arXiv subjects

Clotilde Djuikem

Publications and source records attributed to Clotilde Djuikem.

5 recordsLinked to original sources

arXiv2026

Within-host immunology to age-of-infection epidemiology via a virtual cohort

We present a methodology providing a one-directional link from within-host individual heterogeneity to population-level disease transmission dynamics. The methodology works in several steps. A within-host model is investigated numerically to determine pathogen and immunological parameters leading to the largest variation of model responses. These key parameters are used to generate a synthetic population of individuals whose temporal immunological response profiles are recorded. These responses are ranked in terms of the severity of experienced outcomes, from mild infections to death, as a function of time since infection. This is used to parametrise an age-of-infection structured epidemiological model to study the transmission dynamics of the disease at the population level. The approach is illustrated using a within-host model describing SARS-CoV-2 infection and an SIR population-level model.

q-bio.PE↗

arXiv2026

Deterministic and stochastic infection dynamics in a population subject to stress

Physiological stress fundamentally alters disease susceptibility in aquatic environments. In this paper, we develop a stress-structured epidemiological model where host vulnerability is dynamically driven by water quality. Analytically, we establish that the system exhibits a classic forward bifurcation at $\mathcal{R}_0=1$, confirming that the basic reproduction number remains a valid threshold for eradication. However, stochastic analysis reveals a critical asymmetry not captured by deterministic thresholds. We show that while $\mathcal{R}_0$ predicts stability, the probability of an outbreak depends on the initial physiological state. Introducing infection into a stressed sub-population leads to immediate rapid growth of the disease, whereas introduction into the normal class faces a stochastic barrier that significantly delays the epidemic peak.

q-bio.PE↗

arXiv2025

Threshold-based impulsive biocontrol for coffee leaf rust

Coffee leaf rust (CLR) severely affects coffee production worldwide, leading to reduced yields and economic losses. To reduce the cost of control, small-scale farmers often only apply control measures once a noticeable level of infection is reached. In this work, we develop mathematical models to better understand CLR dynamics and impulsive biocontrol with threshold-based interventions. We first use ordinary and impulsive differential equations to describe disease spread and the application of control measures once a certain infection level is detected. These models help determine when and how often interventions should occur. To capture the early stages of the disease and the chance that it might die out by itself, we then use a continuous-time Markov chain approach. This stochastic model allows us to estimate the probability that the pathogen fails to establish, thereby avoiding serious outbreaks.

q-bio.PE↗

arXiv2025

Transmission of multiple pathogens across species

We analyse a model that describes the propagation of many pathogens within and between many species. A branching process approximation is used to compute the probability of disease outbreaks. Special cases of aquatic environments with two host species and one or two pathogens are considered both analytically and computationally.

q-bio.PE↗

arXiv2025

Dynamics and control of maize infection by Busseola fusca: multi-seasonal modeling and biocontrol strategies

Maize production in sub-Saharan Africa faces significant challenges due to the maize stalk borer (Busseola fusca), a major pest that causes substantial yield losses. Chemical control methods have raised concerns about environmental impact and pest resistance, making biological control a promising alternative. In this study, we develop a multi-seasonal mathematical model using an impulsive system of differential equations to describe stalk borer population dynamics and evaluate pest control strategies. We analyze the stability of the pest-free solution using Floquet theory and study the effects of periodic predator releases on pest suppression. Numerical simulations illustrate the impact of cultural practice and predator release frequency. Moreover, our simulations show that, under good cultural practices, releasing predators once or three times a year is an effective biocontrol strategy. However, in cases of poor cultural practices, biocontrol has only a limited effect, and the best outcome is achieved when predators are released once a year at the beginning of the cropping season.

q-bio.PE↗