Mathematical assessment of the impact of human-antibodies on sporogony during the within-mosquito dynamics of Plasmodium falciparum parasites. (21st April 2021)

• Record Type: Journal Article
• Authors: Teboh-Ewungkem, Miranda I.; Woldegerima, Woldegebriel Assefa; Ngwa, Gideon A.
• Is Part Of: Journal of theoretical biology. Volume 515(2021)
• Publication Date: 2021-04-21
• Subjects: Malaria parasites -- Within-mosquito -- Sporogony -- Gametogenesis -- Human antibodies -- Transmission blocking -- Mathematical modelling; Biology -- Periodicals; Biological Science Disciplines -- Periodicals; Biology -- Periodicals; Biologie -- Périodiques; Theoretische biologie; Biology; Periodicals; 571.05
• DOI: 10.1016/j.jtbi.2020.110562
• Languages: English
• ISSNs: 0022-5193

Abstract

Highlights: Effects of ingested human antibodies on oocyst density in mosquitoes are studied. Boosting ingested antibodies efficiency and size inhibit sporozoite formation. We examine sizes of ingested gametocytes and antibodies under which a mosquito is infectious. Naïve immune humans may be more infectious to mosquitoes than mature immune humans. At high fertilization rate, ingested antibodies can render mosquitoes non-infectious. Abstract: We develop and analyze a deterministic ordinary differential equation mathematical model for the within-mosquito dynamics of the Plasmodium falciparum malaria parasite. Our model takes into account the action and effect of blood resident human-antibodies, ingested by the mosquito during a blood meal from humans, in inhibiting gamete fertilization. The model also captures subsequent developmental processes that lead to the different forms of the parasite within the mosquito. Continuous functions are used to model the switching transition from oocyst to sporozoites as well as human antibody density variations within the mosquito gut are proposed and used. In sum, our model integrates the developmental stages of the parasite within the mosquito such as gametogenesis, fertilization and sporogenesis culminating in the formation of sporozoites. Quantitative and qualitative analyses including a sensitivity analysis for influential parameters are performed. We quantify the average sporozoite load produced at the end of the within-mosquito malaria parasite's developmental stages. Our analysis shows that an increase in the efficiency of the ingested human antibodies in inhibiting fertilization within the mosquito's gut results in lowering the density of oocysts and hence sporozoites that are eventually produced by each mosquito vector. So, it is possible to control and limit oocysts development and hence sporozoites development within a mosquito by boosting the efficiency of antibodies as a pathway to the development of transmission-blocking vaccines which could potentially reduce oocysts prevalence among mosquitoes and hence reduce the transmission potential from mosquitoes to human.