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1.Temporal and spatial variations of tsetse flies and trypanosome infections allows simulation of these parameters for future prediction of disease dynamics and designing of appropriate vector control regimes 2. Correlates of land use / cover with tsetse fly distribution will help to designate potential hotpots of infection and hence targeted control for African Trypanosomiasis 3.Maasai communities in Simanjiro district may be vulnerable to African Trypanosomiasis as shown by presence of human DNA in blood meals from tsetse flies Paul S. Gwakisa, Mary Simwango, Happiness Nnko, Anibariki Ngonyoka, Linda P. Salekwa, Moses Ole-Neselle, Anna Estes, Isabella Cattadori, Peter Hudson The Nelson Mandela African Institution of Science and Technology, PO Box 447, Arusha, Tanzania; correspondence: psgwakisa@gmail.compsgwakisa@gmail.com Distribution of tsetse flies is profoundly affected by changes in climate and land use/cover. These changes are exacerbated in the Maasai steppe by close interactions between humans, domestic and wild animals. We have shown that tsetse fly abundance varies with season and temperature, with G. swynertonni and G. m. morsitan abundance peaks differing from G. pallidipes peaks. Further, there was limited relationship between fly species abundance and temperature variation. The generalised linear mixed (GLMM) effect model indicated siginificant negative relationship between maximum temperature and vector abundance across habitats. The highest tsetse catches were recorded in the woodland-swampy ecotone habitat and lowest in riverine, where G. pallidipes was significantly abundant. Molecular analysis of over 4500 tsetse flies over a period of 15 months revealed a 5.6% overall prevalence of trypanosome infections, which varied by season and location. The most prevalent trypanosome species was T. vivax while T. congolense and T. brucei were least abundant. DNA sequencing of blood meals from caught tsetse flies revealed a diversity of hosts including ostrich, buffalo and humans. Further analysis of 1002 cattle DNA samples revealed a prevalence of 17.2% with 5% of these being T. brucei infections, which could be human infective. We are currently developing an ecohealth partnership on trypanosomiasis control through collaboration with Maasai opinion leaders and early adopters in order to reduce vulnerability and enhance community resilience. Tsetse fly abundance varied with season and temperature, with G. swynertonni and G. m. morsitan abundance peaks differing from G. pallidipes peaks. Further, there was limited relationship between tsetse fly species abundance and temperature variation (fig. 1). The generalised linear mixed (GLMM) effect model indicated siginificant negative elationship between maximum temperature and abundance of G. m. morsitan and G. pallidipes. The months with high catches corresponded to a dry period with the exception of March which is the start of the rainy season and presumably included remaining flies from the dry season. High tsetse flies catches were recorded between 25-280C maximum temperatures which also reflects the high activity of tsetse fly. The highest tsetse catches were recorded in the woodland- swampy ecotone habitat and lowest in riverine, where G. pallidipes was significantly abundant (Fig. 2). Tsetse fly abundance varied in time and space, and this may be associated with proximity to wildlife. Overall, highest abundance of tsetse flies was found in Loiborsiret village. A 5.6% prevalence of trypanosome infections was found in tsetse flies and this was highest in Loiborsiret and Emboreet villages. Prevalence of trypanosomes in cattle was 17.2% with variations between the 4 villages. Three species of trypanosomes, T. vivax, T. congolense and T. brucei were detected, whereas T. vivax was the most predominant species in both cattle and tsetse flies (Fig. 3). Aim: To develop an ecohealth partnership on vector- borne disease control that encompasses local leadership, contemporary modeling and other approaches to enhance community resilience and to mitigate the impact of environmental change. Objectives: 1. To downscale global climate models to the Maasai Steppe and predict current and future localised hotspots of infection 2a. To use land cover models to describe recent and predict future changes that influence the spatial variation in vector abundance and distribution, incorporate host availability and compare the spatial overlap with the climate models 2b. To determine prevalence of trypanosome infections in tsetse flies and cattle in Maasai villages using molecular techniques 3. To identify the opinion leaders and technology adopters in the Maasai community and work with them to develop an ecohealth partnership on disease control that will reduce the impact of vector borne infections Paul S. Gwakisa, Mary Simwango, Happiness Nnko, Anibariki Ngonyoka, Linda P. Salekwa, Moses Ole-Neselle, Anna Estes, Isabella Cattadori, Peter Hudson The Nelson Mandela African Institute of Science and Technology (NMAIST), Tanzania; Penn State University (PSU), Pennsylvania, USA; Climate Systems Analysis Group, University of Cape Town (UCT), South Africa; National Institute for Medical Research (NIMR), Tanzania; Sokoine University of Agriculture (SUA), Morogoro, Tanzania 1.The Maasai communities in Simanjiro district, Tanzania 2.WHO/TDR Special Programme for Research and Training in Tropical Diseases 3.IDRC We sampled tsetse flies monthly for a period of 15 months in the village of Emboreet for a temporal dimension of tsetse abundance and infection rates. To study the spatial distribution of tsetse flies and their infection rates we carried out an extensive survey once during rainy and dry seasons in four villages (Emboreet, Oltukai, Loiborsiret and Kimotorok). In each village 10 sites were identified and three traps (Epsilon baited with attractants) were deployed at least 200m apart.. Traps were checked and emptied every 24 hours for six days each month and the numbers and species within each trap recorded. The relationship between months, maximum, minimum temperature and abundance of each tsetse fly species were analyzed using generalized linear mixed effect models (GLMM) in R 3. 24. In order to study land use/cover change correlates of tsetse distribution, four habitat types namely woodland-swampy ecotone, open woodland, swampy and riverine were selected. Three sites were selected from each habitat type and traps setting followed standard tsetse survery protocol (FAO, 1982; Malele et al., 2011). Data on ground cover, vegetation cover and hosts abundance data were recorded at each site. A total of 4500 tsetse flies were screened for Internal Transcribed Spacer 1 (ITS 1) gene found in trypanosome species by Polymerase Chain Reaction (PCR, Njiru et al., 2004), One thousand and two cattle blood samples were collected from the same 4 villages, where tsetse traps were placed and these were also screened for trypanosome infections using ITS 1 primers. PCR products were scored for presence of trypanosome species-specific fragments on agarose gels. Additionally, DNA from blood meals in caught tsetse flies was amplified using primers targeting the mitochondrial cytochrome oxidase 1 (CO1) as well as the Cytochrome b (Cyt b) genes. PCR products were sequenced (Inqaba biotec™, South Africa) and the generated sequences were analysed using CLC main work bench before querying Genbank using BlastN and host species identification using NCBI database. Fig 2: Variation in the mean catches of tsetse fly species in different habitats in the Maasai steppe. Abundance is expressed as geometric mean Log (x+1) and shows G. mortisans and G. swyennertoni active in Ecotone with G. pallidipes inhabiting riverine habitat. Fig 1: Seasonal variation in the abundance of tsetse fly species over multiple months and the concomitant change in temperature observed during the study period at Emboreet village. Fig 3: Tsetse fly abundance and Spatial distribution of trypanosome infections in cattle and tsetse flies
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