Zika virus and neurological disease—approaches to the unknown
Solomon T, Baylis M, Brown D
The early part of the 21st century has seen an unparalleled number of emerging infectious disease events: West Nile virus across the Americas, severe acute respiratory syndrome in China and beyond, chikungunya, avian influenza, Middle East respiratory syndrome coronavirus, Ebola virus. So many in fact that perhaps we should no longer consider them extraordinary.
The latest in this series of events is Zika virus (family Flaviviridae, genus Flavivirus), a mosquito-borne pathogen that was first isolated from a sentinel rhesus monkey in the Zika forest of Uganda in 1947, and identified in human beings in 1952. Since then there have been occasional reports of Zika virus infection in human beings in Africa and later in southeast Asia, characterised by the fever, arthralgia, and rash typical of many arthropod-borne viruses (arboviruses). Phylogenetic studies suggest the virus emerged in east Africa in the early part of the 20th century, later spreading to southeast Asia.1 In 2007 there was a small outbreak in Yap, Federated States of Micronesia, and in 2013 a larger outbreak in French Polynesia, with 28 000 cases recorded in the first 4 months. Since the first reports of Zika virus infection in Brazil in early 2015,2 its rapid and explosive spread has resulted in an estimated 1.5 million cases with 4 million predicted across the continent by the end of the year, and the declaration by WHO of a Public Health Emergency of International Concern.
1 O Faye, CC Freire, A Iamarino, et al. Molecular evolution of Zika virus during its emergence in the 20(th) century. PLoSNegl Trop Dis, 8 (2014), p. e2636
2 GS Campos, AC Bandeira, SI Sardi. Zika virus outbreak, Bahia, Brazil.Emerg Infect Dis, 21 (2015), pp. 1885–1886
The Lancet Infectious Diseases
Vector Biology & Climate Modelling