Mosquitos in a lab at the International Training and Medical Research Training Center (CIDEIM) in Cali, Colombia, Feb. 2, 2016.
The following timeline charts the origin and spread of the Zika virus from its discovery in Uganda nearly 70 years ago:
1947 – Scientists researching yellow fever in Uganda's Zika Forest isolate the virus in samples taken from a rhesus monkey
1948 – Virus recovered from Aedes africanus mosquito in the Zika forest
1952 – First human cases detected in Uganda and Tanzania
1954 – Virus found in young girl in Nigeria
1960s-1980s – Zika detected in mosquitoes and monkeys in band of countries stretching across equatorial Africa
1969–1983 – Zika is found in equatorial Asia, including India, Indonesia, Malaysia and Pakistan
2007 – Zika spreads from Africa and Asia to cause the first large outbreak in the Pacific island of Yap
2012 – Two distinct lineages of the virus, African and Asian, are identified by researchers
2013–2014 – Zika outbreaks in French Polynesia, Easter Island, the Cook Islands and New Caledonia. Retrospective analysis shows possible link to birth defects and severe neurological complications in babies in French Polynesia
March 2, 2015 – Brazil reports an illness characterized by skin rash in northeastern states
Apr 29, 2015 – Brazilian samples test positive for Zika
July 17, 2015 – Brazil reports detection of neurological disorders in newborns associated with history of infection
Oct 5, 2015 – Cape Verde reports cases of illness with skin rash
Oct 22, 2015 – Colombia confirms cases of Zika
Oct 30, 2015 – Brazil reports unusual increase in cases of microcephaly – abnormally small heads – among newborns
Nov 11, 2015 – Brazil declares a national public health emergency
Nov 2015-Jan 2016 – Cases reported in Suriname, Panama, El Salvador, Mexico, Guatemala, Paraguay, Venezuela, French Guiana, Martinique, Puerto Rico, Guyana, Ecuador, Barbados, Bolivia, Dominican Republic, Nicaragua, Curacao, Jamaica
Feb 1, 2016 – World Health Organization declares a public health emergency of international concern
Source: World Health Organization.
(Reporting by Ben Hirschler; Editing by Pravin Char)