Research Article
Small Area Risk Mapping of Under-five Mortality: A District-level Analysis using Parametric Approach
Issue:
Volume 11, Issue 1, March 2026
Pages:
1-17
Received:
30 November 2025
Accepted:
20 December 2025
Published:
20 January 2026
Abstract: Mortality of under-five children remains a pressing public health concern in Tanzania, with spatial disparities contributed by the intersection of socioeconomic, health and environmental factors. This study employs Bayesian techniques and epidemiological spatial methods to estimate and map district-level under-five mortality, focusing on malaria prevalence, maternal education and source of drinking water. The districts with high risk are identified using georeferenced data of under-five mortality from recent Tanzania Demographic and Health Survey. We estimated the relative risk (RR) of under-five mortality within a hierarchical Bayesian spatial framework using three priors namely Besang-York-Mollie (BYM), Dean & Cressie (DC) and Leroux (BMY2). The model performance was evaluated using Watanabe-Akaike Information criterion (WAIC) to identify the best, from which the relative risk of under-five mortality was estimated and visualized using interactive and static maps. The Leroux (BYM2) model effectively estimated the relative risk compared to BYM and DC. The findings reveal that there are disparities of under-five mortality even across districts of the same region. The top ten districts with higher relative risk of under-five mortality based on model estimates are Ifakara (RR = 3.2), Nyasa ( RR = 3.0), Babati (RR = 2.74), Rungwe (RR = 2.58), Songea (RR = 2.58), Mbarali (RR = 2.55), Rorya (RR = 2.36), Namtumbo (RR = 2.36), Mbulu (RR = 2.11) and Mbogwe (RR = 2.11). The findings advocate for targeted interventions in these districts that may reduce under-five mortality and consequently increase child survival rates in Tanzania.
Abstract: Mortality of under-five children remains a pressing public health concern in Tanzania, with spatial disparities contributed by the intersection of socioeconomic, health and environmental factors. This study employs Bayesian techniques and epidemiological spatial methods to estimate and map district-level under-five mortality, focusing on malaria pr...
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Research Article
Bifurcation and Stability Analysis of HIV-1 Coronavirus
Co-infection Model
Cherono Pela*,
Kirui Wesley,
Adicka Daniel
Issue:
Volume 11, Issue 1, March 2026
Pages:
18-27
Received:
17 September 2025
Accepted:
21 January 2026
Published:
23 March 2026
DOI:
10.11648/j.mma.20261101.12
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Views:
Abstract: The co-infection of HIV-1 viruses has emerged as a significant threat to global public health as a result of shared mode of transmission. This article presents a novel mathematical model that addresses the dynamics of this co-infection by extending the SVEIR (Susceptible – Vaccinated – Exposed – Infectious - Recovered) framework to incorporate time-delay, chemotherapy and quarantine compartments. The population is divided into twelve compartments, with infections individuals further subdivided into symptomatic and asymptomatic individuals. The mathematical model developed is constrained to adhere to fundamental epidemiology properties such as non-negativity and boundedness within a feasible. We investigate the fundamental reproduction number that guarantees stability of equilibrium points are disease free and endemic qualitative behavior of models are examined. Stability threshold explicitly state that when reproduction number is less than one the disease free equilibrium is globally asymptotically stable, meaning the infection can be eliminated. Using Lyapunov functions, local and global stability of these states are explored and findings presented graphically. They were used to account for the history dependent nature of time delay. Our research assessed control policies and proposed alternatives, performing bifurcation analysis so as to establish prevention strategies. We investigated Hopf bifurcation analytically and numerically to demonstrate disease dynamics, which is novel to our study.. Numerical simulations, performed using the MATLAB dde23 solver, demonstrate that the introduction of chemotherapy and quarantine significantly reduces the peak of symptomatic infections. Crucially, our Hopf bifurcation analysis identifies a critical delay threshold beyond which stable equilibrium is lost to sustained periodic oscillations, representing recurrent waves of infection or rather viral blips. This offered new insights into the long-term management of HIV-1 co-infection cycles.
Abstract: The co-infection of HIV-1 viruses has emerged as a significant threat to global public health as a result of shared mode of transmission. This article presents a novel mathematical model that addresses the dynamics of this co-infection by extending the SVEIR (Susceptible – Vaccinated – Exposed – Infectious - Recovered) framework to incorporate time...
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,
Robert Too
