1
|
Bessell PR, Salmon G, Schnier C, Tjasink K, Al-Riyami L, Peters A. A high level estimation of the net economic benefits to small-scale livestock producers arising from animal health product distribution initiatives. Front Vet Sci 2023; 10:1171989. [PMID: 37346278 PMCID: PMC10279859 DOI: 10.3389/fvets.2023.1171989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/11/2023] [Indexed: 06/23/2023] Open
Abstract
Introduction A fundamental challenge for charities that facilitate distribution of animal health products to small-scale livestock producers (SSPs) in low and middle income countries (LMICs) is identifying the products and market mechanisms that provide the greatest positive impact for SSPs and estimating their associated impact. This paper describes a pragmatic approach to modeling the impact of market-led product distribution initiatives based on estimating the net economic benefit of administration of animal health products. Methods The model estimates the economic impact of diseases at the individual animal level for poultry, small ruminants, and cattle. The economic impact of mortality and growth inhibition associated with disease are then estimated in conjunction with the losses averted or recovered by preventing or treating the disease. Economic benefit is estimated in 2014-2017 values and also adjusted to 2023 values. The flexible model structure allows for addition of new geographies, new products, and increased granularity of modeled production systems. Results Applied to the Global Alliance for Livestock Veterinary Medicines (GALVmed) product distribution initiatives conducted in Africa and South Asia (SA) between 2014 and 2017, the model estimates an adjusted total net economic benefit of 139.9 million USD from sales of vaccines and poultry anthelminthics in these initiatives. Within SSA, the greatest net economic benefit was realized from East Coast fever and Newcastle disease vaccines, while in SA, peste des petits ruminants and Newcastle disease vaccines had the greatest net economic benefits. This translated to an adjusted $37.97 of net economic benefit on average per SSP customer, many of whom were small poultry producers. Discussion While the model currently estimates impacts from mortality and growth inhibition in livestock, there is the potential to extend it to cover impacts of further initiatives, including interventions targeted at diseases that impact production of milk, eggs, and reproduction.
Collapse
Affiliation(s)
| | - Gareth Salmon
- SEBI-L Supporting Evidence Based Interventions in Livestock, University of Edinburgh, Edinburgh, United Kingdom
| | - Christian Schnier
- SEBI-L Supporting Evidence Based Interventions in Livestock, University of Edinburgh, Edinburgh, United Kingdom
| | - Katharine Tjasink
- Global Alliance for Livestock Veterinary Medicines (GALVmed), Edinburgh, United Kingdom
| | - Lamyaa Al-Riyami
- Global Alliance for Livestock Veterinary Medicines (GALVmed), Edinburgh, United Kingdom
| | - Andrew Peters
- SEBI-L Supporting Evidence Based Interventions in Livestock, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
2
|
Zirra-Shallangwa B, González Gordon L, Hernandez-Castro LE, Cook EAJ, Bronsvoort BMDC, Kelly RF. The Epidemiology of Bovine Viral Diarrhea Virus in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis. Front Vet Sci 2022; 9:947515. [PMID: 36032291 PMCID: PMC9404877 DOI: 10.3389/fvets.2022.947515] [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] [Received: 05/18/2022] [Accepted: 06/23/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Bovine viral diarrhea virus (BVDV) causes reproductive inefficiencies and negatively impacts the economy of low- and middle-income countries (LMICs). It is characterized by a combination of syndromes that result in poor production performance and calf morbidity and mortality. BVDV control is possible by introduction of biosecurity measures, test-and-cull, and vaccination programs as accomplished in high-income countries. Knowledge of BVDV epidemiology is limited in many LMICs, which hinders implementation of effective control programs. We carried out a systematic review and meta-analysis to estimate the burden of BVDV, identify risk factors related to its occurrence, and health and economic impacts on production systems. Materials and Methods Relevant BVD articles were collated from library databases; 690 abstracts and full texts were found in an initial search followed by filtering of 59 manuscripts. We accounted for quality and risk of bias in the meta-analysis. Prevalence, exposure, and current infection at regional, production, and farming system levels were estimated using logistic random-effects meta-regression models. Finally, we calculated the proportion of studies that addressed risk factors and health and economic impacts across different production systems to inform future preventative strategies in LMICs. Results Seroprevalence was high and varied between regions. Mean weighted prevalence was 39.5% (95% CI 25-56.1), 45.2% (95% CI 35.9-54.8), 49.9% (95% CI 25.5-74.3), and 21.6% (95% CI 0.5-56) for sub-Saharan Africa, South America, Middle East, and Asia, respectively. Seroprevalence varied across farming systems, with smallholder farming showing the highest values. Herdsize was the most frequently reported risk factor, and the percentage of articles that reported herdsize as a risk factor were 20.6%, 33.3%, and 38.4% for dairy, beef and mixed systems respectively. Abortion (13.7% of articles) was the main reported health impact in dairy systems. Some articles reported milk drop (4.6% of articles), but no article investigated the economic cost of BVDV in farming systems. Conclusion Animal-level seroprevalence varied across all regions. Most of the studies focused on BVDV seroprevalence. There were some articles that investigated risk factors and health impacts, and there were even less that investigated economic impacts. Future studies should focus on identifying risk factors and quantifying health and economic impacts across systems. Understanding these aspects is crucial to develop management strategies to apply across diverse production systems in LMICs.
Collapse
Affiliation(s)
- Bibiana Zirra-Shallangwa
- The Royal (Dick) School of Veterinary Studies, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Lina González Gordon
- The Royal (Dick) School of Veterinary Studies, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Luis E. Hernandez-Castro
- The Royal (Dick) School of Veterinary Studies, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Elizabeth A. J. Cook
- Centre for Tropical Livestock Genetics and Health, International Livestock Research Institute, Nairobi, Kenya
| | - Barend M. de Clare Bronsvoort
- The Royal (Dick) School of Veterinary Studies, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Robert F. Kelly
- The Royal (Dick) School of Veterinary Studies, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| |
Collapse
|
3
|
Wragg D, Cook EAJ, Latré de Laté P, Sitt T, Hemmink JD, Chepkwony MC, Njeru R, Poole EJ, Powell J, Paxton EA, Callaby R, Talenti A, Miyunga AA, Ndambuki G, Mwaura S, Auty H, Matika O, Hassan M, Marshall K, Connelley T, Morrison LJ, Bronsvoort BMD, Morrison WI, Toye PG, Prendergast JGD. A locus conferring tolerance to Theileria infection in African cattle. PLoS Genet 2022; 18:e1010099. [PMID: 35446841 PMCID: PMC9022807 DOI: 10.1371/journal.pgen.1010099] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/14/2022] [Indexed: 12/30/2022] Open
Abstract
East Coast fever, a tick-borne cattle disease caused by the Theileria parva parasite, is among the biggest natural killers of cattle in East Africa, leading to over 1 million deaths annually. Here we report on the genetic analysis of a cohort of Bos indicus (Boran) cattle demonstrating heritable tolerance to infection with T. parva (h2 = 0.65, s.e. 0.57). Through a linkage analysis we identify a 6 Mb genomic region on bovine chromosome 15 that is significantly associated with survival outcome following T. parva exposure. Testing this locus in an independent cohort of animals replicates this association with survival following T. parva infection. A stop gained variant in a paralogue of the FAF1 gene in this region was found to be highly associated with survival across both related and unrelated animals, with only one of the 20 homozygote carriers (T/T) of this change succumbing to the disease in contrast to 44 out of 97 animals homozygote for the reference allele (C/C). Consequently, we present a genetic locus linked to tolerance of one of Africa’s most important cattle diseases, raising the promise of marker-assisted selection for cattle that are less susceptible to infection by T. parva. More than a million cattle die of East Coast fever in Africa each year, the impact of which disproportionately falls onto low-income, smallholder farmers. The lack of a widely accessible vaccine, heavy reliance on chemicals to control the tick vector and inadequate drug treatments means that new approaches for controlling the disease are urgently required. Through a genetic study of an extended pedigree of Boran cattle that are more than three times less likely to succumb to the disease than matched controls, we identify a region on chromosome 15 of the cattle genome associated with a high level of tolerance to the disease. We show that a nonsense variant in a predicted paralogue of FAS-associated factor 1 (FAF1) in this region is also associated with survival in an independent cohort, and is linked to rates of cell expansion during infection. This genetic variant can therefore support marker-assisted selection, allowing farmers to breed tolerant cattle and offers a route to introduce this beneficial DNA to non-native breeds, enabling reduced disease incidence and increased productivity, which would be of benefit to millions of rural smallholder farmers across Africa.
Collapse
Affiliation(s)
- David Wragg
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Elizabeth A. J. Cook
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Perle Latré de Laté
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Johanneke D. Hemmink
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Regina Njeru
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Jessica Powell
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Edith A. Paxton
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Rebecca Callaby
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- The Epidemiology, Economics and Risk Assessment (EEA) Group, Easter Bush Campus, Edinburgh, United Kingdom
| | - Andrea Talenti
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Antoinette A. Miyunga
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Gideon Ndambuki
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Harriet Auty
- Institute of Biodiversity Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Oswald Matika
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Musa Hassan
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Karen Marshall
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Timothy Connelley
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Liam J. Morrison
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - B. Mark deC. Bronsvoort
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - W. Ivan Morrison
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Philip G. Toye
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
- * E-mail: (PGT); (JGDP)
| | - James G. D. Prendergast
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (PGT); (JGDP)
| |
Collapse
|
4
|
Venter F, Matthews KR, Silvester E. Parasite co-infection: an ecological, molecular and experimental perspective. Proc Biol Sci 2022; 289:20212155. [PMID: 35042410 PMCID: PMC8767208 DOI: 10.1098/rspb.2021.2155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Laboratory studies of pathogens aim to limit complexity in order to disentangle the important parameters contributing to an infection. However, pathogens rarely exist in isolation, and hosts may sustain co-infections with multiple disease agents. These interact with each other and with the host immune system dynamically, with disease outcomes affected by the composition of the community of infecting pathogens, their order of colonization, competition for niches and nutrients, and immune modulation. While pathogen-immune interactions have been detailed elsewhere, here we examine the use of ecological and experimental studies of trypanosome and malaria infections to discuss the interactions between pathogens in mammal hosts and arthropod vectors, including recently developed laboratory models for co-infection. The implications of pathogen co-infection for disease therapy are also discussed.
Collapse
Affiliation(s)
- Frank Venter
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Scotland EH9 3FL, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Scotland EH9 3FL, UK
| | - Eleanor Silvester
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Scotland EH9 3FL, UK.,Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
| |
Collapse
|
5
|
Chiuya T, Villinger J, Masiga DK, Ondifu DO, Murungi MK, Wambua L, Bastos ADS, Fèvre EM, Falzon LC. Molecular prevalence and risk factors associated with tick-borne pathogens in cattle in western Kenya. BMC Vet Res 2021; 17:363. [PMID: 34838023 PMCID: PMC8627057 DOI: 10.1186/s12917-021-03074-7] [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] [Received: 05/25/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022] Open
Abstract
Background Tick-borne pathogens (TBPs) are of global importance, especially in sub-Saharan Africa where they represent a major constraint to livestock production. Their association with human disease is also increasingly recognized, signalling their zoonotic importance. It is therefore crucial to investigate TBPs prevalence in livestock populations and the factors associated with their presence. We set out to identify TBPs present in cattle and to determine associated risk factors in western Kenya, where smallholder livestock production is important for subsistence and market-driven income. Results Tick-borne pathogen infections in blood samples collected from cattle at livestock markets and slaughterhouses between May 2017 and January 2019 were identified by high-resolution melting analysis and sequencing of PCR products of genus-specific primers. Of the 422 cattle sampled, 30.1% (127/422) were infected with at least one TBP, while 8.8% (37/422) had dual infections. Anaplasma spp. (19.7%) were the most prevalent, followed by Theileria (12.3%), Ehrlichia (6.6%), and Babesia (0.2%) spp. Sequence analysis of the TBPs revealed them to be Anaplasma platys-like organisms (13.5%), Theileria velifera (7.4%), Anaplasma marginale (4.9%), Theileria mutans (3.1%), Theileria parva (1.6%), and Babesia bigemina (0.2%). Ehrlichia ruminantium, Rickettsia spp., and arboviruses were not detected. Exotic breeds of cattle were more likely to be infected with A. marginale compared to local breeds (OR: 7.99, 95% CI: 3.04–22.02, p < 0.001). Presence of ticks was a significant predictor for Anaplasma spp. (OR: 2.18, 95% CI: 1.32–3.69, p = 0.003) and Ehrlichia spp. (OR: 2.79, 95% CI: 1.22–7.23, p = 0.022) infection. Cattle sampled at slaughterhouses were more likely to be positive for Anaplasma spp. (OR: 1.64, 95% CI: 1.01–2.70, p = 0.048) and A. marginale (OR: 3.84, 95% CI: 1.43–12.21, p = 0.012), compared to those sampled at livestock markets. Conclusion This study reports TBP prevalence and associated risk factors in western Kenya, factors which are key to informing surveillance and control measures.
Collapse
Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya. .,Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Pretoria, 0028, South Africa.
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Dickens O Ondifu
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Maurice K Murungi
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya
| | - Lillian Wambua
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Pretoria, 0028, South Africa
| | - Eric M Fèvre
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK
| | - Laura C Falzon
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya. .,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK.
| |
Collapse
|
6
|
Allan FK, Sindoya E, Adam KE, Byamungu M, Lea RS, Lord JS, Mbata G, Paxton E, Mramba F, Torr SJ, Morrison WI, Handel I, Morrison LJ, Auty HK. A cross-sectional survey to establish Theileria parva prevalence and vector control at the wildlife-livestock interface, Northern Tanzania. Prev Vet Med 2021; 196:105491. [PMID: 34562810 PMCID: PMC8573586 DOI: 10.1016/j.prevetmed.2021.105491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/02/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022]
Abstract
East Coast fever (ECF) in cattle is caused by the protozoan parasite Theileria parva, transmitted by Rhipicephalus appendiculatus ticks. In cattle ECF is often fatal, causing annual losses >$500 million across its range. The African buffalo (Syncerus caffer) is the natural host for T. parva but the transmission dynamics between wild hosts and livestock are poorly understood. This study aimed to determine the prevalence of T. parva in cattle, in a 30 km zone adjacent to the Serengeti National Park, Tanzania where livestock and buffalo co-exist, and to ascertain how livestock keepers controlled ECF and other vector-borne diseases of cattle. A randomised cross-sectional cattle survey and questionnaire of vector control practices were conducted. Blood samples were collected from 770 cattle from 48 herds and analysed by PCR to establish T. parva prevalence. Half body tick counts were recorded on every animal. Farmers were interviewed (n = 120; including the blood sampled herds) using a standardised questionnaire to obtain data on vector control practices. Local workshops were held to discuss findings and validate results. Overall prevalence of T. parva in cattle was 5.07% (CI: 3.70-7.00%), with significantly higher prevalence in older animals. Although all farmers reported seeing ticks on their cattle, tick counts were very low with 78% cattle having none. Questionnaire analysis indicated significant acaricide use with 79% and 41% of farmers reporting spraying or dipping with cypermethrin-based insecticides, respectively. Some farmers reported very frequent spraying, as often as every four days. However, doses per animal were often insufficient. These data indicate high levels of acaricide use, which may be responsible for the low observed tick burdens and low ECF prevalence. This vector control is farmer-led and aimed at both tick- and tsetse-borne diseases of livestock. The levels of acaricide use raise concerns regarding sustainability; resistance development is a risk, particularly in ticks. Integrating vaccination as part of this community-based disease control may alleviate acaricide dependence, but increased understanding of the Theileria strains circulating in wildlife-livestock interface areas is required to establish the potential benefits of vaccination.
Collapse
Affiliation(s)
- Fiona K Allan
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom.
| | - Emmanuel Sindoya
- Minstry of Livestock and Fisheries, Serengeti District Livestock Office, Mugumu, Tanzania
| | - Katherine E Adam
- Innogen Institute, Science Technology and Innovation Studies; School of Social and Political Science, University of Edinburgh, Old Surgeons' Hall, High School Yards, Edinburgh, United Kingdom
| | | | - Rachel S Lea
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jennifer S Lord
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Geofrey Mbata
- Vector and Vector-borne Diseases Research Institute, Tanga, Tanzania
| | - Edith Paxton
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
| | - Furaha Mramba
- Tanzania Veterinary Laboratory Agency, Dar es Salaam, Tanzania
| | - Stephen J Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - W Ivan Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
| | - Ian Handel
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
| | - Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
| | - Harriet K Auty
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, United Kingdom (Previously Epidemiology Research Unit, SRUC, Inverness, United Kingdom)
| |
Collapse
|
7
|
Development of a Novel Loop Mediated Isothermal Amplification Assay (LAMP) for the Rapid Detection of Epizootic Haemorrhagic Disease Virus. Viruses 2021; 13:v13112187. [PMID: 34834993 PMCID: PMC8621080 DOI: 10.3390/v13112187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
Epizootic haemorragic disease (EHD) is an important disease of white-tailed deer and can cause a bluetongue-like illness in cattle. A definitive diagnosis of EHD relies on molecular assays such as real-time RT-qPCR or conventional PCR. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a cost-effective, specific, and sensitive technique that provides an alternative to RT-qPCR. We designed two sets of specific primers targeting segment-9 of the EHD virus genome to enable the detection of western and eastern topotypes, and evaluated their performance in singleplex and multiplex formats using cell culture isolates (n = 43), field specimens (n = 20), and a proficiency panel (n = 10). The limit of detection of the eastern and western RT-LAMP assays was estimated as ~24.36 CT and as ~29.37 CT in relation to real-time RT-qPCR, respectively, indicating a greater sensitivity of the western topotype singleplex RT-LAMP. The sensitivity of the western topotype RT-LAMP assay, relative to the RT-qPCR assay, was 72.2%, indicating that it could be theoretically used to detect viraemic cervines and bovines. For the first time, an RT-LAMP assay was developed for the rapid detection of the EHD virus that could be used as either a field test or high throughput screening tool in established laboratories to control the spread of EHD.
Collapse
|
8
|
Campbell Z, Coleman P, Guest A, Kushwaha P, Ramuthivheli T, Osebe T, Perry B, Salt J. Prioritizing smallholder animal health needs in East Africa, West Africa, and South Asia using three approaches: Literature review, expert workshops, and practitioner surveys. Prev Vet Med 2021; 189:105279. [PMID: 33581421 PMCID: PMC8024747 DOI: 10.1016/j.prevetmed.2021.105279] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/18/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022]
Abstract
Managing the health needs of livestock contributes to reducing poverty and improving the livelihoods of smallholder and pastoralist livestock keepers globally. Animal health practitioners, producers, policymakers, and researchers all must prioritize how to mobilize limited resources. This study employed three approaches to prioritize animal health needs in East and West Africa and South Asia to identify diseases and syndromes that impact livestock keepers. The approaches were a) systematic literature review, b) a series of expert workshops, and c) a practitioner survey of veterinarians and para-veterinary professionals. The top constraints that emerged from all three approaches include endo/ ectoparasites, foot and mouth disease, brucellosis, peste des petits ruminants, Newcastle disease, and avian influenza. Expert workshops additionally identified contagious caprine pleuropneumonia, contagious bovine pleuropneumonia, mastitis, and reproductive disorders as constraints not emphasized in the literature review. Practitioner survey results additionally identified nutrition as a constraint for smallholder dairy and pastoralist small ruminant production. Experts attending the workshops agreed most constraints can be managed using existing veterinary technologies and best husbandry practices, which supports a shift away from focusing on individual diseases and new technologies towards addressing systemic challenges that limit access to veterinary services and inputs. Few research studies focused on incidence/ prevalence of disease and impact, suggesting better incorporation of socio-economic impact measures in future research would better represent the interests of livestock keepers.
Collapse
Affiliation(s)
- Zoë Campbell
- International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi, 00100, Kenya.
| | - Paul Coleman
- H20 Venture Partners, 33-35 George Street, Oxford, OX1 2AY, United Kingdom
| | - Andrea Guest
- H20 Venture Partners, 33-35 George Street, Oxford, OX1 2AY, United Kingdom
| | - Peetambar Kushwaha
- GALVmed Asia Office, Unit 118 & 120 B, Splendor Forum, Plot No 3, Jasola District Centre, Jasola, New Delhi, 110025, India
| | - Thembinkosi Ramuthivheli
- GALVmed Africa Office, International Livestock Research Institute (ILRI), Swing One, Naivasha Road, Nairobi, Kenya
| | - Tom Osebe
- GALVmed Africa Office, International Livestock Research Institute (ILRI), Swing One, Naivasha Road, Nairobi, Kenya
| | - Brian Perry
- Nuffield College of Clinical Medicine, University of Oxford, United Kingdom; College of Medicine and Veterinary Medicine, University of Edinburgh, Arthurstone House, Meigle, Blairgowrie, PH12 8QW, Scotland, United Kingdom
| | - Jeremy Salt
- GALVmed UK Office, Doherty Building, Pentlands Science Park, Bush Loan, Penicuik Edinburgh, EH26 0PZ, Scotland, United Kingdom
| |
Collapse
|
9
|
Freitas PHF, Wang Y, Yan P, Oliveira HR, Schenkel FS, Zhang Y, Xu Q, Brito LF. Genetic Diversity and Signatures of Selection for Thermal Stress in Cattle and Other Two Bos Species Adapted to Divergent Climatic Conditions. Front Genet 2021; 12:604823. [PMID: 33613634 PMCID: PMC7887320 DOI: 10.3389/fgene.2021.604823] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/15/2021] [Indexed: 12/21/2022] Open
Abstract
Understanding the biological mechanisms of climatic adaptation is of paramount importance for the optimization of breeding programs and conservation of genetic resources. The aim of this study was to investigate genetic diversity and unravel genomic regions potentially under selection for heat and/or cold tolerance in thirty-two worldwide cattle breeds, with a focus on Chinese local cattle breeds adapted to divergent climatic conditions, Datong yak (Bos grunniens; YAK), and Bali (Bos javanicus) based on dense SNP data. In general, moderate genetic diversity levels were observed in most cattle populations. The proportion of polymorphic SNP ranged from 0.197 (YAK) to 0.992 (Mongolian cattle). Observed and expected heterozygosity ranged from 0.023 (YAK) to 0.366 (Sanhe cattle; SH), and from 0.021 (YAK) to 0.358 (SH), respectively. The overall average inbreeding (±SD) was: 0.118 ± 0.028, 0.228 ± 0.059, 0.194 ± 0.041, and 0.021 ± 0.004 based on the observed versus expected number of homozygous genotypes, excess of homozygosity, correlation between uniting gametes, and runs of homozygosity (ROH), respectively. Signatures of selection based on multiple scenarios and methods (F ST, HapFLK, and ROH) revealed important genomic regions and candidate genes. The candidate genes identified are related to various biological processes and pathways such as heat-shock proteins, oxygen transport, anatomical traits, mitochondrial DNA maintenance, metabolic activity, feed intake, carcass conformation, fertility, and reproduction. This highlights the large number of biological processes involved in thermal tolerance and thus, the polygenic nature of climatic resilience. A comprehensive description of genetic diversity measures in Chinese cattle and YAK was carried out and compared to 24 worldwide cattle breeds to avoid potential biases. Numerous genomic regions under positive selection were detected using three signature of selection methods and candidate genes potentially under positive selection were identified. Enriched function analyses pinpointed important biological pathways, molecular function and cellular components, which contribute to a better understanding of the biological mechanisms underlying thermal tolerance in cattle. Based on the large number of genomic regions identified, thermal tolerance has a complex polygenic inheritance nature, which was expected considering the various mechanisms involved in thermal stress response.
Collapse
Affiliation(s)
- Pedro H. F. Freitas
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States
| | - Yachun Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA – National Engineering Laboratory for Animal Breeding – College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Ping Yan
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hinayah R. Oliveira
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Flavio S. Schenkel
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Yi Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA – National Engineering Laboratory for Animal Breeding – College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Qing Xu
- College of Life Sciences and Bioengineering, School of Science, Beijing Jiaotong University, Beijing, China
| | - Luiz F. Brito
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States
| |
Collapse
|
10
|
Callaby R, Hurst E, Handel I, Toye P, Bronsvoort BMDC, Mellanby RJ. Determinants of vitamin D status in Kenyan calves. Sci Rep 2020; 10:20590. [PMID: 33239727 PMCID: PMC7688966 DOI: 10.1038/s41598-020-77209-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/19/2020] [Indexed: 12/30/2022] Open
Abstract
Vitamin D plays a critical role in calcium homeostasis and in the maintenance and development of skeletal health. Vitamin D status has increasingly been linked to non-skeletal health outcomes such as all-cause mortality, infectious diseases and reproductive outcomes in both humans and veterinary species. We have previously demonstrated a relationship between vitamin D status, assessed by the measurement of serum concentrations of the major vitamin D metabolite 25 hydroxyvitamin D (25(OH)D), and a wide range of non-skeletal health outcomes in companion and wild animals. The aims of this study were to define the host and environmental factors associated with vitamin D status in a cohort of 527 calves from Western Kenya which were part of the Infectious Disease of East African Livestock (IDEAL) cohort. A secondary aim was to explore the relationship between serum 25(OH)D concentrations measured in 7-day old calves and subsequent health outcomes over the following 12 months. A genome wide association study demonstrated that both dietary and endogenously produced vitamin D metabolites were under polygenic control in African calves. In addition, we found that neonatal vitamin D status was not predictive of the subsequent development of an infectious disease event or mortality over the 12 month follow up period.
Collapse
Affiliation(s)
- Rebecca Callaby
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, EH25 9RG, Midlothian, UK
- Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, EH25 9RG, UK
| | - Emma Hurst
- The Vitamin D Animal Laboratory (VitDAL), The Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, EH25 9RG, Midlothian, UK
| | - Ian Handel
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, EH25 9RG, Midlothian, UK
| | - Phil Toye
- International Livestock Research Institute and Centre for Tropical Livestock Genetics and Health, Nairobi, Kenya
| | - Barend M de C Bronsvoort
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, EH25 9RG, Midlothian, UK
- Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, EH25 9RG, UK
| | - Richard J Mellanby
- The Vitamin D Animal Laboratory (VitDAL), The Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, EH25 9RG, Midlothian, UK.
| |
Collapse
|
11
|
IDEAL, the Infectious Diseases of East African Livestock project open access database and biobank. Sci Data 2020; 7:224. [PMID: 32647128 PMCID: PMC7347598 DOI: 10.1038/s41597-020-0559-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/28/2020] [Indexed: 11/23/2022] Open
Abstract
The Infectious Diseases of East African Livestock (IDEAL) project was a longitudinal cohort study of calf health which was conducted in Western Kenya between 2007–2010. A total of 548 East African shorthorn zebu calves were recruited at birth and followed at least every 5 weeks during the first year of life. Comprehensive clinical and epidemiological data, blood and tissue samples were collected at every visit. These samples were screened for over 100 different pathogens or infectious exposures, using a range of diagnostic methods. This manuscript describes this comprehensive dataset and bio-repository, and how to access it through a single online site (http://data.ctlgh.org/ideal/). This provides extensive filtering and searching capabilities. These data are useful to illustrate outcomes of multiple infections on health, investigate patterns of morbidity and mortality due to parasite infections, and to study genotypic determinants of immunity and disease. Measurement(s) | Health • disease • genotype • Phenotypic variability | Technology Type(s) | Examination • single-nucleotide polymorphism analysis | Sample Characteristic - Organism | Bos indicus | Sample Characteristic - Environment | farm | Sample Characteristic - Location | Kenya |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12459737
Collapse
|
12
|
Reflections on IDEAL: What we have learnt from a unique calf cohort study. Prev Vet Med 2020; 181:105062. [PMID: 32615453 PMCID: PMC7456772 DOI: 10.1016/j.prevetmed.2020.105062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/07/2020] [Accepted: 06/10/2020] [Indexed: 11/20/2022]
Abstract
The year 2020 marks a decade since the final visit was made in the ‘Infectious Diseases of East African Livestock’ (IDEAL) project. However, data generation from samples obtained during this ambitious longitudinal study still continues. As the project launches its extensive open-access database and biobank to the scientific community, we reflect on the challenges overcome, the knowledge gained, and the advantages of such a project. We discuss the legacy of the IDEAL project and how it continues to generate evidence since being adopted by the Centre for Tropical Livestock Genetics and Health (CTLGH). We also examine the impact of the IDEAL project, from the authors perspective, for each of the stakeholders (the animal, the farmer, the consumer, the policy maker, the funding body, and the researcher and their institution) involved in the project and provide recommendations for future researchers who are interested in running longitudinal field studies.
Collapse
|
13
|
Onasanya GO, Msalya GM, Thiruvenkadan AK, Sreekumar C, Tirumurugaan GK, Sanni TM, Decampos JS, Amusan SA, Olowofeso O, Fafiolu AO, Okpeku M, Yakubu A, Ikeobi CO. Single nucleotide polymorphisms at heat shock protein 90 gene and their association with thermo-tolerance potential in selected indigenous Nigerian cattle. Trop Anim Health Prod 2020; 52:1961-1970. [PMID: 31981054 DOI: 10.1007/s11250-020-02222-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/17/2020] [Indexed: 11/24/2022]
Abstract
Heat shock protein (HSP) 90 gene provides protection and adaptation to thermal assault and certain polymorphisms have been associated to heat tolerance in humans and animals. Single nucleotide polymorphisms (SNPs) of HSP 90 gene were used to evaluate the scientific basis of heat tolerance in four zebu breeds of Nigeria. The DNA was extracted from skin tissue of 90 adult bulls representing White Fulani (WF), Sokoto Gudali (SG), Red Bororo (RB), and Ambala (AM). The SNPs were determined in DNAs using PCR, sequencing, and visualization and bio-editing by chromatogram in SeqMan Ngen tool. Subsequently, respective genotypes were constructed and genotypic and allelic frequencies were computed. Also, body parameters related to heat stress (HS) including body temperature (BT), rectal temperature (RT), and respiratory rates (RR) were taken for each animal before biological sampling and heat tolerance coefficient (HTC) was calculated. We detected four SNPs distinct/specific for each breed as follows: change from thymine (T) to guanine (G) at position 116 (T116G) in RB, G to cytosine (C) at 220 (G220C) in SG, G to adenine (A) at two positions, 346 (G346A) and 390 (G390A) in AM and WF, respectively. Heterozygous SNPs showed significantly lower values (P < 0.0001) for BT, RT, RR, and HTC than homozygous genotypes at all positions. We hypothesize that animals with heterozygous SNPs in exon 3 of HSP 90 may be tolerant to HS. These SNPs can be used as bio-markers for screening large populations of cattle for tolerance to hot tropical conditions in Nigeria and other sub-humid places.
Collapse
Affiliation(s)
- Gbolabo O Onasanya
- Department of Animal Science, Federal University Dutse, Dutse, Nigeria
- Deparment of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
- Mecheri Sheep Research Station, Pottaneri, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
- Biotechnology Center, Postgraduate Research Institute in Animal Sciences, Kattupakkum, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - George M Msalya
- Mecheri Sheep Research Station, Pottaneri, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India.
- Department of Animal, Aquaculture and Range Sciences (DAARS), Sokoine University of Agriculture (SUA), PO Box 3004, Morogoro, Tanzania.
| | - Aranganoor K Thiruvenkadan
- Mecheri Sheep Research Station, Pottaneri, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Chirukandoth Sreekumar
- Biotechnology Center, Postgraduate Research Institute in Animal Sciences, Kattupakkum, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Gopalan K Tirumurugaan
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Timothy M Sanni
- Deparment of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - John S Decampos
- Department of Animal Production, University of Ilorin, Ilorin, Kwara State, Nigeria
| | - Samuel A Amusan
- Department of Animal production, Federal College of Animal Health and Production Technology, Moor Plantation, Ibadan, Nigeria
| | - Olajide Olowofeso
- Deparment of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Adeboye O Fafiolu
- Department of Animal Nutrition, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Moses Okpeku
- Department of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westvile Campus, Durban, South Africa
| | - Abdulmojeed Yakubu
- Department of Animal Science, Faculty of Agriculture, Nasarawa State University, Keffi, Shabu-Lafia Campus, Lafia, Nigeria
| | - Christian O Ikeobi
- Deparment of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| |
Collapse
|
14
|
Ibeagha-Awemu EM, Peters SO, Bemji MN, Adeleke MA, Do DN. Leveraging Available Resources and Stakeholder Involvement for Improved Productivity of African Livestock in the Era of Genomic Breeding. Front Genet 2019; 10:357. [PMID: 31105739 PMCID: PMC6499167 DOI: 10.3389/fgene.2019.00357] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 04/03/2019] [Indexed: 01/13/2023] Open
Abstract
The African continent is home to diverse populations of livestock breeds adapted to harsh environmental conditions with more than 70% under traditional systems of management. Animal productivity is less than optimal in most cases and is faced with numerous challenges including limited access to adequate nutrition and disease management, poor institutional capacities and lack of adequate government policies and funding to develop the livestock sector. Africa is home to about 1.3 billion people and with increasing demand for animal proteins by an ever growing human population, the current state of livestock productivity creates a significant yield gap for animal products. Although a greater section of the population, especially those living in rural areas depend largely on livestock for their livelihoods; the potential of the sector remains underutilized and therefore unable to contribute significantly to economic development and social wellbeing of the people. With current advances in livestock management practices, breeding technologies and health management, and with inclusion of all stakeholders, African livestock populations can be sustainably developed to close the animal protein gap that exists in the continent. In particular, advances in gene technologies, and application of genomic breeding in many Western countries has resulted in tremendous gains in traits like milk production with the potential that, implementation of genomic selection and other improved practices (nutrition, healthcare, etc.) can lead to rapid improvement in traits of economic importance in African livestock populations. The African livestock populations in the context of this review are limited to cattle, goat, pig, poultry, and sheep, which are mainly exploited for meat, milk, and eggs. This review examines the current state of livestock productivity in Africa, the main challenges faced by the sector, the role of various stakeholders and discusses in-depth strategies that can enable the application of genomic technologies for rapid improvement of livestock traits of economic importance.
Collapse
Affiliation(s)
- Eveline M. Ibeagha-Awemu
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| | - Sunday O. Peters
- Department of Animal Science, Berry College, Mount Berry, GA, United States
| | - Martha N. Bemji
- Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Abeokuta, Nigeria
| | - Matthew A. Adeleke
- School of Life Sciences, University of Kwazulu-Natal, Durban, South Africa
| | - Duy N. Do
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| |
Collapse
|
15
|
Floyd JR, Ruktanonchai NW, Wardrop N, Tatem AJ, Ogola J, Fèvre EM. Exploring fine-scale human and livestock movement in western Kenya. One Health 2019; 7:100081. [PMID: 30911595 PMCID: PMC6416412 DOI: 10.1016/j.onehlt.2019.100081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 12/29/2018] [Accepted: 02/07/2019] [Indexed: 12/03/2022] Open
Abstract
Human and livestock mobility are key factors in the transmission of several high-burden zoonoses such as rift valley fever and trypanosomiasis, yet our knowledge of this mobility is relatively poor due to difficulty in quantifying population-level movement patterns. Significant variation in the movement patterns of individual hosts means it is necessary to capture their fine-scale mobility in order to gain useful knowledge that can be extrapolated to a population level. Here we explore how the movements of people and their ruminants, and their exposure to various types of land cover, correlate with ruminant ownership and other demographic factors which could affect individual exposure to zoonoses. The study was conducted in Busia County, western Kenya, where the population are mostly subsistence farmers operating a mixed crop/livestock farming system. We used GPS trackers to collect movement data from 26 people and their ruminants for 1 week per individual in July/August 2016, and the study was repeated at the end of the same year to compare movement patterns between the short rainy and dry seasons respectively. We found that during the dry season, people and their ruminants travelled further on trips outside of the household, and that people spent less time on swampland compared to the short rainy season. Our findings also showed that ruminant owners spent longer and travelled further on trips outside the household than non-ruminant owners, and that people and ruminants from poorer households travelled further than people from relatively wealthier households. These results indicate that some individual-level mobility may be predicted by season and by household characteristics such as ruminant ownership and household wealth, which could have practical uses for assessing individual risk of exposure to some zoonoses and for future modelling studies of zoonosis transmission in similar rural areas.
Collapse
Affiliation(s)
- Jessica R Floyd
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, UK
| | - Nick W Ruktanonchai
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, UK.,Flowminder Foundation, Stockholm, Sweden
| | - Nicola Wardrop
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, UK
| | - Andrew J Tatem
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, UK.,Flowminder Foundation, Stockholm, Sweden
| | - Joseph Ogola
- International Livestock Research Institute, Old Naivasha Road, PO BOX 30709, 00100 Nairobi, Kenya
| | - Eric M Fèvre
- International Livestock Research Institute, Old Naivasha Road, PO BOX 30709, 00100 Nairobi, Kenya.,Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, UK
| |
Collapse
|
16
|
Bahbahani H, Tijjani A, Mukasa C, Wragg D, Almathen F, Nash O, Akpa GN, Mbole-Kariuki M, Malla S, Woolhouse M, Sonstegard T, Van Tassell C, Blythe M, Huson H, Hanotte O. Signatures of Selection for Environmental Adaptation and Zebu × Taurine Hybrid Fitness in East African Shorthorn Zebu. Front Genet 2017. [PMID: 28642786 PMCID: PMC5462927 DOI: 10.3389/fgene.2017.00068] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The East African Shorthorn Zebu (EASZ) cattle are ancient hybrid between Asian zebu × African taurine cattle preferred by local farmers due to their adaptability to the African environment. The genetic controls of these adaptabilities are not clearly understood yet. Here, we genotyped 92 EASZ samples from Kenya (KEASZ) with more than 770,000 SNPs and sequenced the genome of a pool of 10 KEASZ. We observe an even admixed autosomal zebu × taurine genomic structure in the population. A total of 101 and 165 candidate regions of positive selection, based on genome-wide SNP analyses (meta-SS, Rsb, iHS, and ΔAF) and pooled heterozygosity (Hp) full genome sequence analysis, are identified, in which 35 regions are shared between them. A total of 142 functional variants, one novel, have been detected within these regions, in which 30 and 26 were classified as of zebu and African taurine origins, respectively. High density genome-wide SNP analysis of zebu × taurine admixed cattle populations from Uganda and Nigeria show that 25 of these regions are shared between KEASZ and Uganda cattle, and seven regions are shared across the KEASZ, Uganda, and Nigeria cattle. The identification of common candidate regions allows us to fine map 18 regions. These regions intersect with genes and QTL associated with reproduction and environmental stress (e.g., immunity and heat stress) suggesting that the genome of the zebu × taurine admixed cattle has been uniquely selected to maximize hybrid fitness both in terms of reproduction and survivability.
Collapse
Affiliation(s)
- Hussain Bahbahani
- Department of Biological Sciences, Faculty of Science, Kuwait UniversityKuwait, Kuwait
| | - Abdulfatai Tijjani
- School of Life Sciences, University of NottinghamNottingham, United Kingdom.,Centre for Genomics Research and Innovation, National Biotechnology Development AgencyAbuja, Nigeria
| | | | - David Wragg
- Centre for Tropical Livestock Genetics and Health, Roslin InstituteEdinburgh, United Kingdom
| | - Faisal Almathen
- Department of Veterinary Public Health and Animal Husbandry, College of Veterinary Medicine, King Faisal UniversityAl-Hasa, Saudi Arabia
| | - Oyekanmi Nash
- Centre for Genomics Research and Innovation, National Biotechnology Development AgencyAbuja, Nigeria
| | - Gerald N Akpa
- Department of Animal Science, Ahmadu Bello UniversityZaria, Nigeria
| | - Mary Mbole-Kariuki
- School of Life Sciences, University of NottinghamNottingham, United Kingdom
| | - Sunir Malla
- Deep Seq Department, University of NottinghamNottingham, United Kingdom
| | - Mark Woolhouse
- Ashworth Laboratories, Centre for Immunity, Infection and Evolution, University of EdinburghEdinburgh, United Kingdom
| | | | - Curtis Van Tassell
- Animal Genomics and Improvement Laboratory, United States Department of Agriculture, Agricultural Research ServiceBeltsville, MD, United States
| | - Martin Blythe
- Deep Seq Department, University of NottinghamNottingham, United Kingdom
| | - Heather Huson
- Animal Genomics and Improvement Laboratory, United States Department of Agriculture, Agricultural Research ServiceBeltsville, MD, United States
| | - Olivier Hanotte
- School of Life Sciences, University of NottinghamNottingham, United Kingdom.,International Livestock Research Institute (ILRI)Addis Ababa, Ethiopia
| |
Collapse
|
17
|
Leahy E, Bronsvoort B, Gamble L, Gibson A, Kaponda H, Mayer D, Mazeri S, Shervell K, Sargison N. Proof of concept of faecal egg nematode counting as a practical means of veterinary engagement with planned livestock health management in a lower income country. Ir Vet J 2017; 70:16. [PMID: 28588763 PMCID: PMC5457739 DOI: 10.1186/s13620-017-0094-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/30/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The wellbeing and livelihood of farmers in impoverished regions of the world is intrinsically linked to the health and welfare of their livestock; hence improved animal health is a pragmatic component of poverty alleviation. Prerequisite knowledge and understanding of the animal health challenges facing cattle keepers in Malawi is constrained by the lack of veterinary infrastructure, which inevitably accompanies under-resourced rural development in a poor country. METHODS We collaborated with public and private paraveterinary services to locate 62 village Zebu calves and 60 dairy co-operative calves dispersed over a wide geographical area. All calves were visited twice about 2 to 3 weeks apart, when they were clinically examined and faecal samples were collected. The calves were treated with 7.5 mg/kg of a locally-available albendazole drench on the first visit, and pre- and post- treatment trichostrongyle and Toxocara faecal egg counts were performed using a modified McMaster method. RESULTS Our clinical findings point towards a generally poor level of animal health, implying a role of ticks and tick-transmitted diseases in village calves and need for improvement in neonatal calf husbandry in the dairy co-operative holdings. High faecal trichostrongyle egg counts were not intuitive, based on our interpretation of the animal management information that was provided. This shows the need for better understanding of nematode parasite epidemiology within the context of local husbandry and environmental conditions. The albendazole anthelmintic was effective against Toxocara, while efficacy against trichostrongyle nematodes was poor in both village and dairy co-operative calves, demonstrating the need for further research to inform sustainable drug use. CONCLUSIONS Here we describe the potential value of faecal nematode egg counting as a platform for communicating with and gaining access to cattle keepers and their animals, respectively, in southern Malawi, with the aim of providing informative background knowledge and understanding that may aid in the establishment of effective veterinary services in an under-resourced community.
Collapse
Affiliation(s)
- Eithne Leahy
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | - Barend Bronsvoort
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK.,The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute, Easter Bush, Roslin, Midlothian EH26 9RG UK
| | - Luke Gamble
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | | | - Henderson Kaponda
- Blantyre District Agricultural Development Office, Kunthembwe EPA, Malawi
| | - Dagmar Mayer
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | - Stella Mazeri
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK.,The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute, Easter Bush, Roslin, Midlothian EH26 9RG UK
| | | | - Neil Sargison
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK
| |
Collapse
|
18
|
de Glanville WA, Conde-Álvarez R, Moriyón I, Njeru J, Díaz R, Cook EAJ, Morin M, Bronsvoort BMDC, Thomas LF, Kariuki S, Fèvre EM. Poor performance of the rapid test for human brucellosis in health facilities in Kenya. PLoS Negl Trop Dis 2017; 11:e0005508. [PMID: 28388625 PMCID: PMC5413359 DOI: 10.1371/journal.pntd.0005508] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 05/02/2017] [Accepted: 03/20/2017] [Indexed: 02/07/2023] Open
Abstract
Human brucellosis is considered to be an important but typically under-diagnosed cause of febrile illness in many low and middle-income countries. In Kenya, and throughout East Africa, laboratory diagnosis for the disease is based primarily on the febrile antigen Brucella agglutination test (FBAT), yet few studies of the diagnostic accuracy of this test exist. Assessment of the performance of the FBAT is essential for its appropriate clinical use, as well as for evaluating surveillance data reported by public health systems. To assess FBAT performance, we collected sera from people with symptoms compatible with brucellosis attending two health facilities in Busia County, Kenya. Sera were tested using the FBAT and results compared with those from the Rose Bengal Test (RBT), an assay with well-known performance characteristics. Positives on either test were confirmed using the classical serum agglutination test (SAT)-Coombs test combination and a rapid IgM/IgG lateral flow immunochromatography assay (LFA). A questionnaire focussing on known risk factors for exposure to Brucella spp. was also conducted, and relationships with FBAT positivity examined using logistic regression. Out of 825 recruited individuals, 162 (19.6%) were classified as positive using the FBAT. In contrast, only eight (1.0%) were positive using the RBT. Of the 162 FBAT positives, one (0.62%) had an atypical agglutination in SAT and three (1.9%) showed low Coombs titres. Out of 148 FBAT positive individuals tested using the LFA, five (3.4%) were IgM positive and none were IgG positive. Poor or no correlation was observed between FBAT results and most established risk factors for Brucella infection. We observed substantial disagreement between the FBAT and a number of well-known serological tests, with the majority of reactive FBAT results appearing to be false positives. Poor FBAT specificity, combined with a lack of confirmatory testing, strongly suggests overdiagnosis of brucellosis is common in this low prevalence setting. This is expected to have important economic impacts on affected patients subjected to the long and likely unnecessary courses of multiple antibiotics required for treatment of the disease. Brucellosis is a debilitating disease of people caused by infection with one of a number of different Brucella species. In almost all cases, people acquire the infection through exposure to infected animals or contaminated animal products. Human brucellosis is well known for its wide range of symptoms, and is often clinically indistinguishable from other infectious diseases, such as malaria or typhoid. Diagnosing the disease therefore typically relies on laboratory tests. A wide range of tests are available, but little is known about the accuracy of the principal test used in Government health facilities in Kenya, the febrile Brucella agglutination test (FBAT). In this study, we identified people with symptoms compatible with brucellosis attending health centres in Kenya. By comparing results from the FBAT performed on samples collected from these individuals with the results from a range of well-established diagnostic tests, we were able to show that the FBAT produces large numbers of false positive results. We expect that this leads to a high levels of overdiagnosis of brucellosis in some parts of Kenya. Treatment of the disease involves multiple weeks of multiple antibiotics, and these incorrect diagnoses may have important and unnecessary negative impacts on affected patients.
Collapse
Affiliation(s)
- William A de Glanville
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Raquel Conde-Álvarez
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - Ignacio Moriyón
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - John Njeru
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya.,Institute for Bacterial Infections and Zoonoses, Friedrich Loeffler Institute, Berlin, Germany
| | - Ramón Díaz
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - Elizabeth A J Cook
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Matilda Morin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Barend M de C Bronsvoort
- Epidemiology, Economics and Risk Assessment Group, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Lian F Thomas
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eric M Fèvre
- International Livestock Research Institute, Nairobi, Kenya.,Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| |
Collapse
|
19
|
Makau DN, Gitau GK, Muchemi GK, Thomas LF, Cook EAJ, Wardrop NA, Fèvre EM, de Glanville WA. Environmental predictors of bovine Eimeria infection in western Kenya. Trop Anim Health Prod 2017; 49:409-416. [PMID: 28054227 PMCID: PMC5253148 DOI: 10.1007/s11250-016-1209-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/05/2016] [Indexed: 11/24/2022]
Abstract
Eimeriosis is caused by a protozoan infection affecting most domestic animal species. Outbreaks in cattle are associated with various environmental factors in temperate climates but limited work has been done in tropical settings. The objective of this work was to determine the prevalence and environmental factors associated with bovine Eimeria spp. infection in a mixed farming area of western Kenya. A total of 983 cattle were sampled from 226 cattle-keeping households. Faecal samples were collected directly from the rectum via digital extraction and analysed for the presence of Eimeria spp. infection using the MacMaster technique. Individual and household level predictors of infection were explored using mixed effects logistic regression. The prevalence of individual animal Eimeria infection was 32.8% (95% CI 29.9-35.9). A positive linear relationship was found between risk of Eimeria infection and increasing temperature (OR = 1.4, 95% CI 1.06-1.86) and distance to areas at risk of flooding (OR = 1.49, 95% CI 1.17-1.91). There was weak evidence of non-linear relationship between Eimeria infection and the proportion of the area around a household that was classified as swamp (OR = 1.12, 95% CI 0.87-1.44; OR (quadratic term) = 0.85, 95% CI 0.73-1.00), and the sand content of the soil (OR = 1.18, 95% CI 0.91-1.53; OR (quadratic term) = 1.1, 95% CI 0.99-1.23). The risk of animal Eimeria spp. infection is influenced by a number of climatic and soil-associated conditions.
Collapse
Affiliation(s)
- D N Makau
- Department of Public Health Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, PO BOX 29053-00625, Kenya.
| | - G K Gitau
- Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, PO BOX 29053-00625, Kenya
| | - G K Muchemi
- Department of Public Health Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, PO BOX 29053-00625, Kenya
| | - L F Thomas
- International Livestock Research Institute, Old Naivasha Road, PO Box 30709-00100, Nairobi, Kenya
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, Kings Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK
| | - E A J Cook
- International Livestock Research Institute, Old Naivasha Road, PO Box 30709-00100, Nairobi, Kenya
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, Kings Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK
| | - N A Wardrop
- Geography and Environment, University of Southampton, Highfield Campus, University Road, Southampton, SO17 1BJ, UK
| | - E M Fèvre
- International Livestock Research Institute, Old Naivasha Road, PO Box 30709-00100, Nairobi, Kenya
- Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, UK
| | - W A de Glanville
- International Livestock Research Institute, Old Naivasha Road, PO Box 30709-00100, Nairobi, Kenya.
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, Kings Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK.
| |
Collapse
|
20
|
Callaby R, Toye P, Jennings A, Thumbi SM, Coetzer JAW, Conradie Van Wyk IC, Hanotte O, Mbole-Kariuki MN, Bronsvoort BMDC, Kruuk LEB, Woolhouse MEJ, Kiara H. Seroprevalence of respiratory viral pathogens of indigenous calves in Western Kenya. Res Vet Sci 2016; 108:120-4. [PMID: 27663380 PMCID: PMC5040193 DOI: 10.1016/j.rvsc.2016.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 10/24/2022]
Abstract
Most studies of infectious diseases in East African cattle have concentrated on gastro-intestinal parasites and vector-borne diseases. As a result, relatively little is known about viral diseases, except for those that are clinically symptomatic or which affect international trade such as foot and mouth disease, bluetongue and epizootic haemorrhagic disease. Here, we investigate the seroprevalence, distribution and relationship between the viruses involved in respiratory disease, infectious bovine rhinotracheitis virus (IBR), bovine parainfluenza virus Type 3 (PIV3) and bovine viral diarrhoea virus (BVDV) in East African Shorthorn Zebu calves. These viruses contribute to the bovine respiratory disease complex (BRD) which is responsible for major economic losses in cattle from intensive farming systems as a result of pneumonia. We found that calves experience similar risks of infection for IBR, PIV3, and BVDV with a seroprevalence of 20.9%, 20.1% and 19.8% respectively. We confirm that positive associations exist between IBR, PIV3 and BVDV; being seropositive for any one of these three viruses means that an individual is more likely to be seropositive for the other two viruses than expected by chance.
Collapse
Affiliation(s)
- R Callaby
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh EH9 3JT, UK; James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
| | - P Toye
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - A Jennings
- The Farm Animal Practice, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK
| | - S M Thumbi
- Paul G Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7079, USA
| | - J A W Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - I C Conradie Van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - O Hanotte
- School of Life Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - M N Mbole-Kariuki
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya; School of Life Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - B M de C Bronsvoort
- The Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK
| | - L E B Kruuk
- Division of Evolution, Ecology & Genetics, Research School of Biology, The Australian National University, Canberra ACT 0200, Australia; Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - M E J Woolhouse
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - H Kiara
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| |
Collapse
|
21
|
Risk factors for stillbirths and mortality during the first 24h of life on dairy farms in Hokkaido, Japan 2005–2009. Prev Vet Med 2016; 127:50-5. [DOI: 10.1016/j.prevetmed.2016.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 03/05/2016] [Accepted: 03/22/2016] [Indexed: 11/22/2022]
|
22
|
Bahbahani H, Clifford H, Wragg D, Mbole-Kariuki MN, Van Tassell C, Sonstegard T, Woolhouse M, Hanotte O. Signatures of positive selection in East African Shorthorn Zebu: A genome-wide single nucleotide polymorphism analysis. Sci Rep 2015; 5:11729. [PMID: 26130263 PMCID: PMC4486961 DOI: 10.1038/srep11729] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 06/03/2015] [Indexed: 12/02/2022] Open
Abstract
The small East African Shorthorn Zebu (EASZ) is the main indigenous cattle across East Africa. A recent genome wide SNP analysis revealed an ancient stable African taurine x Asian zebu admixture. Here, we assess the presence of candidate signatures of positive selection in their genome, with the aim to provide qualitative insights about the corresponding selective pressures. Four hundred and twenty-five EASZ and four reference populations (Holstein-Friesian, Jersey, N’Dama and Nellore) were analysed using 46,171 SNPs covering all autosomes and the X chromosome. Following FST and two extended haplotype homozygosity-based (iHS and Rsb) analyses 24 candidate genome regions within 14 autosomes and the X chromosome were revealed, in which 18 and 4 were previously identified in tropical-adapted and commercial breeds, respectively. These regions overlap with 340 bovine QTL. They include 409 annotated genes, in which 37 were considered as candidates. These genes are involved in various biological pathways (e.g. immunity, reproduction, development and heat tolerance). Our results support that different selection pressures (e.g. environmental constraints, human selection, genome admixture constrains) have shaped the genome of EASZ. We argue that these candidate regions represent genome landmarks to be maintained in breeding programs aiming to improve sustainable livestock productivity in the tropics.
Collapse
Affiliation(s)
- Hussain Bahbahani
- 1] School of Life Sciences, University of Nottingham, NG7 2RD, Nottingham, UK [2] Department of Biological Sciences, Faculty of Science, Kuwait University, Safat 13060, Kuwait
| | - Harry Clifford
- Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3QX, Oxford, UK
| | - David Wragg
- Institut National de la Recherche Agronomique (INRA), UMR 1338 Génétique, Physiologie et Systèmes d'Elevage (GenPhySE), 31326 Castanet Tolosan, France
| | - Mary N Mbole-Kariuki
- African Union - InterAfrican Bureau of Animal Resources (AU-IBAR), P. O. Box 30786, 00100 Nairobi, Kenya
| | - Curtis Van Tassell
- United States Department of Agriculture, Agricultural Research Service, Animal Genomics and Improvement Laboratory, USA
| | - Tad Sonstegard
- United States Department of Agriculture, Agricultural Research Service, Animal Genomics and Improvement Laboratory, USA
| | - Mark Woolhouse
- Centre for Immunity, Infection &Evolution, Ashworth Laboratories, Kings Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Olivier Hanotte
- School of Life Sciences, University of Nottingham, NG7 2RD, Nottingham, UK
| |
Collapse
|
23
|
Njiiri NE, Bronsvoort BMD, Collins NE, Steyn HC, Troskie M, Vorster I, Thumbi SM, Sibeko KP, Jennings A, van Wyk IC, Mbole-Kariuki M, Kiara H, Poole EJ, Hanotte O, Coetzer K, Oosthuizen MC, Woolhouse M, Toye P. The epidemiology of tick-borne haemoparasites as determined by the reverse line blot hybridization assay in an intensively studied cohort of calves in western Kenya. Vet Parasitol 2015; 210:69-76. [PMID: 25858115 PMCID: PMC4427107 DOI: 10.1016/j.vetpar.2015.02.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 10/25/2022]
Abstract
The development of sensitive surveillance technologies using PCR-based detection of microbial DNA, such as the reverse line blot assay, can facilitate the gathering of epidemiological information on tick-borne diseases, which continue to hamper the productivity of livestock in many parts of Africa and elsewhere. We have employed a reverse line blot assay to detect the prevalence of tick-borne parasites in an intensively studied cohort of indigenous calves in western Kenya. The calves were recruited close to birth and monitored for the presence of infectious disease for up to 51 weeks. The final visit samples from 453 calves which survived for the study period were analyzed by RLB. The results indicated high prevalences of Theileria mutans (71.6%), T. velifera (62.8%), Anaplasma sp. Omatjenne (42.7%), A. bovis (39.9%), Theileria sp. (sable) (32.7%), T. parva (12.9%) and T. taurotragi (8.5%), with minor occurrences of eight other haemoparasites. The unexpectedly low prevalence of the pathogenic species Ehrlichia ruminantium was confirmed by a species-specific PCR targeting the pCS20 gene region. Coinfection analyses of the seven most prevalent haemoparasites indicated that they were present as coinfections in over 90% of the cases. The analyses revealed significant associations between several of the Theileria parasites, in particular T. velifera with Theileria sp. sable and T. mutans, and T. parva with T. taurotragi. There was very little coinfection of the two most common Anaplasma species, although they were commonly detected as coinfections with the Theileria parasites. The comparison of reverse line blot and serological results for four haemoparasites (T. parva, T. mutans, A. marginale and B. bigemina) indicated that, except for the mostly benign T. mutans, indigenous cattle seem capable of clearing infections of the three other, pathogenic parasites to below detectable levels. Although the study site was located across four agroecological zones, there was little restriction of the parasites to particular zones.
Collapse
Affiliation(s)
- Nyawira E Njiiri
- The International Livestock Research Institute, PO Box, 30709, 00100 Nairobi, Kenya; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | | | - Nicola E Collins
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Helena C Steyn
- Agricultural Research Council-Onderstepoort Veterinary Institute, Private Bag X05, Onderstepoort 0110, South Africa
| | - Milana Troskie
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Ilse Vorster
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - S M Thumbi
- Centre for Immunity, Infection & Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK; Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7090, USA
| | - Kgomotso P Sibeko
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Amy Jennings
- The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK
| | - Ilana Conradie van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Mary Mbole-Kariuki
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; African Union InterAfrican Bureau for Animal Resources (AU-IBAR), PO Box 30786, 00100 Nairobi, Kenya
| | - Henry Kiara
- The International Livestock Research Institute, PO Box, 30709, 00100 Nairobi, Kenya
| | - E Jane Poole
- The International Livestock Research Institute, PO Box, 30709, 00100 Nairobi, Kenya
| | - Olivier Hanotte
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Koos Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Marinda C Oosthuizen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Mark Woolhouse
- Centre for Immunity, Infection & Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Philip Toye
- The International Livestock Research Institute, PO Box, 30709, 00100 Nairobi, Kenya.
| |
Collapse
|
24
|
Woolhouse MEJ, Thumbi SM, Jennings A, Chase-Topping M, Callaby R, Kiara H, Oosthuizen MC, Mbole-Kariuki MN, Conradie I, Handel IG, Poole EJ, Njiiri E, Collins NE, Murray G, Tapio M, Auguet OT, Weir W, Morrison WI, Kruuk LEB, Bronsvoort BMDC, Hanotte O, Coetzer K, Toye PG. Co-infections determine patterns of mortality in a population exposed to parasite infection. SCIENCE ADVANCES 2015; 1:e1400026. [PMID: 26601143 PMCID: PMC4643819 DOI: 10.1126/sciadv.1400026] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/11/2015] [Indexed: 05/11/2023]
Abstract
Many individual hosts are infected with multiple parasite species, and this may increase or decrease the pathogenicity of the infections. This phenomenon is termed heterologous reactivity and is potentially an important determinant of both patterns of morbidity and mortality and of the impact of disease control measures at the population level. Using infections with Theileria parva (a tick-borne protozoan, related to Plasmodium) in indigenous African cattle [where it causes East Coast fever (ECF)] as a model system, we obtain the first quantitative estimate of the effects of heterologous reactivity for any parasitic disease. In individual calves, concurrent co-infection with less pathogenic species of Theileria resulted in an 89% reduction in mortality associated with T. parva infection. Across our study population, this corresponds to a net reduction in mortality due to ECF of greater than 40%. Using a mathematical model, we demonstrate that this degree of heterologous protection provides a unifying explanation for apparently disparate epidemiological patterns: variable disease-induced mortality rates, age-mortality profiles, weak correlations between the incidence of infection and disease (known as endemic stability), and poor efficacy of interventions that reduce exposure to multiple parasite species. These findings can be generalized to many other infectious diseases, including human malaria, and illustrate how co-infections can play a key role in determining population-level patterns of morbidity and mortality due to parasite infections.
Collapse
Affiliation(s)
- Mark E. J. Woolhouse
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- Corresponding author. E-mail:
| | - Samuel M. Thumbi
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164–7090, USA
| | - Amy Jennings
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
- The Roslin Institute, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
| | - Margo Chase-Topping
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - Rebecca Callaby
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Henry Kiara
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Marinda C. Oosthuizen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Mary N. Mbole-Kariuki
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ilana Conradie
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Ian G. Handel
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
- The Roslin Institute, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
| | - E. Jane Poole
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Evalyne Njiiri
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Nicola E. Collins
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Gemma Murray
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - Miika Tapio
- Natural Resources Institute Finland (Luke), Green technology, FI-31600 Jokioinen, Finland
| | - Olga Tosas Auguet
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - Willie Weir
- Henry Wellcome Building, Institute of Biodiversity, Animal Health and Comparative Medicine, Garscube Campus, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
| | - W. Ivan Morrison
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
- The Roslin Institute, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
| | - Loeske E. B. Kruuk
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - B. Mark de C. Bronsvoort
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
- The Roslin Institute, University of Edinburgh, The Roslin Building, Easter Bush, Midlothian EH25 9RG, UK
| | - Olivier Hanotte
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Koos Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Philip G. Toye
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| |
Collapse
|
25
|
Abstract
Parasite burden varies widely between individuals within a population, and can covary with multiple aspects of individual phenotype. Here we investigate the sources of variation in faecal strongyle eggs counts, and its association with body weight and a suite of haematological measures, in a cohort of indigenous zebu calves in Western Kenya, using relatedness matrices reconstructed from single nucleotide polymorphism (SNP) genotypes. Strongyle egg count was heritable (h2 = 23·9%, s.e. = 11·8%) and we also found heritability of white blood cell counts (WBC) (h2 = 27·6%, s.e. = 10·6%). All the traits investigated showed negative phenotypic covariances with strongyle egg count throughout the first year: high worm counts were associated with low values of WBC, red blood cell count, total serum protein and absolute eosinophil count. Furthermore, calf body weight at 1 week old was a significant predictor of strongyle EPG at 16–51 weeks, with smaller calves having a higher strongyle egg count later in life. Our results indicate a genetic basis to strongyle EPG in this population, and also reveal consistently strong negative associations between strongyle infection and other important aspects of the multivariate phenotype.
Collapse
|
26
|
A longitudinal assessment of the serological response to Theileria parva and other tick-borne parasites from birth to one year in a cohort of indigenous calves in western Kenya. Parasitology 2014; 141:1289-98. [PMID: 24838078 PMCID: PMC4113304 DOI: 10.1017/s003118201400050x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Tick-borne diseases are a major impediment to improved productivity of livestock in sub-Saharan Africa. Improved control of these diseases would be assisted by detailed epidemiological data. Here we used longitudinal, serological data to determine the patterns of exposure to Theileria parva, Theileria mutans, Babesia bigemina and Anaplasma marginale from 548 indigenous calves in western Kenya. The percentage of calves seropositive for the first three parasites declined from initial high levels due to maternal antibody until week 16, after which the percentage increased until the end of the study. In contrast, the percentage of calves seropositive for T. mutans increased from week 6 and reached a maximal level at week 16. Overall 423 (77%) calves seroconverted to T. parva, 451 (82%) to T. mutans, 195 (36%) to B. bigemina and 275 (50%) to A. marginale. Theileria parva antibody levels were sustained following infection, in contrast to those of the other three haemoparasites. Three times as many calves seroconverted to T. mutans before seroconverting to T. parva. No T. parva antibody response was detected in 25 calves that died of T. parva infection, suggesting that most deaths due to T. parva are the result of acute disease from primary exposure.
Collapse
|
27
|
VAN WYK ILANACONRADIE, GODDARD AMELIA, DE C. BRONSVOORT BMARK, COETZER JACOBUSA, HANDEL IANG, HANOTTE OLIVIER, JENNINGS AMY, LESOSKY MAIA, KIARA HENRY, THUMBI SAMM, TOYE PHIL, WOOLHOUSE MARKW, PENZHORN BANIEL. The impact of co-infections on the haematological profile of East African Short-horn Zebu calves. Parasitology 2014; 141:374-88. [PMID: 24553080 PMCID: PMC4021814 DOI: 10.1017/s0031182013001625] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 08/07/2013] [Accepted: 08/15/2013] [Indexed: 11/06/2022]
Abstract
The cumulative effect of co-infections between pathogen pairs on the haematological response of East African Short-horn Zebu calves is described. Using a longitudinal study design a stratified clustered random sample of newborn calves were recruited into the Infectious Diseases of East African Livestock (IDEAL) study and monitored at 5-weekly intervals until 51 weeks of age. At each visit samples were collected and analysed to determine the infection status of each calf as well as their haematological response. The haematological parameters investigated included packed cell volume (PCV), white blood cell count (WBC) and platelet count (Plt). The pathogens of interest included tick-borne protozoa and rickettsias, trypanosomes and intestinal parasites. Generalized additive mixed-effect models were used to model the infectious status of pathogens against each haematological parameter, including significant interactions between pathogens. These models were further used to predict the cumulative effect of co-infecting pathogen pairs on each haematological parameter. The most significant decrease in PCV was found with co-infections of trypanosomes and strongyles. Strongyle infections also resulted in a significant decrease in WBC at a high infectious load. Trypanosomes were the major cause of thrombocytopenia. Platelet counts were also affected by interactions between tick-borne pathogens. Interactions between concomitant pathogens were found to complicate the prognosis and clinical presentation of infected calves and should be taken into consideration in any study that investigates disease under field conditions.
Collapse
Affiliation(s)
- ILANA CONRADIE VAN WYK
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, 0110, South Africa
| | - AMELIA GODDARD
- Clinical Pathology, Department Companion Animal Medicine, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, 0110, South Africa
| | | | - JACOBUS A. W. COETZER
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, 0110, South Africa
| | - IAN G. HANDEL
- The Roslin Institute at the R (D) SVS, University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - OLIVIER HANOTTE
- School of Biology, University of Nottingham, Nottingham NG7 2RD, UK
| | - AMY JENNINGS
- The Roslin Institute at the R (D) SVS, University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - MAIA LESOSKY
- Department of Production Animal Health, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, 0110, South Africa
- Department of Medicine, University of Cape Town, 1000, South Africa
| | - HENRY KIARA
- International Livestock Research Institute, P.O. Box 30709-00100, Nairobi, Kenya
| | - SAM M. THUMBI
- Centre for Immunology, Infection and Evolution, University of Edinburgh, EH9 3JT, UK
| | - PHIL TOYE
- International Livestock Research Institute, P.O. Box 30709-00100, Nairobi, Kenya
| | - MARK W. WOOLHOUSE
- Centre for Immunology, Infection and Evolution, University of Edinburgh, EH9 3JT, UK
| | - BANIE L. PENZHORN
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, 0110, South Africa
| |
Collapse
|
28
|
Parasite co-infections and their impact on survival of indigenous cattle. PLoS One 2014; 9:e76324. [PMID: 24586220 PMCID: PMC3930515 DOI: 10.1371/journal.pone.0076324] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 08/23/2013] [Indexed: 12/14/2022] Open
Abstract
In natural populations, individuals may be infected with multiple distinct pathogens at a time. These pathogens may act independently or interact with each other and the host through various mechanisms, with resultant varying outcomes on host health and survival. To study effects of pathogens and their interactions on host survival, we followed 548 zebu cattle during their first year of life, determining their infection and clinical status every 5 weeks. Using a combination of clinical signs observed before death, laboratory diagnostic test results, gross-lesions on post-mortem examination, histo-pathology results and survival analysis statistical techniques, cause-specific aetiology for each death case were determined, and effect of co-infections in observed mortality patterns. East Coast fever (ECF) caused by protozoan parasite Theileria parva and haemonchosis were the most important diseases associated with calf mortality, together accounting for over half (52%) of all deaths due to infectious diseases. Co-infection with Trypanosoma species increased the hazard for ECF death by 6 times (1.4-25; 95% CI). In addition, the hazard for ECF death was increased in the presence of Strongyle eggs, and this was burden dependent. An increase by 1000 Strongyle eggs per gram of faeces count was associated with a 1.5 times (1.4-1.6; 95% CI) increase in the hazard for ECF mortality. Deaths due to haemonchosis were burden dependent, with a 70% increase in hazard for death for every increase in strongyle eggs per gram count of 1000. These findings have important implications for disease control strategies, suggesting a need to consider co-infections in epidemiological studies as opposed to single-pathogen focus, and benefits of an integrated approach to helminths and East Coast fever disease control.
Collapse
|
29
|
Murray GGR, Woolhouse MEJ, Tapio M, Mbole-Kariuki MN, Sonstegard TS, Thumbi SM, Jennings AE, van Wyk IC, Chase-Topping M, Kiara H, Toye P, Coetzer K, deC Bronsvoort BM, Hanotte O. Genetic susceptibility to infectious disease in East African Shorthorn Zebu: a genome-wide analysis of the effect of heterozygosity and exotic introgression. BMC Evol Biol 2013; 13:246. [PMID: 24209611 PMCID: PMC3828575 DOI: 10.1186/1471-2148-13-246] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 11/04/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Positive multi-locus heterozygosity-fitness correlations have been observed in a number of natural populations. They have been explained by the correlation between heterozygosity and inbreeding, and the negative effect of inbreeding on fitness (inbreeding depression). Exotic introgression in a locally adapted population has also been found to reduce fitness (outbreeding depression) through the breaking-up of co-adapted genes, or the introduction of non-locally adapted gene variants. In this study we examined the inter-relationships between genome-wide heterozygosity, introgression, and death or illness as a result of infectious disease in a sample of calves from an indigenous population of East African Shorthorn Zebu (crossbred Bos taurus x Bos indicus) in western Kenya. These calves were observed from birth to one year of age as part of the Infectious Disease in East African Livestock (IDEAL) project. Some of the calves were found to be genetic hybrids, resulting from the recent introgression of European cattle breed(s) into the indigenous population. European cattle are known to be less well adapted to the infectious diseases present in East Africa. If death and illness as a result of infectious disease have a genetic basis within the population, we would expect both a negative association of these outcomes with introgression and a positive association with heterozygosity. RESULTS In this indigenous livestock population we observed negative associations between heterozygosity and both death and illness as a result of infectious disease and a positive association between European taurine introgression and episodes of clinical illness. CONCLUSION We observe the effects of both inbreeding and outbreeding depression in the East African Shorthorn Zebu, and therefore find evidence of a genetic component to vulnerability to infectious disease. These results indicate that the significant burden of infectious disease in this population could, in principle, be reduced by altered breeding practices.
Collapse
Affiliation(s)
- Gemma GR Murray
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
- Department of Genetics, University of Cambridge, Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Mark EJ Woolhouse
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Miika Tapio
- MTT Agrifood Research Finland, Biotechnology and Food Research, Jokioinen FI-31600, Finland
| | - Mary N Mbole-Kariuki
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Tad S Sonstegard
- United States Department of Agriculture, Agricultural Research Service, Bovine Functional Genomics Laboratory, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - Samuel M Thumbi
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
- Current address: Paul G Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7079, USA
| | - Amy E Jennings
- Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian, EH25 9RG, Edinburgh, UK
| | - Ilana Conradie van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - Margo Chase-Topping
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Henry Kiara
- International Livestock Research, P.O. Box 30709, Nairobi 00100, Kenya
| | - Phil Toye
- International Livestock Research, P.O. Box 30709, Nairobi 00100, Kenya
| | - Koos Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - Barend M deC Bronsvoort
- Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian, EH25 9RG, Edinburgh, UK
| | - Olivier Hanotte
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| |
Collapse
|
30
|
Thumbi SM, Bronsvoort MBM, Kiara H, Toye PG, Poole J, Ndila M, Conradie I, Jennings A, Handel IG, Coetzer JAW, Steyl J, Hanotte O, Woolhouse MEJ. Mortality in East African shorthorn zebu cattle under one year: predictors of infectious-disease mortality. BMC Vet Res 2013; 9:175. [PMID: 24010500 PMCID: PMC3848692 DOI: 10.1186/1746-6148-9-175] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 08/23/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Infectious livestock diseases remain a major threat to attaining food security and are a source of economic and livelihood losses for people dependent on livestock for their livelihood. Knowledge of the vital infectious diseases that account for the majority of deaths is crucial in determining disease control strategies and in the allocation of limited funds available for disease control. Here we have estimated the mortality rates in zebu cattle raised in a smallholder mixed farming system during their first year of life, identified the periods of increased risk of death and the risk factors for calf mortality, and through analysis of post-mortem data, determined the aetiologies of calf mortality in this population. A longitudinal cohort study of 548 zebu cattle was conducted between 2007 and 2010. Each calf was followed during its first year of life or until lost from the study. Calves were randomly selected from 20 sub-locations and recruited within a week of birth from different farms over a 45 km radius area centered on Busia in the Western part of Kenya. The data comprised of 481.1 calf years of observation. Clinical examinations, sample collection and analysis were carried out at 5 week intervals, from birth until one year old. Cox proportional hazard models with frailty terms were used for the statistical analysis of risk factors. A standardized post-mortem examination was conducted on all animals that died during the study and appropriate samples collected. RESULTS The all-cause mortality rate was estimated at 16.1 (13.0-19.2; 95% CI) per 100 calf years at risk. The Cox models identified high infection intensity with Theileria spp., the most lethal of which causes East Coast Fever disease, infection with Trypanosome spp., and helminth infections as measured by Strongyle spp. eggs per gram of faeces as the three important infections statistically associated with infectious disease mortality in these calves. Analysis of post-mortem data identified East Coast Fever as the main cause of death accounting for 40% of all deaths, haemonchosis 12% and heartwater disease 7%. CONCLUSION The findings demonstrate the impact of endemic parasitic diseases in indigenous animals expected to be well adapted against disease pressures. Additionally, agreement between results of Cox models using data from simple diagnostic procedures and results from post-mortem analysis underline the potential use such diagnostic data to reduce calf mortality. The control strategies for the identified infectious diseases have been discussed.
Collapse
Affiliation(s)
- Samuel M Thumbi
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7090, USA
- Kenya Medical Research Institute/CDC Public Health and Research Collaboration, P.O BOX, 1578, Kisumu 40100, Kenya
| | - Mark BMdec Bronsvoort
- The Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian, EH25 9RG, Edinburgh, UK
| | - Henry Kiara
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - PG Toye
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Jane Poole
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Mary Ndila
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Ilana Conradie
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - Amy Jennings
- The Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian, EH25 9RG, Edinburgh, UK
| | - Ian G Handel
- The Roslin Institute, Easter Bush, University of Edinburgh, Roslin, Midlothian, EH25 9RG, Edinburgh, UK
| | - JAW Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - Johan Steyl
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, South Africa
| | - Olivier Hanotte
- University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Mark EJ Woolhouse
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| |
Collapse
|
31
|
Parasite co-infections show synergistic and antagonistic interactions on growth performance of East African zebu cattle under one year. Parasitology 2013; 140:1789-98. [PMID: 24001119 PMCID: PMC3829697 DOI: 10.1017/s0031182013001261] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The co-occurrence of different pathogen species and their simultaneous infection of hosts are common, and may affect host health outcomes. Co-infecting pathogens may interact synergistically (harming the host more) or antagonistically (harming the host less) compared with single infections. Here we have tested associations of infections and their co-infections with variation in growth rate using a subset of 455 animals of the Infectious Diseases of East Africa Livestock (IDEAL) cohort study surviving to one year. Data on live body weight, infections with helminth parasites and haemoparasites were collected every 5 weeks during the first year of life. Growth of zebu cattle during the first year of life was best described by a linear growth function. A large variation in daily weight gain with a range of 0·03-0·34 kg, and a mean of 0·135 kg (0·124, 0·146; 95% CI) was observed. After controlling for other significant covariates in mixed effects statistical models, the results revealed synergistic interactions (lower growth rates) with Theileria parva and Anaplasma marginale co-infections, and antagonistic interactions (relatively higher growth rates) with T. parva and Theileria mutans co-infections, compared with infections with T. parva only. Additionally, helminth infections can have a strong negative effect on the growth rates but this is burden-dependent, accounting for up to 30% decrease in growth rate in heavily infected animals. These findings present evidence of pathogen-pathogen interactions affecting host growth, and we discuss possible mechanisms that may explain observed directions of interactions as well as possible modifications to disease control strategies when co-infections are present.
Collapse
|
32
|
Toye P, Handel I, Gray J, Kiara H, Thumbi S, Jennings A, van Wyk IC, Ndila M, Hanotte O, Coetzer K, Woolhouse M, Bronsvoort M. Maternal antibody uptake, duration and influence on survival and growth rate in a cohort of indigenous calves in a smallholder farming system in western Kenya. Vet Immunol Immunopathol 2013; 155:129-34. [PMID: 23838470 PMCID: PMC3740236 DOI: 10.1016/j.vetimm.2013.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 11/07/2022]
Abstract
The passive transfer of antibodies from dams to offspring via colostrum is believed to play an important role in protecting neonatal mammals from infectious disease. The study presented here investigates the uptake of colostrum by 548 calves in western Kenya maintained under smallholder farming, an important agricultural system in eastern Africa. Serum samples collected from the calves and dams at recruitment (within the first week of life) were analysed for the presence of antibodies to four tick-borne haemoparasites: Anaplasma marginale, Babesia bigemina, Theileria mutans and Theileria parva. The analysis showed that at least 89.33% of dams were seropositive for at least one of the parasites, and that 93.08% of calves for which unequivocal results were available showed evidence of having received colostrum. The maternal antibody was detected up until 21 weeks of age in the calves. Surprisingly, there was no discernible difference in mortality or growth rate between calves that had taken colostrum and those that had not. The results are also important for interpretation of serosurveys of young calves following natural infection or vaccination.
Collapse
Affiliation(s)
- Philip Toye
- The International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Ian Handel
- The Roslin Institute, University of Edinburgh, Easter Bush EH25 9RG, UK
| | - Julia Gray
- College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Henry Kiara
- The International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Samuel Thumbi
- Centre for Immunology, Infection & Evolution, University of Edinburgh, EH9 3JT, UK
| | - Amy Jennings
- Centre for Immunology, Infection & Evolution, University of Edinburgh, EH9 3JT, UK
| | - Ilana Conradie van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Mary Ndila
- School of Biology, University of Nottingham, Nottingham NG7 2RD, UK
| | - Olivier Hanotte
- School of Biology, University of Nottingham, Nottingham NG7 2RD, UK
| | - Koos Coetzer
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - Mark Woolhouse
- Centre for Immunology, Infection & Evolution, University of Edinburgh, EH9 3JT, UK
| | - Mark Bronsvoort
- The Roslin Institute, University of Edinburgh, Easter Bush EH25 9RG, UK
| |
Collapse
|