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Guimapi RA, Klingen I, Tonnang HEZ, Nana P. Linking spatial distribution of Rhipicephalus appendiculatus to climatic variables important for the successful biocontrol by Metarhizium anisopliae in Eastern Africa. Acta Trop 2023; 238:106800. [PMID: 36535510 DOI: 10.1016/j.actatropica.2022.106800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Cattle production is constantly threatened by diseases like East Coast fever, also known as theileriosis, caused by the protozoan parasite Theileria parva which is transmitted by ticks such as the brown ear tick, Rhipicephalus appendiculatus. To reduce the extensive use of chemical acaricides, fungal-based microbial control agents such as Metarhizium anisopliae have been tested and show promising results against R. appendiculatus both in field and in semi-field experiments in Africa. However, no known endeavors to link the spatial distribution of R. appendiculatus to climatic variables important for the successful application of M. anisopliae in selected East African countries exists. This work therefore aims to improve the successful application of M. anisopliae against R. appendiculatus by designing a temperature-dependent model for the efficacy of M. anisopliae against three developmental stages (larvae, nymphs, adults) of R. appendiculatus. Afterward a spatial prediction of potential areas where this entomopathogenic fungus might cause a significant epizootic in R. appendiculatus population in three selected countries (Kenya, Tanzania, Uganda) in Eastern Africa were generated. This can help to determine whether the temperature and rainfall at a local or regional scale might give good conditions for application of M. anisopliae and successful microbial control of R. appendiculatus.
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Affiliation(s)
- Ritter A Guimapi
- Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box, Ås 1433, Norway.
| | - Ingeborg Klingen
- Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box, Ås 1433, Norway
| | - Henri E Z Tonnang
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Paulin Nana
- Advanced School of Agriculture, Forestry, Water Resources and Environment, University of Ebolowa, P.O. Box 786, Ebolowa, Cameroon
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Molecular detection of selected tick-borne pathogens infecting cattle at the wildlife-livestock interface of Queen Elizabeth National Park in Kasese District, Uganda. Ticks Tick Borne Dis 2021; 12:101772. [PMID: 34214889 DOI: 10.1016/j.ttbdis.2021.101772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 04/19/2021] [Accepted: 06/03/2021] [Indexed: 11/22/2022]
Abstract
In Uganda, ticks and tick-borne diseases (TBDs) pose a big challenge to farmers. They reduce cattle productivity and cause severe economic damage. Several studies have documented the prevalence of tick-borne pathogens in cattle; however, their genetic characteristics and the role of wildlife-livestock interaction in the epidemiology of the TBDs are not well documented. This study assessed the prevalence and genetic diversity of various tick-borne pathogens (TBPs) as well as the risk factors associated with the occurrence of TBPs in blood samples of 208 randomly selected cattle from 16 farms located around Queen Elizabeth National Park (QENP) in Kasese District in western Uganda. Farming practices, disease challenges, and the level of wildlife-livestock interactions were assessed by a questionnaire survey amongst farm owners. Polymerase chain reaction (PCR) assays revealed that 62.9% (131/208) cattle samples were positive for one or more pathogens. Using specific PCR assays, we detected Theileria spp., Theileria parva, Anaplasma marginale, Anaplasma platys-like, and Babesia bigemina at 50.5%, 27.9%, 19.2%, 11.5% and 8.7%, respectively. We also confirmed the infection of samples by Theileria velifera and Theileria mutans after sequencing the Theileria spp. 18S rRNA gene. The risk factors associated with the occurrence of TBPs included communal grazing, herd size, age, and proximity to QENP. Phylogenetic analysis of the T. parva p104 gene showed a high identity to the previous isolates from Uganda and other East African countries and clustered closer to the buffalo (Syncerus caffer) isolates, suggesting a possible cross-species transmission. The sequences of A. marginale groEL and B. bigemina RAP-1a formed well-supported clades with high identities to the previous isolates identified from central and eastern Uganda. The isolates obtained from A. phagocytophilum 16S rRNA gene sequences showed relationship with A. platys-like, Anaplasma sp., uncultured Anaplasma species and A. phagocytophilum isolates from Africa, Asia, Europe, and the USA. The findings of the present study showed that TBDs are still a burden to farmers and that management practices in this area may increase the transmission of pathogens between livestock and wildlife.
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Associations between monthly rainfall and mortality in cattle due to East Coast fever, anaplasmosis and babesiosis. Parasitology 2020; 147:1743-1751. [PMID: 32907657 DOI: 10.1017/s0031182020001638] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Weather conditions can impact infectious disease transmission, causing mortalities in humans, wild and domestic animals. Although rainfall in dry tropical regions is highly variable over the year, rainfall is thought to play an important role in the transmission of tick-borne diseases. Whether variation in rainfall affects disease-induced mortalities, is, however, poorly understood. Here, we use long-term data on monthly rainfall and Boran cattle mortality (1998-2017) to investigate associations between within-year variation in rainfall and cattle mortalities due to East Coast fever (ECF), anaplasmosis and babesiosis in Laikipia, Kenya, using ARIMAX modelling. Results show a negative correlation between monthly rainfall and cattle mortality for ECF and anaplasmosis, with a lag effect of 2 and 6 months, respectively. There was no association between babesiosis-induced mortalities and monthly rainfall. The results of this study suggest that control of the tick-borne diseases ECF and anaplasmosis to reduce mortalities should be intensified during rainy periods after the respective estimated time lags following dry periods.
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Hoch T, Breton E, Vatansever Z. Dynamic Modeling of Crimean Congo Hemorrhagic Fever Virus (CCHFV) Spread to Test Control Strategies. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:1124-1132. [PMID: 29618023 DOI: 10.1093/jme/tjy035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Indexed: 06/08/2023]
Abstract
Crimean Congo hemorrhagic fever is a zoonotic disease which has emerged or re-emerged recently in Eastern Europe and Turkey. The causative agent is a virus, mainly transmitted by ticks of the species Hyalomma marginatum (Koch, 1844, Ixodida, Amblyommidae). To test potential scenarios for the control of pathogen spread, a dynamic mechanistic model has been developed that takes into account the major processes involved in tick population dynamics and pathogen spread. The tick population dynamics model represents both abiotic (meteorological variables) and biotic (hare and cattle densities) factors in the determination of processes (development, host finding, and mortality). The infection model consists of an SIRS model for the host part whereas a lifelong infectiousness was considered for ticks. The model was first applied to a zone in Central Anatolia (Turkey). Simulated dynamics represent the average reported level of infection in vectors and hosts. A sensitivity analysis to parameter value has been carried out and highlighted the role of transstadial transmission as well as acquisition of the pathogen by immature stages. Applying the model to different sites of Turkey shows different patterns in the dynamics of acarological risk (number of infectious questing adults). This model was thereafter used to test control strategies. Simulation results indicate that acaricide treatments and decrease in hare density could have valuable effects when combined, either on the acarological risk or on the prevalence in cattle. The kind of model we have developed provides insight into the ability of different strategies to prevent and control disease spread.
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Affiliation(s)
- Thierry Hoch
- BIOEPAR, INRA, Oniris, Université Bretagne Loire, Nantes, France
| | - Eric Breton
- BIOEPAR, INRA, Oniris, Université Bretagne Loire, Nantes, France
| | - Zati Vatansever
- Department of Parasitology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
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5
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Young HS, McCauley DJ, Dirzo R, Nunn CL, Campana MG, Agwanda B, Otarola-Castillo ER, Castillo ER, Pringle RM, Veblen KE, Salkeld DJ, Stewardson K, Fleischer R, Lambin EF, Palmer TM, Helgen KM. Interacting effects of land use and climate on rodent-borne pathogens in central Kenya. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0116. [PMID: 28438909 PMCID: PMC5413868 DOI: 10.1098/rstb.2016.0116] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2016] [Indexed: 12/13/2022] Open
Abstract
Understanding the effects of anthropogenic disturbance on zoonotic disease risk is both a critical conservation objective and a public health priority. Here, we evaluate the effects of multiple forms of anthropogenic disturbance across a precipitation gradient on the abundance of pathogen-infected small mammal hosts in a multi-host, multi-pathogen system in central Kenya. Our results suggest that conversion to cropland and wildlife loss alone drive systematic increases in rodent-borne pathogen prevalence, but that pastoral conversion has no such systematic effects. The effects are most likely explained both by changes in total small mammal abundance, and by changes in relative abundance of a few high-competence species, although changes in vector assemblages may also be involved. Several pathogens responded to interactions between disturbance type and climatic conditions, suggesting the potential for synergistic effects of anthropogenic disturbance and climate change on the distribution of disease risk. Overall, these results indicate that conservation can be an effective tool for reducing abundance of rodent-borne pathogens in some contexts (e.g. wildlife loss alone); however, given the strong variation in effects across disturbance types, pathogen taxa and environmental conditions, the use of conservation as public health interventions will need to be carefully tailored to specific pathogens and human contexts. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.
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Affiliation(s)
- Hillary S Young
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA .,Mpala Research Centre, Box 555, Nanyuki, Kenya
| | - Douglas J McCauley
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA.,Mpala Research Centre, Box 555, Nanyuki, Kenya
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Charles L Nunn
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,Duke Global Health Institute, Duke University, Durham, NC 27710, USA
| | - Michael G Campana
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC 20008, USA
| | | | | | - Eric R Castillo
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Robert M Pringle
- Mpala Research Centre, Box 555, Nanyuki, Kenya.,Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Kari E Veblen
- Mpala Research Centre, Box 555, Nanyuki, Kenya.,Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT 84322, USA
| | - Daniel J Salkeld
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Kristin Stewardson
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC 20008, USA
| | - Robert Fleischer
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC 20008, USA
| | - Eric F Lambin
- Department of Earth System Science and Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
| | - Todd M Palmer
- Mpala Research Centre, Box 555, Nanyuki, Kenya.,Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Kristofer M Helgen
- Division of Mammals, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.,School of Biological Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
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Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells. PLoS One 2016; 11:e0162571. [PMID: 27611868 PMCID: PMC5017765 DOI: 10.1371/journal.pone.0162571] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/24/2016] [Indexed: 11/19/2022] Open
Abstract
As part of an international effort to develop vaccines for Theileria lestoquardi, we undertook a limited screen to test T. lestoquardi orthologues of antigens recognised by CD8+ T lymphocyte responses against T. annulata and T. parva in cattle. Five MHC defined sheep were immunized by live T. lestoquardi infection and their CD8+ T lymphocyte responses determined. Thirteen T. lestoquardi orthologues of T. parva and T. annulata genes, previously shown to be targets of CD8+ T lymphocyte responses of immune cattle, were expressed in autologous fibroblasts and screened for T cell recognition using an IFNγ assay. Genes encoding T. lestoquardi antigens Tl8 (putative cysteine proteinase, 349 aa) or Tl9 (hypothetical secreted protein, 293 aa) were recognise by T cells from one animal that displayed a unique MHC class I genotype. Antigenic 9-mer peptide epitopes of Tl8 and Tl9 were identified through peptide scans using CD8+ T cells from the responding animal. These experiments identify the first T. lestoquardi antigens recognised by CD8+ T cell responses linked to specific MHC class I alleles.
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Hoch T, Breton E, Josse M, Deniz A, Guven E, Vatansever Z. Identifying main drivers and testing control strategies for CCHFV spread. EXPERIMENTAL & APPLIED ACAROLOGY 2016; 68:347-359. [PMID: 26174420 DOI: 10.1007/s10493-015-9937-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 06/05/2015] [Indexed: 06/04/2023]
Abstract
Crimean Congo Haemorrhagic Fever (CCHF) is an emerging zoonotic disease. The causative agent is a virus (CCHFV), mainly transmitted by ticks of the species Hyalomma marginatum in Eastern Europe and Turkey. In order to test potential scenarios for the control of pathogen spread, the basic reproduction number (R0) for CCHF was calculated. This calculation was based on a population dynamics model and parameter values from the literature for pathogen transmission. The tick population dynamics model takes into account the major processes involved and gives estimates for tick survival from one stage to the other and number of feeding ticks. It also considers the influence of abiotic (meteorological variables) and biotic factors (host densities) on model outputs, which were compared with data collected in Central Anatolia (Turkey). R0 computation was thereafter used to test control strategies and especially the effect of acaricide treatment. Simulation results indicate that such treatments could have valuable effects provided that the acaricide is applied regularly throughout the spring and summer, and over several years. Furthermore, a sensitivity analysis to abiotic and biotic factors showed that, even though temperature has a strong impact on model outputs, host (mainly hare) densities also play a role. The kind of model we have developed provides insight into the ability of different strategies to prevent and control disease spread and has proved its relevance when associated with field trials.
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Affiliation(s)
- T Hoch
- INRA, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France.
- LUNAM Université, ONIRIS, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France.
| | - E Breton
- INRA, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France
- LUNAM Université, ONIRIS, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France
| | - M Josse
- INRA, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France
- LUNAM Université, ONIRIS, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, 44307, Nantes, France
| | - A Deniz
- Etlik Central Veterinary Control and Research Institute, Ankara, Turkey
| | - E Guven
- Department of Parasitology, Faculty of Veterinary Medicine, Ataturk University, Erzurum, Turkey
| | - Z Vatansever
- Department of Parasitology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
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Byaruhanga C, Collins NE, Knobel D, Kabasa W, Oosthuizen MC. Endemic status of tick-borne infections and tick species diversity among transhumant zebu cattle in Karamoja Region, Uganda: Support for control approaches. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2016; 1-2:21-30. [PMID: 31018404 DOI: 10.1016/j.vprsr.2015.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/13/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
Abstract
We conducted a study to investigate tick species diversity, seroprevalence of antibodies to Anaplasma marginale and Theileria parva, and the risk factors for these infections among cattle under a transhumant production system in Karamoja Region, Uganda, from November 2013 through January 2014. Twenty herds were randomly selected from 20 purposively-selected superherds. Semi-structured interviews and piling for annual proportion of tick-borne disease (TBD) cases in different age groups, with pastoralist groups, clinical examinations and field observations were employed to obtain information related to the epidemiology of TBDs. Ticks were collected and identified from whole body inspections of at least seven systematically selected cattle in each herd. Concurrently, serum was collected from 397 cattle. Antibodies to A. marginale were detected by MSP-5 competitive inhibition enzyme-linked immunosorbent assay, and to T. parva by indirect fluorescent antibody test. Clinical examinations and informant interviews showed that TBDs affected all age groups of cattle. Tick species that have not been reported in recent studies from other parts of Uganda were collected, namely Amblyomma lepidum, Hyalomma truncatum, Amblyomma gemma, and Rhipicephalus pulchellus. Out of the 10,923 ticks collected, Rhipicephalus appendiculatus (54.4%) was the most abundant species followed by Rhipicephalus (Boophilus) decoloratus (17.7%), Amblyomma variegatum (12%) and A. lepidum (11.6%). Two-thirds of the sampled cattle had moderate (37.3%, 11-50 ticks) to abundant (28.6%, >50 ticks) numbers of ticks. Seroprevalence of A. marginale was high (86.6%, 95% confidence interval [CI] 80.8%-91.8%), while that of T. parva was low (14.6%, 95% CI 7.1%-22.4%). Cattle of 5-12months (18.3%, Odds ratio [OR]=4.1) and 13-24months (30.3%, OR=8.0) were more likely to be seropositive for T. parva than those >24months. For A. marginale, cattle of 13-24months (92.4%, OR=2.7) and >24months (89.7%, OR=2.0) were more likely to be seropositive than those 5-12months. There was a significant difference (p<0.001, OR=6.5) in the proportion of T. parva seropositive animals between Moroto (24.5%) and Kotido districts (4.8%), but not for A. marginale. In conclusion, the low seroprevalence for T. parva, possibly due to limited exposure in calves, may suggest a high likelihood of ECF in cattle. High seroprevalence for A. marginale suggests that a high proportion of cattle were exposed to infection. The findings provide knowledge of epidemiology of TBDs in Karamoja cattle and support for strategic control and improvement of cattle productivity.
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Affiliation(s)
- C Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa; National Agricultural Research Organisation, P.O. Box 259, Entebbe, Uganda.
| | - N E Collins
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - D Knobel
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - W Kabasa
- College of Veterinary Medicine, Animal Resources and Bio-security, Makerere University, P.O. Box 7062, Kampala, Uganda
| | - M C Oosthuizen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
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Ueti MW, Olafson PU, Freeman JM, Johnson WC, Scoles GA. A Virulent Babesia bovis Strain Failed to Infect White-Tailed Deer (Odocoileus virginianus). PLoS One 2015; 10:e0131018. [PMID: 26083429 PMCID: PMC4471175 DOI: 10.1371/journal.pone.0131018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/26/2015] [Indexed: 11/18/2022] Open
Abstract
Wildlife are an important component in the vector-host-pathogen triangle of livestock diseases, as they maintain biological vectors that transmit pathogens and can serve as reservoirs for such infectious pathogens. Babesia bovis is a tick-borne pathogen, vectored by cattle fever ticks, Rhipicephalus spp., that can cause up to 90% mortality in naive adult cattle. While cattle are the primary host for cattle fever ticks, wild and exotic ungulates, including white-tailed deer (WTD), are known to be viable alternative hosts. The presence of cattle fever tick populations resistant to acaricides raises concerns regarding the possibility of these alternative hosts introducing tick-borne babesial parasites into areas free of infection. Understanding the B. bovis reservoir competence of these alternative hosts is critical to mitigating the risk of introduction. In this study, we tested the hypothesis that WTD are susceptible to infection with a B. bovis strain lethal to cattle. Two groups of deer were inoculated intravenously with either B. bovis blood stabilate or a larval extract supernatant containing sporozoites from infected R. microplus larvae. The collective data demonstrated that WTD are neither a transient host nor reservoir of B. bovis. This conclusion is supported by the failure of B. bovis to establish an infection in deer regardless of inoculum. Although specific antibody was detected for a short period in the WTD, the PCR results were consistently negative at multiple time points throughout the experiment and blood from WTD that had been exposed to parasite, transferred into naïve recipient susceptible calves, failed to establish infection. In contrast, naïve steers inoculated intravenously with either B. bovis blood stabilate or the larval extract supernatant containing sporozoites rapidly succumbed to disease. These findings provide evidence that WTD are not an epidemiological component in the maintenance of B. bovis infectivity to livestock.
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Affiliation(s)
- Massaro W. Ueti
- USDA, ARS, Animal Disease Research Unit, Washington State University, Pullman, Washington, United States of America
- * E-mail:
| | - Pia U. Olafson
- USDA, ARS, Knipling-Bushland United States Livestock Insects Research Laboratory, Kerrville, Texas, United States of America
| | - Jeanne M. Freeman
- USDA, ARS, Knipling-Bushland United States Livestock Insects Research Laboratory, Kerrville, Texas, United States of America
| | - Wendell C. Johnson
- USDA, ARS, Animal Disease Research Unit, Washington State University, Pullman, Washington, United States of America
| | - Glen A. Scoles
- USDA, ARS, Animal Disease Research Unit, Washington State University, Pullman, Washington, United States of America
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Jabbar A, Abbas T, Sandhu ZUD, Saddiqi HA, Qamar MF, Gasser RB. Tick-borne diseases of bovines in Pakistan: major scope for future research and improved control. Parasit Vectors 2015; 8:283. [PMID: 25994588 PMCID: PMC4443554 DOI: 10.1186/s13071-015-0894-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/11/2015] [Indexed: 11/12/2022] Open
Abstract
Ticks and tick-borne diseases (TBDs) affect the productivity of bovines in tropical and subtropical regions of the world, leading to a significant adverse impact on the livelihoods of resource-poor farming communities. Globally, four main TBDs, namely anaplasmosis, babesiosis, theileriosis, and cowdriosis (heartwater) affect bovines, and the former three are of major economic importance in bovines in Pakistan. Given that the livestock sector has become an integral part of Pakistan’s economy and a large number of dairy cattle are being imported into the country, in order to meet an increasing demand of milk and milk products, it is timely to review current status of bovine TBDs in Pakistan and to identify gaps in the knowledge of TBDs and their control. Although there has been a recent increase in the number of studies of TBDs in this country, information on their prevalence, distribution, tick vectors, and control is limited. This article provides a brief background on key bovine TBDs and ticks and reviews the current status of bovine TBDs in Pakistan to identify gaps in knowledge and understanding of these diseases, propose areas for future research and draw attention to the need for improved tools for the diagnosis and control of TBDs in this country.
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Affiliation(s)
- Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia.
| | - Tariq Abbas
- University College of Veterinary & Animal Sciences, The Islamia University of Bahawalpur, Punjab, Pakistan.
| | - Zia-ud-Din Sandhu
- Department of Parasitology, University of Agriculture, Faisalabad, Punjab, Pakistan.
| | - Hafiz A Saddiqi
- Department of Zoology, Government College University, Faisalabad, Punjab, Pakistan.
| | - Muhammad F Qamar
- College of Veterinary and Animal Sciences, University College of Veterinary and Animal Sciences, Jhang, Punjab, Pakistan.
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia.
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Fakoorziba MR, Naddaf-Sani AA, Moemenbellah-Fard MD, Azizi K, Ahmadnia S, Chinikar S. First phylogenetic analysis of a Crimean-Congo hemorrhagic fever virus genome in naturally infected Rhipicephalus appendiculatus ticks (Acari: Ixodidae). Arch Virol 2015; 160:1197-209. [PMID: 25742932 DOI: 10.1007/s00705-015-2379-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 02/22/2015] [Indexed: 11/30/2022]
Abstract
Crimean-Congo haemorrhagic fever (CCHF) is a potentially fatal systemic viral disease in many parts of the world, including Iran. The nationwide incidence of human CCHF in endemic areas was 870 confirmed cases with 126 deaths (case fatality rate, CFR = 17.6 %) in the decade leading to 2012. The detection of the CCHF virus (CCHFV) genome in tick vectors is of fundamental importance for identifying these ticks as potential reservoirs of CCHFV infection. From May to October 2013, following detection of four new clinical cases resulting in two deaths in the city of Mashhad (northeast Iran), hard ticks were recovered from infested livestock in 40 villages in Khorasan-Razavi province and examined by the microscopic method for species identification. About a quarter of the ticks were then subjected to reverse-transcription polymerase chain reaction (RT-PCR) to detect the CCHFV genome. The PCR products were then sequenced, and their phylogenetic lineages were determined. A total of 407 hard ticks were captured, representing seven different species in two distinct genera. Members of the genus Hyalomma were widely distributed in all but two of the villages studied, and this was also the most frequent (83.3 %) tick genus. Of 105 adult ticks subjected to RT-PCR, four (3.8 %) ticks were found positive for the CCHFV genome. One brown ear tick, Rhipicephalus appendiculatus, was found to be naturally infected for the first time anywhere in the world. Ticks of Hyalomma asiaticum, Hyalomma marginatum, and Rhipicephalus turanicus were also found to be naturally infected with CCHFV. CCHFV found in these four different tick species were clustered in the same lineage with the Matin and SR3 strains from Pakistan and some other strains from Iran, indicating that these tick species were naturally infected with genetically closely related CCHFV in the region. The presence of CCHFV infection in four different hard tick species was confirmed using RT-PCR in northeast Iran. Part of this infection was attributed to Rh. appendiculatus, which is thus a potential new natural vector of CCHFV in Iran. It is also confirmed by phylogenetic analysis that CCHFV in this region is genetically closely related, even in the different tick species.
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Affiliation(s)
- Mohammad Reza Fakoorziba
- Department of Medical Entomology and Vector Control, Research Centre for Health Sciences, School of Health, Shiraz University of Medical Sciences, P.O. Box 71645-111, Shiraz, Iran,
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Eygelaar D, Jori F, Mokopasetso M, Sibeko KP, Collins NE, Vorster I, Troskie M, Oosthuizen MC. Tick-borne haemoparasites in African buffalo (Syncerus caffer) from two wildlife areas in Northern Botswana. Parasit Vectors 2015; 8:26. [PMID: 25589064 PMCID: PMC4302575 DOI: 10.1186/s13071-014-0627-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/29/2014] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The African buffalo (Syncerus caffer) is a host for many pathogens known to cause economically important diseases and is often considered an important reservoir for livestock diseases. Theileriosis, heartwater, babesiosis and anaplasmosis are considered the most important tick-borne diseases of livestock in sub-Saharan Africa, resulting in extensive economic losses to livestock farmers in endemic areas. Information on the distribution of tick-borne diseases and ticks is scarce in Northern Botswana. Nevertheless, this data is necessary for targeting surveillance and control measures in livestock production at national level. METHODS In order to address this gap, we analyzed 120 blood samples from buffalo herds for the presence of common tick-borne haemoparasites causing disease in livestock, collected in two of the main wildlife areas of Northern Botswana: the Chobe National Park (CNP, n=64) and the Okavango Delta (OD, n=56). RESULTS Analysis of the reverse line blot (RLB) hybridization assay results revealed the presence of Theileria, Babesia, Anaplasma and Ehrlichia species, either as single or mixed infections. Among the Theileria spp. present, T. parva (60%) and T. mutans (37%) were the most prevalent. Other species of interest were Anaplasma marginale subsp. centrale (30%), A. marginale (20%), Babesia occultans (23%) and Ehrlichia ruminantium (6%). The indirect fluorescent antibody test (IFAT) indicated 74% of samples to be positive for the presence of T. parva antibodies. Quantitative real-time PCR (qPCR) detected the highest level of animals infected with T. parva (81% of the samples). The level of agreement between the tests for detection of T. parva positive animals was higher between qPCR and IFAT (kappa=0.56), than between qPCR and RLB (kappa=0.26) or the latter and IFAT (kappa=0.15). CONCLUSIONS This is the first report of tick-borne haemoparasites in African buffalo from northern Botswana, where animals from the CNP showed higher levels of infection than those from OD. Considering the absence of fences separating wildlife and livestock in the CNP and the higher levels of some parasite species in buffalo from that area, surveillance of tick-borne diseases in livestock at the interface in the CNP should be prioritized.
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Affiliation(s)
- Dewald Eygelaar
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
| | - Ferran Jori
- Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa.
- UPR AGIRs, CIRAD, Campus International de Baillarguet, Montpellier, 34398, France.
- Department of Animal Science and Production, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana.
| | - Mokganedi Mokopasetso
- FAO-ECTAD Office for Southern Africa, Gaborone, Botswana.
- Botswana Vaccine Institute, Private Bag 0031, Gabarone, Botswana.
| | - Kgomotso P Sibeko
- 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.
| | - Ilse Vorster
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, 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.
| | - Marinda C Oosthuizen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
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Thirty years of tick population genetics: A comprehensive review. INFECTION GENETICS AND EVOLUTION 2015; 29:164-79. [DOI: 10.1016/j.meegid.2014.11.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 11/06/2014] [Accepted: 11/10/2014] [Indexed: 11/22/2022]
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Target evaluation of deoxyhypusine synthase from Theileria parva the neglected animal parasite and its relationship to Plasmodium. Bioorg Med Chem 2014; 22:4338-46. [PMID: 24909679 DOI: 10.1016/j.bmc.2014.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/02/2014] [Accepted: 05/05/2014] [Indexed: 11/20/2022]
Abstract
East Coast fever (ECF) is a tick-borne disease caused by the parasite Theileria parva which infects cattle. In Sub-Saharan Africa it leads to enormous economic costs. After a bite of a tick, sporozoites invade the host lymphocytes and develop into schizonts. At this stage the parasite transforms host lymphocytes resulting in the clonal expansion of infected lymphocytes. Animals develop a lymphoma like disorder after infection which is rapidly fatal. Hitherto, a few drugs of the quinone type can cure the disease. However, therapy can only be successful after early diagnosis. The genera Theileria and Plasmodium, which includes the causative agent of human malaria, are closely related apicomplexan parasites. Enzymes of the hypusine pathway, a posttranslational modification in eukaryotic initiation factor EIF-5A, have shown to be druggable targets in Plasmodium. We identified the first enzyme of the hypusine pathway from T. parva, the deoxyhypusine synthase (DHS), which is located on chromosome 2 of the Muguga strain. Transcription is significantly increased in schizonts. The expressed T. parva DHS reveals an open reading frame (ORF) of 370 amino acids after expression in Escherichia coli Rosetta cells with a molecular size of 41.26 kDa and a theoretical pI of 5.26. Screening of the Malaria Box which consists of 400 active compounds resulted in a novel heterocyclic compound with a guanyl spacer which reduced the activity of T. parva DHS to 45%. In sum, the guanyl residue seems to be an important lead structure for inhibition of Theileria DHS. Currently, more different guanyl analogues from the Malaria Box are tested in inhibitor experiments to determine their efficacy.
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