Re-visiting the evolution, dispersal and epidemiology of Zika virus in Asia

John H.-O Pettersson,Jon Bohlin,Myrielle Dupont-Rouzeyrol,Ola B Brynildsrud,Kristian Alfsnes,Van-Mai Cao-Lormeau,Michael W Gaunt,Andrew K Falconar,Xavier De Lamballerie,Vegard Eldholm,Didier Musso,Ernest A Gould

doi:10.1038/s41426-018-0082-5

Abstract

Based on serological evidence and viral isolation, Zika virus (ZIKV) has circulated for many years relatively benignly in a sylvatic cycle in Africa and an urban cycle in South East Asia (SEA). With the recent availability of limited but novel Indian ZIKV sequences to add to the plethora of SEA sequences, we traced the phylogenetic history and spatio-temporal dispersal pattern of ZIKV in Asia prior to its explosive emergence in the Pacific region and the Americas. These analyses demonstrated that the introduction and dispersal of ZIKV on the Pacific islands were preceded by an extended period of relatively silent transmission in SEA, enabling the virus to expand geographically and evolve adaptively before its unanticipated introduction to immunologically naive populations on the Pacific islands and in the Americas. Our findings reveal new features of the evolution and dispersal of this intriguing virus and may benefit future disease control strategies.

Highlights

Zika virus (ZIKV) was first isolated in 1947 from rhesus monkey serum collected in the Zika Forest of Uganda (Africa)[1]
Africa and Asia, including partial data from a recently available Indian ZIKV sequence[13], indicate that the Indian virus shares a more recent ancestry with all of the other Asian sequences than with the Malaysian sequence, which is positioned as a sister-group to all of the other Asian sequences
Our results demonstrated that Indian ZIKV shared a more recent ancestry with the South East Asia (SEA) viruses compared to the Malaysian virus

Summary

Introduction

Zika virus (ZIKV) was first isolated in 1947 from rhesus monkey serum collected in the Zika Forest of Uganda (Africa)[1]. Serosurveys conducted from the 1950s onwards suggested that ZIKV circulated in several countries of Africa and Asia. ZIKV emerged in Africa (African lineage) and subsequently spread through Asia (Asian Lineage). In 2007, an Asian lineage strain of ZIKV unpredictably caused a unique explosive epidemic on the Pacific island of Yap in Micronesia[4], involving 70% of the population. Within months, the epidemic (mother to child, sexual and blood transfusion transmission) was confirmed with the emergence of ZIKV in the Americas[2, 9]. Following its establishment on the FP islands, ZIKV radiated eastwards and westwards[10] and subsequently emerged in Brazil before dispersing and causing epidemics in the Americas[2, 11]

Methods

Results

Conclusion