Current Advances in Zika Virus Transmission: Urgency for Effective Therapeutics and Prevention

Global emergence of Zika Virus (ZIKV) with prevalent outbreaks has been reported in numerous countries of South America, Central America and the Caribbean region. According to recent World Health Organization (WHO)-ZIKV situation report, 84 countries/territories/subnational areas represented with established mosquito-borne transmission of ZIKV. As of 10 August 2017, cumulative Zika cases and congenital syndrome associated with Zika virus reported by countries and territories in the Americas, 2015 – 2017 includes 217,471 confirmed cases with the Case Fatality Rate (CFR) of 0.01% and 78.08 incidence rate. ZIKV has undoubtedly become a major threat in countries endemic for other Flavivirus infection. Factors such as urbanization, global trade and travel, tropical/sub-tropical climate, prevalence of Aedes vector and poor waste management altogether are responsible for ZIKV infection in Southeast Asian countries. The occurrence of co-infection by other Flavivirus (Dengue) and ZIKV have been reported in tropical/sub-tropical region, implying the role of sero-cross reactivity and initiating antibody dependent enhancement of ZIKV infection. The trans-placental transmission of ZIKV in pregnant women makes the fetus more susceptible to ZIKV infection. In order to control ZIKV infection, development of robust vaccine and effective antivirals are required urgently. This review majorly discusses about ZIKV epidemiology, modes of transmission, antibody dependent enhancement and prevention and control strategies.