Abstract

We consider the dynamic vector–host–pathogen interaction motivated by tick-borne diseases such as tick-borne encephalitis and Lyme disease. We stratify the vector population in terms of the stage before and after the vector’s contact with hosts when co-feeding transmission may take place, and we also consider the case where vector development may involve two time lags due to normal development and diapause. We derive threshold conditions for disease persistence and for nonlinear oscillations in the vector population and in the diseased vector and host populations. Our objective here is to use a simple mechanistic dynamic model to show that diapause and co-feeding transmission may generate periodic and irregular oscillations even when seasonal variations of the environmental conditions are ignored. These oscillations are not necessary in synchrony with the seasonality of vector development, and hence complicated oscillatory patterns of vector-borne disease dynamics in the field and surveillance observations should be expected.

Highlights

  • We consider the transmission dynamics of tick-borne diseases such as tick-borne encecphalitis and Lyme disease

  • Tick-borne diseases can be caused by infection

  • In Europe and Asia, Ixodes ricinus and Ixodes persulcatus ticks are primary species transmitting tick-borne encephalitis and Lyme borreliosis, infections can be transmitted through ingesting contaminated unpasteurized cow, sheep or goat milk and milk products obtained from infected animals

Read more

Summary

Introduction

We consider the transmission dynamics of tick-borne diseases such as tick-borne encecphalitis and Lyme disease. Dunn et al.[7] performed a global sensitivity analysis to rank the importance of model parameters in terms of their contribution to the observed variations in the basic reproduction number They concluded that there are three most influential factors: the transmission efficiency from the vertebrate host to ticks, the survival rate from fed larva to feeding nymph, and the fraction of nymphs finding a competent host. Lou et al.[8] proposed a stage-structured periodic model to identify the tick reproduction threshold and the disease spread threshold, and investigated effects of seasonal temperature variation and host community composition on the pattern of Lyme disease spread. None of these models have incorporated the roles of co-feeding transmission and diapause. A natural question is whether such a model can exhibit nonlinear oscillations

The Framework and Hypotheses
The Model
Critical Value for Vector Population Oscillations
Implication for Pathogen Spread
Numerical Illustrations
Discussions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.