Will Zika return to the 'Old World'?

Introduction

Zika virus infection is now rapidly disseminating throughout Latin American and the Caribbean, and possibly soon into the Gulf Coast of the United States. TheWorld Health Organization estimates that up to four million people could be infected in the Western Hemisphere by the end of 2016.

In the coming months could Zika virus infection travel across the Atlantic Ocean and begin causing infections (and microcephaly cases) in Europe, the Middle East, and Africa? The Zika virus was first described in the Zika Forest of Uganda during the late 1940s and isolated in 1952 [1]. The first human case was described in Nigeria in 1954 [2], and it is believed that Zika caused localized epidemics of Zika virus infection before it migrated from Africa and across Asia in the ensuing decades. In the 21st century molecular genetic comparisons suggest that Zika mutated to a pandemic strain that resulted in high virus attack rates in Micronesia and French Polynesia, before causing widespread infections in the ‘New World’ of the Americas [3]. There are several reasons to believe that Zika could complete its trip around the planet by spreading to vulnerable areas of the ‘Old World’ e Europe, the Middle East, and Africa. This is true particularly in urban areas that meet the major criteria responsible for current Zika outbreaks in the Americas, especially crowding and human migrations, poverty, and the presence of Aedes mosquitoes.