Modeling the potential of wAu-Wolbachia strain invasion in mosquitoes to control Aedes-borne arboviral infections

Samson T Ogunlade,Emma S Mcbryde,Diana P Rojas,Michael T Meehan,Adeshina I Adekunle

doi:10.1038/s41598-020-73819-1

Samson T Ogunlade, Emma S Mcbryde + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-73819-1

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Abstract

Arboviral infections such as dengue, Zika and chikungunya are fast spreading diseases that pose significant health problems globally. In order to control these infections, an intracellular bacterium called Wolbachia has been introduced into wild-type mosquito populations in the hopes of replacing the vector transmitting agent, Aedes aegypti with one that is incapable of transmission. In this study, we developed a Wolbachia transmission model for the novel wAu strain which possesses several favourable traits (e.g., enhanced viral blockage and maintenance at higher temperature) but not cyctoplasmic incompatibility (CI)—when a Wolbachia-infected male mosquito mates with an uninfected female mosquito, producing no viable offspring. This model describes the competitive dynamics between wAu-Wolbachia-infected and uninfected mosquitoes and the role of imperfect maternal transmission. By analysing the system via computing the basic reproduction number(s) and stability properties, the potential of the wAu strain as a viable strategy to control arboviral infections is established. The results of this work show that enhanced maintenance of Wolbachia infection at higher temperatures can overcome the lack of CI induction to support wAu-Wolbachia infected mosquito invasion. This study will support future arboviral control programs, that rely on the introduction of new Wolbachia variants.

Highlights

Arthropod-borne viruses, or arboviruses, are viruses that are transmitted via blood feeding arthropods[1]
Unlike the modeling work in Adekunle et al.[37], apart from the non-induction of cyctoplasmic incompatibility (CI), we considered the loss of Wolbachia infections due to seasonal fluctuation in temperature, a key dynamics that is absent in wAu strain
We modelled and investigated a general Wolbachia model that contained the transmission dynamics of wAu and wMel Wolbachia strains in Aedes mosquitoes as special cases

Summary

Introduction

Arthropod-borne viruses, or arboviruses, are viruses that are transmitted via blood feeding arthropods[1] Arboviral infections such as dengue, Zika and chikungunya are fast spreading diseases that pose significant health problems globally[2,3,4,5]. There is no specific universal treatment for dengue infections: the vaccine envelopment targets young populations; the efficacy of the only vaccine licensed depends on prior immunity to at least one serotype of dengue; and it provides heterogeneous protection against the different s erotypes[11,12] Other arboviral infections such as Zika, chikungunya and yellow fever are of global health c oncern[13]. Whilst Wolbachia is not naturally present in Aedes aegypti, it can be introduced via stable transinfections using microinjections[29,30]

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