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Djiman TA, Biguezoton AS, Saegerman C. Tick-Borne Diseases in Sub-Saharan Africa: A Systematic Review of Pathogens, Research Focus, and Implications for Public Health. Pathogens 2024; 13:697. [PMID: 39204297 PMCID: PMC11356977 DOI: 10.3390/pathogens13080697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 08/11/2024] [Accepted: 08/12/2024] [Indexed: 09/03/2024] Open
Abstract
Sub-Saharan Africa, with its hot and humid climate, is a conducive zone for tick proliferation. These vectors pose a major challenge to both animal and human health in the region. However, despite the relevance of emerging diseases and evidence of tick-borne disease emergence, very few studies have been dedicated to investigating zoonotic pathogens transmitted by ticks in this area. To raise awareness of the risks of tick-borne zoonotic diseases in sub-Saharan Africa, and to define a direction for future research, this systematic review considers the trends of research on tick-borne bacteria, parasites, and viruses from 2012 to 2023, aiming to highlight the circulation of these pathogens in ticks, cattle, sheep, goats, and humans. For this purpose, three international databases were screened to select 159 papers fitting designed inclusion criteria and used for qualitative analyses. Analysis of these studies revealed a high diversity of tick-borne pathogens in sub-Saharan Africa, with a total of 37 bacterial species, 27 parasite species, and 14 viruses identified. Among these, 27% were zoonotic pathogens, yet only 11 studies investigated their presence in humans. Furthermore, there is growing interest in the investigation of bacteria and parasites in both ticks and ruminants. However, research into viruses is limited and has only received notable interest from 2021 onwards. While studies on the detection of bacteria, including those of medical interest, have focused on ticks, little consideration has been given to these vectors in studies of parasites circulation. Regarding the limited focus on zoonotic pathogens transmitted by ticks, particularly in humans, despite documented cases of emerging zoonoses and the notable 27% proportion reported, further efforts should be made to fill these gaps. Future studies should prioritize the investigation of zoonotic pathogens, especially viruses, which represent the primary emerging threats, by adopting a One Health approach. This will enhance the understanding of their circulation and impact on both human and animal health. In addition, more attention should be given to the risk factors/drivers associated to their emergence as well as the perception of the population at risk of infection from these zoonotic pathogens.
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Affiliation(s)
- Tidjani A. Djiman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Fundamental and Applied Research for Animals and Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, 4000 Liège, Belgium;
- Vector-Borne Diseases and Biodiversity Unit (UMaVeB), International Research and Development Centre on Livestock in Sub-humid Areas (CIRDES), Bobo-Dioulasso 454, Burkina Faso;
| | - Abel S. Biguezoton
- Vector-Borne Diseases and Biodiversity Unit (UMaVeB), International Research and Development Centre on Livestock in Sub-humid Areas (CIRDES), Bobo-Dioulasso 454, Burkina Faso;
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Fundamental and Applied Research for Animals and Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, 4000 Liège, Belgium;
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Muriuki R, Ndichu M, Githigia S, Svitek N. Novel CRISPR-Cas-powered pen-side test for East Coast fever. Int J Parasitol 2024; 54:507-521. [PMID: 38677399 DOI: 10.1016/j.ijpara.2024.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/04/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Theileria parvacauses East Coast fever (ECF), one of the most important and lethal tick-borne diseases of cattle in sub-Saharan Africa. ECF is a considerable burden to the livestock industry, causing annual losses exceeding US $300 million. Currently, diagnosis of T. parva infections relies mainly on clinical signs, serology, and microscopic identification of parasites in either blood or lymph fluid samples. However, some of these tests might not indicate ongoing infection and they all lack the sensitivity to detect low-level infections. Molecular tests such as nested and quantitative PCR assays offer high sensitivity for detection of T. parva. However, these tests remain highly complex technologies that are impractical to use in resource-limited settings where economic losses due to the disease have the most significant impact. A field-deployable, point-of-care test will be of significant value in the treatment and control of ECF in endemic areas. For this purpose, we have developed a CRISPR-Cas12a-based pen-side tool that can sensitively and specifically detect T. parva based on the p104 gene. We describe a streamlined, field-applicable diagnostic tool comprising a 20 min recombinase polymerase amplification (RPA) reaction followed by a 60 min CRISPR-Cas12a reaction using a FAM/Biotin lateral flow strip readout. We tested two different RPA primer pairs and four different CRISPR-RNAs (crRNAs). The p104-based assay displayed high sensitivity, detecting as low as one infected lymphocyte per three microliters of blood and universally detecting eight different T. parva strains without detecting DNA from other Theileria spp. such as Theileria mutans and Theileria lestoquardi. This work opens the way for a field-applicable diagnostic tool for the sensitive point-of-care early diagnosis of T. parva infections in cattle.
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Affiliation(s)
- Robert Muriuki
- University of Nairobi, Faculty of Veterinary Medicine, Department of Veterinary Pathology and Parasitology P.O. Box 30197, Nairobi, Kenya; International Livestock Research Institute (ILRI), Animal and Human Health Program, P.O. Box 30709, Nairobi, Kenya
| | - Maingi Ndichu
- University of Nairobi, Faculty of Veterinary Medicine, Department of Veterinary Pathology and Parasitology P.O. Box 30197, Nairobi, Kenya
| | - Samuel Githigia
- University of Nairobi, Faculty of Veterinary Medicine, Department of Veterinary Pathology and Parasitology P.O. Box 30197, Nairobi, Kenya
| | - Nicholas Svitek
- International Livestock Research Institute (ILRI), Animal and Human Health Program, P.O. Box 30709, Nairobi, Kenya.
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Ngetich W, Gitau GK, Okumu TA, Aboge GO, Muasya D. Seroprevalence and risk factors associated with Theileria parva infection among calves in Narok County, Kenya. Vet World 2024; 17:620-629. [PMID: 38680144 PMCID: PMC11045520 DOI: 10.14202/vetworld.2024.620-629] [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: 11/08/2023] [Accepted: 02/21/2024] [Indexed: 05/01/2024] Open
Abstract
Background and Aim East Coast fever (ECF), caused by Theileria parva, is a devastating disease that causes significant economic losses to cattle production in sub-Saharan Africa. Prevention and control of ECF are challenging in pastoral settings due to inadequate epidemiological information. This study aimed to estimate the seroprevalence and risk factors associated with T. parva infection among calves in different production systems to help design appropriate control interventions. Materials and Methods Blood samples were collected from 318 calves and tested using an indirect enzyme-linked immunosorbent assay targeting antibodies against polymorphic immunodominant molecules found on the surface of T. parva. Information on calf characteristics and management practices was also collected during sampling. Descriptive statistics and logistic regression were used to analyze potential risk factors, such as age and acaricide application, where p < 0.05 was considered significant. Results Of the 318 calves sampled, 41 (12.89%) were positive for T. parva, with a higher proportion in pastoral systems (36.58%) than in mixed farming systems (34.10%) and agropastoral systems (29.27%). From univariate analysis, calf age (p = 0.002), body weight (p = 0.001), suckling status (p = 0.026), rectal temperature (p = 0.06), calves on pasture (p = 0.022), other feeds (p = 0.004), feed grown within the farm (p = 0.004), acaricide application (p = 0.001), and acaricide application frequency (p = 0.001) were significantly associated with seropositivity. However, calf age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.91-0.99; p = 0.04), other feeds (OR, 8.82; 95% CI, 1.74-44.63; p = 0.009), and suckling status (OR, 0.38; 95% CI, 0.15-0.99; p = 0.05) were significantly associated with T. parva infection in the multivariable mixed logistic model. Conclusion T. parva is circulating in young calves in the study area (and possibly in cattle populations due to maternal transfer of antibodies to the calves). There is a need for molecular surveillance to determine the presence and burden of T. parva infection.
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Affiliation(s)
- Wyckliff Ngetich
- Department of Clinical Studies, University of Nairobi, P.O Box 29053-00625, Kangemi, Nairobi
- Department of Veterinary Surgery, Theriogenology and Medicine, Egerton University, P.O Box 536-20115, Egerton, Kenya
| | - George Karuoya Gitau
- Department of Clinical Studies, University of Nairobi, P.O Box 29053-00625, Kangemi, Nairobi
| | - Tequiero Abuom Okumu
- Department of Clinical Studies, University of Nairobi, P.O Box 29053-00625, Kangemi, Nairobi
| | - Gabriel Oluga Aboge
- Department of Public Health, Pharmacology and Toxicology, University of Nairobi, P.O Box 29053-00625, Kangemi, Nairobi
| | - Daniel Muasya
- Department of Clinical Studies, University of Nairobi, P.O Box 29053-00625, Kangemi, Nairobi
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Kamani J, Vieira TSWJ, da Costa Vieira RF, Shekaro A, Nahum-Biala Y, Olubade T, Abasiama MS, Gajibo UA, Bukar L, Shand M, Harrus S, Baneth G. Molecular detection of Theileria annulata, Theileria mutans and Theileria velifera but no evidence of Theileria parva infected or vaccinated cattle in Nigeria despite extensive transboundary migrations. Vet Parasitol Reg Stud Reports 2023; 41:100887. [PMID: 37208076 DOI: 10.1016/j.vprsr.2023.100887] [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: 12/16/2022] [Revised: 04/11/2023] [Accepted: 05/03/2023] [Indexed: 05/21/2023]
Abstract
The extensive livestock management system predominant in Nigeria necessitates active disease surveillance for the early detection and prompt control of transboundary animal diseases. Theileriae are obligate intracellular protozoa which infect both wild and domestic bovidae throughout much of the world causing East Coast Fever (Theileria parva), Tropical or Mediterranean theileriosis (Theileria annulata) or benign theileriosis (Theileria mutans; Theileria velifera). This study aimed to detect and characterize Theileria spp. infecting cattle in Nigeria using conventional PCR and sequencing approach. Five hundred and twenty-two DNA samples obtained from different cattle blood samples were subjected to PCR targeting the 18S rRNA gene of piroplasmida and specifically, the p104 kDa and Tp1 genes for the evidence of infection or vaccination respectively, with T. parva. A total of 269 out of 522 (51.5%) of the cattle tested PCR- positive for DNA of piroplasmida. Nucleotide sequence and phylogenetic analyses showed that the cattle were infected with T. annulata, T. mutans and T. velifera. Piroplasmida DNA was associated with sex (ꭓ2 = 7.2; p = 0.007), breed (ꭓ2 = 115; p = 0.000002) of animals and the state where the samples were collected (ꭓ2 = 78.8; p = 0.000002). None of the samples tested positive for T. parva DNA or showed evidence of vaccination (Tp1 gene). This is the first report on the molecular detection and characterization of T. annulata in the blood of cattle from Nigeria. Continuous surveillance of Nigerian cattle for East Coast Fever (ECF) is encouraged considering the recent report of the disease in cattle in the neighboring country, Cameroon, where unregulated transboundary cattle movement into Nigeria has been observed.
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Affiliation(s)
- Joshua Kamani
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria.
| | | | - Rafael Felipe da Costa Vieira
- Vector-borne Diseases Laboratory, Department of Veterinary Medicine, Universidade Federal do Parana, Brazil; Department of Public Health Sciences, University of North Carolina at Charlotte, Charlotte, USA; Center for Computational Intelligence to Predict Health and Environmental Risks (CIPHER), University of North Carolina at Charlotte, Charlotte, USA
| | - Audu Shekaro
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria
| | - Yaarit Nahum-Biala
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Toyin Olubade
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria
| | | | - Umar A Gajibo
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria
| | - Laminu Bukar
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria
| | - Mike Shand
- School of Geographical & Earth Sciences, University of Glasgow, UK
| | - Shimon Harrus
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Gad Baneth
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
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Obara I, Makori P, Sibeko KP, Bishop RP, Nijhof AM, Mwamuye M. Conservation and variation in the region of the Theileria parva p104 antigen coding gene used for PCR surveillance of the parasite. Parasitol Res 2023; 122:1381-1390. [PMID: 37081209 PMCID: PMC10172223 DOI: 10.1007/s00436-023-07838-y] [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: 01/17/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023]
Abstract
The range of the protozoan parasite Theileria parva, which causes East Coast fever in cattle, has been expanding to countries where it has not previously been detected, as a result of cross-border domestic cattle movement. Countries where T. parva has not previously been observed until recently include Cameroon and South Sudan. This raises the issue of the conservation of the p104 antigen gene, on which the nested PCR assay that is widely used for T. parva surveillance in the blood of infected cattle is based. We sampled 40 isolates from six countries widely distributed across the geographical range of the parasite, including eastern, central and southern Africa, for p104 sequence polymorphism. These included parasites from both domestic cattle and the Cape buffalo (Syncerus caffer) wildlife reservoir. The most frequent allelic variants were present in cattle transmissible isolates from multiple widely separated geographical regions in Zambia, Uganda, Kenya, Tanzania, Rwanda and South Africa. These frequent p104 variants were also present in the three component stocks of the Muguga cocktail used for the infection and treatment live immunisation procedure to control T. parva in the field. Other isolates exhibited unique alleles. This includes some of the p104 sequences from Cameroon, which is outside the known range of the Rhipicephalus tick vector and whose origin is therefore unclear. The nested primer oligonucleotides used to generate the amplicons were universally conserved in cattle-derived parasites and a majority of buffalo-derived isolates across the geographical range of the parasite. However, some rare South African buffalo-derived isolates exhibited one or two mismatches with the primer sequences. It therefore remains possible that some p104 alleles may be so divergent that they do not amplify with the current diagnostic primers and are not detectable in surveys, hence the need for increasing knowledge of genetic heterogeneity of diagnostic targets. There was no evidence for positive selection among those p104 mutations that resulted in residue changes. Importantly, the data indicate that the p104-based PCR detection assay should be effective across the majority of the range of T. parva, and if the one or two mismatches are shown in future to result in the primers annealing less efficiently, then the assay can be further improved by introduction of degenerate bases to enable amplification of the less frequent South African buffalo-derived variant p104 genes.
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Affiliation(s)
- Isaiah Obara
- Department of Veterinary Medicine, Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
- Department of Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.
| | | | - Kgomotso P Sibeko
- Vector and Vector-Borne Disease Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Richard P Bishop
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | - Ard M Nijhof
- Department of Veterinary Medicine, Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- Department of Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| | - Micky Mwamuye
- Department of Veterinary Medicine, Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- Department of Environment and Natural Resource Management, Africa Nazarene University, Kajiado, Kenya
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Ngnindji-Youdje Y, Diarra AZ, Lontsi-Demano M, Tchuinkam T, Parola P. Detection of Tick-Borne Pathogens in Ticks from Cattle in Western Highlands of Cameroon. Microorganisms 2022; 10:microorganisms10101957. [PMID: 36296233 PMCID: PMC9609823 DOI: 10.3390/microorganisms10101957] [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: 08/12/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 11/15/2022] Open
Abstract
This study aimed to detect and identify microorganisms in ticks collected in the Western Highlands of Cameroon. Quantitative real-time and standard PCR assays, coupled with sequencing, were used. A total of 944 ticks collected from cattle in five distinct sites in Cameroon were selected for the analyses. They belonged to five genera (Amblyomma, Hyalomma, Rhipicephalus, Haemaphysalis, and Ixodes) and twelve species. Real-time PCR revealed that 23% (n = 218) of the ticks were positive for Rickettsia spp., 15% (n = 141) for bacteria of the Anaplasmataceae family, 3% (n = 29) for Piroplasmida, 0.5% (n = 5) for Coxiella burnetii, 0.4% (n = 4) for Borrelia spp., and 0.2% (n = 2) for Bartonella spp. The co-infection rate (3.4%, n = 32) involved mainly Rickettsia spp. and Anaplasmataceae. Of the Rickettsia spp. positive ticks, the targeted PCR and sequencing yielded Rickettsia africae (78.9%), Rickettsia aeschlimannii (6.4%), Rickettsia massiliae (7.8%), Candidatus Rickettsia barbariae (0.9%), and Rickettsia sp. (0.9%). Anaplasmataceae included Anaplasma marginale (4.3%), Anaplasma platys (1.4%), Anaplasma centrale (0.7%), Ehrlichia ruminantium (0.7%), Wolbachia sp., Candidatus Ehrlichia rustica (13.5%), Candidatus Ehrlichia urmitei (7%), and an uncultured Ehrlichia sp. (4.2%). Borrelia theileri was identified in one Rhipicephalus microplus tick. Unfortunately, Piroplasmida could not be identified to the species level. This study demonstrates that in Cameroon, ticks harbour a wide variety of microorganisms and present a risk of zoonotic diseases.
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Affiliation(s)
- Yannick Ngnindji-Youdje
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, 13005 Marseille, France
- IHU-Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Adama Zan Diarra
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, 13005 Marseille, France
- IHU-Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
| | - Michel Lontsi-Demano
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Timoléon Tchuinkam
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Philippe Parola
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, 13005 Marseille, France
- IHU-Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Correspondence: ; Tel.: +33-(0)-4-13-73-24-01; Fax: +33-(0)-4-13-73-24-02
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Sado Yousseu F, Simo Tchetgna H, Kamgang B, Djonabaye D, McCall PJ, Ndip RN, Wondji CS. Infestation rates, seasonal distribution, and genetic diversity of ixodid ticks from livestock of various origins in two markets of Yaoundé, Cameroon. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:283-300. [PMID: 35656818 DOI: 10.1111/mve.12589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
Little is known about the impact of ticks on livestock and humans in Cameroon. This study aimed to determine the prevalence, seasonal variation, and genetic diversity of hard ticks in the country. Ticks were collected during a cross-sectional survey on domestic livestock in two markets of Yaoundé in 2019 and 2020 and identified using morphological keys, 16S ribosomal DNA, (16S rDNA), and the cytochrome c oxidase subunit 1 (Cox1) genes. The infestation rates were 39.18%, 11.53%, and 2.74% in cattle, sheep, and goats respectively. Three genera of ticks were identified, Rhipicephalus, Amblyomma, and Hyalomma comprising eleven tick species. The main species were Rhipicephalus decoloratus (30.25%), R. microplus (24.43%), and Amblyomma variegatum (12.96%). Rhipicephalus spp. (81.31%) and Amblyomma variegatum (51.54%) were abundant during the rainy season, while Hyalomma spp. (83.86%) during the dry season (p-value <0.00001). Cox1 and 16S rDNA analysis showed a high level of genetic diversity among tick species with sequences close to those observed across Africa. Phylogenetic analysis revealed that our R. microplus belong to clade A and we identified R. sanguineus s.l. as R. linnea. This study shows a high tick infestation rate in cattle, while low in small ruminants with an extensive diversity of tick species, including several known vectors of important tick-borne diseases.
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Affiliation(s)
- Francine Sado Yousseu
- Microbiology and Parasitology Department, Centre for Research in Infectious Diseases, Yaounde, Cameroon
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Huguette Simo Tchetgna
- Microbiology and Parasitology Department, Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Basile Kamgang
- Microbiology and Parasitology Department, Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Doumani Djonabaye
- Microbiology and Parasitology Department, Centre for Research in Infectious Diseases, Yaounde, Cameroon
- Department of Biochemistry, Laboratory of Pharmacology and Toxicology, University of Yaounde I, Yaounde, Cameroon
| | - Philip J McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Roland Ndip Ndip
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Charles S Wondji
- Microbiology and Parasitology Department, Centre for Research in Infectious Diseases, Yaounde, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
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Jia W, Chen S, Chi S, He Y, Ren L, Wang X. Recent Progress on Tick-Borne Animal Diseases of Veterinary and Public Health Significance in China. Viruses 2022; 14:v14020355. [PMID: 35215952 PMCID: PMC8875255 DOI: 10.3390/v14020355] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
Ticks and tick-borne diseases pose a growing threat to human and animal health, which has brought great losses to livestock production. With the continuous expansion of human activities and the development of natural resources, there are more and more opportunities for humans to contract ticks and tick-borne pathogens. Therefore, research on ticks and tick-borne diseases is of great significance. This paper reviews recent progress on tick-borne bacterial diseases, viral diseases, and parasitic diseases in China, which provides a theoretical foundation for the research of tick-borne diseases.
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Affiliation(s)
- Weijuan Jia
- College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao 028000, China; (W.J.); (S.C.); (Y.H.)
| | - Si Chen
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, Changchun 130062, China;
| | - Shanshan Chi
- College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao 028000, China; (W.J.); (S.C.); (Y.H.)
| | - Yunjiang He
- College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao 028000, China; (W.J.); (S.C.); (Y.H.)
| | - Linzhu Ren
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, Changchun 130062, China;
- Correspondence: (L.R.); (X.W.); Tel.: +86-15924529577 (X.W.)
| | - Xueli Wang
- College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao 028000, China; (W.J.); (S.C.); (Y.H.)
- Correspondence: (L.R.); (X.W.); Tel.: +86-15924529577 (X.W.)
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9
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Whittle L, Chapman R, van Diepen M, Rybicki EP, Williamson AL. Characterization of a Novel Chimeric Theileria parva p67 Antigen Which Incorporates into Virus-like Particles and Is Highly Immunogenic in Mice. Vaccines (Basel) 2022; 10:vaccines10020210. [PMID: 35214669 PMCID: PMC8880696 DOI: 10.3390/vaccines10020210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 11/16/2022] Open
Abstract
The current method to protect cattle against East Coast Fever (ECF) involves the use of live Theileria parva sporozoites. Although this provides immunity, using live parasites has many disadvantages, such as contributing to the spread of ECF. Subunit vaccines based on the sporozoite surface protein p67 have been investigated as a replacement for the current method. In this study, two DNA vaccines expressing recombinant forms of p67 designed to display on retrovirus-like particles were constructed with the aim of improving immunogenicity. The native leader sequence was replaced with the human tissue plasminogen activator leader in both vaccines. The full-length p67 gene was included in the first DNA vaccine (p67); in the second, the transmembrane domain and cytoplasmic tail were replaced with those of an influenza A virus hemagglutinin 5 (p67HA). Immunofluorescent staining of fixed and live transfected mammalian cells showed that both p67 and p67HA were successfully expressed, and p67HA localised on the cell surface. Furthermore, p67HA was displayed on the surface of both bovine leukaemia virus (BLV) Gag and HIV-1 Gag virus-like particles (VLPs) made in the same cells. Mice vaccinated with DNA vaccines expressing p67 and p67HA alone, or p67HA with BLV or HIV-1 Gag, developed high titres of p67 and BLV Gag-binding antibodies. Here we show that it is possible to integrate a form of p67 containing all known antigenic domains into VLPs. This p67HA–VLP combination has the potential to be incorporated into a vaccine against ECF, as a DNA vaccine or as other vaccine platforms.
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Affiliation(s)
- Leah Whittle
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (L.W.); (M.v.D.); (E.P.R.); (A.-L.W.)
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Ros Chapman
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (L.W.); (M.v.D.); (E.P.R.); (A.-L.W.)
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Correspondence:
| | - Michiel van Diepen
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (L.W.); (M.v.D.); (E.P.R.); (A.-L.W.)
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Edward P. Rybicki
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (L.W.); (M.v.D.); (E.P.R.); (A.-L.W.)
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town 7925, South Africa
| | - Anna-Lise Williamson
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (L.W.); (M.v.D.); (E.P.R.); (A.-L.W.)
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
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Vimonish R, Dinkel KD, Fry LM, Johnson WC, Capelli-Peixoto J, Bastos RG, Scoles GA, Knowles DP, Madder M, Chaka G, Ueti MW. Isolation of infectious Theileria parva sporozoites secreted by infected Rhipicephalus appendiculatus ticks into an in vitro tick feeding system. Parasit Vectors 2021; 14:616. [PMID: 34952641 PMCID: PMC8704063 DOI: 10.1186/s13071-021-05120-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022] Open
Abstract
Background Vector-borne diseases pose an increasing threat to global food security. Vaccines, diagnostic tests, and therapeutics are urgently needed for tick-borne diseases that affect livestock. However, the inability to obtain significant quantities of pathogen stages derived from ticks has hindered research. In vitro methods to isolate pathogens from infected tick vectors are paramount to advance transcriptomic, proteomic, and biochemical characterizations of tick-borne pathogens. Methods Nymphs of Rhipicephalus appendiculatus were infected with Theileria parva by feeding on a calf during an acute infection. Isolation of sporozoites was accomplished by feeding infected adult ticks on an in vitro tick feeding system. Sporozoite viability was tested using in vitro bovine lymphocytes. Results We isolated infectious T. parva sporozoites secreted into an in vitro tick feeding system. Infected adult R. appendiculatus ticks attached to and successfully fed on silicone membranes in the in vitro tick feeding system. Bovine blood in the receptacle was replaced with cell-free medium and the ticks were allowed to feed for 3 h to collect secreted T. parva sporozoites. Secreted sporozoites infected in vitro bovine lymphocytes, demonstrating that isolated sporozoites remained viable and infectious. Conclusions This work is the first to report the isolation of mature infectious T. parva sporozoites using an in vitro tick feeding system, which represents a significant step towards the development of a more efficient control strategy for T. parva. Isolation of infectious tick-stage parasites will facilitate the examination of the vector-pathogen interface, thereby accelerating the development of next-generation vaccines and treatment interventions for tick-borne pathogens. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05120-7.
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Silatsa BA, Simo G, Githaka N, Kamga R, Oumarou F, Keambou Tiambo C, Machuka E, Domelevo JB, Odongo D, Bishop R, Kuiate JR, Njiokou F, Djikeng A, Pelle R. First detection of Theileria parva in cattle from Cameroon in the absence of the main tick vector Rhipicephalus appendiculatus. Transbound Emerg Dis 2020; 67 Suppl 1:68-78. [PMID: 32174039 PMCID: PMC7216920 DOI: 10.1111/tbed.13425] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A major risk factor for the spread of livestock diseases and their vectors is the uncontrolled transboundary movement of live animals for trade and grazing. Such movements constrain effective control of tick-transmitted pathogens, including Theileria parva. Only limited studies have been undertaken to identify ticks and tick-borne diseases (TTBDs) affecting cattle in central African countries, including Cameroon. We hereby report the collection of baseline data on the prevalence of T. parva in Cameroon through a countrywide cross-sectional survey, conducted in 2016, involving collection of blood samples from cattle from 63 sites across the five agro-ecological zones (AEZs) of the country. ELISA-based surveillance of infected cattle was performed on 479 randomly selected samples and revealed specific antibodies to T. parva in 22.7% and T. mutans in 41.1% of cattle. Screening of 1,340 representative DNA samples for the presence of T. parva identified 25 (1.86%) positives using a p104 antigen gene-based nested PCR assay. The positives were distributed across agro-ecological zones I, II, III and V. None of the p104 positive cattle exhibited clinical symptoms of East Coast fever (ECF). Using reverse line blot (RLB), 58 (4.3%) and 1,139 (85%) of the samples reacted with the T. parva and T. mutans oligonucleotide probes, respectively. This represents the first report of T. parva from Cameroon. Surprisingly, no Rhipicephalus appendiculatus ticks, the main vector of T. parva, were identified in a parallel study involving comprehensive morphological and molecular survey of tick species present in the country. Only two of the 25 p104 positive cattle were PCR-positive for the CD8+ T-cell target schizont-expressed antigen gene Tp1. Cloning and sequencing of Tp1 amplicons revealed sequence identity with the reference T. parva Muguga. This new finding raises serious concerns of a potential spread of ECF into the central African region.
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Affiliation(s)
- Barberine A Silatsa
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Sciences, University of Dschang, Dschang, Cameroon
| | - Naftaly Githaka
- Department of Biosciences, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Rolin Kamga
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Sciences, University of Dschang, Dschang, Cameroon
| | - Farikou Oumarou
- Special Mission for Eradication of Tsetse Flies, Regional tsetse Division of Adamawa, MINEPIA, Adamawa, Cameroon
| | - Christian Keambou Tiambo
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - Eunice Machuka
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - Jean-Baka Domelevo
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - David Odongo
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - Richard Bishop
- Veterinary Microbiology and Pathology (VMP), Washington State University, Pullman, WA, USA
| | - Jules-Roger Kuiate
- Department of Biochemistry, Faculty of Sciences, University of Dschang, Dschang, Cameroon
| | - Flobert Njiokou
- Laboratory of General Biology, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon
| | - Appolinaire Djikeng
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - Roger Pelle
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
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Genetic Diversity and Sequence Polymorphism of Two Genes Encoding Theileria parva Antigens Recognized by CD8 + T Cells among Vaccinated and Unvaccinated Cattle in Malawi. Pathogens 2020; 9:pathogens9050334. [PMID: 32365795 PMCID: PMC7281522 DOI: 10.3390/pathogens9050334] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/24/2020] [Accepted: 04/26/2020] [Indexed: 01/07/2023] Open
Abstract
East Coast fever (ECF) is an acute fatal tick-borne disease of cattle caused by Theileria parva. It causes major losses in exotic and crossbreed cattle, but this could be prevented by a vaccine of T. parva if the vaccine is selected properly based on information from molecular epidemiology studies. The Muguga cocktail (MC) vaccine (Muguga, Kiambu 5 and Serengeti-transformed strains) has been used on exotic and crossbreed cattle. A total of 254 T. parva samples from vaccinated and unvaccinated cattle were used to understand the genetic diversity of T. parva in Malawi using partial sequences of the Tp1 and Tp2 genes encoding T. parva CD8+ antigens, known to be immunodominant and current candidate antigens for a subunit vaccine. Single nucleotide polymorphisms were observed at 14 positions (3.65%) in Tp1 and 156 positions (33.12%) in Tp2, plus short deletions in Tp1, resulting in 6 and 10 amino acid variants in the Tp1 and Tp2 genes, respectively. Most sequences were either identical or similar to T. parva Muguga and Kiambu 5 strains. This may suggest the possible expansion of vaccine components into unvaccinated cattle, or that a very similar genotype already existed in Malawi. This study provides information that support the use of MC to control ECF in Malawi.
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