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Gebeyehu S, Degneh E. Parasitological investigation of bovine Trypanosomosis, vector distribution and tsetse flies infection rate study, Dabo Hana District, Buno Bedelle Zone, Southwest Ethiopia. Vet Parasitol Reg Stud Reports 2023; 41:100867. [PMID: 37208073 DOI: 10.1016/j.vprsr.2023.100867] [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: 04/12/2022] [Revised: 03/24/2023] [Accepted: 04/03/2023] [Indexed: 05/21/2023]
Abstract
A cross-sectional study was conducted to explore the prevalence of Trypanosome infections in cattle and within the tsetse flies from December 2020 to May 2021 in Dabo Hana district, Buno Bedelle Zone, Southwest Ethiopia. A total of 415 blood samples were examined utilizing Buffy coat and Giemsa-stained thin blood smear techniques. Vector distribution and tsetse fly infection rate were studied by deploying 60 traps in four purposively chosen villages of the district. The prevalence of Trypanosomes was 10.6% and 6.5% in cattle and in tsetse flies, respectively. Trypanosoma congolense (59.1%) in cattle and T. vivax (62.5%) in tsetse flies, were the foremost common species distinguished in the area. A significant difference (P ≤ 0.05) was observed in the prevalence of bovine Trypanosomosis between body condition scores of cattle. However, differences were not significant between coat color, sex, and age categories (P > 0.05). The mean PCV values of Trypanosome-infected cattle (22.6 ± 0.6) were significantly (P < 0.05) lower than those of non-infected cattle (25.6 ± 0.3). Out of 1441 flies caught, 1242 (86.2%) were Glossina, 113 (7.84%) were Stomoxys, and 86 (5.97%) were Tabanus. Of 1242 Glossina, 85% were G. tachinoides and the remaining 15% were G. m. sub-morsitans. This finding revealed that, three Trypanosoma species are circulating in cattle as well as in tsetse flies. It is recommended that, sustainable and integrated tsetse and Trypanosomosis control practices should be implemented to foster live stock health and agricultural development in the district. Other sensitive methods should be employed to determine the true picture of infection in the area.
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Affiliation(s)
- Surra Gebeyehu
- Wollega University, School of Veterinary Medicine, Nekemte, Ethiopia
| | - Efrem Degneh
- Wollega University, School of Veterinary Medicine, Nekemte, Ethiopia.
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Coelho J, Domingues J, Waap H, Stilwell G. Epidemiological characteristics of bovine besnoitiosis ( Besnoitia besnoiti) in a beef cattle farm: a cross-sectional serological assessment. Front Vet Sci 2023; 10:1158235. [PMID: 37180061 PMCID: PMC10169686 DOI: 10.3389/fvets.2023.1158235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/31/2023] [Indexed: 05/15/2023] Open
Abstract
Background Bovine besnoitiosis is an emerging disease caused by the protozoa Besnoitia besnoiti that can have a serious economic impact on affected farms. The fact that there is no effective vaccine nor treatment, along with the lack of consistent epidemiologic data, renders the implementation of preventive medicine and control strategies much harder. Objectives A cross-sectional serological assessment was performed to better understand the distribution and prevalence of this parasite in a large beef cattle farm in Portugal and to establish some epidemiological characteristics of besnoitiosis. Methods A random blood sampling of 450 animals from a farm that keeps around 2,000 cattle head was performed and sera were submitted to an indirect immunofluorescent antibody test (IFAT). Data on breed, age, sex, and birthplace of the tested animals and their mothers were recorded. Results The overall prevalence of positive animals was 16.89%, with significant differences between under 1-year-old calves (4.8%) and adults (19.67%). A higher antibody prevalence was shown in animals 1-2 years and >7 years old, in Salers breed and in cows imported from France or whose mothers had come from this country. Calves under 1 year old and crossbreed animals with ancestry born in the current farm presented the lowest antibody prevalence. Discussion and conclusions The most significant risk factors revealed were age (>7 years old) and breed (Salers). Genetic studies should be carried out in order to confirm whether indeed there is a breed susceptibility to bovine besnoitiosis. We suggest that similar studies should be performed across southern Europe to establish strong epidemiologic data that would allow a rigorous transnational control program to be launched.
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Affiliation(s)
- Joana Coelho
- Animal Behaviour and Welfare Laboratory, Centre of Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, Lisbon University, Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal
| | - Joana Domingues
- Animal Behaviour and Welfare Laboratory, Centre of Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, Lisbon University, Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal
| | - Helga Waap
- Animal Behaviour and Welfare Laboratory, Centre of Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, Lisbon University, Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal
- Laboratório de Parasitologia, Instituto Nacional de Investigação Agrária e Veterinária, Oeiras, Portugal
| | - George Stilwell
- Animal Behaviour and Welfare Laboratory, Centre of Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, Lisbon University, Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal
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Efrem D, Kassa T, Kebede N, Worku T. Seasonal prevalence of bovine trypanosomosis and trypanosome species distribution in Jimma Horo district, Oromia regional state, Western Ethiopia. Parasite Epidemiol Control 2022; 20:e00280. [PMID: 36545242 PMCID: PMC9761842 DOI: 10.1016/j.parepi.2022.e00280] [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: 03/26/2022] [Revised: 08/04/2022] [Accepted: 11/26/2022] [Indexed: 12/02/2022] Open
Abstract
A study was conducted to determine the prevalence of bovine trypanosomosis in rainy (June 2019) and dry (February 2020) seasons in Jimma Horoo district, Kellem Wollega Zone, Oromia Regional State, Ethiopia. A total of 720 blood samples were examined using buffy coat and thin blood smear techniques. The packed cell volume (PCV) of each animal was determined. The overall bovine trypanosomosis prevalence was 4.3% (χ2 = 1.25, P = 0.26). The prevalence was 5% (95% CI = 4.1-8.3) and 3.3% (95% CI = 2.7-6.3) in the dry and rainy reasons, respectively (P > 0.05). Trypanosoma congolense, T. vivax and T. b. brucei were detected in (60%), (33.3%) and (6.7%) of infected cattle, respectively. The highest trypanosome prevalence was observed in Burka Gudina (7.6%), and the lowest in Melka Nega village (2.1%). There were significant variations between trypanosome prevalence in relation to body condition scores (χ2 = 23.16; P = 0.0.00) of examined cattle. No significant difference (P > 0.05) was observed between seasons, age, and sex categories of cattle. The PCV values of trypanosome infected (22.94%) was significantly lower than non-infected cattle (26.47%) (χ2 = 19.60; (P < 0.05). The prevalence of bovine trypanosomosis in Jimma Horo district was low and it can be controlled by treatment of infected cattle using sanative pairs of trypanocidal drugs with additional application of deltamethrin pour-on in the dry season. Further, in view of poor sensitivity of buffy coat technique used the use of molecular techniques should be encouraged.
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Affiliation(s)
- Degneh Efrem
- School of Veterinary Medicine, Wollega University, Nekemte, Ethiopia,Corresponding author.
| | - Tesfu Kassa
- Aklilu Lemma, Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Nigatu Kebede
- Aklilu Lemma, Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tesfaye Worku
- School of Veterinary Medicine, Wollega University, Nekemte, Ethiopia
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Kizza D, Ocaido M, Mugisha A, Azuba R, Nalubwama S, Nalule S, Onyuth H, Musinguzi SP, Waiswa C. The economic cost of bovine trypanosomosis in pastoral and ago pastoral communities surrounding Murchision Falls National park, Buliisa district, Uganda. BMC Vet Res 2022; 18:372. [PMID: 36253776 PMCID: PMC9578198 DOI: 10.1186/s12917-022-03468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 09/27/2022] [Accepted: 10/05/2022] [Indexed: 11/14/2022] Open
Abstract
Background: Animal diseases that are endemic like tsetse transmitted trypanosomosis cause the continuous expenditure of financial resources of livestock farmers and loss of productivity of livestock. Estimating the cost of controlling animal trypanosomosis can provide evidence for priority setting and targeting cost-effective control strategies. Methodology: A cross-sectional survey to estimate the economic cost of bovine trypanosomosis was conducted in cattle-keeping communities living around Murchision falls National Park, in Buliisa district Uganda. Data was collected on herd structure, the cost of treatment and control, prevalence of morbidity and mortality rates due to trypanosomosis, and salvage sales losses in cattle herds in the last year. Results: In this study, 55.4% (n = 87) of the households reported their cattle had been affected by trypanosomosis during the previous last year. There was a high economic cost of trypanosomosis (USD 653) per household in cattle-keeping communities in Buliisa district of which 83% and 9% were due to mortality and milk loss respectively/ High mortality loss was due to low investment in treatment. The study showed that prophylactic treatment 3 times a year of the whole herd of cattle using Samorin ® (Isometamidium chloride) at a cost of USD 110 could drastically reduce cattle mortality loss due to trypanosomosis due to trypanosomosis with a return on investment of USD 540 annually per herd. This could be coupled with strategic restricted insecticide spraying of cattle with deltamethrin products. Conclusion: The results show a high economic cost of trypanosomosis in cattle-keeping communities in Buliisa district, with cattle mortality contributing the largest proportion of the economic cost. The high mortality loss was due to low investment in treatment of sick cattle.
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Affiliation(s)
- Daniel Kizza
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.
| | - Michael Ocaido
- Department of Wildlife, Aquatic and Animal Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Anthony Mugisha
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Rose Azuba
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Sylvia Nalubwama
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Sarah Nalule
- Department of Wildlife, Aquatic and Animal Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Howard Onyuth
- Department of Wildlife, Aquatic and Animal Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Simon Peter Musinguzi
- Faculty of Agriculture Department of Agricultural Production, Kyambogo University, Kampala, Uganda
| | - Charles Waiswa
- Department of Veterinary Pharmacy, Clinical and Comparative Medicine, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
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Boundenga L, Mombo IM, Augustin MO, Barthélémy N, Nzassi PM, Moukodoum ND, Rougeron V, Prugnolle F. Molecular Identification of Trypanosome Diversity in Domestic Animals Reveals the Presence of Trypanosoma brucei gambiense in Historical Foci of Human African Trypanosomiasis in Gabon. Pathogens 2022; 11:pathogens11090992. [PMID: 36145424 PMCID: PMC9502807 DOI: 10.3390/pathogens11090992] [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: 07/12/2022] [Revised: 08/21/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Human African Trypanosomiasis (HAT) is an infectious disease caused by protozoan parasites belonging to the Trypanosoma genus. In sub-Saharan Africa, there is a significant threat as many people are at risk of infection. Despite this, HAT is classified as a neglected tropical disease. Over the last few years, several studies have reported the existence of a wide diversity of trypanosome species circulating in African animals. Thus, domestic and wild animals could be reservoirs of potentially dangerous trypanosomes for human populations. However, very little is known about the role of domestic animals in maintaining the transmission cycle of human trypanosomes in central Africa, especially in Gabon, where serious cases of infection are recorded each year, sometimes leading to hospitalization or death of patients. Komo-Mondah, located within Estuaries (Gabonese province), stays the most active HAT disease focus in Gabon, with a mean of 20 cases per year. In this study, we evaluated the diversity and prevalence of trypanosomes circulating in domestic animals using the Polymerase Chain Reaction (PCR) technique. We found that 19.34% (53/274) of the domestic animals we studied were infected with trypanosomes. The infection rates varied among taxa, with 23.21% (13/56) of dogs, 16.10% (19/118) of goats, and 21.00% (21/100) of sheep infected. In addition, we have observed a global mixed rate of infections of 20.75% (11/53) among infected individuals. Molecular analyses revealed that at least six Trypanosome species circulate in domestic animals in Gabon (T. congolense, T. simiae, T. simiae Tsavo, T. theileri, T. vivax, T. brucei (including T. brucei brucei, and T. brucei gambiense)). In conclusion, our study showed that domestic animals constitute important potential reservoirs for trypanosome parasites, including T. brucei gambiense, which is responsible for HAT.
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Affiliation(s)
- Larson Boundenga
- International Centre for Medical Research in Franceville (CIRMF), Franceville BP 769, Gabon
- Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK
- Correspondence: ; Tel.: +241-62521281
| | - Illich Manfred Mombo
- International Centre for Medical Research in Franceville (CIRMF), Franceville BP 769, Gabon
| | | | - Ngoubangoye Barthélémy
- International Centre for Medical Research in Franceville (CIRMF), Franceville BP 769, Gabon
- Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK
| | - Patrice Makouloutou Nzassi
- International Centre for Medical Research in Franceville (CIRMF), Franceville BP 769, Gabon
- Department of Animal Biology and Ecology, Tropical Ecology Research Institute (IRET-CENAREST), Libreville BP 13354, Gabon
| | - Nancy D. Moukodoum
- International Centre for Medical Research in Franceville (CIRMF), Franceville BP 769, Gabon
| | - Virginie Rougeron
- REHABS, International Research Laboratory, CNRS-NMU-UCBL, George Campus, Nelson Mandela University, George 6529, South Africa
| | - Franck Prugnolle
- REHABS, International Research Laboratory, CNRS-NMU-UCBL, George Campus, Nelson Mandela University, George 6529, South Africa
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Cattle-Derived Unsaturated Aldehydes Repel Biting Midges and Mosquitoes. J Chem Ecol 2022; 48:359-369. [PMID: 35107692 PMCID: PMC9079034 DOI: 10.1007/s10886-021-01347-x] [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: 10/21/2021] [Revised: 12/09/2021] [Accepted: 12/21/2021] [Indexed: 11/30/2022]
Abstract
Host-derived repellents offer a novel way to reduce disease vector–host interactions, particularly for vectors and nuisance pests where commercial repellents are not available, e.g., Culicoides biting midges. By revising the criteria previously used to identify bioactive volatile organic compounds for Culicoides nubeculosus, we identify (E)-2-hexenal, (E)-2-heptenal, (E)-2-octenal, and (E)-2-nonenal to be differentially present in the headspace odour of cattle hair and to elicit antennal responses in this research model species. A blend of these unsaturated aldehydes elicited an aversive response in C. nubeculosus, as well as a repellent response in three disease vector mosquito species, Aedes aegypti, Culex quinquefasciatus and Anopheles coluzzii, a response that was stronger than that to the commercially available repellents tested (DEET, IR3535, PMD, icaridin, and d-allethrin). Culicoides nubeculosus was behaviourally indifferent to these commercially available repellents tested, except d-allethrin to which it was attracted. The identification of a host-derived repellent odour blend, which reduces the interaction between biting midges extends the array of tools to be used in integrated vector management of these and other disease vectors.
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Prevalence of Bovine Trypanosomosis and Its Associated Risk Factor in Hawa Galan District, Kelem Wollega Zone of Ethiopia. Vet Med Int 2021; 2021:4531586. [PMID: 34950445 PMCID: PMC8692041 DOI: 10.1155/2021/4531586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/15/2021] [Indexed: 11/27/2022] Open
Abstract
An analytical cross-sectional study was performed between November 2015 and April 2016 at Hawa Galan woreda, Kelem Wollega Zone, Oromia Region, Ethiopia, to estimate the proportion of cattle with trypanosomosis and to evaluate the elements associated with the prevalence of bovine trypanosomosis. A haemoparasitological examination of the Buffy coat method was implemented to determine the proportion of trypanosomosis-positive cattle. A study population of 428 bovines was randomly selected from three peasant associations (PAs) and tested for the presence of the disease. Findings of the laboratory results indicate that among all animals tested at the study time, 26 (6%) animals were positive for the disease. Among the positive results, the proportion of trypanosome species was Trypanosoma congolense 18 (69.3%) and Trypanosoma vivax 8 (30.7%). The prevalence at the selected PAs was 12.5%, 3.8%, and 3% for Lemlem, Madawalkituma, and Ifajiru, respectively. From this finding, the relationship has a statistically significant variation (P < 0.05) among peasant associations and body condition state, and the proportion was significantly greater (P < 0.05) in animals categorized under poor body condition score. The relationships between age and sex of cattle show no statistically significant variation among them (P > 0.05). This study indicates that the proportion of trypanosomosis was greater in anemic (PCV<24%) cattle than nonanemic (PCV≥24%). Therefore, based on this finding, the proportion of bovine trypanosomosis is evident that can cause a major effect on the health of cattle in the study population in the study area. So, effective control methods could be applied to decrease the disease and its related economic loss.
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Kizza D, Ocaido M, Mugisha A, Azuba R, Nalule S, Onyuth H, Musinguzi SP, Okwasiimire R, Waiswa C. Prevalence and risk factors for trypanosome infection in cattle from communities surrounding the Murchison Falls National Park, Uganda. Parasit Vectors 2021; 14:513. [PMID: 34620230 PMCID: PMC8499574 DOI: 10.1186/s13071-021-04987-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 08/31/2021] [Indexed: 11/10/2022] Open
Abstract
Background Bovine trypanosomosis transmitted by tsetse flies is a major constraint to cattle health and productivity in all sub-Saharan countries, including Uganda. The objectives of this study were to determine the prevalence of bovine trypanosomosis and identify its associated risk factors and the species of trypanosomes associated with the disease. Methodology A cross-sectional study was conducted around Murchison Falls National Park, Uganda from January 2020 to April 2020. Trypanosomes were detected in blood samples by PCR analysis targeting the internal transcribed spacer 1 (ITS-PCR assays), and trypanosomes in positive blood samples were sequenced. Results Of 460 blood samples collected and tested, 136 (29.6%) were positive for trypanosome infections and 324 (70.4%) were negative. The overall trypanosome prevalence was 29.6% (95% confidence interval 25.4–33.8%), attributed to three trypanosome species. Of these three species, Trypanosoma vivax was the most prevalent (n = 130, 28.3%) while the others were detected as mixed infections: T. vivax + Trypanosomacongolense (n = 2, 0.4%) and T. vivax + Trypanosomaevansi (n = 1, 0.2%). There were significant differences in trypanosome prevalence according to sex (χ2 = 62, df = 1, P < 0.05), age (χ2 = 6.28, df = 2, P = 0.0043) and cattle breed (χ2 = 10.61, df = 1, P = 0.001). Conclusions Trypanosomosis remains a major limitation to cattle production around Murchison Falls National Park and interventions are urgently needed. In our study, the prevalence of trypanosome infections was high, with T. vivax identified as the most prevalent species. Age, sex and breed of cattle were risk factors for trypanosome infection. Graphical Abstract ![]()
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Affiliation(s)
- Daniel Kizza
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.
| | - Michael Ocaido
- Department of Wildlife, Aquatic and Animal Resources College of Veterinary Medicine Animal Resources, Biosecurity Makerere University, Kampala, Uganda
| | - Anthony Mugisha
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Rose Azuba
- Department of Livestock and Industrial Resources, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Sarah Nalule
- Department of Wildlife, Aquatic and Animal Resources College of Veterinary Medicine Animal Resources, Biosecurity Makerere University, Kampala, Uganda
| | - Howard Onyuth
- Department of Wildlife, Aquatic and Animal Resources College of Veterinary Medicine Animal Resources, Biosecurity Makerere University, Kampala, Uganda
| | - Simon Peter Musinguzi
- Department of Agriculture, Faculty of Vocational studies, Kyambogo University, P.0 Box 1 Kyambogo, Kampala, Uganda
| | - Rodney Okwasiimire
- Central Diagnostic Laboratory, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Charles Waiswa
- Department of Veterinary Pharmacy, Clinical and Comparative Medicine, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
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Degneh E, Kassa T, Kebede N, Asefa Z. Epidemiological investigation of bovine trypanosomosis in Bedele district, Buno Bedele zone, Oromia regional state, Ethiopia. Parasite Epidemiol Control 2021; 14:e00218. [PMID: 34235278 PMCID: PMC8246633 DOI: 10.1016/j.parepi.2021.e00218] [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: 12/12/2020] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 11/22/2022] Open
Abstract
A cross-sectional study was conducted in December 2018 in four purposively selected villages of Bedele district, Oromia Regional State, Southwest Ethiopia. The study aimed to determine the prevalence of bovine trypanosomosis and associated risk factors of trypanosome infections in cattle. A total of 384 blood samples were collected from systematically selected cattle and examined using buffy coat and thin blood smear examination methods. The overall prevalence of bovine trypanosomosis was 8.3%. Trypanosoma congolense (68.8%) and T. vivax (31.2%) were the prevailing trypanosome species identified in the area. A statistically significant difference (P < 0.05) was observed in the prevalence of bovine trypanosomosis between body condition scores of cattle. The prevalence of bovine trypanosomosis was slightly higher in female (9%) as opposed to male (7.3%) cattle, but the difference was not statistically significant (P > 0.05). Similarly, no statistically significant difference (P > 0.05) was observed between age categories of cattle. The mean PCV value of trypanosome infected cattle (21.4 ± 3.6) was significantly (P < 0.05) lower than that of non-infected (25.6 ± 4.6). The current study indicated that, despite vector control measures implemented for several years, bovine trypanosomosis persists and continues to be a core problem to cattle health and production in the Bedele district. Therefore, more attention should be given to control the disease and its vectors based on temporal and spatial distribution. Also, the use of molecular techniques should be encouraged in view of their greater sensitivity when compared to the buffy coat method.
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Affiliation(s)
- Efrem Degneh
- School of Veterinary Medicine, Wollega University, Nekemte, Ethiopia
| | - Tesfu Kassa
- Aklilu Lemma, Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Nigatu Kebede
- Aklilu Lemma, Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Zerihun Asefa
- College of Veterinary Medicine and Agriculture, Department of Pathology and Parasitology, Addis Ababa University, Addis Ababa, Ethiopia
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Ibrahim MAM, Weber JS, Ngomtcho SCH, Signaboubo D, Berger P, Hassane HM, Kelm S. Diversity of trypanosomes in humans and cattle in the HAT foci Mandoul and Maro, Southern Chad-A matter of concern for zoonotic potential? PLoS Negl Trop Dis 2021; 15:e0009323. [PMID: 34106914 PMCID: PMC8224965 DOI: 10.1371/journal.pntd.0009323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 06/24/2021] [Accepted: 03/23/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND African trypanosomes are parasites mainly transmitted by tsetse flies. They cause trypanosomiasis in humans (HAT) and animals (AAT). In Chad, HAT/AAT are endemic. This study investigates the diversity and distribution of trypanosomes in Mandoul, an isolated area where a tsetse control campaign is ongoing, and Maro, an area bordering the Central African Republic (CAR) where the control had not started. METHODS 717 human and 540 cattle blood samples were collected, and 177 tsetse flies were caught. Trypanosomal DNA was detected using PCR targeting internal transcribed spacer 1 (ITS1) and glycosomal glyceraldehyde-3 phosphate dehydrogenase (gGAPDH), followed by amplicon sequencing. RESULTS Trypanosomal DNA was identified in 14 human samples, 227 cattle samples, and in tsetse. Besides T. b. gambiense, T. congolense was detected in human in Maro. In Mandoul, DNA from an unknown Trypanosoma sp.-129-H was detected in a human with a history of a cured HAT infection and persisting symptoms. In cattle and tsetse samples from Maro, T. godfreyi and T. grayi were detected besides the known animal pathogens, in addition to T. theileri (in cattle) and T. simiae (in tsetse). Furthermore, in Maro, evidence for additional unknown trypanosomes was obtained in tsetse. In contrast, in the Mandoul area, only T. theileri, T. simiae, and T. vivax DNA was identified in cattle. Genetic diversity was most prominent in T. vivax and T. theileri. CONCLUSION Tsetse control activities in Mandoul reduced the tsetse population and thus the pathogenic parasites. Nevertheless, T. theileri, T. vivax, and T. simiae are frequent in cattle suggesting transmission by other insect vectors. In contrast, in Maro, transhumance to/from Central African Republic and no tsetse control may have led to the high diversity and frequency of trypanosomes observed including HAT/AAT pathogenic species. Active HAT infections stress the need to enforce monitoring and control campaigns. Additionally, the diverse trypanosome species in humans and cattle indicate the necessity to investigate the infectivity of the unknown trypanosomes regarding their zoonotic potential. Finally, this study should be widened to other trypanosome hosts to capture the whole diversity of circulating trypanosomes.
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Affiliation(s)
- Mahamat Alhadj Moussa Ibrahim
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
- Department of Biology, Faculty of Exacts and Applied sciences, University of N’Djamena, N’Djamena, Chad
- * E-mail: (MAMI); (SK)
| | - Judith Sophie Weber
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
- Centre for Marine Environmental Sciences MARUM, University of Bremen, Bremen, Germany
| | - Sen Claudine Henriette Ngomtcho
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
- Department of Microbiology, Haematology and Immunology, Faculty of medicine and pharmaceutical Sciences, University of Dschang, Dschang, Cameroon
| | - Djoukzoumka Signaboubo
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Petra Berger
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
| | | | - Sørge Kelm
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
- * E-mail: (MAMI); (SK)
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11
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Degneh E, Kassa T, Kebede N, Desta T. Bovine trypanosomosis: Prevalence and vector distribution in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2021; 23:100535. [PMID: 33678388 DOI: 10.1016/j.vprsr.2021.100535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 11/15/2022]
Abstract
Bovine trypanosomosis remains an important livestock disease constraint, which is threatening livestock health and production, despite ongoing tsetse and trypanosomosis control efforts in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia. A cross-sectional study was conducted in May 2018, to determine the prevalence of bovine trypanosomosis and distribution of the vectors of disease in Sadi Chanka district, Western Ethiopia. A total of 370 blood samples were collected from randomly selected local Horro and Abigar cattle breeds covering five villages of the district. The collected samples were examined using buffy coat microscopy and Giemsa-stained thin blood smear techniques. In this study, 12.4% (95% CI: 12.3-12.4) of the animals were found to be infected with trypanosomes. The study showed that 69.6% of trypanosome infections were caused by T. congolense followed by 26.1% T. vivax and 4.3% mixed T. congolense and T. vivax. In the present study, the association of bovine trypanosomosis was assessed in releation to body condition scores, sex, and age of cattle, and a significant association (P < 0.05) was observed between body condition scores. However, significant differences were not observed between sex and age categories (P > 0.05). The Mean Packed Cell Volume (PCV) of infected (21.6%) and non-infected (24.5%) groups of cattle had significant variation (P < 0.05). In an entomological survey, a total of 616 flies were trapped, of which 280 (45.5%) were Glossina and the remaining 336 (54.5%) were Stomoxys, Tabanus, and Haematopota. The apparent density of Glossina, Stomoxys, Tabanus, and Haematopota was 3.5, 3.1, 0.7 and 0.4 fly per trap per day, respectively. This study generated basic scientific data on the epidemiology of bovine trypanosomosis and its vectors in Sadi Chanka district, which can be used in planning the control of bovine trypanosomosis in the area.
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Affiliation(s)
- Efrem Degneh
- School of Veterinary Medicine, Wollega University, Nekemte, Ethiopia.
| | - Tesfu Kassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Nigatu Kebede
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tekalegn Desta
- National Institute for Control and Eradication of Tsetse Flies and Trypanosomosis, Ministry of Agriculture, Addis Ababa, Ethiopia
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12
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Large-scale disease patterns explained by climatic seasonality and host traits. Oecologia 2020; 194:723-733. [DOI: 10.1007/s00442-020-04782-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 10/09/2020] [Indexed: 12/19/2022]
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13
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Skinner EB, Rudd PA, Peel AJ, McCallum H, Reid SA, Herrero LJ. Species Traits and Hotspots Associated with Ross River Virus Infection in Nonhuman Vertebrates in South East Queensland. Vector Borne Zoonotic Dis 2020; 21:50-58. [PMID: 32996845 DOI: 10.1089/vbz.2020.2648] [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: 11/13/2022] Open
Abstract
Ross River virus (RRV) is a mosquito-borne zoonotic arbovirus associated with high public health and economic burdens across Australia, but particularly in South East Queensland (SEQ). Despite this high burden, humans are considered incidental hosts. Transmission of RRV is maintained among mosquitoes and many nonhuman vertebrate reservoir hosts, although the relative contributions of each of these hosts are unclear. To clarify the importance of a range of vertebrates in RRV transmission in SEQ, a total of 595 serum samples from 31 species were examined for RRV exposure using a gold-standard plaque reduction neutralization test. Data were analyzed statistically using generalized linear models and a coefficient inference tree, and spatially. RRV exposure was highly variable between and within species groups. Critically, species group ("placental mammal," "marsupial," and "bird"), which has previously been used as a proxy for reservoir hosts, was a poor correlate for exposure. Instead, we found that generalized "diet" and greater "body mass" were most strongly correlated with seropositivity. We also identified significant differences in seropositivity between the two major possum species (ringtail possums and brushtail possums), which are ecologically and taxonomically different. Finally, we identified distinct hotspots and coldspots of seropositivity in nonhuman vertebrates, which correlated with human notification data. This is the largest diversity of species tested for RRV in a single study to date. The analysis methods within this study provide a framework for analyzing serological data in combination with species traits for other zoonotic disease, but more specifically for RRV highlight areas to target further public health research and surveillance effort.
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Affiliation(s)
- Eloise B Skinner
- Biology Department, Stanford University, Stanford, California, USA.,Environmental Futures Research Institute, Griffith University, Brisbane, Australia.,Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Australia
| | - Penny A Rudd
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Australia
| | - Alison J Peel
- Environmental Futures Research Institute, Griffith University, Brisbane, Australia
| | - Hamish McCallum
- Environmental Futures Research Institute, Griffith University, Brisbane, Australia
| | - Simon A Reid
- School of Public Health, The University of Queensland, Brisbane, Australia
| | - Lara J Herrero
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Australia.,Redlands Hospital, QLD Health, Cleveland, Australia
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14
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Prevalence and control implications of bovine trypanosomes in endemic areas of northern Uganda. Trop Anim Health Prod 2020; 52:3259-3264. [PMID: 32699961 DOI: 10.1007/s11250-020-02353-z] [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: 02/23/2020] [Accepted: 07/13/2020] [Indexed: 10/23/2022]
Abstract
African animal trypanosomiasis (AAT), a disease complex caused by tsetse fly-transmitted Trypanosoma brucei brucei, T. congolense savannah ITS, and T. vivax, continues to inflict heavy losses to the animal industry in terms of decreased livestock production and productivity. Live bait technology and chemotherapy have been used as a control strategy in northern Uganda since 2006 with minimal success. Here, we report the results of a cross-sectional study carried out in Lango subregion, Uganda, to assess the species prevalence of bovine trypanosome in cattle using the internal transcribed spacer (ITS) of trypanosome ribosomal DNA (rDNA). Blood samples were collected from 1090 cattle by ear vein puncture and screened using a single pair of primers designed to amplify ITS ribosomal DNA (rDNA). Our results indicate an overall prevalence of 40.18% (438/1090, 95% CI 30.82-54.51). T. vivax constituted 32.66% (356/1090), T. congolense 2.39% (26/1090), T. brucei 1.28% (14/1090), T. godfreyi 0.09%(1/1090), T. brucei and T. congolense 0.36% (4/1090), T. brucei and T. vivax 1.47% (16/1090), T. vivax and T. congolense 1.65% (18/1090), T. vivax and T. simiae 0.18% (2/1090), and T. vivax and T. godfreyi 0.09% (1/1090) of infections. Over 91.7% of infections involved single species, while 9.5% were mixed infections. Over 90.2% (37/41) of the mixed infections involved T. vivax as one of the species, while 53.7% (22/41) involved T. congolense. The high prevalence of AAT and the continued presence of T. brucei raise public health concerns because of the zoonotic implications. An integrated approach that involves mass treatment of cattle, vector, and animal movement control should be adopted to reduce the risk of both AAT and HAT.
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15
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Gutiérrez-López R, Martínez-de la Puente J, Gangoso L, Soriguer R, Figuerola J. Effects of host sex, body mass and infection by avian Plasmodium on the biting rate of two mosquito species with different feeding preferences. Parasit Vectors 2019; 12:87. [PMID: 30867014 PMCID: PMC6416876 DOI: 10.1186/s13071-019-3342-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 02/26/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The transmission of mosquito-borne pathogens is strongly influenced by the contact rates between mosquitoes and susceptible hosts. The biting rates of mosquitoes depend on different factors including the mosquito species and host-related traits (i.e. odour, heat and behaviour). However, host characteristics potentially affecting intraspecific differences in the biting rate of mosquitoes are poorly known. Here, we assessed the impact of three host-related traits on the biting rate of two mosquito species with different feeding preferences: the ornithophilic Culex pipiens and the mammophilic Ochlerotatus (Aedes) caspius. Seventy-two jackdaws Corvus monedula and 101 house sparrows Passer domesticus were individually exposed to mosquito bites to test the effect of host sex, body mass and infection status by the avian malaria parasite Plasmodium on biting rates. RESULTS Ochlerotatus caspius showed significantly higher biting rates than Cx. pipiens on jackdaws, but non-significant differences were found on house sparrows. In addition, more Oc. caspius fed on female than on male jackdaws, while no differences were found for Cx. pipiens. The biting rate of mosquitoes on house sparrows increased through the year. The bird infection status and body mass of both avian hosts were not related to the biting rate of both mosquito species. CONCLUSIONS Host sex was the only host-related trait potentially affecting the biting rate of mosquitoes, although its effect may differ between mosquito and host species.
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Affiliation(s)
- Rafael Gutiérrez-López
- Department of Wetland Ecology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio 26, 41092 Seville, Spain
| | - Josué Martínez-de la Puente
- Department of Wetland Ecology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio 26, 41092 Seville, Spain
- CIBER de Epidemiología y Salud Publica, Seville, Spain
| | - Laura Gangoso
- Department of Wetland Ecology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio 26, 41092 Seville, Spain
- Present Address: Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Ramón Soriguer
- Department of Ethology & Biodiversity Conservation, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio 26, 41092 Seville, Spain
- CIBER de Epidemiología y Salud Publica, Seville, Spain
| | - Jordi Figuerola
- Department of Wetland Ecology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio 26, 41092 Seville, Spain
- CIBER de Epidemiología y Salud Publica, Seville, Spain
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16
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Chahda JS, Soni N, Sun JS, Ebrahim SAM, Weiss BL, Carlson JR. The molecular and cellular basis of olfactory response to tsetse fly attractants. PLoS Genet 2019; 15:e1008005. [PMID: 30875383 PMCID: PMC6420007 DOI: 10.1371/journal.pgen.1008005] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 02/05/2019] [Indexed: 12/12/2022] Open
Abstract
Dipteran or "true" flies occupy nearly every terrestrial habitat, and have evolved to feed upon a wide variety of sources including fruit, pollen, decomposing animal matter, and even vertebrate blood. Here we analyze the molecular, genetic and cellular basis of odor response in the tsetse fly Glossina morsitans, which feeds on the blood of humans and their livestock, and is a vector of deadly trypanosomes. The G. morsitans antenna contains specialized subtypes of sensilla, some of which line a sensory pit not found in the fruit fly Drosophila. We characterize distinct patterns of G. morsitans Odor receptor (GmmOr) gene expression in the antenna. We devise a new version of the "empty neuron" heterologous expression system, and use it to functionally express several GmmOrs in a mutant olfactory receptor neuron (ORN) of Drosophila. GmmOr35 responds to 1-hexen-3-ol, an odorant found in human emanations, and also alpha-pinene, a compound produced by malarial parasites. Another receptor, GmmOr9, which is expressed in the sensory pit, responds to acetone, 2-butanone and 2-propanol. We confirm by electrophysiological recording that neurons of the sensory pit respond to these odorants. Acetone and 2-butanone are strong attractants long used in the field to trap tsetse. We find that 2-propanol is also an attractant for both G. morsitans and the related species G. fuscipes, a major vector of African sleeping sickness. The results identify 2-propanol as a candidate for an environmentally friendly and practical tsetse attractant. Taken together, this work characterizes the olfactory system of a highly distinct kind of fly, and it provides an approach to identifying new agents for controlling the fly and the devastating diseases that it carries.
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Affiliation(s)
- J. Sebastian Chahda
- Dept. of Molecular Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Neeraj Soni
- Dept. of Molecular Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Jennifer S. Sun
- Dept. of Molecular Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Shimaa A. M. Ebrahim
- Dept. of Molecular Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Brian L. Weiss
- Dept. of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - John R. Carlson
- Dept. of Molecular Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
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17
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Molecular identification of bovine trypanosomes in relation to cattle sources in southwest Nigeria. Parasitol Int 2018; 68:1-8. [PMID: 30243980 DOI: 10.1016/j.parint.2018.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 11/22/2022]
Abstract
Bovine trypanosomosis is a problem in the livestock industry in Nigeria. A longitudinal survey of cattle sampled during the wet and dry seasons was conducted from April 2016 to March 2017. Blood samples were collected by random sampling from 745 cattle in southwest Nigeria and screened for trypanosomes by internal transcribed spacer-polymerase chain reaction (ITS-PCR). Cattle positive for Trypanozoon DNA were further screened with the Rode Trypanozoon antigen type (RoTat) 1.2 PCR and Trypanosoma brucei gambiense glycoprotein (TgsGP) genes for T. evansi and T. b. gambiense respectively. Trypanosome DNA was amplified in 23.8% (95%CI: 20.8-26.9) of cattle with significantly higher prevalence in wet season (95%CI: 22.9-30.8) when compared to the dry season (95%CI: 14.3-23.6). A high prevalence was observed in Fulani cattle farms 54.1% (95%CI: 42.78-64.93%) while the prevalence was lower in institutional farms 14.7% (95%CI: 10.10-20.97%). Trypanosoma vivax was the most prevalent trypanosome observed (11.54% (95%CI: 9.44-14.04%)), followed by T. congolense 8.5% (95%CI: 6.67-10.67%) T. b. brucei 4.8% (95%CI: 3.51-6.62%) and T. evansi 1.74% (95%CI: 1.02-2.96%). Mixed infections were observed in 2.8% (95%CI: 1.85-4.27%) of cattle. Seasonal variation revealed a predominance of T. congolense and T. vivax in wet and dry season, respectively. The high prevalence of Trypanosoma species in cattle indicates a need for expanded surveillance for AAT in southwest Nigeria. Migration, settlement patterns, increased marketing and management types were some of the risk factors identified for AAT.
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18
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Migbaru KB, Mabure SB. Prevalence of bovine trypanosomiosis in Gamogoffa Zone, Ouba Debrestahay District, Southern Ethiopia. ACTA ACUST UNITED AC 2017. [DOI: 10.5897/jvmah2015.0421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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19
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Victoriano Llopis I, Tomassone L, Grego E, Serrano E, Mosca A, Vaschetti G, Andrade D, Rossi L. Evaluating the feeding preferences of West Nile virus mosquito vectors using bird-baited traps. Parasit Vectors 2016; 9:479. [PMID: 27580694 PMCID: PMC5006430 DOI: 10.1186/s13071-016-1744-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/10/2016] [Indexed: 01/05/2023] Open
Abstract
Background The total contact rates (TCRs) between mosquito vectors and their potential hosts have a serious impact on disease transmission dynamics. Culex pipiens (sensu stricto) (s.s.) is considered the main vector of the West Nile Virus (WNV) in Europe and birds are the reservoir hosts. The results of our previous study showed that WNV seroreactors are significantly more prevalent among raptors compared to a range of other wild avian groups. The current study aims to assess the role of bird type (raptor vs others) and bird size on mosquito feeding preferences in a free-choice experiment using bird-baited traps. Methods From July to September 2014, a battery of six bird-baited traps was operated in twelve mosquito capture sessions. Eight bird species, belonging to five different orders, including raptors, were used. After each session, the trapped mosquitoes were collected and identified using standard keys. Two sets of independent generalized linear mixed models (GLMM) were used to assess mosquito vector feeding preferences (MFp) among different bird species and types. Results A total of 304 mosquitoes belonging to seven taxa were collected, C. pipiens being by far the most abundant (84.2 % of the total mosquito catch). Most C. pipiens were engorged (83.59 %). The selected model showed that 25.6 % of the observed variability of MFp is explained by the interaction between bird size and bird type, with C. pipiens preferring to feed on large birds, especially raptors. The proportion of engorged mosquitoes was 1.9-fold higher in large (22.88 %; range 0–42 %) than in medium-sized raptors (11.71 %; range 0–33 %), and was nearly the same in medium-sized (9.08 %; range 0–26 %) and large (8.5 %; 6–24 %) non-raptor species. Conclusion Culex pipiens showed an obvious preference for large raptors, which concurs with the higher seroprevalence to WNV in our previous study. The appreciable feeding by C. pipiens on large raptors makes them useful alternative sentinels to poultry for WNV surveillance. Thus, wildlife parks and rehabilitation centers can contribute to surveillance efforts to a greater extent.
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Affiliation(s)
| | - Laura Tomassone
- Dipartimento di Scienze Veterinarie, University of Turin, Turin, Italy
| | - Elena Grego
- Dipartimento di Scienze Veterinarie, University of Turin, Turin, Italy
| | - Emmanuel Serrano
- CESAM, Departamento de Biologia, Universidade de Aveiro, Aveiro, Portugal.,Servei d' Ecopatologia de Fauna Salvatge, Departamento de Medicina y Cirugia Animal, Universidad Autónoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Andrea Mosca
- Istituto per le Piante da Legno e l'Ambiente, IPLA spa, Turin, Italy
| | | | - Daniela Andrade
- Dipartimento di Scienze Veterinarie, University of Turin, Turin, Italy
| | - Luca Rossi
- Dipartimento di Scienze Veterinarie, University of Turin, Turin, Italy
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20
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Getz WM, Salter R, Seidel DP, van Hooft P. Sympatric speciation in structureless environments. BMC Evol Biol 2016; 16:50. [PMID: 26922946 PMCID: PMC4770699 DOI: 10.1186/s12862-016-0617-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Darwin and the architects of the Modern Synthesis found sympatric speciation difficult to explain and suggested it is unlikely to occur. Increasingly, evidence over the past few decades suggest that sympatric speciation can occur under ecological conditions that require at most intraspecific competition for a structured resource. Here we used an individual-based population model with variable foraging strategies to study the evolution of mating behavior among foraging strategy types. Initially, individuals were placed at random on a structureless resource landscape, with subsequent spatial variation induced through foraging activity itself. The fitness of individuals was determined by their biomass at the end of each generational cycle. The model incorporates three diallelic, codominant foraging strategy genes, and one mate-choice or m-trait (i.e. incipient magic trait) gene, where the latter is inactive when random mating is assumed. RESULTS Under non-random mating, the m-trait gene promotes increasing levels of either disassortative or assortative mating when the frequency of m respectively increases or decreases from 0.5. Our evolutionary simulations demonstrate that, under initial random mating conditions, an activated m-trait gene evolves to promote assortative mating because the system, in trying to fit a multipeak adaptive landscape, causes heterozygous individuals to be less fit than homozygous individuals. CONCLUSION Our results extend our theoretical understanding that sympatric speciation can evolve under nicheless or gradientless resource conditions: i.e. the underlying resource is monomorphic and initially spatially homogeneous. Further the simplicity and generality of our model suggests that sympatric speciation may be more likely than previously thought to occur in mobile, sexually-reproducing organisms.
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Affiliation(s)
- Wayne M Getz
- Department ESPM, University of California, Berkeley, CA, 94720-3114, USA. .,School of Mathematical Sciences, University of KwaZulu-Natal, PB X54001, Durban, 4000, South Africa.
| | - Richard Salter
- Computer Science Department, Oberlin College, Oberlin, OH, 44074, USA.
| | - Dana Paige Seidel
- Department ESPM, University of California, Berkeley, CA, 94720-3114, USA.
| | - Pim van Hooft
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB, Wageningen, The Netherlands.
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21
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Macharia R, Mireji P, Murungi E, Murilla G, Christoffels A, Aksoy S, Masiga D. Genome-Wide Comparative Analysis of Chemosensory Gene Families in Five Tsetse Fly Species. PLoS Negl Trop Dis 2016; 10:e0004421. [PMID: 26886411 PMCID: PMC4757090 DOI: 10.1371/journal.pntd.0004421] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/11/2016] [Indexed: 12/04/2022] Open
Abstract
For decades, odour-baited traps have been used for control of tsetse flies (Diptera; Glossinidae), vectors of African trypanosomes. However, differential responses to known attractants have been reported in different Glossina species, hindering establishment of a universal vector control tool. Availability of full genome sequences of five Glossina species offers an opportunity to compare their chemosensory repertoire and enhance our understanding of their biology in relation to chemosensation. Here, we identified and annotated the major chemosensory gene families in Glossina. We identified a total of 118, 115, 124, and 123 chemosensory genes in Glossina austeni, G. brevipalpis, G. f. fuscipes, G. pallidipes, respectively, relative to 127 reported in G. m. morsitans. Our results show that tsetse fly genomes have fewer chemosensory genes when compared to other dipterans such as Musca domestica (n>393), Drosophila melanogaster (n = 246) and Anopheles gambiae (n>247). We also found that Glossina chemosensory genes are dispersed across distantly located scaffolds in their respective genomes, in contrast to other insects like D. melanogaster whose genes occur in clusters. Further, Glossina appears to be devoid of sugar receptors and to have expanded CO2 associated receptors, potentially reflecting Glossina's obligate hematophagy and the need to detect hosts that may be out of sight. We also identified, in all species, homologs of Ir84a; a Drosophila-specific ionotropic receptor that promotes male courtship suggesting that this is a conserved trait in tsetse flies. Notably, our selection analysis revealed that a total of four gene loci (Gr21a, GluRIIA, Gr28b, and Obp83a) were under positive selection, which confers fitness advantage to species. These findings provide a platform for studies to further define the language of communication of tsetse with their environment, and influence development of novel approaches for control. Chemical sensing is crucial to survival of tsetse flies; the sole cyclical vectors of African trypanosomes that cause the neglected zoonotic tropical disease sleeping sickness in humans. For many years, vector control has been used to mitigate trypanosome infections among rural populations of sub-Saharan Africa. Nevertheless, development of an all-inclusive strategy to control tsetse flies using odour-baited traps has been limited by disparate responses to the odors exhibited by various tsetse species. In this study, proteins that are putatively involved in chemical sensing were identified and compared among five tsetse species and their close relatives with an aim of enhancing our knowledge on tsetse olfaction. Our findings suggest that the chemosensory genes are conserved across tsetse fly species despite their documented differential responses in odours. We found no species-specific sequence variations among the five species to suggest that differential response to odours is due to loss or gain of genes. It could therefore be hypothesized that the observed differences emerge during the downstream processing of odour molecules involving post translational modification of the chemosensory proteins. We thus recommend functional studies on the identified proteins to determine their roles and molecular interactions.
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Affiliation(s)
- Rosaline Macharia
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- South African National Bioinformatics Institute, University of the Western Cape, Cape Town, South Africa
| | - Paul Mireji
- Department of Epidemiology of Microbial Diseases, Yale School of Public Heath, New Haven, Connecticut, United States of America
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- * E-mail: (PM); (DM)
| | - Edwin Murungi
- Department of Biochemistry and Molecular Biology, Egerton University, Njoro, Kenya
| | - Grace Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Alan Christoffels
- South African National Bioinformatics Institute, University of the Western Cape, Cape Town, South Africa
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Heath, New Haven, Connecticut, United States of America
| | - Daniel Masiga
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- * E-mail: (PM); (DM)
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22
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Angwech H, Nyeko JHP, Opiyo EA, Okello-Onen J, Opiro R, Echodu R, Malinga GM, Njahira MN, Skilton RA. Heterogeneity in the prevalence and intensity of bovine trypanosomiasis in the districts of Amuru and Nwoya, Northern Uganda. BMC Vet Res 2015; 11:255. [PMID: 26449544 PMCID: PMC4599665 DOI: 10.1186/s12917-015-0567-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 09/30/2015] [Indexed: 11/11/2022] Open
Abstract
Background Livestock trypanosomiasis, transmitted mainly by tsetse flies of the genus Glossina is a major constraint to livestock health and productivity in the sub-Saharan Africa. Knowledge of the prevalence and intensity of trypanosomiasis is important in understanding the epidemiology of the disease. The objectives of this study were to (a) assess the prevalence and intensity of trypanosome infections in cattle, and (b) to investigate the reasons for the heterogeneity of the disease in the tsetse infested districts of Amuru and Nwoya, northern Uganda. Methods A cross-sectional study was conducted from September, 2011 to January, 2012. Blood samples were collected from 816 cattle following jugular vein puncture, and screened for trypanosomes by HCT and ITS-PCR. A Pearson chi-squared test and logistic regression analyses were performed to determine the association between location, age, sex, and prevalence of trypanosome infections. Results Out of the 816 blood samples examined, 178 (22 %) and 338 (41 %) tested positive for trypanosomiasis by HCT and ITS-PCR, respectively. Trypanosoma vivax infection accounted for 77 % of infections detected by ITS-PCR, T. congolense (16 %), T. brucei s.l (4 %) and mixed (T. vivax/ T. congolense/T.brucei) infections (3 %). The risk of trypanosome infection was significantly associated with cattle age (χ2
= 220.4, df = 3, P < 0.001). The highest proportions of infected animals were adult males (26.7 %) and the least infected were the less than one year old calves (2.0 %). In addition, the risk of trypanosome infection was significantly associated with sex (χ2 = 16.64, df = 1, P < 0.001), and males had a significantly higher prevalence of infections (26.8 %) than females (14.6 %). Conclusion Our results indicate that the prevalence and intensity of trypanosome infections are highly heterogeneous being associated with cattle age, location and sex.
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Affiliation(s)
- Harriet Angwech
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda.
| | - Jack H P Nyeko
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda.
| | - Elizabeth A Opiyo
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda.
| | - Joseph Okello-Onen
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda
| | - Robert Opiro
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda.
| | - Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda.
| | - Geoffrey M Malinga
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda. .,Department of Biology, University of Eastern Finland, P. O. Box 111, 80101, Joensuu, Finland.
| | - Moses N Njahira
- Biosciences Eastern and Central Africa (BecA), International Livestock Research Institute (ILRI) - Hub, Old Naivasha Road, P.O. Box 30709- 00100, Nairobi, Kenya.
| | - Robert A Skilton
- Biosciences Eastern and Central Africa (BecA), International Livestock Research Institute (ILRI) - Hub, Old Naivasha Road, P.O. Box 30709- 00100, Nairobi, Kenya.
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Palacio S, Bergeron R, Lachance S, Vasseur E. The effects of providing portable shade at pasture on dairy cow behavior and physiology. J Dairy Sci 2015; 98:6085-93. [DOI: 10.3168/jds.2014-8932] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 05/28/2015] [Indexed: 11/19/2022]
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Arnold SEJ, Stevenson PC, Belmain SR. Responses to colour and host odour cues in three cereal pest species, in the context of ecology and control. BULLETIN OF ENTOMOLOGICAL RESEARCH 2015; 105:417-425. [PMID: 25916219 DOI: 10.1017/s0007485315000346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many insects show a greater attraction to multimodal cues, e.g. odour and colour combined, than to either cue alone. Despite the potential to apply the knowledge to improve control strategies, studies of multiple stimuli have not been undertaken for stored product pest insects. We tested orientation towards a food odour (crushed white maize) in combination with a colour cue (coloured paper with different surface spectral reflectance properties) in three storage pest beetle species, using motion tracking to monitor their behaviour. While the maize weevil, Sitophilus zeamais (Motsch.), showed attraction to both odour and colour stimuli, particularly to both cues in combination, this was not observed in the bostrichid pests Rhyzopertha dominica (F.) (lesser grain borer) or Prostephanus truncatus (Horn) (larger grain borer). The yellow stimulus was particularly attractive to S. zeamais, and control experiments showed that this was neither a result of the insects moving towards darker-coloured areas of the arena, nor their being repelled by optical brighteners in white paper. Visual stimuli may play a role in location of host material by S. zeamais, and can be used to inform trap design for the control or monitoring of maize weevils. The lack of visual responses by the two grain borers is likely to relate to their different host-seeking behaviours and ecological background, which should be taken into account when devising control methods.
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Affiliation(s)
- S E J Arnold
- Natural Resources Institute,University of Greenwich,Chatham Maritime,Kent ME4 4TB,UK
| | - P C Stevenson
- Natural Resources Institute,University of Greenwich,Chatham Maritime,Kent ME4 4TB,UK
| | - S R Belmain
- Natural Resources Institute,University of Greenwich,Chatham Maritime,Kent ME4 4TB,UK
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25
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Know your foe: lessons from the analysis of tsetse fly behaviour. Trends Parasitol 2015; 31:95-9. [DOI: 10.1016/j.pt.2014.12.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 11/21/2022]
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26
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Waap H, Nunes T, Cortes H, Leitão A, Vaz Y. Prevalence and geographic distribution of Besnoitia besnoiti infection in cattle herds in Portugal. Parasitol Res 2014; 113:3703-11. [DOI: 10.1007/s00436-014-4035-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/04/2014] [Indexed: 10/25/2022]
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von Wissmann B, Fyfe J, Picozzi K, Hamill L, Waiswa C, Welburn SC. Quantifying the association between bovine and human trypanosomiasis in newly affected sleeping sickness areas of Uganda. PLoS Negl Trop Dis 2014; 8:e2931. [PMID: 24901845 PMCID: PMC4046956 DOI: 10.1371/journal.pntd.0002931] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 04/26/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Uganda has active foci of both chronic and acute HAT with the acute zoonotic form of disease classically considered to be restricted to southeast Uganda, while the focus of the chronic form of HAT was confined to the northwest of the country. Acute HAT has however been migrating from its traditional disease focus, spreading rapidly to new districts, a spread linked to movement of infected cattle following restocking. Cattle act as long-term reservoirs of human infective T. b. rhodesiense showing few signs of morbidity, yet posing a significant risk to human health. It is important to understand the relationship between infected cattle and infected individuals so that an appropriate response can be made to the risk posed to the community from animals infected with human pathogens in a village setting. METHODOLOGY/PRINCIPAL FINDINGS This paper examines the relationship between human T. b. rhodesiense infection and human infective and non-human T. brucei s.l. circulating in cattle at village level in Kaberamaido and Dokolo Districts, Uganda. The study was undertaken in villages that had reported a case of sleeping sickness in the six months prior to sample collection and those villages that had never reported a case of sleeping sickness. CONCLUSIONS AND SIGNIFICANCE The sleeping sickness status of the villages had a significant effect with higher odds of infection in cattle from case than from non-case villages for T. brucei s.l. (OR: 2.94, 95%CI: 1.38-6.24). Cattle age had a significant effect (p<0.001) on the likelihood of T. brucei s.l. infection within cattle: cattle between 18-36 months (OR: 3.51, 95%CI: 1.63-7.51) and cattle over 36 months (OR: 4.20, 95%CI: 2.08-8.67) had significantly higher odds of T. brucei s. l. infection than cattle under 18 months of age. Furthermore, village human sleeping sickness status had a significant effect (p<0.05) on the detection of T. b. rhodesiense in the village cattle herd, with significantly higher likelihood of T. b. rhodesiense in the village cattle of case villages (OR: 25, 95%CI: 1.2-520.71). Overall a higher than average T. brucei s.l. prevalence (>16.3%) in a village herd over was associated with significantly higher likelihood of T. b. rhodesiense being detected in a herd (OR: 25, 95%CI: 1.2-520.71).
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Affiliation(s)
- Beatrix von Wissmann
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- Health Protection Scotland, Glasgow, Scotland, United Kingdom
| | - Jenna Fyfe
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Kim Picozzi
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Louise Hamill
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Charles Waiswa
- Department of Pharmacy, Clinical and Comparative studies, School of Veterinary Medicine and Animal Resources, Makerere University, Kampala, Uganda
| | - Susan C. Welburn
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Baldacchino F, Manon S, Puech L, Buatois B, Dormont L, Jay-Robert P. Olfactory and behavioural responses of tabanid horseflies to octenol, phenols and aged horse urine. MEDICAL AND VETERINARY ENTOMOLOGY 2014; 28:201-9. [PMID: 24188243 DOI: 10.1111/mve.12038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/17/2013] [Accepted: 06/25/2013] [Indexed: 05/21/2023]
Abstract
Electrophysiological and behavioural responses of females of two tabanid species, Tabanus bromius L. and Atylotus quadrifarius (Loew) (Diptera: Tabanidae), to ammonia, octenol (1-octen-3-ol), phenols and aged horse urine were compared. Electroantennogram (EAG) responses in both species to octenol, 4-methylphenol (4MP), 3-propylphenol (3PP) and a phenol mixture (4MP and 3PP at a ratio of 16 : 1) increased in a dose-dependent fashion. The most effective stimulus was 4MP and synergism between the two phenols may exist. Aged horse urine also elicited strong EAG responses in both species. Using gas chromatography-mass spectrometry (GC-MS) analysis, we identified 29 compounds in horse urine, which included, in particular, ketones, fatty alcohols and phenols, among which 4MP was the most abundant component (~ 80%). Trapping experiments were carried out using Nzi traps baited with various odours. Octenol and the phenol mixture in combination with ammonia increased catches of tabanids by 1.8-2.8 times relative to ammonia alone. Aged horse urine increased catches of T. bromius and A. quadrifarius by 2.2 and 4.1 times, respectively. The high attractiveness of aged horse urine, especially for A. quadrifarius, is not likely to derive from 4MP alone, but from the mixture of various active compounds used in host location.
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Affiliation(s)
- F Baldacchino
- Unité Mixte de Recherche (UMR) 5175, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry (UM3), Montpellier, France
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29
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Mavoungou JF, Picard N, Kohagne LT, M'batchi B, Gilles J, Duvallet G. Spatio-temporal variation of biting flies, Stomoxys spp. (Diptera: Muscidae), along a man-made disturbance gradient, from primary forest to the city of Makokou (North-East, Gabon). MEDICAL AND VETERINARY ENTOMOLOGY 2013; 27:339-345. [PMID: 23278278 DOI: 10.1111/j.1365-2915.2012.01064.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Understanding the pattern of abundance of vector populations is important to control the potential of transmission of associated pathogens. The pattern of abundance of Stomoxys Geoffroy, an ubiquitous blood-sucking fly, is poorly known in tropical Africa. In this study, we investigated the spatio-temporal pattern of abundance of the Stomoxys genus along a gradient of man-made disturbance in north-eastern Gabon. Three sites (one in primary forest, one in secondary forest and one in a man-made environment) were monitored during 13 months using Vavoua traps. Seven species and subspecies were found to live in sympatry, but with distinct patterns of abundance with respect to space and time. The most abundant species was Stomoxys transvittatus Villeneuve, whereas the rarest species was S. xanthomelas Roubaud. Stomoxys calcitrans Linné was preferentially found in man-made environments, whereas S. xanthomelas was preferentially found in primary forest. Stomoxys abundance was the greatest in secondary forest, then in man-made environments and finally in primary forest. A seasonal variation in Stomoxys abundance was also found. In conclusion, forest degradation and deforestation are likely both to favour the concentration of populations of Stomoxys, and to change the specific composition of the Stomoxys community.
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Affiliation(s)
- J-F Mavoungou
- Département d'écologie animale, Institut de Recherche en Ecologie Tropicale (IRET), Libreville, Gabon.
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30
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Baldacchino F, Cadier J, Porciani A, Buatois B, Dormont L, Jay-Robert P. Behavioural and electrophysiological responses of females of two species of tabanid to volatiles in urine of different mammals. MEDICAL AND VETERINARY ENTOMOLOGY 2013; 27:77-85. [PMID: 22681479 DOI: 10.1111/j.1365-2915.2012.01022.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Urine volatiles from different ungulates (cows, horses and sheep) were tested as bait for tabanids in southeastern France using Nzi traps during the early summer of 2011. Tabanus bromius Linnaeus, 1758 and Atylotus quadrifarius (Loew, 1874) (both: Diptera: Tabanidae) were the most captured species, respectively representing 57% and 41% of all tabanids collected (all of which were female). Horse urine significantly increased catches of T. bromius (1.6-fold) and A. quadrifarius (3.5-fold), and sheep urine significantly increased catches of A. quadrifarius (2.5-fold). In parallel, an electroantennogram (EAG) study was conducted for the first time on these two species, in which EAGs were recorded using 1-octen-3-ol and extracts of the same urine samples used in the field. For T. bromius, the EAG response to 1-octen-3-ol increased quasi-sigmoidally with dose, with a maximum response at ≥100 µg on filter paper. For both species of tabanid, cow and horse urine elicited larger EAGs than did sheep urine. The behavioural implications in host-seeking and feeding habits are discussed.
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Affiliation(s)
- F Baldacchino
- Dynamique et Gouvernance des Systèmes Ecologiques, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, Université Paul-Valéry (UM3), Montpellier, France.
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31
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Friesen KM, Johnson GD. Stable fly phenology in a mixed agricultural--wildlife ecosystem in northeast Montana. ENVIRONMENTAL ENTOMOLOGY 2013; 42:49-57. [PMID: 23339785 DOI: 10.1603/en12231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The stable fly, Stomoxys calcitrans (L.), is a cosmopolitan species of blood-feeding Muscidae and an important pest of cattle. Although the cattle industry is the largest commodity in Montana, no research has been conducted on the abundance, distribution, or impact of stable flies in the state. Observations of stable flies attacking West Nile virus (family Flaviviridae, genus Flavivirus, WNV) -infected pelicans on a refuge in close proximity to pastured and confined cattle provided an opportunity to describe stable fly phenology in a mixed agricultural-wildlife ecosystem. Coroplast cards used to monitor and compare adult populations in three habitats (peninsula, pasture, confinement lot) located within 1.5-4.5 km of each other revealed that temporal dynamics differed by site. Adult abundance was generally lowest at the confinement lot, the only location where larval development was identified. Stable flies were collected on all traps placed in pasture, with traps adjacent to pastured cattle consistently collecting the most. Adults also were collected on the peninsula supporting the pelicans' nesting site, but whether the potential hosts or physical landscape served as an attractant is unclear. At all three sites, data indicated that overwintering was not successful and that a transition occurred from early season immigrating adults that used suitable local larval development substrates to subsequent autochthonous populations.
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Affiliation(s)
- Kristina M Friesen
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA
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Biryomumaisho S, Rwakishaya EK, Melville SE, Cailleau A, Lubega GW. Livestock trypanosomosis in Uganda: parasite heterogeneity and anaemia status of naturally infected cattle, goats and pigs. Parasitol Res 2013; 112:1443-50. [PMID: 23344247 DOI: 10.1007/s00436-013-3275-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 01/08/2013] [Indexed: 10/27/2022]
Abstract
The prevalence and pathogenic effects of trypanosomosis were determined in cattle, goats and pigs reared in Kasese, Jinja and Rakai districts, Uganda; presence of trypanosomes was detected by buffy coat technique (BCT). The overall prevalence of trypanosomosis in cattle was 7.6% (144/1,891), 0.7% in goats (4/573) and 2.3% in pigs (9/386). Internal transcribed spacer 1 (ITS1) of ribosomal DNA polymerase chain reaction was utilised to identify trypanosomes to species level and revealed infections in 108 of the 144 trypanosome-positive cattle while all infected goats and pigs gave amplicons. Trypanosoma vivax was the most prevalent trypanosome species in cattle in single and mixed infections compared to infections involving Trypanosoma congolense and Trypanosoma brucei; in pigs, eight were mixed infections with one single T. vivax infection. No predominant trypanosome species was detected in goats. Anaemia, the main trypanosomosis pathological feature, was investigated by determining packed cell volume (PCV). Mean PCV values by t test in infected individuals were significantly lower than non-infected individuals (P<0.05) for all animal species. However, the proportion of anaemic animals was not significantly different in infected and non-infected individuals. In addition, the percent of infected animals by Fisher's exact test depended on district of origin and species but not sex. These findings show that trypanosomosis is a major cause of anaemia in livestock in endemic areas. Cattle were the major animal species affected by trypanosomosis; similar genotypes of trypanosomes were detected in the three animal species. BCT was more effective than ITS1 rDNA detecting trypanosomes in naturally infected cattle.
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Affiliation(s)
- Savino Biryomumaisho
- Department of Veterinary Pharmacy, Clinical and Comparative Medicine, Makerere University, P.O. Box 7062, Kampala, Uganda.
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Keawrayup S, Duvallet G, Sukonthabhirom S, Chareonviriyaphap T. Diversity of Stomoxys spp. (Diptera: Muscidae) and diurnal variations of activity of Stomoxys indicus and S. calcitrans in a farm, in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand. Parasite 2013; 19:259-65. [PMID: 22910668 PMCID: PMC3671447 DOI: 10.1051/parasite/2012193259] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A study of species diversity of Stomoxys spp. and diurnal variations of activity of the most abundant was performed during a one year period at a local dairy cattle farm in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand. Four species of stomoxyine flies were morphologically identified, including Stomoxys indicus Picard 1908, S. calcitrans (Linnaeus 1758), S. sitiens Rondani 1873 and S. uruma Shinonaga and Kanao 1966. The most common species were S. indicus (50.2%) and S. calcitrans (49.5%). S. sitiens and S. uruma were found in small proportions (< 1%). The number of flies captured was significantly different among the three seasons with the greatest number in the rainy season (mean = 66%; df = 2, P < 0.05). The variations of diurnal activity were observed during different period of times (06:00 to 18:00) during three seasons. Both sexes of S. indicus and males of S. calcitrans showed unimodal activity pattern in cool and summer seasons. But a bimodal activity pattern was recorded in rainy season. For females S. calcitrans, a unimodal peak of activity was observed in cool season and a constant variation of activity all along the day in summer and rainy seasons, with an increase from the morning to the evening. A better understanding of stomoxyine fly behavior, especially the daily flight activity, can assist in prioritization and design of appropriate vector prevention and control strategies.
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Affiliation(s)
- S Keawrayup
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
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Abstract
Mosquitoes use plant sugars and vertebrate blood as nutritional resources. When searching for blood hosts, some mosquitoes express preferential behavior for selected species. Here, we review the available knowledge on host preference, as this is expected to affect the life history and transmission of infectious pathogens. Host preference is affected by myriad extrinsic and intrinsic factors. Inherent factors are determined by genetic selection, which appears to be controlled by adaptive advantages that result from feeding on certain host species. Host preference of mosquitoes, although having a genetic basis, is characterized by high plasticity mediated by the density of host species, which by their abundance form a readily accessible source of blood. Host-selection behavior in mosquitoes is an exception rather than the rule. Those species that express strong and inherent host-selection behavior belong to the most important vectors of infectious diseases, which suggests that this behavioral trait may have evolved in parallel with parasite-host evolution.
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Affiliation(s)
- Willem Takken
- Laboratory of Entomology, Wageningen University and Research Center, 6700 EH Wageningen, The Netherlands.
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35
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Arnold SEJ, Stevenson PC, Belmain SR. Odour-mediated orientation of beetles is influenced by age, sex and morph. PLoS One 2012; 7:e49071. [PMID: 23145074 PMCID: PMC3492127 DOI: 10.1371/journal.pone.0049071] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 10/03/2012] [Indexed: 11/18/2022] Open
Abstract
The behaviour of insects is dictated by a combination of factors and may vary considerably between individuals, but small insects are often considered en masse and thus these differences can be overlooked. For example, the cowpea bruchid Callosobruchus maculatus F. exists naturally in two adult forms: the active (flight) form for dispersal, and the inactive (flightless), more fecund but shorter-lived form. Given that these morphs show dissimilar biology, it is possible that they differ in odour-mediated orientation and yet studies of this species frequently neglect to distinguish morph type, or are carried out only on the inactive morph. Along with sex and age of individual, adult morph could be an important variable determining the biology of this and similar species, informing studies on evolution, ecology and pest management. We used an olfactometer with motion-tracking to investigate whether the olfactory behaviour and orientation of C. maculatus towards infested and uninfested cowpeas and a plant-derived repellent compound, methyl salicylate, differed between morphs or sexes. We found significant differences between the behaviour of male and female beetles and beetles of different ages, as well as interactive effects of sex, morph and age, in response to both host and repellent odours. This study demonstrates that behavioural experiments on insects should control for sex and age, while also considering differences between adult morphs where present in insect species. This finding has broad implications for fundamental entomological research, particularly when exploring the relationships between physiology, behaviour and evolutionary biology, and the application of crop protection strategies.
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Affiliation(s)
- Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom.
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Mihok S, Lange K. Synergism between ammonia and phenols for Hybomitra tabanids in northern and temperate Canada. MEDICAL AND VETERINARY ENTOMOLOGY 2012; 26:282-90. [PMID: 22150639 DOI: 10.1111/j.1365-2915.2011.00999.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Baits for tabanids (Diptera: Tabanidae) were tested in the Northwest Territories (60 °N) and Ontario (45 °N) using Nzi traps. Tests targeted ammonia, phenols/cow urine and octenol. About 200 000 tabanids were captured in 15 experiments with a maximum capture of 4182 in one trap in 1 day. In the Northwest Territories, phenols, urine and octenol were effective single baits for only some species. At both locations, adding ammonia to an unbaited or an octenol-baited trap had no effect on catches. By contrast, catches were increased for several species when ammonia was combined with phenols or urine. In Ontario, including ammonia in various baits increased catches by 1.5- to 3.4-fold relative to octenol alone for three Hybomitra and one Tabanus species. Synergism between ammonia and phenols was clearly demonstrated for the dominant Hybomitra species in Ontario (Hybomitra lasiophthalma), but not for the dominant species in the Northwest Territories (Hybomitra epistates). In five other northern Hybomitra species, baits of ammonia and/or octenol in combination with phenols resulted in a 1.7- to 4.1-fold increase in catch relative to an unbaited trap. Further tests of ammonia as a synergist for biting flies may prove useful in, for example, tsetse, which respond strongly to phenols.
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Affiliation(s)
- S Mihok
- Department of Civil and Environmental Engineering, Carleton University, Ottawa, ON, Canada.
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Factors associated with acquisition of human infective and animal infective trypanosome infections in domestic livestock in Western Kenya. PLoS Negl Trop Dis 2011; 5:e941. [PMID: 21311575 PMCID: PMC3022529 DOI: 10.1371/journal.pntd.0000941] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 12/07/2010] [Indexed: 11/19/2022] Open
Abstract
Background Trypanosomiasis is regarded as a constraint on livestock production in Western Kenya where the responsibility for tsetse and trypanosomiasis control has increasingly shifted from the state to the individual livestock owner. To assess the sustainability of these localised control efforts, this study investigates biological and management risk factors associated with trypanosome infections detected by polymerase chain reaction (PCR), in a range of domestic livestock at the local scale in Busia, Kenya. Busia District also remains endemic for human sleeping sickness with sporadic cases of sleeping sickness reported. Results In total, trypanosome infections were detected in 11.9% (329) out of the 2773 livestock sampled in Busia District. Multivariable logistic regression revealed that host species and cattle age affected overall trypanosome infection, with significantly increased odds of infection for cattle older than 18 months, and significantly lower odds of infection in pigs and small ruminants. Different grazing and watering management practices did not affect the odds of trypanosome infection, adjusted by host species. Neither anaemia nor condition score significantly affected the odds of trypanosome infection in cattle. Human infective Trypanosoma brucei rhodesiense were detected in 21.5% of animals infected with T. brucei s.l. (29/135) amounting to 1% (29/2773) of all sampled livestock, with significantly higher odds of T. brucei rhodesiense infections in T. brucei s.l. infected pigs (OR = 4.3, 95%CI 1.5-12.0) than in T. brucei s.l. infected cattle or small ruminants. Conclusions Although cattle are the dominant reservoir of trypanosome infection it is unlikely that targeted treatment of only visibly diseased cattle will achieve sustainable interruption of transmission for either animal infective or zoonotic human infective trypanosomiasis, since most infections were detected in cattle that did not exhibit classical clinical signs of trypanosomiasis. Pigs were also found to be reservoirs of infection for T. b. rhodesiense and present a risk to local communities. Rhodesian sleeping sickness caused by Trypanosome brucei rhodesiense is a parasitic disease transmitted by tsetse flies which is fatal in humans if it is not treated. The parasites also infect a range of animal species in which they do not cause acute disease and may co-exist with other non human infective parasites. Busia District (Western Kenya) is a historic sleeping sickness focus. Human cases of this disease are still reported occasionally in Busia and neighbouring Teso District, most recently in 2008, showing that the human infective parasite species are still present in the area. However, trypanosomes in this region are mainly regarded as a threat to the productivity of domestic livestock and the responsibility for trypanosomiasis control has shifted from the state to livestock holders. To examine whether farmer-based control strategies can be successful, this study assessed the factors that influence trypanosomiasis in livestock at the local level. The study showed that cattle are the livestock species most frequently affected by trypanosomes. However infection in cattle was not necessarily associated with signs of disease; furthermore pigs were shown to be important carriers of the human infective parasite. The treatment of only visibly diseased cattle to avoid losses in productivity will not successfully control the parasite in the long term. Keeping livestock in the vicinity of the homesteads also did not protect the animals from trypanosome infection. This indicated that the tsetse fly transmits the parasite in close proximity to human habitation, which could increase the risk of humans being infected.
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Pinto MC, Barbieri K, Silva MCE, Graminha MAS, Casanova C, Andrade AJ, Eiras AE. Octenol as attractant to Nyssomyia neivai (Diptera:Psychodidae:Phlebotominae) in the field. JOURNAL OF MEDICAL ENTOMOLOGY 2011; 48:39-44. [PMID: 21337946 DOI: 10.1603/me10081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The kairomone octenol is known as attractive to hematophagous Diptera such as mosquitoes, tsetse flies, and midges. There is little evidence that traps baited with octenol are also effective in attracting phlebotomine sand flies. The present report evaluated octenol in modified Centers for Disease Control and Prevention (CDC) traps in two experiments: 1) modified CDC trap without light and 2) modified CDC trap with light. The traps were baited with octenol at concentrations of 0.5, 27, and 43 mg/h in Rincão locality, São Paulo, Brazil. Traps without octenol were used as controls. The sand fly Nyssomyia neivai (Pinto) (= Lutzomyia neivai) (Diptera: Psychodidae: Phlebotominae) was the prevalent species (99.9%) in both experiments. The results of the experiments showed that traps baited with octenol at 27 and 43 mg/h caught significantly more N. neivai than control and octenol at 0.5 mg/h with and without light. This is the first report that shows that octenol itself is attractive to N. neivai and associated with light traps significantly increases the catches.
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Affiliation(s)
- M C Pinto
- Laboratório de Parasitologia, Departamento de Ciências Biológicas, Faculdade de Ciências Farmacêuticas, Universidade Estadual Julio de Mesquita Filho, 14801-902 Araraquara-SP, Brazil.
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Bett B, Randolph TF, Irungu P, Nyamwaro SO, Kitala P, Gathuma J, Grace D, Vale G, Hargrove J, McDermott J. Field trial of a synthetic tsetse-repellent technology developed for the control of bovine trypanosomosis in Kenya. Prev Vet Med 2010; 97:220-7. [PMID: 20980070 DOI: 10.1016/j.prevetmed.2010.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 08/31/2010] [Accepted: 09/02/2010] [Indexed: 10/18/2022]
Abstract
We conducted a field trial among Maasai cattle-keepers in Nkuruman and Nkineji areas of Kenya to evaluate the effectiveness of a synthetic tsetse-repellent technology developed for the control of trypanosomosis in cattle. The technology was a repellent (2-methoxy 4-methylphenol) emitted from dispensers attached to collars worn by cattle. Treatment was allocated at the herd level to ensure adequate protection of all the animals in a herd, with measurements of effectiveness conducted at the individual-animal level. The trial began in April 2005 and ran for 16 months including a baseline phase of 4 months. We recruited 12 herds in each area using a restricted random-sampling technique and distributed them equally into intervention (repellent) and control groups. Sample size was determined using a formal power calculation. Effectiveness or minimal worthwhile difference was defined as a 50% reduction in the incidence of trypanosome infection in the treated versus control group (effectiveness below which the technology was considered by experts as not viable compared to existing control techniques). All the animals in the recruited herds were screened monthly (buffy-coat technique) for trypanosome infections. The analysis followed the principle of intention-to-treat by which subjects are analysed according to their initial treatment assignment, regardless of the mechanical performance of the device. Crude and adjusted effects of the technology were 23% (p<0.001) and 18% (p=0.08) reduction in the infection incidence in the treatment compared to the control groups, respectively. The impact of the technology estimated in this study did not achieve the threshold of 50% reduction in the trypanosome infection incidence set a priori to indicate effectiveness (p<0.001). We therefore concluded that the prototype repellent technology package was not sufficiently effective in reducing trypanosome infection incidence under natural tsetse challenge to merit commercial development.
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Affiliation(s)
- B Bett
- International Livestock Research Institute, P.O. Box 30709-00100, Nairobi, Kenya.
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Mihok S, Mulye H. Responses of tabanids to Nzi traps baited with octenol, cow urine and phenols in Canada. MEDICAL AND VETERINARY ENTOMOLOGY 2010; 24:266-72. [PMID: 20572930 DOI: 10.1111/j.1365-2915.2010.00889.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Cow urine and the two phenols responsible for the attraction of biting flies to cow urine (4-methylphenol, 3-n-propylphenol) were compared with octenol (1-octen-3-ol) as baits for Tabanidae. Relative to an unbaited Nzi trap, catches of the horseflies Hybomitra lasiophthalma (Macquart), Tabanus similis Macquart and Tabanus quinquevittatus Wiedemann (Diptera: Tabanidae) were increased by 1.5-2.6, 1.4-2.0 and 1.4-1.9 times, respectively, whenever a bait included octenol released at either 0.13 mg/h or 1.5 mg/h, regardless of the presence of phenols or urine. Catches were not affected when traps were baited with phenols alone at evaporation rates of 0.38 mg/h (4-methylphenol) and 0.022 mg/h (3-n-propylphenol). Catches of Hybomitra horseflies were increased by 1.5-1.9 times with cow urine and 2.6 times with cow urine + octenol. This bait combination could prove to be particularly useful for Hybomitra horseflies, the common tabanids of northern environments.
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Muenworn V, Duvallet G, Thainchum K, Tuntakom S, Tanasilchayakul S, Prabaripai A, Akratanakul P, Sukonthabhirom S, Chareonviriyaphap T. Geographic distribution of stomoxyine flies (Diptera: Muscidae) and diurnal activity of Stomoxys calcitrans in Thailand. JOURNAL OF MEDICAL ENTOMOLOGY 2010; 47:791-797. [PMID: 20939373 DOI: 10.1603/me10001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Stomoxyine flies (Stomoxys spp.) were collected in 10 localities of Thailand using the Vavoua traps. These localities represented four major ecological settings, as follows: small local dairy farms, large industrial dairy farms, a national park, and one elephant conservation area. Three species of stable flies were identified in the following proportions: Stomoxys calcitrans (91.5%), Stomoxys indicus (7.9%), and Stomoxys sitiens (0.6%). The number of flies collected differed significantly among collection sites (chi2 = 360.15, df=3, P < 0.05). The greatest number of stomoxyine flies was captured in dairy farms. Seasonal and daily activity of S. calcitrans was observed during a 1-yr period at two selected locations (Dairy Farming Promotion Organization of Thailand and Khao Kheow Open Zoo). S. calcitrans was more abundant during the rainy season (March-September), but was not associated with the total rainfall (r2 = 0.0002, P > 0.05). Peak of daily flight activity of males S. calcitrans was at 1000 and 1600 h, whereas females showed an increase of activity all along the day until 1600 h. A better understanding of stomoxyine fly behavior related to patterns of daily activity will facilitate and improve the efficiency of fly control measures in private and government sectors.
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Affiliation(s)
- Vithee Muenworn
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
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Feeding success and trappability of horse flies evaluated with electrocuting nets and odour-baited traps. Vet Parasitol 2010; 171:321-6. [DOI: 10.1016/j.vetpar.2010.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/19/2010] [Accepted: 03/22/2010] [Indexed: 11/22/2022]
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Bovine trypanosomosis and its vectors in two districts of Bench Maji zone, South Western Ethiopia. Trop Anim Health Prod 2010; 42:1757-62. [PMID: 20577803 DOI: 10.1007/s11250-010-9632-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2010] [Indexed: 10/19/2022]
Abstract
A cross-sectional study was carried out from November 2008 to February 2009 in Guraferda and Sheko districts of Bench Maji Zone, South Western Ethiopia. The objective of the study was to determine the prevalence of bovine trypanosomosis and the density of its vectors. An overall prevalence of trypanosome infection in the study area was 4.4%. Trypanosoma congolense (36.36%) was the dominant trypanosome species followed by Trypanosoma vivax (18.18%) and Trypanosoma brucei (9.09%). Mean packed cell volume value of parasitemic animals (21.8%) was significantly (P<0.05) lower than that of aparasitemic animals (27.7%). Biconical and NGU traps were deployed for 72 h, and the result indicated Glossina pallidipes followed by Glossina fuscipes as the only tsetse fly species caught in the study area along with other biting flies like Stomoxys and Tabanus. The apparent density of tsetse flies was 2.83 flies trap(-1) day(-1). NGU trap caught more of G. pallidipes while biconical trap caught more G. fuscipes, and the difference was significant (P<0.05). Although the current study indicated low prevalence of trypanosomosis in the study area, the impacts of trypanosomosis on cattle production and productivity should not be neglected. Therefore, attention should be given to control the disease and also the vector.
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Prospects for the development of odour baits to control the tsetse flies Glossina tachinoides and G. palpalis s.l. PLoS Negl Trop Dis 2010; 4:e632. [PMID: 20300513 PMCID: PMC2838779 DOI: 10.1371/journal.pntd.0000632] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 01/28/2010] [Indexed: 12/01/2022] Open
Abstract
Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (∼5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2×) the trap catch significantly but not the catch from electric targets. For G. p. palpalis, odours from pigs and humans increased (∼5×) the numbers of tsetse attracted to the vicinity of the odour source but had little effect on landing or trap-entry. For G. tachinoides a blend of POCA (P = 3-n-propylphenol; O = 1-octen-3-ol; C = 4-methylphenol; A = acetone) alone or synthetic cattle odour (acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol with carbon dioxide) consistently caught more tsetse than natural cattle odour. For G. p. gambiensis, POCA consistently increased catches from both traps and targets. For G. p. palpalis, doses of carbon dioxide similar to those produced by a host resulted in similar increases in attraction. Baiting traps with super-normal (∼500 mg/h) doses of acetone also consistently produced significant but slight (∼1.6×) increases in catches of male flies. The results suggest that odour-baited traps and insecticide-treated targets could assist the AU-Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) in its current efforts to monitor and control Palpalis group tsetse in West Africa. For all three species, only ∼50% of the flies attracted to the vicinity of the trap were actually caught by it, suggesting that better traps might be developed by an analysis of the visual responses and identification of any semiochemicals involved in short-range interaction. Sleeping sickness, otherwise known as Human African Trypanosomiasis, continues to be a serious threat to human health. This disease, which is transmitted by tsetse flies, normally afflicts poor and isolated communities. No vaccines or prophylactic drugs are available to prevent the disease, which, once it has been contracted, is treated with curative drugs that often prove ineffective because of emerging disease resistance in the trypanosomes. These drugs can often have unpleasant and sometimes fatal side effects. Prospects for development of effective vaccines or prophylactic drugs are poor. Killing the tsetse fly vector remains the only method of preventing disease transmission. This can be done at either a local level or regionally. However, a major problem is the cost and logistical difficulty of implementing fly control programmes. To overcome this, we are trying to develop cost-effective insecticide-treated targets by identifying chemicals that will increase the numbers of tsetse that will be lured to a target and killed. Here we show that G. tachinoides is significantly attracted to cow odour, G. p. gambiensis to both cow and human odour, and G. p. palpalis to odours from pigs and humans. This opens the way for further work to identify the attractants present in these natural odours that can then be simply and cheaply incorporated into targets to reduce the cost of control.
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Oyarzún MP, Palma R, Alberti E, Hormazabal E, Pardo F, Birkett MA, Quiroz A. Olfactory response of Haematobia irritans (Diptera: Muscidae) to cattle-derived volatile compounds. JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:1320-1326. [PMID: 19960676 DOI: 10.1603/033.046.0610] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In Chile, the horn fly, Hematobia irritans (L., 1758), is a major pest of grazing cattle and affects livestock production during the summer. Previous studies in Europe and the United States have shown that cattle flies, including H. irritans, are differentially attracted to individual cattle within herds and that volatile semiochemicals are responsible for this phenomenon. This study provides evidence that similar differential attractiveness occurs for the interaction between Chilean Holstein-Friesian cattle herds and local H. irritans populations. Thus, Holstein-Friesian dairy cattle, Bos taurus, which were of similar age and physiological condition, were shown to possess an uneven distribution of H. irritans. Heifers h6904 and h8104 were defined as low-carrier heifers and h5804, h2304 and h1404 as high-carrier heifers. Gas chromatography (GC) and coupled GC-mass spectrometric (GC-MS) analysis of samples collected from heifers revealed the presence of compounds previously reported as semiochemicals for cattle flies, including meta- and para-cresol, methylketones (C8-C11), and 6-methyl-5-hepten-2-one. Other compounds identified included carboxylic acids (butanoic, 3-methylbutanoic, pentanoic, and hexanoic acids), 1-hexanol, and 3-octanone. In Y-tube olfactometer studies, both m- and p-cresol attracted H. irritans at the highest doses tested (10(-6) g), as did the positive control 1-octen-3-ol. Of the other compounds tested, only 2-decanone and 2-undecanone produced a behavioral response, with significantly more flies being recorded in the control arm when the former compound was tested (at 10(-6) and 10(-8) g), and more flies being recorded in the treated arm for the latter compound (at 10(-7) g). This demonstration of behavioral activity with the identified compounds represents a first step for research into the application of semiochemicals in monitoring and control of cattle flies in Chile.
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Affiliation(s)
- M P Oyarzún
- Instituto de Ecología y Evolución, Universidad Austral de Chile, Valdivia, Chile
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Omolo MO, Hassanali A, Mpiana S, Esterhuizen J, Lindh J, Lehane MJ, Solano P, Rayaisse JB, Vale GA, Torr SJ, Tirados I. Prospects for developing odour baits to control Glossina fuscipes spp., the major vector of human African trypanosomiasis. PLoS Negl Trop Dis 2009; 3:e435. [PMID: 19434232 PMCID: PMC2674566 DOI: 10.1371/journal.pntd.0000435] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 04/16/2009] [Indexed: 11/19/2022] Open
Abstract
We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1x1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of all four odours on the proportion of tsetse that entered a biconical trap were also determined. Sources of natural host odour were produced by placing live hosts in a tent or metal hut (volumes approximately 16 m(3)) from which the air was exhausted at approximately 2000 L/min. Odours from cattle, pigs and humans had no significant effect on attraction of G. f. fuscipes but lizard odour doubled the catch (P<0.05). Similarly, mammalian odours had no significant effect on landing or trap entry whereas lizard odour increased these responses significantly: landing responses increased significantly by 22% for males and 10% for females; the increase in trap efficiency was relatively slight (5-10%) and not always significant. For G. f. quanzensis, only pig odour had a consistent effect, doubling the catch of females attracted to the source and increasing the landing response for females by approximately 15%. Dispensing CO(2) at doses equivalent to natural hosts suggested that the response of G. f. fuscipes to lizard odour was not due to CO(2). For G. f. quanzensis, pig odour and CO(2) attracted similar numbers of tsetse, but CO(2) had no material effect on the landing response. The results suggest that identifying kairomones present in lizard odour for G. f. fuscipes and pig odour for G. f. quanzensis may improve the performance of targets for controlling these species.
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Affiliation(s)
- Maurice O. Omolo
- International Center for Insect Physiology and Ecology, ICIPE, Nairobi, Kenya
- Masinde Muliro University of Science & Technology, Kakamega, Kenya
| | - Ahmed Hassanali
- International Center for Insect Physiology and Ecology, ICIPE, Nairobi, Kenya
| | | | | | - Jenny Lindh
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Mike J. Lehane
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Philippe Solano
- Institut de Recherche pour le Développement (IRD), UMR 177 IRD-CIRAD, Montpellier, France
| | - Jean Baptiste Rayaisse
- Centre International de Recherche-Développement sur l'Elevage en Zone Subhumide (CIRDES), Bobo Dioulasso, Burkina Faso
| | - Glyn A. Vale
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
| | - Steve J. Torr
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
| | - Inaki Tirados
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
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Beresford DV, Sutcliffe JF. Male stable fly (Stomoxys calcitrans) response to CO2 changes with age: evidence from wind tunnel experiments and field collections. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2008; 33:247-254. [PMID: 19263843 DOI: 10.3376/1081-1710-33.2.247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Male stable flies require at least one or more blood meals to reach sexual maturity and are often caught in CO2-baited traps. We tested the hypothesis that young male stable flies (one to three days, one blood feeding session) would be more responsive to CO2 bait than older male stable flies by monitoring the upwind movement of different-aged male stable flies exposed to CO2 using a wind tunnel. The proportion of males moving upwind toward CO2 decreased with age (days), from 49% for males < or = 3 days old, to 4.5% for males > 3 days old. To further test this, we conducted daily sampling of stable fly populations at a beef farm using a CO2-baited cloth trap. We found that days on which a high proportion of males were caught, females were predominantly from early developmental stages, indicating that proportionately more males were caught from field populations made up of younger cohorts. These results were consistent with the wind tunnel experiment patterns.
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Affiliation(s)
- D V Beresford
- Biology Department, Trent University, 1600 West Bank Drive, Peterborough ON, Canada
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Oyarzún MP, Quiroz A, Birkett MA. Insecticide resistance in the horn fly: alternative control strategies. MEDICAL AND VETERINARY ENTOMOLOGY 2008; 22:188-202. [PMID: 18816268 DOI: 10.1111/j.1365-2915.2008.00733.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The horn fly, Haematobia irritans (Linnaeus 1758) (Diptera: Muscidae) is one of the most widespread and economically important pests of cattle. Although insecticides have been used for fly control, success has been limited because of the development of insecticide resistance in all countries where the horn fly is found. This problem, along with public pressure for insecticide-free food and the prohibitive cost of developing new classes of compounds, has driven the investigation of alternative control methods that minimize or avoid the use of insecticides. This review provides details of the economic impact of horn flies, existing insecticides used for horn fly control and resistance mechanisms. Current research on new methods of horn fly control based on resistant cattle selection, semiochemicals, biological control and vaccines is also discussed.
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Affiliation(s)
- M P Oyarzún
- Laboratorio Química Ecológica, Departamento de Ciencias Químicas, Universidad de La Frontera, Temuco, Chile
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Acute haemorrhagic syndrome of bovine trypanosomosis in Uganda. Acta Trop 2008; 107:186-91. [PMID: 18599006 DOI: 10.1016/j.actatropica.2008.05.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/22/2008] [Accepted: 05/23/2008] [Indexed: 11/21/2022]
Abstract
A study was undertaken in July 2005 to investigate an acute haemorrhagic syndrome that caused cattle mortality starting March 2005 in Mifumi, Senda, Kainja and Nyagoke villages of Tororo district in Uganda; areas dominantly infested with Glossina fuscipes fuscipes with scanty G. pallidipes. Four hundred and one (401) cattle belonging to 158 farmers were randomly sampled from a population of 549 and screened using a combination of Haematocrit Centrifugation Technique (HCT) and Buffy Coat Technique (BCT) for trypanosomosis. Of which 49 (12.2%) had trypanosome infection. Clinical cases manifested bleeding through the ears, severe weight loss, anaemia, weakness and enlarged lymph nodes prior to death. Out of an original population of 844 cattle 295 (35%) had died. The prevalence of bovine trypanosomosis in herds experiencing mortality (21.5%) was significantly higher than in those without mortality (2.6%) (chi(2)=33.4, P<0.001). Herd size, number of draught oxen and lactating cows in a given herd significantly influenced the risk of mortality (P<0.001). Males had a significantly higher prevalence of trypanosomosis (17.8%) than females (9.5%) (chi(2)=5.58, P<0.05) and significantly lower mean packed cell volume (PCV) (23.7%) than females (25.4%) (P<0.05). Older calves (7-12 months), yearlings (13-24 months) and adults (>24 months) with prevalences of 11.1%, 15.4% and 11.8%, respectively, were the most affected age categories. Trypanosome-infected cattle had a significantly lower mean PCV (17.9%) than non-infected ones (25.8%) (P<0.001), and a significantly higher proportion of anaemic animals (81.6%) than non-infected ones (37.2%) (chi(2)=34.6, P<0.001). Trypanosoma vivax was the dominant trypanosome species, constituting 82% of trypanosome infections. This work has provided further evidence on the importance of T. vivax-induced acute haemorrhagic syndrome in livestock trypanosomosis.
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Guerenstein PG, Hildebrand JG. Roles and effects of environmental carbon dioxide in insect life. ANNUAL REVIEW OF ENTOMOLOGY 2008; 53:161-78. [PMID: 17803457 DOI: 10.1146/annurev.ento.53.103106.093402] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Carbon dioxide (CO(2)) is a ubiquitous sensory cue that plays multiple roles in insect behavior. In recent years understanding of the well-known role of CO(2) in foraging by hematophagous insects (e.g., mosquitoes) has grown, and research on the roles of CO(2) cues in the foraging and oviposition behavior of phytophagous insects and in behavior of social insects has stimulated interest in this area of insect sensory biology. This review considers those advances, as well as some of the mechanistic bases of the modulation of behavior by CO(2) and important progress in our understanding of the detection and CNS processing of CO(2) information in insects. Finally, this review briefly addresses how the ongoing increase in atmospheric CO(2) levels may affect insect life.
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Affiliation(s)
- Pablo G Guerenstein
- Arizona Research Laboratories, Division of Neurobiology, The University of Arizona, Tucson, AZ 85721-0077, USA.
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