Browsing by Author "Stephano, Mussa"

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Control strategies for the dynamics of catheter-associated urinary tract infection
(Elsevier, 2026-02-21) John, Innocent; Stephano, Mussa; Mayengo, Maranya
Catheter-associated urinary tract infections (CAUTI) remain a major challenge in healthcare, particularly among hospitalized and long term catheterized patients. This study develops a deterministic compartmental model integrated with optimal control theory to evaluate the effects of three time dependent interventions: public health education, alternative catheteriza tion methods, and environmental hygiene control. Unlike existing CAUTI models, the proposed framework explicitly incorporates both host to host transmission and environmental contami nation, and quantifies intervention effectiveness using Pontryagin’s Maximum Principle and the forward backward sweep algorithm. Simulation results show that the combined application of all three controls yields the highest reduction in disease burden, decreasing infection preva lence by approximately 82%, catheterized individuals by 75%, and environmental bacterial concentration by 85% within 60 days compared to the uncontrolled scenario. Among dual interventions, education with environmental hygiene achieves a 68% reduction in infections, followed by catheterization reduction with hygiene at 63%. Education with catheterization reduction produces a smaller decline of 49%. For individual interventions, environmental hygiene is the most effective, achieving a 58% reduction, followed by education 46% and catheterization minimization 32%. Closed-form threshold conditions derived from the effective reproduction number (𝑒) provide practical bounds for control intensities needed to ensure 𝑒 < 1, particularly highlighting minimum hygiene requirements. Optimal-control profiles indicate high initial intervention intensity that declines as infections decrease. Overall, the findings demonstrate that integrated control especially when environmental hygiene is included offers the most impactful strategy for r
The role of asymptomatic carriers on the dynamics of a lymphatic filariasis model incorporating control strategies
(ELSEVIER, 2024-05-03) Stephano, Mussa; Mayengo, Maranya; Irunde, Jacob
This study presents a mathematical model to investigate the patterns of transmission in lymphatic filariasis. The model considers chronic, acute, and asymptomatic individuals and integrates key control strategies. Random synthetic data is generated robustly through numerical solutions to closely replicate real-world scenarios and encompass uncertainties. The synthetic data adheres to a Gaussian distribution to ensure validity and reliability. Following the derivation of the basic and effective reproduction number using the next generation matrix approach, Latin Hypercube Sampling (LHS) and the Partial Rank Correlation Coefficient (PRCC) algorithm is utilized to assess the parameters that significantly influence the model outputs. The study examine the trajectories of different population compartments through numerical simulations over time, with particular emphasis on the role played by asymptomatic individuals in the transmission of the disease. To assess the potential for disease elimination, the study introduces a range of strategies involving protective measures, treatment interventions, and mosquito control. These strategies are determined through sensitivity analysis. The findings demonstrate that the simultaneous implementation of all control measures has a noteworthy effect in managing lymphatic filariasis. In conclusion, the proposed model enhances understanding of lymphatic filariasis dynamics and informs effective control strategies.
The Significance of Stochastic CTMC Over Deterministic Model in Understanding the Dynamics of Lymphatic Filariasis With Asymptomatic Carriers
(Hindawi, 2024-05-04) Stephano, Mussa; Irunde, Jacob; Mayengo, Maranya; Kuznetsov, Dmitry
Lymphatic filariasis is a leading cause of chronic and irreversible damage to human immunity. This paper presents deterministic and continuous-time Markov chain (CTMC) stochastic models regarding lymphatic filariasis dynamics. To account for randomness and uncertainties in dynamics, the CTMC model was formulated based on deterministic model possible events. A deterministic model’s outputs suggest that disease extinction is feasible when the secondary threshold infection number is below one, while persistence becomes likely when the opposite holds true. Furthermore, the significant contribution of asymptomatic carriers was identified. Results indicate that persistence is more likely to occur when the infection results from asymptomatic, acutely infected, or infectious mosquitoes. Consequently, the CTMC stochastic model is essential in capturing variabilities, randomness, associated probabilities, and validity across different scales, whereas oversimplification and unpredictability of inherent may not be featured in a deterministic model.