ECOP Subgroup Contributed Talks

Prince Harvim

University of Ottawa

"Transmission Dynamics and Control Mechanisms of Vector-Borne Diseases with Active and Passive Movements Between Urban and Satellite Cities"

We formulate a metapopulation model to investigate the role of active and passive mobility on the spread of an epidemic between an urban center connected to a satellite city. The epidemic disease considered is transmitted via both sexual and vector mode (eg Zika virus). The basic reproduction number of the disease is explicitly determined as a combination of sexual and vector-borne transmission parameters. The sensitivity analysis reveals that the disease is primarily transmitted via the vector-borne mode, rather than via sexual transmission, and that sexual transmission by itself may not initiate or sustain an outbreak. Furthermore, increasing the mobility of the population from urban center to the satellite city leads to an increase in the basic reproduction number of the satellite city but a decrease in the basic reproduction number in the urban center. We explore the potential effects of optimal control strategies relying upon several distinct restrictions on population movement. We find that although travel restrictions from the urban center to the satellite city may reduce the prevalence of the disease in the satellite city, significant control measures targeting the densely populated cities are required in order to eradicate the disease in the entire region.

Qianying Lin

University of Michigan, Ann Arbor

"Viral Phylodynamics and A Class of Markov Genealogy Processes"

Phylodynamic studies aim to extract information on the population process of pathogens from genome sequences. In this talk, I focus on the relationship between genealogies or phylogenies reconstructed from sampled virus genomes and the population processes that generate them. I show how the problem is naturally formulated in terms of a class of interrelated Markov processes that are built on the stochastic dynamics of births and deaths in the population. For interesting transmission models, the exact likelihood is intractable, but I show how to construct an efficient sequential Monte Carlo algorithm to estimate it with high accuracy.

Sipkaduwa Arachchige Sashika Sureni Wickramasooriya

Clarkson University

"Biological Control via Alternative Food to Predator"

Biological control is a means by which pest/invasive populations are kept in check by the use ofnatural enemies of the pest, or perhaps even parasites, pathogens or a combination thereof. The classic work ofSrinivasu et. al. demonstrates how such a process can be facilitated, by providing additional food to an introducedpredator to control a target pest. A critical assumption in the literature is that the additional food is constant.Theoretical studies carried out previously in this direction indicate that incorporating mutual interference betweenpredators can stabilize the system. In this work, Beddington–DeAngelis type functional response has been used tomodel the mutual interference between predators. The conditions for eradication of pest is derived and the mainconcern is to determine whether the model exhibit different bifurcation. Various biological implications of ourmathematical results are drawn in conclusion.