Key events in the spread of Ebola
Sanitized gloves and boots hang to dry as a burial team collects Ebola victims for cremation in Monrovia, Liberia, on Oct. 2. (John Moore / Getty Images)
It began in December 2013 in a village deep in the forests of southeastern Guinea, when a 2-year-old boy named Emile developed a mysterious illness.
But it wasn’t until August that the World Health Organization conceded that the worst Ebola outbreak on record had become an international public health emergency. By then, the deadly tide had reached Nigeria, Africa’s most populous nation. Infections soon cropped up in the U.S. and Western Europe.
Here are some key events in the disease’s spread. Click the check boxes below to add and remove events from specific regions.
Reviving a practice common during the medieval Black Death, the leaders of Guinea, Liberia and Sierra Leone announce plans to set up a cordon sanitaire. Troops are deployed to seal off the area where the three countries meet, a region that accounts for about 70% of the Ebola cases so far.
Nancy Writebol, a 59-year-old American missionary who contracted the virus while working in Liberia, arrives at Emory University Hospital. Both Writebol and Brantly make full recoveries after being treated with the experimental drug ZMapp, though it is unclear whether the drug was helpful.
Global toll to date: 1,779 cases, 961 deaths
The WHO Emergency Committee declares a Public Health Emergency of International Concern, saying the Ebola outbreak in West Africa constitutes a public health risk to other states and requires a coordinated international response.
Global toll to date: 2,615 cases, 1,427 deaths
The WHO acknowledges that its Ebola counts underestimate the true number of cases. It cites the existence of “shadow zones,” or small villages where outbreak rumors can’t be investigated because of public resistance or lack of staff.
The WHO warns that the Ebola outbreak is accelerating and could infect more than 20,000 people before it is brought under control.
The National Institute of Allergy and Infectious Diseases says it will begin human tests of a vaccine developed by the U.S. military and GlaxoSmithKline.
The WHO endorses the use of blood transfusions from recovered patients to boost antibodies for the sick.
American aid worker Dr. Rick Sacra is taken to the University of Nebraska Medical Center after contracting Ebola in Liberia. He will make a full recovery after receiving experimental treatments, including blood plasma transfusions from Brantly and the drug TKM-Ebola.
Sierra Leone begins a nationwide lockdown to identify and count cases of Ebola. The country’s residents are required to stay home for three days while healthcare workers and volunteers go door to door searching for Ebola victims and distributing information about the virus.
NBC says a freelance cameraman in Liberia has contracted the virus and will be flown back to the U.S. for treatment. The journalist, U.S. native Ashoka Mukpo, will be taken to the Nebraska medical center Oct. 6. He will receive a blood transfusion from Brantly and be treated with brincidofovir, the same drug Duncan got.
Teresa Romero Ramos tests positive for Ebola in Spain, becoming the first person known to have contracted the virus outside West Africa in the current outbreak. The nursing assistant had treated two infected missionaries.
Duncan dies at Texas Health Presbyterian Hospital.
Dr. Nancy Snyderman and other members of the NBC News crew that worked with Mukpo in West Africa go out in New Jersey, violating their quarantine.
Global toll to date: 8,399 cases, 4,033 deaths
Nina Pham, a 26-year-old nurse who had treated Duncan at Texas Health Presbyterian Hospital, reports having a fever and is put into isolation at the Dallas hospital.
Amber Vinson, a 29-year-old nurse who also had treated Duncan at the hospital, flies to Ohio with approval from the CDC.
Tests performed by the CDC confirm Pham has Ebola. She stays in isolation at the Dallas hospital.
The Obama administration appoints an “Ebola czar,” advisor Ron Klain.
Teresa Romero Ramos in Spain no longer has any traces of Ebola in her blood, a test shows.
The WHO declares Nigeria to be free of Ebola.
American journalist Ashoka Mukpo and nurse Amber Vinson no longer have any traces of Ebola in their blood, tests show.
Dr. Craig Allen Spencer enters isolation at Bellevue Hospital in New York City and is diagnosed with Ebola. He had recently worked with Doctors Without Borders in Guinea.
Global toll to date: 10,141 cases; 4,922 deaths
Mali records its first Ebola case: a 2-year-old girl taken to the country by a relative after her mother died of Ebola in Guinea.
Nina Pham, declared free of Ebola, is released from the NIH clinic and meets President Obama.
Nurse Kaci Hickox — who, despite testing negative for Ebola, has been quarantined for three days in a tent on the grounds of Newark University Hospital in New Jersey after returning from Sierra Leone — will be released. The decision to quarantine her caused an outcry.
Amber Vinson, the second of two Dallas nurses diagnosed with Ebola, is free of the disease and is discharged from Emory University Hospital in Atlanta.