Vector-Borne Transmission of the Zika Virus Asian Genotype in Europe.

Guillaume A Durand,Gilda Grard,Anna-Bella Failloux,Jessica Denis,Isabelle Leparc-Goffart,Géraldine Piorkowski,Cyril Badaut,Christine Zandotti,Xavier De Lamballerie,Laetitia Ninove,Sandra Giron,Laurence Thirion

doi:10.3390/v12030296

Abstract

Three autochthonous cases of Zika virus occurred in southern France in August 2019. Diagnosis relied on serology and transcription-mediated amplification. Attempts for virus isolation and ZIKV genome RT-PCR detection remained negative. Since the index case was not identified, we addressed the issue of genotyping and geographical origin by performing hemi-nested PCR and sequencing in the Pr gene. Analysis of 16 genotype-specific Single Nucleotides Polymorphisms identified the Asian genotype and suggested a Southeast Asia origin.

Highlights

The first vector-borne transmission of Zika virus (ZIKV) in Europe has been reported recently [1].It occurred during August 2019 in the Mediterranean coastal department of Var within an area of permanent implantation of Aedes albopictus, which represents the only potential vector locally.During the first steps of investigation, a small cluster of three cases that occurred in August 2019 was discovered retrospectively within a circle with a radius 50 meters
The strain implicated in ZIKV autochthonous vector-borne transmission in the Var region belonged to the Asian genotype and was most probably imported from Southeast Asia
The actual transmission potential of the incriminated ZIKV strain by local Ae. albopictus

Summary

Introduction

The first vector-borne transmission of Zika virus (ZIKV) in Europe has been reported recently [1] It occurred during August 2019 in the Mediterranean coastal department of Var (city of Hyeres) within an area of permanent implantation of Aedes albopictus, which represents the only potential vector locally. The index case was not identified and the issue of the geographical origin and genetic typing of the virus strain remained unanswered. This question is of specific importance since recent vector competence studies suggested that Ae. albopictus from France can transmit more efficiently the African genotype of ZIKV than the Asian genotype [2]. The aim of the current study was to determine the ZIKV genotype implicated in cases of local transmission in France, 2019

Standard Laboratory Investigations

Discussion