, sala 308, Avenida Brasil 4365, Manguinhos, Rio de Janeiro, RJ, 21040-900, Brazil.,Fundação Oswaldo Cruz, Rua Magalhães Filho, 519, Teresina, Piauí, 64000-128, Brazil
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15
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Promoting Science in Secondary School Education. Trends Parasitol 2017; 33:416-420. [PMID: 28274801 DOI: 10.1016/j.pt.2017.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 11/20/2022]
Abstract
Engaging secondary school students with science education is crucial for a society that demands a high level of scientific literacy in order to deal with the economic and social challenges of the 21st century. Here we present how parasitology could be used to engage and promote science in secondary school students under the auspice of a 'Specialist Centre' model for science education.
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16
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Pilot Study of a Slow-Release Ivermectin Formulation for Malaria Control in a Pig Model. Antimicrob Agents Chemother 2017; 61:AAC.02104-16. [PMID: 28031202 DOI: 10.1128/aac.02104-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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17
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Chaccour C, Killeen GF. Mind the gap: residual malaria transmission, veterinary endectocides and livestock as targets for malaria vector control. Malar J 2016; 15:24. [PMID: 26755345 PMCID: PMC4709969 DOI: 10.1186/s12936-015-1063-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 12/22/2015] [Indexed: 11/10/2022] Open
Affiliation(s)
- Carlos Chaccour
- Department of Internal Medicine, Clinica Universidad de Navarra, Pamplona, Spain. .,ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain. .,Instituto de Salud Tropical, Universidad de Navarra, Pamplona, Spain.
| | - Gerry F Killeen
- Ifakara Health Institute, Environmental Health and Ecological Sciences Thematic Group, Ifakara, Kilombero, Morogoro, United Republic of Tanzania. .,Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
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Modeling the burden of poultry disease on the rural poor in Madagascar. One Health 2015; 1:60-65. [PMID: 28616466 PMCID: PMC5441326 DOI: 10.1016/j.onehlt.2015.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/12/2015] [Accepted: 10/14/2015] [Indexed: 11/22/2022] Open
Abstract
Livestock represent a fundamental economic and nutritional resource for many households in the developing world; however, a high burden of infectious disease limits their production potential. Here we present an ecological framework for estimating the burden of poultry disease based on coupled models of infectious disease and economics. The framework is novel, as it values humans and livestock as co-contributors to household wellbeing, incorporating feedbacks between poultry production and human capital in disease burden estimates. We parameterize this coupled ecological-economic model with household-level data to provide an estimate of the overall burden of poultry disease for the Ifanadiana District in Madagascar, where over 72% of households rely on poultry for economic and food security. Our models indicate that households may lose 10-25% of their monthly income under current disease conditions. Results suggest that advancements in poultry health may serve to support income generation through improvements in both human and animal health.
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