1947: Scientists researching yellow fever in Uganda's Zika Forest identify the virus in a rhesus monkey 1948: Virus recovered from Aedes africanus mosquito in Zika Forest 1952: First human cases detected in Uganda and Tanzania 1960s-80s: Zika detected in mosquitoes and monkeys across equatorial Africa 1960s–80s: Zika found in equatorial Asia, including India, Indonesia, Malaysia and Pakistan 2007: Zika spreads from Africa and Asia, first large outbreak on Pacific island of Yap 2012: Researchers identify two distinct lineages of the virus, African and Asian 2013–14: 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 illness characterized by skin rash in northeastern states July 17: Brazil reports detection of neurological disorders in newborns associated with history of infection Oct. 22: Colombia confirms cases of Zika Oct. 30: Brazil reports increase in microcephaly, abnormally small heads, among newborns Nov. 11: Brazil declares public health emergency November 2015-January 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: World Health Organization (WHO) declares public health emergency of international concern Feb. 2: First case of Zika transmission in United States; local health officials say likely contracted through sex, not mosquito bite Feb. 5: U.S. Centers for Disease Control and Prevention says virus being actively transmitted in 30 countries, mostly in the Americas Feb. 8: U.S. President Barack Obama requests $1.9 billion to fight Zika Feb. 18: CDC adds Aruba and Bonaire to countries and territories with active outbreaks, bringing total to 32 Feb. 23: CDC adds Trinidad and Tobago and Marshall Islands to countries and territories with active outbreaks, bringing total to 34 Feb. 25: Brazil says confirmed microcephaly cases number more than 580 and considers most of them to be related to Zika infections in the mothers, with an additional 4,100 suspected cases of microcephaly Feb. 27: France detects first sexually transmitted case of Zika March 8: WHO advises pregnant women to avoid areas with Zika outbreak and said sexual transmission of the virus is "relatively common" March 19: CDC adds Cuba to countries and territories with active outbreaks, bringing total to 38 March 22: CDC adds Dominica to countries and territories with active outbreaks, bringing total to 39 March 31: The World Health Organization says there is a strong scientific consensus that Zika can cause the birth defect microcephaly as well as Guillain-Barre syndrome, a rare neurological disorder that can result in paralysis, though conclusive proof may take months or years April 1: CDC adds Kosrae, Federated States of Micronesia to countries and territories with active outbreaks, bringing total to 40 April 4: CDC adds Fiji to countries and territories with active outbreaks, bringing total to 41 April 13: The CDC concludes that infection with the Zika virus in pregnant women is a cause of the birth defect microcephaly and other severe brain abnormalities in babies. CDC adds St. Lucia to countries and territories with active outbreaks, bringing total to 42 April 18: CDC adds Belize to countries and territories with active outbreaks, bringing total to 43 April 25: Canada confirms first sexually transmitted Zika case April 29: Puerto Rico reports first death related to Zika, according to the CDC. The island territory also confirms 683 Zika cases, including 65 pregnant women, and five suspected cases of Guillain-Barre syndrome from Zika May 4: Panama confirms four microcephaly cases tied to Zika May 6: Spain has first case of Zika-related brain defect in a fetus May 9: CDC adds Papua New Guinea, Saint Barthelemy and Peru to countries and territories with active outbreaks, bringing total to 46 May 12: CDC adds Grenada to countries and territories with active outbreaks, bringing total to 47 May 13: Puerto Rico reports first case of Zika-related microcephaly May 20: WHO says an outbreak of Zika virus on the African island chain of Cape Verde is of the same strain as the one blamed for birth abnormalities in Brazil May 26: CDC adds Argentina to countries and territories with active outbreaks, bringing total to 48 June 9: WHO updates guidelines on prevention of sexual transmission of the Zika virus, including advising women living in areas where the virus is being transmitted to delay getting pregnant June 14: El Salvador confirms first case of microcephaly linked to Zika June 30: CDC adds Anguilla to countries and territories with active outbreaks, bringing total to 49 July 8: CDC confirms a Utah resident's death from the previous month is the first Zika-related death in the continental United States July 14: CDC adds Saint Eustatius to countries and territories with active outbreaks, bringing total to 50 July 15: New York City's health department reports the first female-to-male transmission of the Zika virus. July 18: CDC reports the caregiver of Utah man who died of Zika tested positive for virus, raising questions about its spread July 19: Florida health officials investigate a case of Zika virus infection that may have been caused by local mosquito bite July 22: New York City health officials reports first baby born with Zika-related birth defect July 25: Spain reports first case in Europe of baby born with Zika-related defect; CDC issues updated recommendations for preventing and testing for Zika infection, warning that the virus can be transmitted through unprotected sex with an infected female partner July 26: Honduras detects 8 cases of babies with Zika-related defect; CDC adds Saba to countries and territories with active outbreaks with total at 51 July 27: Paraguay reports first cases of microcephaly linked to Zika July 29: Florida authorities report what is believed to be the first evidence of local Zika transmission in the continental United States Aug. 2: CDC adds Antigua, Barbuda, and Turks and Caicos to countries and territories with active outbreaks, bringing total to 54 Aug. 3: U.S. researchers said they launched Zika vaccine clinical trial Aug. 11: CDC adds Cayman Islands to countries and territories with active outbreaks, bringing total to 55 Aug. 12: The U.S. Department of Health and Human Services declares a public health emergency in Puerto Rico over Zika with 10,690 laboratory-confirmed cases Aug. 13: Brazil reports 1,835 confirmed cases of microcephaly Aug. 16: Haiti reports first case of microcephaly linked to Zika Aug. 17: Guatemala confirms first case of newborn with microcephaly linked to Zika Aug. 19: Florida governor says five cases of Zika are believed to have been contracted in Miami Beach, the second area in Miami-Dade county where the virus is spreading. Aug. 25: CDC adds The Bahamas and the United States to countries and territories with active outbreaks, bringing total to 57 Aug. 26: FDA recommends that all blood donated in the United States and its territories be tested for Zika virus, starting with 11 states in the first phase; Nicaragua confirms first microcephaly birth linked to Zika Aug. 27-29: Singapore confirms first case of locally transmitted Zika virus, which rise to 56 cases two days later Aug. 30: Confirmed cases in Singapore rise to 82, with some of the latest infections detected beyond the area of initial outbreak. Several countries advise pregnant women or those trying to conceive to avoid traveling to the city-state. Australia, Taiwan, South Korea and the United States issue travel warnings Aug. 31: CDC adds Singapore and the British Virgin Islands to countries and territories with active outbreaks, bringing tally to 58 (The CDC groups together Antigua and Barbuda in its updated official count) Sept. 3: Malaysia detects first case of locally transmitted Zika Sept. 5: Philippines confirms first case of Zika virus likely to have been transmitted locally Sept. 6: Florida confirms 56 locally transmitted cases, 577 travel-related infections, and 80 infections involving pregnant women Sept. 8: Singapore reports 283 cases of locally transmitted Zika virus Sept. 10: Singapore locally transmitted Zika cases rise to 329 Sept. 13: Thailand said it has recorded 200 cases of Zika since Januuary, the first time the health ministry has confirmed the number of cases this year. SOURCES: World Health Organization, U.S. Centers for Disease Control and Prevention, Reuters
