1
|
Elati K, Salhi I, Kodia R, Rekik M, Gharbi M. Epidemiological situation of bovine tropical theileriosis in an arid region in central Tunisia with a phylogenetic analysis of Theileria annulata. Vet Med Sci 2023; 9:2862-2870. [PMID: 37725348 PMCID: PMC10650360 DOI: 10.1002/vms3.1276] [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: 12/04/2022] [Revised: 08/03/2023] [Accepted: 09/05/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND Tropical theileriosis, Theileria annulata infection, is the most prevalent summer disease in Tunisia. It is transmitted by Hyalomma scupense, a two-host tick known to be endophilic. OBJECTIVES The present study aimed to estimate the infection prevalence of cattle by T. annulata in two districts from central Tunisia. METHODS Blood samples collected from 270 Holstein cattle from the Sidi Bouzid (140 samples) and Kasserine districts (130 samples) were analysed by Giemsa staining and T. annulata-specific PCR. RESULTS In both regions, PCR revealed a prevalence of 32.6%. This was significantly higher than the 6.3% prevalence obtained by Giemsa staining blood smears (p < 0.001). Giemsa staining also revealed a low parasitaemia of 0.05%. The PCR-based prevalence was not statistically different between the two districts (31.4 ± 0.04 and 33.8 ± 0.04% in Sidi Bouzid and Kasserine districts, respectively, p = 0.6). On the contrary, the results of blood smear examination (2.85 and 10% in Sidi Bouzid and Kasserine, respectively) differed significantly between the two sampling sites (p = 0.01). There was no evidence of a statistically significant difference between the overall molecular infection prevalence when the samples were segregated based on animals' age or gender (p = 0.1 and 0.2, respectively) and a similar trend was observed for Giemsa staining. Ten PCR amplicons of the Tams1 gene (721 bp) were subsequently sequenced from the two regions. The phylogenetic analyses showed 100% similarity between all sequences. The unique conserved Tams1 sequence was deposited in GenBank under the accession number OP428816 and used to infer its phylogenetic relationships with those available in the GenBank repository. CONCLUSIONS This is the first report of the presence of T. annulata in this region of central Tunisia which has no history of tropical theileriosis. Priority areas for future studies include understanding the origin of these T. annulata-positive animals in a region where the presence of a known natural vector tick, H. scupense, has not been reported. Given that the disease severely constrains cattle productivity, it would also be worthwhile to investigate if other potential vectors for T. annulata, such as Hyalomma dromedarii, are present in the arid regions.
Collapse
Affiliation(s)
- Khawla Elati
- Institute of Parasitology and Tropical Veterinary MedicineFreie Universität BerlinBerlinGermany
- Veterinary Centre for Resistance Research, Department of Veterinary MedicineFreie Universität BerlinBerlinGermany
- Laboratoire de ParasitologieÉcole Nationale de Médecine Vétérinaire de Sidi Thabet, Institution de la Recherche et de l'Enseignement Supérieur Agricoles. Univ. ManoubaSidi ThabetTunisia
| | - Ismail Salhi
- Laboratoire de ParasitologieÉcole Nationale de Médecine Vétérinaire de Sidi Thabet, Institution de la Recherche et de l'Enseignement Supérieur Agricoles. Univ. ManoubaSidi ThabetTunisia
| | - Ridha Kodia
- Laboratoire de ParasitologieÉcole Nationale de Médecine Vétérinaire de Sidi Thabet, Institution de la Recherche et de l'Enseignement Supérieur Agricoles. Univ. ManoubaSidi ThabetTunisia
| | - Mourad Rekik
- International Centre for Agricultural Research in the Dry Areas (ICARDA)AmmanJordan
| | - Mohamed Gharbi
- Laboratoire de ParasitologieÉcole Nationale de Médecine Vétérinaire de Sidi Thabet, Institution de la Recherche et de l'Enseignement Supérieur Agricoles. Univ. ManoubaSidi ThabetTunisia
| |
Collapse
|
2
|
Valente D, Dutra AP, Carolino N, Gomes J, Coelho AC, Espadinha P, Pais J, Carolino I. Prevalence and Risk Factors Associated with Theileria annulata Infection in Two Bovine Portuguese Autochthonous Breeds. Pathogens 2023; 12:pathogens12050669. [PMID: 37242339 DOI: 10.3390/pathogens12050669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Tropical Bovine Theileriosis is an important tick-borne disease. This study aims to assess the occurrence of Theileria annulata infection in two indigenous Portuguese cattle breeds. A total of 843 blood samples collected from animals of Alentejana (n = 420) and Mertolenga (n = 423) breeds were analyzed. The detection of Theileria annulata was determined by amplification of a fragment of the merozoite-pyroplasm surface antigen gene with 319 base pairs (bp). The prevalence found (10.8%) is lower than that reported in previous studies (21.3%). A statistically significant difference was found for positivity between breeds (p < 0.05). There is also a higher probability of older animals being positive compared to younger ones (p < 0.05). The region where Mertolenga animals are located is shown to have a significant impact on positivity (p < 0.05). Thus, the development of sustainable T. annulata control strategies and their implementation, adapted to the epidemiological conditions of higher risk, will be extremely important.
Collapse
Affiliation(s)
- Diana Valente
- CIVG-Vasco da Gama Research Center, EUVG-Vasco da Gama University School, 3020-210 Coimbra, Portugal
- Escola de Ciências Agrárias e Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal
- CECAV-Animal and Veterinary Research Center, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal
| | - Ana Paula Dutra
- Unidade Estratégica de Investigação e Serviços-Produção e Saúde Animal (UEIS-PSA), Instituto Nacional de Investigação Agrária e Veterinária, Av. Da República, Quinta do Marquês (edifício sede), 2780-157 Oeiras, Portugal
| | - Nuno Carolino
- CIVG-Vasco da Gama Research Center, EUVG-Vasco da Gama University School, 3020-210 Coimbra, Portugal
- Polo de Inovação da Fonte Boa-Estação Zootécnica Nacional, Instituto Nacional de Investigação Agrária e Veterinária, 2005-424 Santarém, Portugal
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - Jacinto Gomes
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
- Escola Superior Agrária de Elvas, Instituto Politécnico de Portalegre, 7350-092 Elvas, Portugal
| | - Ana Cláudia Coelho
- Escola de Ciências Agrárias e Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal
- CECAV-Animal and Veterinary Research Center, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - Pedro Espadinha
- Associação de Criadores de Bovinos da Raça Alentejana, Herdade da Coutada Real-Assumar, 7450-051 Assumar, Portugal
| | - José Pais
- Associação de Criadores de Bovinos Mertolengos, 7006-806 Évora, Portugal
| | - Inês Carolino
- CIVG-Vasco da Gama Research Center, EUVG-Vasco da Gama University School, 3020-210 Coimbra, Portugal
- Polo de Inovação da Fonte Boa-Estação Zootécnica Nacional, Instituto Nacional de Investigação Agrária e Veterinária, 2005-424 Santarém, Portugal
- ISA-Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal
| |
Collapse
|
3
|
Gharbi M, Darghouth MA, Elati K, Al-Hosary AAT, Ayadi O, Salih DA, El Hussein AM, Mhadhbi M, Khamassi Khbou M, Hassan SM, Obara I, Ahmed LS, Ahmed J. Current status of tropical theileriosis in Northern Africa: A review of recent epidemiological investigations and implications for control. Transbound Emerg Dis 2020; 67 Suppl 1:8-25. [PMID: 32174036 DOI: 10.1111/tbed.13312] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 11/29/2022]
Abstract
Tropical theileriosis caused by the apicomplexan hemoparasite Theileria annulata is a tick-borne disease that constraints livestock production in parts of Europe, Asia and Africa. Four Hyalomma tick species transmit T. annulata in at least eight Africa countries (Mauritania, Morocco, Algeria, Tunisia, Egypt, Sudan, South Sudan and Ethiopia). The two dominant T. annulata vector ticks present in Africa, H. scupense and H. anatolicum, underlie two different patterns of transmission, which in turn greatly influence the epidemiology of tropical theileriosis. H. dromedarii and H. lusitanicum are also capable of transmitting T. annulata in North Africa, but their roles are associated with specific production systems and agro-ecological contexts. The emergence of resistance to the most widely used theilericidal compound, buparvaquone, continues to limit the effectiveness of chemotherapy. In addition, acaricide use is increasingly becoming unsustainable. Deployable T. annulata attenuated live vaccines established from local strains in Tunisia, Sudan and Egypt are available, and recent work has indicated that these vaccines can be protective under conditions of natural transmission. However, vaccination programmes may vary over space and time due to differences in the prevalence of disease amongst cattle populations, as well seasonal variation in vector activity. We review recent descriptive and analytical surveys on the epidemiology of T. annulata infection with reference to (a) demographic aspects such as breeds and ages of cattle herds previously exposed to distinct T. annulata infection pressures and (b) seasonal dynamics of tick activity and disease transmission. We then discuss how the wider endemic patterns that we delineate can underpin the development and execution of future vaccination programmes. We also outline options for integrated control measures targeting tick vectors and husbandry practices.
Collapse
Affiliation(s)
- Mohamed Gharbi
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles and Univ. Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Mohamed Aziz Darghouth
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles and Univ. Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Khawla Elati
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles and Univ. Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Amira A T Al-Hosary
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Ouarda Ayadi
- Laboratoire de Parasitologie, Institut des Sciences Vétérinaire El Khroub, Université Frères Mentouri, Constantine I, Algeria
| | | | | | - Moez Mhadhbi
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles and Univ. Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Médiha Khamassi Khbou
- Laboratoire de Maladies Contagieuses, Zoonoses et Législation Sanitaire, Institution de la Recherche et de l'Enseignement Supérieur Agricoles and Univ Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | | | - Isaiah Obara
- Institute of Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Laila S Ahmed
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Jabbar Ahmed
- Institute of Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
4
|
Mohammed-Ahmed GM, Hassan SM, El Hussein AM, Salih DA. Molecular, serological and parasitological survey of Theileria annulata in North Kordofan State, Sudan. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 13:24-29. [PMID: 31014883 DOI: 10.1016/j.vprsr.2018.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 02/18/2018] [Accepted: 03/23/2018] [Indexed: 01/24/2023]
Abstract
This survey was conducted to detect Theileria annulata infection in indigenous (Zebu) and cross (indigenous × Friesian) cattle (n 604) of different sex & age groups, and to investigate prevalence of ticks infesting cattle in North Kordofan State, Sudan. Ticks, blood smears, serum samples and blood spots on filter paper were collected from four municipalities at four monthly intervals during the period from August 2008 to July 2009. Out of 604 blood smears, 69 (11.4%, 95% CI: 16.9-5.9) were positive for Theileria piroplasms; whereas, out of 240 serum samples, 164 (68.3%, 95% CI: 89.3-47.3) were positive for antibodies against T. annulata using IFA test. Using PCR, out of 100 blood spots on filter paper, 8 (8%, 95% CI: 9.6-6.4) revealed T. annulata DNA. The highest prevalence of Theileria spp. piroplasms and T. annulata antibodies was recorded in August (15.9 ± 4.6) followed by February (13.3 ± 3.8) and the lowest was in May (3.9 ± 1.0). Among cattle breeds, the highest prevalence of piroplasms (11.9 ± 5.0) and T. annulata antibodies (68.9 ± 10) was among zebu cattle. PCR assays revealed the highest prevalence rate of T. annulata DNA in February (12.5 ± 1.4) followed by August (6.1 ± 0.7) and the lowest was in May (5.7 ± 0.7). According to cattle breeds, T. annulata DNA was detected in cross-bred cattle (3.3 ± 0.4) more than zebu cattle (10 ± 1.6). Seven tick species belonging to four genera and were identified, Amblyomma lepidum, Hyalomma dromedarii, H. impeltatum, H. rufipes, Rhipicephalus evertsi evertsi, Rhipicephalus decoloratus, R. annulatus. The most abundant tick species was H. rufipes followed by H. impeltatum, R. e. evertsi, H. dromedarii, R. decoloratus, A. lepidum and R. annulatus. Theileria annulata has been detected for the first time in North Kordofan State, though at a low prevalence rate. This finding is an alarming situation since tropical theileriosis is an emerging disease and it is widely believed that this economically important tick-borne parasite does not exist in this state. The possible alternative vector(s) of T. annulata in the absence of the known vector H. anatolicum is discussed.
Collapse
Affiliation(s)
| | - S M Hassan
- University of Khartoum, P.O. Box 32, Khartoum North, Sudan
| | - A M El Hussein
- Central Veterinary Research Laboratory, P.O. Box 8067, Khartoum, Sudan
| | - D A Salih
- Central Veterinary Research Laboratory, P.O. Box 8067, Khartoum, Sudan.
| |
Collapse
|
5
|
Sallemi S, Rjeibi MR, Rouatbi M, Amairia S, Ben Said M, Khamassi Khbou M, Gharbi M. Molecular prevalence and phylogenetic analysis of Theileria annulata and Trypanosoma evansi in cattle in Northern Tunisia. Vet Med Sci 2017; 4:17-25. [PMID: 29468077 PMCID: PMC5813107 DOI: 10.1002/vms3.79] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to estimate the molecular prevalence of Theileria annulata and Trypanosoma evansi infection in cattle in Northern Tunisia. A total number of 96 cattle from five farms were evaluated. T. annulata and T. evansi prevalences were 61% [56/66] and 10% [7/13], respectively, at a confidence interval (CI) of 95%, while co-infection was present in 6% [4/8] of the tested animals at a CI of 95%. There was a significant correlation between age and the prevalence of T. annulata infection, whereas, there was no significant association shown with the age of cattle and T. evansi infection. Sequence and phylogenetic analyses showed that the T. annulata Tams1 gene and T. evansi ITS1 rDNA gene were highly conserved with 97.1-100% and 98.3-100% sequence identity, respectively.
Collapse
Affiliation(s)
- Souhir Sallemi
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Mohamed R Rjeibi
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Mariem Rouatbi
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Safa Amairia
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Mourad Ben Said
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Madiha Khamassi Khbou
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| | - Mohamed Gharbi
- Laboratoire de ParasitologieUniv. ManoubaInstitution de la Recherche et de l'Enseignement Supérieur AgricolesÉcole Nationale de Médecine Vétérinaire de Sidi Thabet2020Sidi ThabetTunisia
| |
Collapse
|
6
|
Gharbi M, Darghouth MA. A review of Hyalomma scupense (Acari, Ixodidae) in the Maghreb region: from biology to control. ACTA ACUST UNITED AC 2014; 21:2. [PMID: 24507485 PMCID: PMC3917376 DOI: 10.1051/parasite/2014002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 01/26/2013] [Indexed: 12/04/2022]
Abstract
Hyalomma scupense (syn. Hyalomma detritum) is a two-host domestic endophilic tick of cattle and secondarily other ungulates in the Maghreb region (Africa). This species transmits several pathogens, among which two are major livestock diseases: Theileria annulata and Theileria equi. Various other pathogens are also transmitted by this tick species, such as Anaplasma phagocytophilum and Ehrlichia bovis. Hyalomma scupense is common in sub-humid and semi-arid areas of several regions in the world, mainly in the Maghreb region. In this region, adults attach to animals during the summer season; larvae and nymphs attach to their hosts during autumn, but there is a regional difference in H. scupense phenology. There is an overlap between immature and adult ticks, leading in some contexts to a dramatic modification of the epidemiology of tick-borne diseases. This tick species attaches preferentially to the posterior udder quarters and thighs. Tick burdens can reach 130 ticks per animal, with a mean of 60 ticks. Calves are 70 times less infested than adult cattle. The control can be implemented through six options: (i) rehabilitation of the farm buildings by roughcasting and smoothing the outer and inner surfaces of the enclosures and walls. This control option should be recommended to be combined with a thorough cleaning of the farm and its surrounding area. With regard to Theileria annulata infection, this control option is the most beneficial. (ii) Acaricide application to animals during the summer season, targeting adults. (iii) Acaricide application during the autumn period for the control of the immature stages. (iv) Acaricide application to the walls: many field veterinarians have suggested this option but it is only partially efficient since nymphs enter deep into the cracks and crevices. It should be used if there is a very high tick burden or if there is a high risk of tick-borne diseases. (v) Manual tick removal: this method is not efficient since the ticks can feed on several other animal species in the farm. This control option can lead to a reduction of the tick population, but not a decrease in tick-borne disease incidence. (vi) Vaccination: this control option consists of injecting the protein Hd86; trials have shown a partial effect on nymphs, with no effect on adult ticks. Combination of two of these control options is recommended in regions where there are high burdens of important tick vectors. Further studies are needed to improve our knowledge on this tick species in the Maghreb region, since the number of published studies on Hyalomma scupense in this region is very limited.
Collapse
Affiliation(s)
- Mohamed Gharbi
- Laboratoire de Parasitologie, École Nationale de Médecine Vétérinaire, Université de la Manouba, 2020 Sidi Thabet, Tunisia
| | - Mohamed Aziz Darghouth
- Laboratoire de Parasitologie, École Nationale de Médecine Vétérinaire, Université de la Manouba, 2020 Sidi Thabet, Tunisia
| |
Collapse
|
7
|
Gharbi M, Hayouni ME, Sassi L, Dridi W, Darghouth MA. Hyalomma scupense (Acari, Ixodidae) in northeast Tunisia: seasonal population dynamics of nymphs and adults on field cattle. ACTA ACUST UNITED AC 2013; 20:12. [PMID: 23547915 PMCID: PMC3718523 DOI: 10.1051/parasite/2013012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 03/20/2013] [Indexed: 11/15/2022]
Abstract
Hyalomma scupense is a two-host tick infesting mainly cattle representing in North Africa the vector of tropical theileriosis (Theileria annulata infection), a major tick-borne disease affecting cattle. Any effective control programme of ticks requires a good knowledge of the biology of the target species. In the present study, three cattle farms in northeast Tunisia were surveyed during the activity seasons for adult and nymphs of Hyalomma scupense. Several indicators were studied, including chronological indicators, infestation prevalence, infestation intensity and feeding predilection sites of the ticks. The adult ticks were present from mid-June to late November. Nymphs were observed on animals from early September to late November. A large proportion of the ticks were attached in the posterior udder quarters: 41% and 64% of adult ticks and nymphs, respectively. The animals that were heavily infested by adult ticks were also heavily infested by nymphs. Moreover, 17% of adult ticks and 53% of nymphs were present on only 5% of cattle population. These data are important for the success of targeted acaricide application leading to a dramatic decrease of acaricide quantity needed for the treatment. When the preferential sites of attachment are known, the effectiveness of manual removal of ticks can be improved. The presence of highly infested animals is to be considered when any control programme is implemented, since these animals harbour a high proportion of the ticks.
Collapse
Affiliation(s)
- Mohamed Gharbi
- Laboratoire de Parasitologie, École Nationale de Médecine Vétérinaire, Université de la Manouba, 2020 Sidi Thabet, Tunisia
| | | | | | | | | |
Collapse
|
8
|
Modelling the transmission dynamics of Theileria annulata: model structure and validation for the Turkish context. Parasitology 2012; 139:441-53. [PMID: 22309815 PMCID: PMC3296124 DOI: 10.1017/s003118201100223x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A mathematical model that describes the transmission dynamics of Theileria annulata is proposed that consists of 2 host components: the Hyalomma tick population and a compartmental model of T. annulata infection in the cattle population. The model was parameterized using data describing tick infestation and the infection status of cattle in Turkey from 2006 to 2008. The tick attachment rates are highly seasonal and because of the temporal separation of infectious and susceptible ticks virtually all ticks are infected by carrier cattle, so that annual peaks of disease in cattle do not impact on infection in the Hyalomma tick population. The impact of intervention measures that target the tick population both on the host and in the environment and their impact on the transmission of T. annulata were investigated. Interventions that have a limited ‘one-off’ impact and interventions that have a more permanent impact were both considered. The results from the model show the importance of targeting ticks during the period when they have left their first host as nymphs but have yet to feed on their second host.
Collapse
|
9
|
Weir W, Karagenç T, Gharbi M, Simuunza M, Aypak S, Aysul N, Darghouth MA, Shiels B, Tait A. Population diversity and multiplicity of infection in Theileria annulata. Int J Parasitol 2011; 41:193-203. [PMID: 20833170 PMCID: PMC3034872 DOI: 10.1016/j.ijpara.2010.08.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/26/2010] [Accepted: 08/26/2010] [Indexed: 12/03/2022]
Abstract
The tick-borne apicomplexan parasite Theileria annulata is endemic in many sub-tropical countries and causes the bovine disease tropical theileriosis. Although the parasite is known to be highly diverse, detailed information is lacking on the genetic structure of natural populations and levels of multiplicity of infection in the cattle host. With the widespread deployment of live attenuated vaccines and the emergence of drug-resistant parasites in the field, it is vital to appreciate the factors which shape genetic diversity of the parasite both within individual hosts and in the wider population. This study addresses these issues and represents an extensive genetic analysis of T. annulata populations in two endemic countries utilising a high-throughput adaptation of a micro- and mini-satellite genotyping system. Parasite material was collected from infected cattle in defined regions of Turkey and Tunisia to allow a variety of analyses to be conducted. All animals (n=305) were found to harbour multiple parasite genotypes and only two isolates shared an identical predominant multi-locus profile. A modelling approach was used to demonstrate that host age, location and vaccination status play a measurable role in determining multiplicity of infection in an individual animal. Age was shown to positively correlate with multiplicity of infection and while positive vaccination status exerted a similar effect, it was shown to be due not simply to the presence of the immunising genotype. Importantly, no direct evidence was found for the immunising genotype spreading or recombining within the local parasite community. Genetic analysis confirmed the tentative conclusion of a previous study that the parasite population appears to be, in general, panmictic. Nevertheless, evidence supporting linkage disequilibrium and a departure from panmixia was uncovered in some localities and a number of explanations for these findings are advanced.
Collapse
Affiliation(s)
- William Weir
- University of Glasgow, College of Medical, Veterinary and Life Sciences, Garscube Campus, Bearsden Road, Glasgow G61 1QH, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Sayin F, Dinçer S, Karaer Z, Cakmak A, Inci A, Yukari BA, Eren H, Vatansever Z, Nalbantoglu S. Studies on the epidemiology of tropical theileriosis (Theileria annulata infection) in cattle in Central Anatolia, Turkey. Trop Anim Health Prod 2004; 35:521-39. [PMID: 14690090 DOI: 10.1023/a:1027348708038] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An epidemiological survey for Theileria annulata infection was conducted in 12 selected villages around Ankara in Central Anatolia, Turkey, during the period April 1990 to January 1993. During the survey, 198 cattle of 30 local breeds, 84 Holstein-Friesian x local breeds and 84 Holstein-Friesian breed were examined for antibodies to T. annulata and the presence of the vector ticks. Four species of Hyalomma ticks were identified: Hyalomma anatolicum anatolicum, Hyalomma anatolicum excavtum, Hyalomma detritum and Hyalomma marginatum marginatum. Salivary gland staining indicated that infected adult ticks of all four species were present and, therefore, were implicated in the transmission of tropical theileriosis in the field. Generally, the Hyalomma infestation rate was low, with the heaviest infestations occurring on the older animals. Young adults and calves had very low infestation rates. Most ticks seen on cattle were adults, very few nymphs were found. The blood smear and serological examination of the 198 cattle conducted in March, before the start of the first disease season, showed that the prevalence of piroplasmosis was 11.1% (22 out of 198) and the seroprevalence of T. annulata was 10.6% (21 out of 198). Forty-three animals were then excluded from the study because they were seropositive and/or harboured piroplasms. Ninety-two seronegative animals showed piroplasmosis (92 out of 155) and 34 seronegative animals became seropositive for T. annulata (34 out of 155) during the three disease seasons. One animal became clinically ill with tropical theileriosis and required treatment. The incidence of cattle showing piroplasmosis and disease in the total study sample was 50.7% and 0.5% per disease season, respectively. The seroconversion rate of new infection with T. annulata in the total study was 14.3% per animal season. The number of cattle showing piroplasmosis was much greater than the number of seropositive cattle, which may indicate the presence of another species of Theileria. The two different management systems encountered in the study were considered to have influenced the tick infestation levels.
Collapse
Affiliation(s)
- F Sayin
- Department of Protozoology and Medical Entomology, Faculty of Veterinary Medicine, University of Ankara, 06110 Ankara, Turkey.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Yamane I, Koiwai M, Tsusui T, Hamaoka T. A survey of Theileria sergenti infection, daily weight gain and conception proportions in 85 herds of grazing heifers in Japan. Vet Parasitol 2001; 99:189-98. [PMID: 11502366 DOI: 10.1016/s0304-4017(01)00458-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A survey of Theileria sergenti infections, daily weight gain and conception proportion was conducted in 85 herds of grazing heifers in Japan. Basic information and epidemiological data from participating herds were obtained by mailed questionnaires, which were completed by field veterinarians. The average cumulative incidence and proportion of treated animals in the participating herds were 25.7 and 21.1%, respectively. The average daily weight gain and conception proportion were 0.51 kg per day and 56.9%, respectively. The basic information and epidemiological data had a large range and standard deviation, which reflect the wide diversity of the grazing herds in Japan. Herds with heavy tick infestation had significantly higher cumulative incidence and proportion of treated animals, therefore, this factor can be a good estimator to predict the occurrence and loss by theileriosis of the herds. The present questionnaire survey was useful for obtaining information about herds in different regions, and this survey method can be applied to the research of other animal diseases in Japan.
Collapse
Affiliation(s)
- I Yamane
- Laboratory of Epidemiology, National Institute of Animal Health, 3-1-1, Kannondai, Tsukuba-shi, Ibaraki 305-0856, Japan.
| | | | | | | |
Collapse
|
12
|
Kachani M, Flach E, Williamson S, Ouhelli H, El Hasnaoui M, Spooner R. The use of an enzyme-linked immunosorbent assay for tropical theileriosis research in Morocco. Prev Vet Med 1996. [DOI: 10.1016/0167-5877(95)00526-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
13
|
Oliver RA, Williams JL. Altered expression of class I major histocompatibility antigens on bovine cells infected with the protozoan parasite Theileria annulata. Vet Immunol Immunopathol 1996; 50:173-79. [PMID: 9157682 DOI: 10.1016/0165-2427(95)05487-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Theileria annulata infection is controlled by MHC class I restricted cytotoxic T cell killing of infected cells. The long term persistence of parasite suggests that it employs a mechanism to avoid immune surveillance. In this paper we describe the modification of BoLA class I antigens on the surface of Theileria annulata transformed lymphoblastoid cells. The extent of modification is different between individuals varying from extensive to undetectable.
Collapse
|