This flavivirus was only discovered in 1947 from a rhesus macaque monkey in the Zika forest of Uganda. It was isolated from three people in Nigeria in 1953 and seroconversion studies showed the virus to be a mild cause of disease in parts of Africa, India, and Southeast Asia. Only 13 cases were reported until 2007, when an outbreak of 5,000 cases occurred in Micronesia. It was next heard of in French Polynesia in 2013-14, where there were a possible 32,000 cases. Zika came to the Americas in 2015, primarily to Brazil. By March 2016, more than 51,000 cases were reported from Brazil where the first cases of microcephaly were identified in more than 4000 infants.
Zika virus has been reported from 65 countries as of July 6, 2016. 48 of those are new since 2007. Indonesia, Thailand, Philippines, and Vietnam have become endemic for the virus. Fifteen countries have Zika-associated Guillain-Barre cases and 13 countries have reported microcephaly cases, including the United States.
Current Zika risk locations may be seen in the attached map.
