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Jaimes-Dueñez J, Tique-Oviedo M, Arias-Vega L, Castiblanco-Diaz E, Rivero-Rodriguez L, Marin-Cossio L, Gongora-Orjuela A, Jimenez-Leaño A. Epidemiological assessment of Anaplasma marginale, Babesia bigemina, and Babesia bovis infections in Colombian creole cattle breeds: A molecular survey in northeastern Colombia. Vet Parasitol Reg Stud Reports 2024; 50:101011. [PMID: 38644043 DOI: 10.1016/j.vprsr.2024.101011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 04/23/2024]
Abstract
Anaplasmosis and babesiosis are globally distributed arthropod-borne diseases known for causing substantial economic losses due to their high morbidity and mortality rates. This study aims to assess the frequency and epidemiological features associated with the infection of Anaplasma marginale, Babesia bigemina, and Babesia bovis in three Creole cattle breeds (Chino Santandereano (Chino), Casanareño (CAS), and Sanmartinero (SM)) in northeastern Colombia. Between June 2019 and March 2020, a total of 252 Creole cattle were sampled, with Chino, CAS, and SM accounting for 42.8%, 29.5%, and 29.5% of the samples, respectively. Blood samples were subjected to molecular analysis to detect the DNA of A. marginale, B. bigemina, and B. bovis, using species-specific primers. Additionally, Packed Cell Volume (PCV), total serum proteins, and body condition were evaluated. Molecular analyses revealed the presence of B. bigemina, A. marginale, and B. bovis in 83.7% (211/252; 95% CI = 79.1%-88.3%), 59.9% (151/252; 95% CI = 53.8%-66.1%), and 40.9% (103/252; 95% CI = 34.7%-46.9%) of the samples, respectively, with 69% (174/252; 95% CI = 57.8%-80.3%) exhibiting coinfections. Notably, in infected animals, no significant alterations in PCV, total serum proteins, or body condition were observed. Multivariate analyses indicated a statistically significant association between the frequency of A. marginale infection and the breed and season, with a higher frequency in SM during the rainy season (P < 0.05). To our knowledge, this is the first molecular survey that evaluates multiple arthropod-borne pathogens in Colombian Creole breeds. The results revel a high frequency of B. bigemina and A. marginale infections, coupled with a notable frequency of coinfections, all without significant alteration in the PCV, total serum proteins and body conditions. Our findings enhance the understanding of the epidemiological aspects of arthropod-borne pathogens in Colombian Creole breed and contribute to the improvement of sanitary programs for these animals.
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Affiliation(s)
- Jeiczon Jaimes-Dueñez
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia.
| | - Marisol Tique-Oviedo
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia
| | - Laura Arias-Vega
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia
| | - Edinson Castiblanco-Diaz
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia
| | - Leslie Rivero-Rodriguez
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia
| | - Laura Marin-Cossio
- Grupo de Investigación en Reproducción y Genética Animal - GIRGA, Facultad de Medicina Veterinaria y Zootecnia, Universidad de los Llanos, Villavicencio, Colombia
| | - Agustín Gongora-Orjuela
- Grupo de Investigación en Reproducción y Genética Animal - GIRGA, Facultad de Medicina Veterinaria y Zootecnia, Universidad de los Llanos, Villavicencio, Colombia
| | - Angela Jimenez-Leaño
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia UCC, Bucaramanga, Colombia
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Glossina pallidipes Density and Trypanosome Infection Rate in Arba Minch Zuria District of Gamo Zone, Southern Ethiopia. J Parasitol Res 2022; 2022:3004054. [PMID: 36317107 PMCID: PMC9617703 DOI: 10.1155/2022/3004054] [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: 03/02/2022] [Revised: 09/08/2022] [Accepted: 10/02/2022] [Indexed: 11/25/2022] Open
Abstract
Background African trypanosomosis is a disease of both animals and humans resulting from infection with parasitaemic protozoa of the genus Trypanosoma transmitted mainly by the tsetse flies (Glossina species). The disease has been reported in different parts of the country. However, information on the apparent density and trypanosome infection rates of the vectors is very limited in the Southern part of Ethiopia. Therefore, this study was conducted to estimate the apparent density, infection rate of trypanosomes in Glossina pallidipes, and the trypanosome species involved in Arba Minch Zuria district of Southern Ethiopia. Methods A cross-sectional study was conducted from January to June 2018 in two purposely selected kebeles of Arbaminch Zuria district and in the escarpments of Nech Sar National Park of Southern Ethiopia. For entomological survey, a total of 40 standard NGU traps were deployed around the watering and grazing areas. A total of 300 fresh Glossina pallidipes were examined for trypanosome infection using a dissection procedure as described by the FAO Training manual for tsetse control personnel. Results The study revealed the presence of only one Glossina species, known as Glossina pallidipes, and biting flies including Stomoxys and Tabanus. A total of 2176 flies were caught of which 1803 (82.86%) belong to Glossina pallidipes and the remaining 373 (17.14%) were biting flies. The overall apparent density of Glossina pallidipes and biting flies in the study area were 15.03 fly/trap/day (F/T/D) and 3.11 F/T/D, respectively. Relatively higher Glossina pallidipes and biting flies, respectively, were caught in a wood-grass land (15.87 F/T/D and 3.69 F/T/D) and riverine forest (15.13 F/T/D and 3.42 F/T/D) than bush land vegetation types (13.87 F/T/D and 1.76 F/T/D). The overall trypanosome infection rate of Glossina pallidipes was 17.67% (53/300). Two trypanosome species, namely, Trypanosoma congolense (66.04%) and Trypanosoma vivax (33.96%), were responsible for Glossina pallidipes infection in the study area. Trypanosome infection rate was significantly higher in female G. pallidipes than in male (OR = 3.39, 95%CI = 1.53‐7.52). Significantly, higher trypanosome infection rate was observed in flies older than 20 days (OR = 2.5, 95%CI = 1.12‐5.56) and in hunger stage 1 flies (OR = 14.24, 95%CI = 4.01‐50.59). Glossina pallidipes infection was significantly higher in and around park grazing areas (OR = 3.41, 95%CI = 1.76‐6.6) and wood-grass land vegetation type (OR = 2.7, 95%CI = 1.2‐6.5). Conclusion The current study revealed high apparent density and trypanosome infection in Glossina pallidipes in Arba Minch Zuria district of Southern Ethiopia. So, this study warrants the need for strengthening both vector and parasite control strategies in the study area.
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Seyoum W, Tora E, Kore K, Lejebo F. Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia. Front Vet Sci 2022; 9:805564. [PMID: 35359685 PMCID: PMC8961361 DOI: 10.3389/fvets.2022.805564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 01/13/2022] [Indexed: 11/13/2022] Open
Abstract
Bovine trypanosomosis is a parasitic disease causing serious economic losses in livestock productivity and agricultural development. The disease has been reported in different parts of Ethiopia. However, seasonal pattern of trypanosomosis, tsetse fly apparent density, and infection are very limited in the southern rift valley of the country, particularly in Gamo Zone. Therefore, the objective of this cross-sectional study design was to estimate seasonal prevalence of bovine trypanosomosis, assessing tsetse fly apparent density and its infection by trypanosomes. For the parasitological study, a total of 600 cattle (300 in each season) were sampled and assayed using the buffy coat technique. A total of 80 standard NGU traps were deployed around the watering and grazing areas for the entomological survey. An overall prevalence of trypanosomosis was 10.17% (61/600), of which 7.33% (22/300) and 13% (39/300) accounted for the dry and wet seasons, respectively. The prevalence of trypanosomosis was significantly higher during the wet season (OR = 2.47; p < 0.05), in black coat color (OR = 7.2, p < 0.05), and poor body-conditioned (OR = 3.15; p < 0.05) animals. Two species of trypanosomes, Trypanosoma congolense, 68.85% (42/61), and Trypanosoma vivax, 31.15% (19/61), were circulating in the area. The mean PCV value in infected animals (22.56 ± 4.61) was significantly lower than in non-infected animals (25.3 ± 4.75). Entomological result indicated that Glossina pallidipes (G. pallidipes) was the only species of tsetse found in the study area. Totally, 3,789 flies were caught of which 81.42% (3,085/3,789) belong to G. pallidipes and 18.58% (704/3,789) were other biting flies. The overall apparent density of G. pallidipes was 12.85 flies/trap/day (FTD). Relatively higher G. pallidipes/trap/day were caught in the wet season (13.64 F/T/D) than in the dry season (12.07F/T/D). Of the flies caught, 342 G. pallidipes were randomly selected and dissected. The overall proportion of G. pallidipes infection was 18.42% (63/342) of which 12.28% (21/171) and 24.56% (42/171) were accounted in the dry and wet seasons, respectively. Infection in G. pallidipes was significantly higher during the wet season (OR = 2.32; p < 0.05) and in park grazing areas (OR = 2.45; p < 0.05). In conclusion, trypanosomosis is the major challenge for cattle productivity in the district. So this study warrants the need for strengthening the vector and parasite control interventions in the area.
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Affiliation(s)
- Wasihun Seyoum
- Department of Animal Science and Health, College of Agricultural Sciences, Arba Minch University, Arba Minch, Ethiopia
| | - Ephrem Tora
- Department of Animal Science and Health, College of Agricultural Sciences, Arba Minch University, Arba Minch, Ethiopia
- *Correspondence: Ephrem Tora
| | - Kokeb Kore
- National Institute for Control and Eradication of Tsetse Fly and Trypanosomosis, Arba Minch, Ethiopia
| | - Firew Lejebo
- National Institute for Control and Eradication of Tsetse Fly and Trypanosomosis, Arba Minch, Ethiopia
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Eyasu T, Mekuria S, Sheferaw D. Seasonal prevalence of trypanosomosis, Glossina density and infection along the escarpment of Omo River, Loma district, southern Ethiopia. Heliyon 2021; 7:e06667. [PMID: 33997365 PMCID: PMC8095118 DOI: 10.1016/j.heliyon.2021.e06667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/10/2021] [Accepted: 03/29/2021] [Indexed: 11/25/2022] Open
Abstract
Background The temporal information of trypanosomosis and tsetse apparent density is very limited in the southern part of the country. So, the study was conducted to estimate the temporal, dry and wet seasons, prevalence of cattle trypanosomosis, and tsetse fly apparent density and its infection by trypanosome along the escarpment of Omo River, Loma district, Southern Ethiopia. Methods A total of 964 cattle (482 in each seasons) were examined for trypanosomosis using buffy coat technique. For Glossina and biting flies study a total of 80 odor-baited, acetone and aged cow urine, NGU traps were deployed around the watering and grazing areas. Results The overall prevalence of cattle trypanosomosis was 4.98% of which 3.1% and 6.8% accounted to dry and wet seasons, respectively. The prevalence of trypanosomosis was significantly higher during wet season (OR = 1.93, P < 0.05), in poor body condition (OR = 3.71, P < 0.05) and in black coat colour (OR = 13.18, P < 0.05) animals. Two species of Trypanosome, T. congolense and T. vivax, were circulating in the area both in dry and wet seasons. A total of 327 Glossina (126 G. pallidipes and 201 G. fuscipes) were traped by using odour baited 80 NGU traps. The overall apparent density of Glossina was 4.1 Flies/Trap/Day. Relatively higher Glossina/Trap/Day caught in wet season (4.9 Flies/Trap/Day) than dry season (3.3 Flies/Trap/Day). Two species of Glossina namely G. pallidipes and G. fuscipes were distributed in the study areas. From the flies caught 127 Glossina were randomly selected and dissected. The overall proportion of Glossina infection was 15% with higher proportion of infection in wet season (19.6%) than the dry season (11.3%). Higher infection proportion was observed in G. pallidipes. Conclusion Trypansomosis is the major challenge for cattle productivity in the district. So to reduce the impact trypanosomosis and Glossina active community participation can play a key role.
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Affiliation(s)
| | | | - Desie Sheferaw
- Hawassa University Faculty of Veterinary Medicine, Ethiopia
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Nnko HJ, Gwakisa PS, Ngonyoka A, Sindato C, Estes AB. Potential impacts of climate change on geographical distribution of three primary vectors of African Trypanosomiasis in Tanzania's Maasai Steppe: G. m. morsitans, G. pallidipes and G. swynnertoni. PLoS Negl Trop Dis 2021; 15:e0009081. [PMID: 33571190 PMCID: PMC7904224 DOI: 10.1371/journal.pntd.0009081] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 02/24/2021] [Accepted: 12/16/2020] [Indexed: 12/03/2022] Open
Abstract
In the Maasai Steppe, public health and economy are threatened by African Trypanosomiasis, a debilitating and fatal disease to livestock (African Animal Trypanosomiasis -AAT) and humans (Human African Trypanosomiasis—HAT), if not treated. The tsetse fly is the primary vector for both HAT and AAT and climate is an important predictor of their occurrence and the parasites they carry. While understanding tsetse fly distribution is essential for informing vector and disease control strategies, existing distribution maps are old and were based on coarse spatial resolution data, consequently, inaccurately representing vector and disease dynamics necessary to design and implement fit-for-purpose mitigation strategies. Also, the assertion that climate change is altering tsetse fly distribution in Tanzania lacks empirical evidence. Despite tsetse flies posing public health risks and economic hardship, no study has modelled their distributions at a scale needed for local planning. This study used MaxEnt species distribution modelling (SDM) and ecological niche modeling tools to predict potential distribution of three tsetse fly species in Tanzania’s Maasai Steppe from current climate information, and project their distributions to midcentury climatic conditions under representative concentration pathways (RCP) 4.5 scenarios. Current climate results predicted that G. m. morsitans, G. pallidipes and G swynnertoni cover 19,225 km2, 7,113 km2 and 32,335 km2 and future prediction indicated that by the year 2050, the habitable area may decrease by up to 23.13%, 12.9% and 22.8% of current habitable area, respectively. This information can serve as a useful predictor of potential HAT and AAT hotspots and inform surveillance strategies. Distribution maps generated by this study can be useful in guiding tsetse fly control managers, and health, livestock and wildlife officers when setting surveys and surveillance programs. The maps can also inform protected area managers of potential encroachment into the protected areas (PAs) due to shrinkage of tsetse fly habitats outside PAs. Spatial variation of African Trypanosomiasis burden depends on distribution of biotopes necessary for tsetse flies to thrive. Therefore, mapping the occurrence of the tsetse fly species is a useful predictor of African Trypanosomiasis transmission risk areas. Climate is a major determining factor for occurrence and survival of tsetse flies, the vector responsible for both HAT and AAT. Since resources for prevention and control of tsetse fly species and the disease they transmit are generally scarce in endemic settings, understanding potential impacts of climate change on tsetse fly species distribution in space and time is essential for informing coherent strategies for vector and disease control at a local scale.
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Affiliation(s)
| | | | | | - Calvin Sindato
- National Institute for Medical Research, Tabora, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Morogoro Tanzania
| | - Anna Bond Estes
- Carleton College, Northfield, Minnesota, USA
- The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
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Jaimes-Dueñez J, Triana-Chávez O, Mejía-Jaramillo AM. Genetic, host and environmental factors associated with a high prevalence of Anaplasma marginale. Ticks Tick Borne Dis 2018; 9:1286-1295. [DOI: 10.1016/j.ttbdis.2018.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 05/06/2018] [Accepted: 05/09/2018] [Indexed: 10/16/2022]
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Alderton S, Macleod ET, Anderson NE, Palmer G, Machila N, Simuunza M, Welburn SC, Atkinson PM. An agent-based model of tsetse fly response to seasonal climatic drivers: Assessing the impact on sleeping sickness transmission rates. PLoS Negl Trop Dis 2018; 12:e0006188. [PMID: 29425200 PMCID: PMC5806852 DOI: 10.1371/journal.pntd.0006188] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 12/22/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND This paper presents the development of an agent-based model (ABM) to incorporate climatic drivers which affect tsetse fly (G. m. morsitans) population dynamics, and ultimately disease transmission. The model was used to gain a greater understanding of how tsetse populations fluctuate seasonally, and investigate any response observed in Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) disease transmission, with a view to gaining a greater understanding of disease dynamics. Such an understanding is essential for the development of appropriate, well-targeted mitigation strategies in the future. METHODS The ABM was developed to model rHAT incidence at a fine spatial scale along a 75 km transect in the Luangwa Valley, Zambia. The model incorporates climatic factors that affect pupal mortality, pupal development, birth rate, and death rate. In combination with fine scale demographic data such as ethnicity, age and gender for the human population in the region, as well as an animal census and a sample of daily routines, we create a detailed, plausible simulation model to explore tsetse population and disease transmission dynamics. RESULTS The seasonally-driven model suggests that the number of infections reported annually in the simulation is likely to be a reasonable representation of reality, taking into account the high levels of under-detection observed. Similar infection rates were observed in human (0.355 per 1000 person-years (SE = 0.013)), and cattle (0.281 per 1000 cattle-years (SE = 0.025)) populations, likely due to the sparsity of cattle close to the tsetse interface. The model suggests that immigrant tribes and school children are at greatest risk of infection, a result that derives from the bottom-up nature of the ABM and conditioning on multiple constraints. This result could not be inferred using alternative population-level modelling approaches. CONCLUSIONS In producing a model which models the tsetse population at a very fine resolution, we were able to analyse and evaluate specific elements of the output, such as pupal development and the progression of the teneral population, allowing the development of our understanding of the tsetse population as a whole. This is an important step in the production of a more accurate transmission model for rHAT which can, in turn, help us to gain a greater understanding of the transmission system as a whole.
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Affiliation(s)
- Simon Alderton
- Geography and Environment, Faculty of Social and Human Sciences, University of Southampton, Southampton, United Kingdom
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
- Centre for Health Informatics, Computing and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
- * E-mail:
| | - Ewan T. Macleod
- Division of Infection and Pathway Medicine, Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Neil E. Anderson
- The Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh, Roslin, United Kingdom
| | - Gwen Palmer
- Independent Researcher, Leyland, Lancashire, United Kingdom
| | - Noreen Machila
- Division of Infection and Pathway Medicine, Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Martin Simuunza
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Susan C. Welburn
- Division of Infection and Pathway Medicine, Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Peter M. Atkinson
- Geography and Environment, Faculty of Social and Human Sciences, University of Southampton, Southampton, United Kingdom
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
- Centre for Health Informatics, Computing and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
- School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Northern Ireland, United Kingdom
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
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Degneh E, Shibeshi W, Terefe G, Asres K, Ashenafi H. Bovine trypanosomosis: changes in parasitemia and packed cell volume in dry and wet seasons at Gidami District, Oromia Regional State, western Ethiopia. Acta Vet Scand 2017; 59:59. [PMID: 28893322 PMCID: PMC5594549 DOI: 10.1186/s13028-017-0327-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 09/06/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Animal trypanosomosis is one of the major disease problems affecting agricultural productivity in Ethiopia. The impact of the disease is believed to vary with season and agro-ecologies in line with fly vector distribution. A cross-sectional study on bovine trypanosomosis was conducted from November 2015 to June 2016, in seven selected villages of Gidami district, Oromia Regional State, western Ethiopia. A total of 930 blood samples were collected and subjected to parasitological and hematological analysis. RESULT The overall prevalence of bovine trypanosomosis was 14.1%. The seasonal prevalence shows 9.06% in early dry and 18.4% in early rainy seasons. Three trypanosome species, Trypanosoma congolense, Trypanosoma vivax and Trypanosoma brucei were identified in the examined animals. T. congolense followed by T. vivax were the predominant species (respectively 59.0 and 35.9% in early dry season and 62.0 and 22.8% in early rainy season). The prevalence of T. vivax remained similar in both early dry and early rainy seasons in both lowland and midland agroecologies whereas T. congolense was more dominant in the lowland area in both seasons compared to mid land study sites. The disease was more prevalent in lowland (23.9%) compared to midland (11.1%) during early rainy season (P < 0.001) whereas no significant difference was observed between the two agroecologies during early dry season (P = 0.165). Packed cell volume (PCV) was much lower in parasitemic animals than in aparasitemic cattle whereas the mean PCV value for parasitemic animals (20.36%; 95% CI 19.56 to 21.16) in early dry season was similar to values in early rainy season (20.46%, 95% CI 18.84 to 21.08%). A similar situation was noticed for animals in both low land and mid land study sites. CONCLUSION Overall, the detection of trypanosomes in blood was significantly affected by agro-ecology, season and body condition of the animals. Special emphasis should be given to integrated trypanosomosis management in early rainy months where fly population is believed to start increasing.
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Ngonyoka A, Gwakisa PS, Estes AB, Salekwa LP, Nnko HJ, Hudson PJ, Cattadori IM. Patterns of tsetse abundance and trypanosome infection rates among habitats of surveyed villages in Maasai steppe of northern Tanzania. Infect Dis Poverty 2017; 6:126. [PMID: 28866983 PMCID: PMC5582388 DOI: 10.1186/s40249-017-0340-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/26/2017] [Indexed: 12/03/2022] Open
Abstract
Background Changes of land cover modify the characteristics of habitat, host-vector interaction and consequently infection rates of disease causing agents. In this paper, we report variations in tsetse distribution patterns, abundance and infection rates in relation to habitat types and age in the Maasai Steppe of northern Tanzania. In Africa, Tsetse-transmitted trypanosomiasis negatively impacted human life where about 40 million people are at risk of contracting the disease with dramatic socio-economical consequences, for instance, loss of livestock, animal productivity, and manpower. Methods We trapped tsetse flies in dry and wet seasons between October 2014 and May 2015 in selected habitats across four villages: Emboreet, Loiborsireet, Kimotorok and Oltukai adjacent to protected areas. Data collected include number and species of tsetse flies caught in baited traps, PCR identification of trypanosome species and extraction of monitored Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectrometer (MODIS). Results Our findings demonstrate the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance. Results have shown higher tsetse fly abundance in Acacia-swampy ecotone and riverine habitats for Emboreet and other villages, respectively. Tsetse abundance was inconsistent among habitats in different villages. Emboreet was highly infested with Glossina swynnertoni (68%) in ecotone and swampy habitats followed by G. morsitans (28%) and G. pallidipes (4%) in riverine habitat. In the remaining villages, the dominant tsetse fly species by 95% was G. pallidipes in all habitats. Trypanosoma vivax was the most prevalent species in all infected flies (95%) with few observations of co-infections (with T. congolense or T. brucei). Conclusions The findings of this study provide a framework to mapping hotspots of tsetse infestation and trypanosomiasis infection and enhance the communities to plan for effective control of trypanosomiasis. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0340-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anibariki Ngonyoka
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania. .,Department of Conservation Biology, School of Biological Sciences, University of Dodoma, Dodoma, Tanzania.
| | - Paul S Gwakisa
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Genome Sciences Center, Department of Microbiology, Parasitology and Immunology. College of Veterinary and Medical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Anna B Estes
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, USA
| | - Linda P Salekwa
- Genome Sciences Center, Department of Microbiology, Parasitology and Immunology. College of Veterinary and Medical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Happiness J Nnko
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Department of Geography and Environmental studies, University of Dodoma, Dodoma, Tanzania
| | - Peter J Hudson
- School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, USA
| | - Isabella M Cattadori
- Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, USA
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Ngonyoka A, Gwakisa PS, Estes AB, Nnko HJ, Hudson PJ, Cattadori IM. Variation of tsetse fly abundance in relation to habitat and host presence in the Maasai Steppe, Tanzania. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2017; 42:34-43. [PMID: 28504430 DOI: 10.1111/jvec.12237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/28/2016] [Indexed: 06/07/2023]
Abstract
Human activities modify ecosystem structure and function and can also alter the vital rates of vectors and thus the risk of infection with vector-borne diseases. In the Maasai Steppe ecosystem of northern Tanzania, local communities depend on livestock and suitable pasture that is shared with wildlife, which can increase tsetse abundance and the risk of trypanosomiasis. We monitored the monthly tsetse fly abundance adjacent to Tarangire National Park in 2014-2015 using geo-referenced, baited epsilon traps. We examined the effect of habitat types and vegetation greenness (NDVI) on the relative abundance of tsetse fly species. Host availability (livestock and wildlife) was also recorded within 100×100 m of each trap site. The highest tsetse abundance was found in the ecotone between Acacia-Commiphora woodland and grassland, and the lowest in riverine woodland. Glossina swynnertoni was the most abundant species (68%) trapped throughout the entire study, while G. pallidipes was the least common (4%). Relative species abundance was negatively associated with NDVI, with greatest abundance observed in the dry season. The relationship with the abundance of wildlife and livestock was more complex, as we found positive and negative associations depending on the host and fly species. While habitat is important for tsetse distribution, hosts also play a critical role in affecting fly abundance and, potentially, trypanosomiasis risk.
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Affiliation(s)
- Anibariki Ngonyoka
- Nelson Mandela African Institution of Science and Technology. School of Life Sciences and Bioengineering, Arusha, Tanzania
- Department of Conservation Biology, School of Biological Sciences, University of Dodoma, Tanzania
| | - Paul S Gwakisa
- Nelson Mandela African Institution of Science and Technology. School of Life Sciences and Bioengineering, Arusha, Tanzania
- Genome Sciences Center, Department of Veterinary Microbiology and Parasitology, Faculty of Veterinary Medicine, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Anna B Estes
- Nelson Mandela African Institution of Science and Technology. School of Life Sciences and Bioengineering, Arusha, Tanzania
- Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA U.S.A
| | - Happiness J Nnko
- Nelson Mandela African Institution of Science and Technology. School of Life Sciences and Bioengineering, Arusha, Tanzania
- Department of Geography and Environmental Studies, University of Dodoma, Tanzania
| | - Peter J Hudson
- Nelson Mandela African Institution of Science and Technology. School of Life Sciences and Bioengineering, Arusha, Tanzania
- Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA U.S.A
| | - Isabella M Cattadori
- Centre for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA U.S.A
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Sedda L, Mweempwa C, Ducheyne E, De Pus C, Hendrickx G, Rogers DJ. A Bayesian geostatistical Moran Curve model for estimating net changes of tsetse populations in Zambia. PLoS One 2014; 9:e96002. [PMID: 24755848 PMCID: PMC3995969 DOI: 10.1371/journal.pone.0096002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 04/02/2014] [Indexed: 11/18/2022] Open
Abstract
For the first time a Bayesian geostatistical version of the Moran Curve, a logarithmic form of the Ricker stock recruitment curve, is proposed that is able to give an estimate of net change in population demographic rates considering components such as fertility and density dependent and density independent mortalities. The method is applied to spatio-temporally referenced count data of tsetse flies obtained from fly-rounds. The model is a linear regression with three components: population rate of change estimated from the Moran curve, an explicit spatio-temporal covariance, and the observation error optimised within a Bayesian framework. The model was applied to the three main climate seasons of Zambia (rainy – January to April, cold-dry – May to August, and hot-dry – September to December) taking into account land surface temperature and (seasonally changing) cattle distribution. The model shows a maximum positive net change during the hot-dry season and a minimum between the rainy and cold-dry seasons. Density independent losses are correlated positively with day-time land surface temperature and negatively with night-time land surface temperature and cattle distribution. The inclusion of density dependent mortality increases considerably the goodness of fit of the model. Cross validation with an independent dataset taken from the same area resulted in a very accurate estimate of tsetse catches. In general, the overall framework provides an important tool for vector control and eradication by identifying vector population concentrations and local vector demographic rates. It can also be applied to the case of sustainable harvesting of natural populations.
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Affiliation(s)
- Luigi Sedda
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Cornelius Mweempwa
- Department of Veterinary and Livestock Development, Ministry of Agriculture and Co-operatives, Lusaka, Zambia
| | | | - Claudia De Pus
- Animal Health Department, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - David J. Rogers
- Department of Zoology, University of Oxford, Oxford, United Kingdom
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Sanni TM, Onasanya GO, Adefenwa MA, Yakubu A, Ikeobi CON, Adebambo OA, Talabi AO, Ozoje MO, Wheto M, Takeet MI, Peters SO, Donato MD, Thomas BN, Imumorin IG. Molecular Diagnosis of Subclinical African Trypanosoma vivax Infection and Association with Physiological Indices and Serum Metabolites in Extensively Managed Goats in the Tropics. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojvm.2013.31007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Masumu J, Tshilenge G, Mbao V. Epidemiological aspects of bovine trypanosomosis in an endemic focus of eastern Zambia: The role of trypanosome strain variability in disease pattern. ACTA ACUST UNITED AC 2012. [DOI: 10.4102/ojvr.v79i2.468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Bovine trypanosomosis displays various epidemiological aspects in various areas. In some instances the disease has a high prevalence in animals with high impact on production whereas in other cases the disease has a low impact on production despite a high level of infection in animals. In addition epidemiological changes are frequently observed in various areas and are related to many factors including the vectors, the host, the parasites, the environment as well as the livestock management. However the implication of these factors in these changes is not fully elucidated. In eastern Zambia, factors predicting the establishment of severe infection in cattle are all present. However trypanosomosis occurring in cattle in this area has a low impact on livestock production. Several studies on the characterisation of trypanosome strains circulating in domestic and wild animals have been conducted in order to clarify the epidemiology of this disease in this area. These studies aimed at evaluating genetic and biological characteristics of these strains including their virulence profiles, their transmissibility by tsetse flies, their resistance to drugs and interference between different strains. In this review these findings are analysed in order to elucidate the implication of trypanosome strain variability in the distribution and the expression of this disease in the study area. The evolutionary trends of the situation occurring in this study area are also explained. Use of these findings is the context of disease control in the study area is further discussed.
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Munang'andu HM, Siamudaala V, Munyeme M, Nalubamba KS. A review of ecological factors associated with the epidemiology of wildlife trypanosomiasis in the luangwa and zambezi valley ecosystems of zambia. Interdiscip Perspect Infect Dis 2012; 2012:372523. [PMID: 22693499 PMCID: PMC3368204 DOI: 10.1155/2012/372523] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/05/2012] [Accepted: 04/05/2012] [Indexed: 11/17/2022] Open
Abstract
Trypanosomiasis has been endemic in wildlife in Zambia for more than a century. The disease has been associated with neurological disorders in humans. Current conservation strategies by the Zambian government of turning all game reserves into state-protected National Parks (NPs) and game management areas (GMAs) have led to the expansion of the wildlife and tsetse population in the Luangwa and Zambezi valley ecosystem. This ecological niche lies in the common tsetse fly belt that harbors the highest tsetse population density in Southern Africa. Ecological factors such as climate, vegetation and rainfall found in this niche allow for a favorable interplay between wild reservoir hosts and vector tsetse flies. These ecological factors that influence the survival of a wide range of wildlife species provide adequate habitat for tsetse flies thereby supporting the coexistence of disease reservoir hosts and vector tsetse flies leading to prolonged persistence of trypanosomiasis in the area. On the other hand, increase in anthropogenic activities poses a significant threat of reducing the tsetse and wildlife habitat in the area. Herein, we demonstrate that while conservation of wildlife and biodiversity is an important preservation strategy of natural resources, it could serve as a long-term reservoir of wildlife trypanosomiasis.
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Affiliation(s)
- Hetron Mweemba Munang'andu
- Section of Aquatic Medicine and Nutrition, Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Sciences, Ullevalsveien 72, P.O. Box 8146 Dep, 0033 Oslo, Norway
| | - Victor Siamudaala
- Kavango Zambezi Transfrontier Conservation Area Secretariat, Kasane 821, Gaborone, Botswana
| | - Musso Munyeme
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
| | - King Shimumbo Nalubamba
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
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Bonomi A, Bassetti F, Gabrieli P, Beadell J, Falchetto M, Scolari F, Gomulski LM, Regazzini E, Ouma JO, Caccone A, Okedi LM, Attardo GM, Guglielmino CR, Aksoy S, Malacrida AR. Polyandry is a common event in wild populations of the Tsetse fly Glossina fuscipes fuscipes and may impact population reduction measures. PLoS Negl Trop Dis 2011; 5:e1190. [PMID: 21666797 PMCID: PMC3110164 DOI: 10.1371/journal.pntd.0001190] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 04/20/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Glossina fuscipes fuscipes is the main vector of human and animal trypanosomiasis in Africa, particularly in Uganda. Attempts to control/eradicate this species using biological methods require knowledge of its reproductive biology. An important aspect is the number of times a female mates in the wild as this influences the effective population size and may constitute a critical factor in determining the success of control methods. To date, polyandry in G.f. fuscipes has not been investigated in the laboratory or in the wild. Interest in assessing the presence of remating in Ugandan populations is driven by the fact that eradication of this species is at the planning stage in this country. METHODOLOGY/PRINCIPAL FINDINGS Two well established populations, Kabukanga in the West and Buvuma Island in Lake Victoria, were sampled to assess the presence and frequency of female remating. Six informative microsatellite loci were used to estimate the number of matings per female by genotyping sperm preserved in the female spermathecae. The direct count of the minimum number of males that transferred sperm to the spermathecae was compared to Maximum Likelihood and Bayesian probability estimates. The three estimates provided evidence that remating is common in the populations but the frequency is substantially different: 57% in Kabukanga and 33% in Buvuma. CONCLUSIONS/SIGNIFICANCE The presence of remating, with females maintaining sperm from different mates, may constitute a critical factor in cases of re-infestation of cleared areas and/or of residual populations. Remating may enhance the reproductive potential of re-invading propagules in terms of their effective population size. We suggest that population age structure may influence remating frequency. Considering the seasonal demographic changes that this fly undergoes during the dry and wet seasons, control programmes based on SIT should release large numbers of sterile males, even in residual surviving target populations, in the dry season.
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Affiliation(s)
- Angelica Bonomi
- Department of Animal Biology, University of Pavia, Pavia, Italy
| | | | - Paolo Gabrieli
- Department of Animal Biology, University of Pavia, Pavia, Italy
| | - Jon Beadell
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
| | - Marco Falchetto
- Department of Animal Biology, University of Pavia, Pavia, Italy
| | | | | | | | - Johnson O. Ouma
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute, Kikuyu, Kenya
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
| | - Loyce M. Okedi
- National Livestock Resources Research Institute, Tororo, Uganda
| | - Geoffrey M. Attardo
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | | | - Serap Aksoy
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Anna R. Malacrida
- Department of Animal Biology, University of Pavia, Pavia, Italy
- * E-mail:
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16
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Epidemiological analysis of tick-borne diseases in Zambia. Vet Parasitol 2011; 175:331-42. [DOI: 10.1016/j.vetpar.2010.09.027] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 09/15/2010] [Accepted: 09/24/2010] [Indexed: 11/21/2022]
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Simukoko H, Marcotty T, Vercruysse J, Van den Bossche P. Bovine trypanosomiasis risk in an endemic area on the eastern plateau of Zambia. Res Vet Sci 2010; 90:51-4. [PMID: 20466392 DOI: 10.1016/j.rvsc.2010.04.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 04/13/2010] [Accepted: 04/21/2010] [Indexed: 10/19/2022]
Abstract
The control of bovine trypanosomiasis could be improved by using the available control tools during periods when the incidence of the disease is highest. The present study assessed the monthly risk of bovine trypanosomiasis in 85 sentinel cattle kept on the tsetse-infested eastern plateau of Zambia during a period of 19 consecutive months. To avoid problems associated with persistence of infections because of trypanocidal drug resistance and/or the time lag between sampling and molecular analysis, a survival analysis and the subsequent calculation of risk was used as an indicator of challenge. Results showed that the average monthly risk of infection (92.3% due to Trypanosoma congolense) was 6%. It was significantly higher (7.7%) during the beginning of the rainy season (December-February). According to the outcome of the study, bovine trypanosomiasis control in the study area can be improved through increasing control efforts during this period of highest challenge.
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Affiliation(s)
- H Simukoko
- University of Zambia, School of Veterinary Medicine, Department of Biomedical Sciences, Lusaka, Zambia
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18
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Ducheyne E, Mweempwa C, De Pus C, Vernieuwe H, De Deken R, Hendrickx G, Van den Bossche P. The impact of habitat fragmentation on tsetse abundance on the plateau of eastern Zambia. Prev Vet Med 2009; 91:11-8. [PMID: 19523702 PMCID: PMC2722901 DOI: 10.1016/j.prevetmed.2009.05.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tsetse-transmitted human or livestock trypanosomiasis is one of the major constraints to rural development in sub-Saharan Africa. The epidemiology of the disease is determined largely by tsetse fly density. A major factor, contributing to tsetse population density is the availability of suitable habitat. In large parts of Africa, encroachment of people and their livestock resulted in a destruction and fragmentation of such suitable habitat. To determine the effect of habitat change on tsetse density a study was initiated in a tsetse-infested zone of eastern Zambia. The study area represents a gradient of habitat change, starting from a zone with high levels of habitat destruction and ending in an area where livestock and people are almost absent. To determine the distribution and density of the fly, tsetse surveys were conducted throughout the study area in the dry and in the rainy season. Landsat ETM+ imagery covering the study area were classified into four land cover classes (munga, miombo, agriculture and settlements) and two auxiliary spectral classes (clouds and shadow) using a Gaussian Maximum Likelihood Classifier. The classes were regrouped into natural vegetation and agricultural zone. The binary images were overlaid with hexagons to obtain the spatial spectrum of spatial pattern. Hexagonal coverage was selected because of its compact and regular form. To identify scale-specific spatial patterns and associated entomological phenomena, the size of the hexagonal coverage was varied (250 and 500 m). Per coverage, total class area, mean patch size, number of patches and patch size standard deviation were used as fragmentation indices. Based on the fragmentation index values, the study zone was classified using a Partitioning Around Mediods (PAM) method. The number of classes was determined using the Wilks’ lambda coefficient. To determine the impact of habitat fragmentation on tsetse abundance, the correlation between the fragmentation indices and the index of apparent density of the flies was determined and habitat changes most affecting tsetse abundance was identified. From this it followed that there is a clear relationship between habitat fragmentation and the abundance of tsetse flies. Heavily fragmented areas have lower numbers of tsetse flies, but when the fragmentation of natural vegetation decreases, the number of tsetse flies increases following a sigmoidal-like curve.
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Affiliation(s)
- E Ducheyne
- Avia-GIS, Risschotlei 33, 2980 Zoersel, Belgium.
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Gondwe N, Marcotty T, Vanwambeke SO, De Pus C, Mulumba M, Van den Bossche P. Distribution and density of tsetse flies (Glossinidae: Diptera) at the game/people/livestock interface of the Nkhotakota Game Reserve human sleeping sickness focus in Malawi. ECOHEALTH 2009; 6:260-265. [PMID: 19924484 DOI: 10.1007/s10393-009-0252-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 05/29/2009] [Accepted: 08/07/2009] [Indexed: 05/28/2023]
Abstract
In large parts sub-Saharan Africa, tsetse flies, the vectors of African human or animal trypanosomiasis, are, or will in the foreseeable future, be confined to protected areas such as game or national parks. Challenge of people and livestock is likely to occur at the game/livestock/people interface of such infested areas. Since tsetse control in protected areas is difficult, management of trypanosomiasis in people and/or livestock requires a good understanding of tsetse population dynamics along such interfaces. The Nkhotakota Game Reserve, an important focus of human trypanosomiasis in Malawi, is a tsetse-infested protected area surrounded by a virtually tsetse-free zone. The abundance of tsetse (Glossina morsitans morsitans) along the interface, within and outside the game reserve, was monitored over 15 months using epsilon traps. A land cover map described the vegetation surrounding the traps. Few flies were captured outside the reserve. Inside, the abundance of tsetse at the interface was low but increased away from the boundary. This uneven distribution of tsetse inside the reserve is attributed to the uneven distribution of wildlife, the main host of tsetse, being concentrated deeper inside the reserve. Challenge of people and livestock at the interface is thus expected to be low, and cases of trypanosomiasis are likely due to people and/or livestock entering the reserve. Effective control of trypanosomiasis in people and livestock could be achieved by increasing the awareness among people of dangers associated with entering the reserve.
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Affiliation(s)
- Nkwachi Gondwe
- Centre for Ticks and Tick-Borne Diseases, Lilongwe, Malawi
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Mamoudou A, Zoli A, Hamadama H, Abah S, Geerts S, Clausen PH, Zessin KH, Kyule M, van den Bossche P. Seasonal distribution and abundance of tsetse flies (Glossina spp.) in the Faro and Deo Division of the Adamaoua Plateau in Cameroon. MEDICAL AND VETERINARY ENTOMOLOGY 2008; 22:32-36. [PMID: 18380651 DOI: 10.1111/j.1365-2915.2008.00711.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Ten years after the large-scale tsetse control campaigns in the important cattle rearing areas of the Faro and Deo Division of the Adamaoua Plateau in Cameroon, the seasonal distribution and abundance of tsetse flies (Glossina spp.) were determined. During a period of 12 consecutive months (January-December 2005), the tsetse population was monitored along four trap transects consisting of a total of 32 traps and two flyround transects traversing the study area, which comprised the tsetse-infested valley, a buffer zone and the supposedly tsetse-free plateau. Throughout the study period, a total of 2195 Glossina morsitans submorsitans and 23 Glossina tachinoides were captured in the traps and 1007 G. m. submorsitans (78.8% male flies) were captured along the flyround transects. All G. tachinoides and almost all G. m. submorsitans were captured in the valley. Five G. m. submorsitans were captured in traps located in the buffer zone, whereas no flies were captured in traps located on the plateau. The index of apparent abundance (IAA) of G. m. submorsitans was substantially higher in the areas close to game reserves. In the remaining part of the valley, where wildlife is scarce and cattle are present during transhumance (dry season), the IAA of tsetse was substantially lower. In this part of the valley, the abundance of tsetse seemed to be associated with the presence of cattle, with the highest IAA during transhumance when cattle are present and the lowest apparent abundance during the rainy season when cattle have moved to the plateau. It is concluded that the distribution of tsetse in a large part of the valley undergoes substantial seasonal changes depending on the presence or absence of cattle. The repercussions of those findings for the control of tsetse in the valley and the probability of reinvasion of the plateau are discussed.
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Affiliation(s)
- A Mamoudou
- Faculty of Agronomy and Agricultural Sciences, University of Dschang, Dschang, Cameroon
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Simukoko H, Marcotty T, Phiri I, Vercruysse J, Van den Bossche P. Heterogeneity in the trypanosomosis incidence in Zebu cattle of different ages and sex on the plateau of eastern Zambia. Acta Trop 2007; 103:98-101. [PMID: 17618594 PMCID: PMC2771271 DOI: 10.1016/j.actatropica.2007.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 03/05/2007] [Accepted: 05/20/2007] [Indexed: 12/01/2022]
Abstract
On the plateau of eastern Zambia, trypanosomosis is endemic. Glossina morsitans morsitans Westwood (Diptera: Glossinidae), the only tsetse species present, is almost entirely dependent on livestock as its source of food with cattle being the most preferred host. To determine if tsetse challenge is distributed equally over the various age categories and sexes within a cattle herd, a longitudinal study of trypanosomosis incidence was conducted during the rainy season. A total of 354 head of cattle consisting of 40% oxen, 30% cows, 15% young stock, 13% calves and 2% bulls were sampled for three consecutive months and their infection statuses determined using the PCR-RFLP technique as diagnostic method. Results indicated that there were significant differences (P<0.001) in the proportion of infected animals between the various categories. In oxen, the risk of infection was 5.6 times higher than in calves. Those results suggest heterogeneity in the challenge by tsetse flies and are in line with entomological observations on the feeding preference of tsetse on cattle. The implications of these results for the control of trypanosomosis in Eastern Province and other epidemiologically related areas are discussed.
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Affiliation(s)
- H. Simukoko
- University of Zambia, School of Veterinary Medicine, Zambia
| | - T. Marcotty
- Institute of Tropical Medicine Antwerp, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
| | - I. Phiri
- University of Zambia, School of Veterinary Medicine, Zambia
| | - J. Vercruysse
- Ghent University, Vakgroep Virologie, Parasitologie en Immunologie, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - P. Van den Bossche
- Institute of Tropical Medicine Antwerp, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
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Simukoko H, Marcotty T, Phiri I, Geysen D, Vercruysse J, Van den Bossche P. The comparative role of cattle, goats and pigs in the epidemiology of livestock trypanosomiasis on the plateau of eastern Zambia. Vet Parasitol 2007; 147:231-8. [PMID: 17493757 PMCID: PMC2771273 DOI: 10.1016/j.vetpar.2007.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 03/30/2007] [Accepted: 04/03/2007] [Indexed: 11/04/2022]
Abstract
To determine and compare the prevalence of trypanosome infections in different livestock species (cattle, pigs and goats) in areas where game animals are scarce and livestock constitute the main food source of tsetse, a survey was conducted on the plateau of the Eastern Province of Zambia in Katete and Petauke districts where Glossina morsitans morsitans is the only tsetse species present. Blood was collected from a total of 734 cattle, 333 goats and 324 pigs originating from 59 villages in both districts and was examined using the buffy coat method and the PCR-RFLP as diagnostic tools. The prevalence of trypanosome infections differed substantially between livestock species. Using microscopic diagnostic methods, trypanosome infections were detected in 13.5% of the cattle and 0.9% of the pigs. All goats were parasitologically negative. The PCR-RFLP analyses increased the trypanosomiasis prevalence to 33.5, 6.5 and 3.3% in cattle, pigs and goats respectively. The majority of the infections (91.2%) were due to Trypanosoma congolense. The presence of a trypanosome infection in cattle and pigs resulted in a significant decline in the packed cell volume. The outcome of the study clearly shows that despite the availability of goats and pigs, cattle seem to be the major livestock species affected by the disease in trypanosomiasis endemic areas. The high proportion of infections in cattle could be partly attributed to their higher availability and attractiveness to tsetse.
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Affiliation(s)
- H. Simukoko
- University of Zambia, School of Veterinary Medicine, South Africa
| | - T. Marcotty
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
| | - I. Phiri
- University of Zambia, School of Veterinary Medicine, South Africa
| | - D. Geysen
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
| | - J. Vercruysse
- Ghent University, Vakgroep Virologie, parasitologie en Immunologie, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - P. Van den Bossche
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
- Corresponding author. Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, 2000 Antwerp, Belgium Tel.: +32 3 2476396; fax: +32 3 2476268.
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Engstler M, Boshart M. Cold shock and regulation of surface protein trafficking convey sensitization to inducers of stage differentiation in Trypanosoma brucei. Genes Dev 2004; 18:2798-811. [PMID: 15545633 PMCID: PMC528899 DOI: 10.1101/gad.323404] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Transmission of a protozoan parasite from a vertebrate to invertebrate host is accompanied by cellular differentiation. The signals from the environment that trigger the process are poorly understood. The model parasite Trypanosoma brucei proliferates in the mammalian bloodstream and in the tsetse fly. On ingestion by the tsetse, the trypanosome undergoes a rapid differentiation that is marked by replacement of the variant surface glycoprotein (VSG) coat with GPI-anchored EP and GPEET procyclins. Here we show that a cold shock of DeltaT > 15 degrees C is sufficient to reversibly induce high-level expression of the insect stage-specific EP gene in the mammalian bloodstream stages of T. brucei. The 3'-UTR of the EP mRNA is necessary and sufficient for the increased expression. During cold shock, EP protein accumulates in the endosomal compartment in the proliferating, slender, bloodstream stage, whereas the EP is present on the plasma membrane in the quiescent, stumpy, bloodstream stage. Thus, there is a novel developmentally regulated cell surface access control mechanism for a GPI-anchored protein. In addition to inducing EP expression, cold shock results in the acquisition of sensitivity to micromolar concentrations of cis-aconitate and citrate by stumpy but not slender bloodstream forms. The cis-aconitate and citrate commit stumpy bloodstream cells to differentiation to the procyclic stage along with rapid initial proliferation. We propose a hierarchical model of three events that regulate differentiation after transmission to the tsetse: sensing the temperature change, surface access of a putative receptor, and sensing of a chemical cue.
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Affiliation(s)
- Markus Engstler
- Ludwig-Maximilians-Universität, Department Biologie I, Genetik, 80638 München, Germany
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