Insights into intercontinental spread of Zika virus

Abstract

The epidemic of Zika virus (ZIKV) infection in South America has led to World Health Organization’s declaration of a Public Health Emergency of International Concern. To further inform effective public health policy, an understanding of ZIKV’s transmission mechanisms is crucial. To characterize the intercontinental transmission of ZIKV, we compiled and analyzed more than 250 gene sequences together with their sequence-related geographic and temporal information, sampled across 27 countries spanning from 1947 to 2016. After filtering and selecting appropriate sequences, extensive phylogenetic analyses were performed. Although phylogeographic reconstruction supported the transmission route of the virus in Africa, South-eastern Asia, Oceania and Latin America, we discovered that the Eastern Africa origin of ZIKV was disputable. On a molecular level, purifying selection was found to be largely responsible for the evolution of non-structural protein 5 and envelope protein E. Our dataset and ancestral sequences reconstruction analysis captured previously unidentified amino acid changes during evolution. Finally, based on the estimation of the time to the most recent common ancestors for the non-structural protein 5 gene, we hypothesized potential specific historic events that occurred in the 1940s and might have facilitated the spread of Zika virus from Africa to South-eastern Asia. Our findings provide new insights into the transmission characteristics of ZIKV, while further genetic and serologic studies are warranted to support the design of tailored prevention strategies.

Genome-wide diversity of Zika virus: Exploring spatio-temporal dynamics to guide a new nomenclature proposal

“…The type of transmission cycle, together with the lack of an adaptive immune system in mosquitoes, has been suggested to also explain the small number of sites detected to be under positive selection in ZIKV ( Shrivastava et al. 2018 ), as found here and in other studies on ZIKV ( Liang et al. 2017 ).…”

The increasing complexity of arbovirus serology: An in-depth systematic review on cross-reactivity

“…Climate change may also have an impact by influencing the geographical and temporal distribution of arthropods and/or reservoir hosts such as migrating birds [3][4][5][6][7]. Recent examples of unusual arboviral spread are autochthonous chikungunya virus (CHIKV) cases that have been reported in Italy and France throughout the past years [8][9][10][11][12], Usutu virus (USUV) which is frequently observed in birds and occasionally in humans in Europe [13], the Zika virus (ZIKV) epidemic that rapidly spread to the Pacific islands and the Americas [14][15][16][17][18][19][20], Crimean Congo Haemorrhagic fever virus (CCHFV) expansion in Europe [6,[21][22][23], the first autochthonous West Nile virus (WNV) cases in Germany [24] and the Netherlands [25], and locally acquired dengue virus (DENV) cases in France and Spain [26]. Furthermore, there are indications that other arboviruses such as Mayaro virus (MAYV) are further spreading into the Caribbean and Central and South America, likely causing more outbreaks in the near future [27][28][29][30][31][32].…”