Browsing by Author "Ngonyoka, Anibariki"

Now showing 1 - 3 of 3

Land cover correlates of Tsetse distribution and its implications for cattle movement and Trypanosomiasis control in the Maasai steppe
(NM-AIST, 2017-12) Ngonyoka, Anibariki
Anthropogenic activities changes ecosystem structure, and alter the vital rates of vectors, host-vector interaction and consequently disease transmission dynamics across the landscape. This research examined the participatory epidemiology to elicit Maasai pastoralist knowledge on land use changes, cattle grazing patterns and trypanosomiasis control. Furthermore, abundance and infection rates were determined in relation to age of tsetse flies, habitat types, host presence and predicted potential spatial distribution patterns in the Maasai Steppe of northern Tanzania. Tsetse abundance was obtained through geo-referenced straps, host counts around trap sites, between July 2014 and November 2015 in selected habitats across four villages: Emboreet, Loiborsireet, Kimotorok and Oltukai adjacent to protected areas. PCR identification of trypanosome species performed an to establish the infection rates. Extraction of monitored Normalized Difference Vegetation Index (NDVI) data derived from Moderate Resolution Imaging Spectrometer (MODIS) were performed asses vegetation cover changes. Presence only niche modelling approach used to predict spatial distribution of tsetse species through integration of heterogeneous biophysical factors across the entire landscape with tsetse presence data. Our findings show the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance. Results show higher tsetse fly abundance in Acacia-swampy ecotone, open woodland and riverine habitats. Tsetse species 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). The relationship of tsetse with abundance of wildlife and livestock was more complex, as we found positive and negative associations depending on the host and fly species. Furthermore, niche modelling of tsetse species provides the hotspots for tsetse infestations and infections and hence plan for cost effective eco-health intervention approaches to increase the resilience of pastoral communities against Trypanosomiasis.
Pastoralists’ Vulnerability to Trypanosomiasis in Maasai Steppe
(Springer New York LLC, 2017-09-04) Nnko, Happiness; Gwakisa, Paul; Ngonyoka, Anibariki; Saigilu, Meshack; Ole-Neselle, Moses; Kisoka, William; Sindato, Calvin; Estes, Anna
Trypanosomiasis is a neglected tropical disease of both livestock and humans. Although pastoral communities of the Maasai Steppe have been able to adapt to trypanosomiasis in the past, their traditional strategies are now constrained by changes in climate and land regimes that affect their ability to move with their herds and continually shape the communities’ vulnerability to trypanosomiasis. Despite these constraints, information on communities’ vulnerability and adaptive capacity to trypanosomiasis is limited. A cross-sectional study was therefore conducted in Simanjiro and Monduli districts of the Maasai Steppe to establish pastoralists’ vulnerability to animal trypanosomiasis and factors that determined their adaptation strategies. A weighted overlay approach in ArcGIS 10.4 was used to analyze vulnerability levels while binomial and multinomial logistic regressions in R 3.3.2 were used to analyze the determinants of adaptation. Simanjiro district was the most vulnerable to trypanosomiasis. The majority (87.5%, n = 136) of the respondents were aware of trypanosomiasis in animals, but only 7.4% (n = 136) knew about the human form of the disease. Reported impacts of animal trypanosomiasis were low milk production (95.6%, n = 136), death of livestock (96.8%, n = 136) and emaciation of animals (99.9%, n = 136). Crop farming was the most frequently reported animal trypanosomiasis adaptation strategy (66%, n = 136). At a 95% confidence interval, accessibility to livestock extension services (β = 7.61, SE = 3.28, df = 135, P = 0.02), years of livestock keeping experience (β = 6.17, SE = 1.95, df = 135, P = 0.001), number of cattle owned (β = 5.85, SE = 2.70, df = 135, P = 0.03) and membership in associations (β = − 4.11, SE = 1.79, df = 135, P = 0.02) had a significant impact on the probability of adapting to animal trypanosomiasis.
Patterns of tsetse abundance and trypanosome infection rates among habitats of surveyed villages in Maasai steppe of northern Tanzania
(BioMed Central Ltd., 2017-09-04) Ngonyoka, Anibariki; Gwakisa, Paul; Estes, Anna; Salekwa, Linda; Nnko, Happiness; Hudson, Peter; Cattadori, Isabella
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.