Differential transmission of Asian and African Zika virus lineages by Aedes aegypti from New Caledonia

Elodie Calvez,Olivia O’Connor,Morgane Pol,Dominique Rousset,Oumar Faye,Vincent Richard,Arnaud Tarantola,Myrielle Dupont-Rouzeyrol

doi:10.1038/s41426-018-0166-2

Abstract

Zika virus (ZIKV) is a Flavivirus that is transmitted to humans by Aedes mosquitoes. ZIKV is divided into two phylogenetic lineages, African and Asian. In the Asian lineage, Pacific and American clades have been linked to the recent worldwide outbreak of ZIKV. The aim of this study was to measure the vector competence of Aedes aegypti for seven ZIKV strains belonging to both lineages. We demonstrate that Ae. aegypti from New Caledonia (NC), South Pacific region, is a low-competence vector for Asian ZIKV (<10% transmission efficiency). No significant differences were observed in vector competence with respect to the sampling date and collection site of Asian ZIKV strains used (2014 and 2015 for New Caledonia, Pacific clade, and 2016 for French Guiana, American clade). The ability of the New Caledonian Ae. aegypti to transmit ZIKV is significantly greater for the earlier viral isolates belonging to the African lineage (>37% transmission efficiency after 9 days post-infection) compared to recent ZIKV isolates from African (10% transmission efficiency) and Asian lineages (<10% transmission efficiency). The results of this study demonstrate that Ae. aegypti from NC can become infected and replicate different ZIKV strains belonging to all lineages. Our data emphasize the importance of studying the interaction between vectors and their arboviruses according to each local geographic context. This approach will improve our understanding of arbovirus transmission to prevent their emergence and improve health surveillance.

Highlights

Zika virus (ZIKV; family Flaviviridae, genus Flavivirus) was first isolated in the eponymous Ugandan forest in 19471
The dissemination rate was moderate (
When analyzing all the experimental infections, our results showed that New Caledonia (NC) Ae. aegypti more transmit older ZIKV strains belonging to the African lineage (AF1947-MR766 and AF-1991-HD78788) than the other strains tested (Fig. 3a: Table S1–S2)

Summary

Introduction

Zika virus (ZIKV; family Flaviviridae, genus Flavivirus) was first isolated in the eponymous Ugandan forest in 19471. ZIKV has been sporadically detected in Africa and Asia and has recently emerged in the Pacific region and spread to Latin America[2], causing major outbreaks. Zika fever is a predominantly mosquito-borne disease, rarer forms of ZIKV transmission have been described, including sexual or blood-borne transmission and vertical transmission from mother to child[7]. ZIKV infection has been associated with a dramatic increase in congenital abnormalities, including microcephaly and neurological disorders, especially in Brazil and in French Polynesia[8,9,10,11]. Previous phylogenic studies identified two distinct lineages for ZIKV, African, and Asian, which circulated in these two geographic contexts. Two clades have been identified in the Asian lineage, Pacific and American[14,15], which exhibit a low genetic divergence of less than 12% at the nucleotide level[2]

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Conclusion