How Ebola made it to the U.S., a timeline The deadly virus has made it to the shores of the United States from West Africa.

Major events in the worst Ebola outbreak in world history:

March 25, 2014 — The CDC announces an Ebola outbreak has erupted in Guinea, involving 86 suspected cases and 59 deaths. The first infected patient, a 2-year-old Guinean boy, died on Dec. 28, 2013.

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July 27 — Two U.S. aid workers, one a doctor and the other a missionary, are infected with Ebola while working with patients in Liberia.

Aug. 2 — Dr. Kent Brantly flies into Emory University Hospital in Atlanta.

Aug. 5 — Ebola-stricken missionary Nancy Writebol arrives at Emory.

Aug. 8 — World Health Organization declares the West African cases constitute the worst Ebola outbreak ever.

Nancy Writebol arrives to Emory University Hospital in Atlanta for Ebola treatment.

 Aug. 19 — Writebol tests negative for Ebola, discharged from hospital.

Aug. 21 — Brantly, after negative Ebola test, is sent home.

Aug. 27 — A Senegalese doctor who contracted Ebola arrives in Germany for treatment. He’s released on Oct. 3.

Sept. 20 — Liberian national Thomas Eric Duncan flies into Dallas to visit with family.

Sept. 26 — Duncan is sent home with antibiotics after going to Texas Health Presbyterian Hospital, where he tells a nurse that he’s running a fever and came from Liberia.

Sept. 29 — Duncan becomes the first Ebola patient diagnosed in the United States.

Sept. 30 — CDC Director Thomas Frieden declares: “I have no doubt that we will control this case of Ebola so it does not spread widely in this country.”

Oct. 2 - Ashoka Mupko, 33, a cameraman with NBC News, is diagnosed with Ebola in Liberia.

Oct. 6 — Nurse’s assistant in Spain becomes the first Ebola case contracted outside Africa in the current outbreak. She treated two Spanish missionaries who died after coming home. Her dog, a mixed-breed, is put down. Mupko arrives in Nebraska for treatment.

Oct. 8 — Duncan dies.

Oct. 10 - Amber Vinson, a nurse at the Dallas hospital, takes a flight from Dallas to Cleveland.

Oct. 12 — Officials confirm Nina Pham, a Dallas nurse who treated the dying Duncan, tested positive for Ebola.

Oct. 14 — Vinson, is confirmed with Ebola. She flew back from Cleveland Oct. 13. Officials announce that the Ebola death rate has jumped to 70%, up from 50%.

Oct. 15 — Vinson flown to Emory University for treatment.