Search bioRxiv⌕ Search

bioRxiv · 10.1101/2025.11.30.691431

Interactions Between the Frequency of the Duffy Antigenand the Dynamics of P. vivax Malaria Infections

Abstract

The malarial parasite Plasmodium vivax has infected humans for millennia. As such, alleles like the FY*O allele in the Duffy Antigen Receptor for Chemokines (DARC) and the sickle cell allele (HbS) have been naturally selected for in malaria-endemic regions because they confer resistance to malaria, thereby increasing the survival and reproductive success of individuals carrying these protective alleles. As resistance becomes more common in a population, malaria incidence is expected to decline, reducing the evolutionary pressure for additional resistance. In this work, we explore the interaction between these processes. We construct a model with seasonality that tracks the frequency of Duffy genotypes and leverages fast/slow dynamics to analyze the coupled dynamics of malaria transmission and changes in the gene frequency of the DARC genotype. Specifically, we investigate how the burden of malaria changes with the fractions of people with the various DARC genotypes. We derive the basic reproduction number as the threshold condition for the stability of the disease-free equilibrium and interpret the R0 as a weighted sum of the cases generated by infected individuals of each genotype. Additionally, we calibrate our model using data from the Amazonas region in Brazil, which has a polymorphic population with respect to DARC, and still reports a substantial number of P. vivax cases. Analysis of our model determines the proportion of the population that must be Duffy-negative in order for the entire population to be protected against P. vivax without any further interventions. Furthermore, we assess how different proportions of Duffy-negative individuals influence the monthly incidence of P. vivax cases.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ponce, J., Rai, G., Selivonenko, D., Ghartey, E., Wissenbach, R.. 2025-12-01. Interactions Between the Frequency of the Duffy Antigenand the Dynamics of P. vivax Malaria Infections. https://doi.org/10.1101/2025.11.30.691431

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Operationalising the context in regenerative agriculture: decision-making and farm variability

Soil degradation is a widespread challenge that requires a broad response at the individual farm level. To ensure effectivity, the practices should be tailored to the farm context: land manager objectives and farm specific challenges. These have however been difficult to quantify. Here we demonstrate that a workable farm context can be created based on a value survey, open satellite and soil data, and published models for vegetation gross primary productivity and soil erosion. Based on the findings, despite individual differences, farmers value profitability and operational efficiency, but also biodiversity and soil health. At least the regenerative farmers surveyed also value working for the greater good more than maintaining tradition or power. In spite of wide differences in farm production orientation, we also found that each farm also had a broad variation in individual fields GPP. Most fields have a stable GPP level, which is either high or low, and that there is a 2-3-fold difference between the weakest and best producing fields indicating the potential for improving GPP by improving the growing conditions on currently weak fields. In addition, soil loss was found to be highly concentrated in critical source areas, where 10% of the field area contributed to 50% of the soil loss. Overall, open data can be linked to modelling workflows to rapidly produce a decision-making context for farmers. This facilitates benchmarking and co-learning as well as enables land managers and advisors to identify the farm context for planning effective responses to soil degradation.

ecology↗

Fly, land, listen: Autonomous intermittent locomotion enables scalable low-noise drone ecoacoustic surveys

Ecoacoustic monitoring is enabling scientists and land managers to monitor and manage biodiversity more effectively and cost-efficiently in the face of human pressures and rapidly changing climates. Currently, most ecoacoustic surveys use manually deployed static sensors to record data, limiting the scale and reach of surveying efforts. Here we present a proof-of-concept autonomous drone platform that can use intermittent locomotion to conduct ecoacoustic surveys using an onboard sensor. Our custom prototype is able to fly, navigate, and avoid obstacles autonomously, land at a pre-determined location, record audio from an onboard microphone whilst static, before taking off and moving to the next sampling site. Autonomous navigation and operation enable greater sampling flexibility, reach, and scalability. Furthermore, by recording audio only whilst landed, noise from the drone's rotors does not mask signals or disturb animals, simplifying signal processing and downstream ecological analyses. We conducted trials in a scrubland habitat at the Knepp Estate in West Sussex, where our prototype demonstrated successful autonomous navigation and obstacle avoidance. Furthermore, we found that avian biodiversity data collected from the drone platform was comparable to that from traditional static acoustic sensor deployments, and that vocalisation patterns were not significantly impacted by the noise of the drone arriving or leaving a site. While scaled deployments of our technology would require further technical and regulatory challenges to be solved, our first demonstration of autonomous intermittent robotics-assisted ecoacoustic surveys lays the foundations for more cost-effective and far-reaching biodiversity surveys, with transformative potential for conservation, agricultural management, biosecurity, and more.

ecology↗

Do higher-order moments improve inference of population dynamics?

Fitting mathematical models of population dynamics to microbial time-series data allows us to estimate the ecological processes and interactions taking place in the microbiome. Repeated experiments of microbial systems yield replicates which slightly differ from each other. Some of this variability arises due to the fact that births and deaths occur at random. Most prior work focuses on fitting a deterministic mathematical model to the average across replicates. We use a stochastic model to fit the variability to the observed variability across replicates. Using a simulation-driven approach, we study the conditions under which our approach allows us to infer a larger fraction of ecological parameters correctly. We observe a substantial improvement in parameter inference. Lastly, our Bayesian approach not only allows us to incorporate prior information about the system, but also provides a distribution of parameters which conveys some idea of the uncertainty of the estimates.

ecology↗