Browsing by Author "Mushayabasa, Steady"

Now showing 1 - 4 of 4
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    Afractional-Order Trypanosomabrucei Rhodesiense Model With Vector Saturation and Temperature Dependent Parameters
    (SPRINGER, 2020) Helikumi, Mlyashimbi; Kgosimore, Moatlhodi; Kuznetsov, Dmitry; Mushayabasa, Steady
    and density of tsetse fly population. Precisely, ectotherm performance measures, such as development rate, survival probability and reproductive rate, increase from low values (even Temperature is one of the integral environmental drivers that strongly affect the distribution zero) at critical minimum temperature, peak at an optimum temperature and then decline to low levels (even zero) at a critical maximumtemperature. In this study, a fractional-order Trypanosomabrucei rhodesiense model incorporating vector saturation and temperature dependent parameters is considered. The proposed model incorporates the interplay between vectors and two hosts, humans and animals. We computed the basic reproduction number andestablished results on the threshold dynamics. Meanwhile, we explored the effects of vector control and screening of infected host on long-term disease dynamics. We determine threshold levels essential to reducing the basic reproduction number to level below unity at various temperature levels. Our findings indicate that vector control and host screening could significantly control spread of the disease at different temperature levels.
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    Dynamics of a Fractional-Order Chikungunya Model with Asymptomatic Infectious Class
    (Hindawi, 2022) Helikumi, Mlyashimbi; Eustace, Gideon; Mushayabasa, Steady
    In this paper, a nonlinear fractional-order chikungunya disease model that incorporates asymptomatic infectious individuals is proposed and analyzed. The main interest of this work is to investigate the role of memory effects on the dynamics of chikungunya. Qualitative analysis of the model’s equilibria showed that there exists a threshold quantity which governs persistence and extinction of the disease. Model parameters were estimated based on the 2015 weekly reported cases in Colombia. The Adams-Bashforth-Moulton method was used to numerically solve the proposed model. We investigated the role of asymptomatic infectious patients on short- and long-term dynamics of the diseases. We also determined threshold levels for the efficacy of preventative strategies that results in effective management of the disease. We believe that our model can provide invaluable insights for public health authorities to predict the effect of chikungunya transmission and analyze its underlying factors and to guide new control efforts.
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    Optimal Control Applied to a Stage-structured Cassava Mosaic Disease Model with Vector Feeding Behavior
    (ELSEVIER, 2025) Lusekelo, Eva; Helikumi, Mlyashimbi; Daudi, Salamida; Mushayabasa, Steady
    Cassava remains Sub-Saharan Africa’s secondmost crucial staple food crop after maize. However production of sufficient yields is hampered by pests and diseases. In particular, the white fly (Bemisia tabaci)has the potential toreduceexpectedyieldsby50%since it directly damages cassava leaves by feeding on phloem, causing chlorosis and abscission. This study develops an ovel mathematical model for cassava mosaic disease that incorporates immature and adult white fly populations. Additionally, the model includes vector feeding behavior since priorstudieshaveshownthatvectorsexhibitpreferencestosettleforeitherhealthyorinfected hosts.Wedeterminedtheoffspringnumberandcarriedoutitssensitivityanalysis.Additionally, we carried out an optimal control study on the use of insecticides and plantroguing as disease control measures against cassava mosaic disease .Our results show that vector preference and efficiency of disease control strategies plays an important role in shaping the short and long term dynamics of cassava mosaic disease, which subsequently impacts the design of its optimal control strategies
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    Optimal Control Applied to a Stage-Structured Cassava Mosaic Disease Model With Vector Feeding Behavior
    (Elsevier, 2025-01-05) Lusekelo, Eva; Helikumi Mlyashimbi; Mushayabasa, Steady; Mushayabasa, Steady
    Cassava remains Sub-Saharan Africa’s second most crucial staple food crop after maize. However, production of sufficient yields is hampered by pests and diseases. In particular, the whitefly (Bemisia tabaci) has the potential to reduce expected yields by 50% since it directly damages cassava leaves by feeding on phloem, causing chlorosis and abscission. This study develops a novel mathematical model for cassava mosaic disease that incorporates immature and adult whitefly populations. Additionally, the model includes vector feeding behavior since prior studies have shown that vectors exhibit preferences to settle for either healthy or infected hosts. We determined the offspring number and carried out its sensitivity analysis. Additionally, we carried out an optimal control study on the use of insecticides and plant roguing as disease control measures against cassava mosaic disease. Our results show that vector preference and efficiency of disease control strategies plays an important role in shaping the short and long- term dynamics of cassava mosaic disease, which subsequently impacts the design of its optimal control strategies