Then, in 1954, the first human infection was reported in Nigeria, however, it remains limited to sporadic cases in Africa and Asia causing mild disease in about 20% of infected people. The first outbreak of Zika virus occurred in 2007 in Yap. But it became a serious public health concern in 2015 when a large outbreak occurred in Brazil and rapidly spread in the Americas resulting in more than 700,000 cases with occasional miscarriage and severe congenital birth defects, such as fatal microcephaly, intrauterine growth restriction, and other neurodevelopmental malformations .