How Zika made its way from Uganda to the U.S.

Beginning with the first incidence occurring in monkeys in Uganda in 1947, the Zika virus has trickled across the globe until the recent outbreak in Brazil and many other Latin American and Caribbean countries and territories. A look at the origins of Zika:

1947: Uganda

Medical researchers first identified the Zika virus in 1947 in rhesus monkeys of the Zika Forest in Uganda. Testing data retroactively gathered in 1952 detected Zika in humans for the first time in Uganda, Tanzania, Nigeria and Senegal. The first real-time detection in a human occurred in Nigeria in 1954.

2007: Island of Yap

Faced with several residents experiencing denguelike symptoms, physicians in Yap, a Pacific island just north of Australia, sent samples to the U.S. Center for Disease Control and Prevention for testing. Forty-nine cases were eventually confirmed in the virus’ first major outbreak.

2008: Colorado

The first sexually transmitted case originated in Northern Colorado in 2008. The wife of Colorado State University biologist Dr. Brian Foy experienced symptoms after having sex with him. Foy had been in Senegal studying malaria and was bitten by mosquitoes. When he returned home, he didn’t realize he had contracted the virus. Blood tests confirmed the virus for both.

2013-2014: French Polynesia, Pacific islands

Health professionals confirmed 294 incidences in the islands of French Polynesia, after a family of three experienced symptoms associated with the virus: mild fever, headache, joint pain and pink eye. By 2014, Zika had jumped to other islands, including New Caledonia and Cook Islands in the South Pacific and Easter Island, off the coast of Chile, the first cases in the Western Hemisphere.

2015: Brazil

The Pan American Health Organization announced the first cases of Zika in Brazil in May 2015 after noticing a spike in severe congenital birth defects caused by microcephaly. There are theories that major sporting events hosted by Brazil — the Va’a World Sprint Championship in Rio de Janeiro and the World Cup, both in 2014 — ushered in the virus. However, scientists can’t point to one or the other with certainty. Dr. Paola Lichtenberg, director of tropical diseases at UHealth, said, “We just know for sure that the outbreak in Brazil can be traced back to French Polynesia.”

Jan. 15, 2016: Atlanta

The CDC issues a travel alert, warning women who are pregnant or who may become pregnant to take strictly follow steps to avoid mosquito bites while traveling in the affected areas of the Caribbean and Latin America. It says women in their third trimester of pregnancy should avoid traveling to the region.

Feb. 1: Geneva

The World Health Orgnization, saying a link between Zika and microcephaly is strongly suspected, declares a Public Health Emergency and calls for a coordinated global response to the threat, though it stops short of calling for limits on travel or trade.

Feb. 2: Texas

The second case of human-to-human transmission in the U.S. was confirmed in Dallas. Texas health officials reported that a Dallas resident contracted Zika after having sex with someone who had recently returned from Venezuela.

Feb. 6: Washington, D.C.

President Barack Obama asks Congress to allocate $1.8 billion for fighting Zika.

Sources: World Health Organization; Dr. Paola Lichtenberger, director of tropical medicine, UHealth; U.S. National Library of Medicine National Institute of Health; Centers for Disease Control and Prevention; Miami Herald; Florida Department of Health; Xinhua News Agency