A review on Zika virus, a re-emerging arbovirus

Before the recent outbreaks of Zika virus, few people have ever heard of its name. Even virologists had paid little attention to this member of the Flaviviridae family. Hence, up to January 2016, only 269 articles about Zika virus had been indexed in PubMed compared to the 9187 articles related to dengue virus. However, declaration of the World health organization (WHO) about the global Zika virus spreading, which has been associated with birth defects and some neurological problems, diverted more attention to this forgotten virus. Afterwards, the virus hit the headlines and became a research interest. Since then, up to 9 August 2017, the number of Zika related articles indexed in PubMed reached to 3214. Zika virus is a re-emerging arbovirus. The First detection of Zika virus was in Uganda in 1947. It belongs to the Flavivirus genus in the Flaviviridae family. Zika can typically cause a mild and self-limiting disease in a healthy person. However, in pregnant women, it might cause birth defects and occasionally it can be associated with peripheral neuropathy such as Guillain-Barre syndrome. Although many research have been conducted to find out the casual link between this virus and these disorders but this relationship is still dim and controversial. Considering its recent epidemics in 2015 and 2016 the geographical distribution of Zika virus seems to expand all over the world progressively. Interaction between virus and vector is dynamic. Variety of competent vectors and adaptability of virus to new arthropod vectors are the two major factors for this process. According to the last report published by WHO, 84 countries/territories in five continents have reported the circulation of Zika virus in their area. In the recent outbreak, WHO regional office in our region (EMRO) have reported no case of Zika virus transmission from this region. Nonetheless, because specific and competent vectors exist in some countries, this region has a potential of epidemic risk. Until now we have neither autochthonous nor imported case of Zika virus in our country but we should prepare for any unexpected situation. In this review, we will discuss new findings about the history, virological features, vectors, transmission routes and epidemiological aspects as well as laboratory diagnosis of Zika virus. In addition, the epidemiology of this virus in Iran will be discussed.