Human illness caused by Zika virus was first recognized in Nigeria in 1953,
when viral infection was confirmed in three ill persons.
Despite recognition that
Zika virus infection could produce a mild, febrile illness, only 13 naturally ac-quired cases were reported during the next 57 years.
Thus, it came as a great
surprise when a 2007 outbreak on several islands in the State of Yap, Federated
States of Micronesia, resulted in an estimated 5000 infections among the total
population of 6700.