Since March, the Ebola outbreak in West Africa has claimed more than 4,500 lives — and all the while, US health officials have prepared for and addressed cases in the US.
To date, only two patients have contracted Ebola on US soil. While those patients recover and people who might have been exposed are monitored, officials are hopeful the virus can be stamped out in the US.
Here are the facts about Ebola in the United States.
Patients Diagnosed in the US
Only two patients have contracted Ebola on US soil. Both of these patients were nurses who treated a Liberian Ebola patient who came to the US and was diagnosed at a Texas hospital.
Nina Pham, a nurse at Texas Presbyterian Hospital in Dallas, treated Liberian man Thomas Eric Duncan. Duncan was exposed to the virus in Liberia and sought treatment in Dallas after developing symptoms. Duncan died on Oct. 8 from Ebola virus disease — the often fatal disease caused by the Ebola virus. A few days later, on Oct. 12, Pham was diagnosed with the disease. On Oct. 24, Pham was declared free of Ebola.
A second nurse who treated Duncan, Amber Vinson, tested positive for Ebola on Oct. 15. Concerns about the spread of the virus in the US spiked when officials announced Vinson had traveled by plane from Ohio to Dallas with a slight fever the day before she was diagnosed. On Oct. 28, officials at Emory University Hospital announced that Vinson was free of Ebola and would be released from the hospital.
Craig Spencer, a Doctors Without Borders physician who was treating Ebola patients in West Africa, tested positive for the virus after returning to the US. Spencer, who was exposed to the virus in West Africa, returned to the US on Oct. 17. On Oct. 23, he developed a fever and other symptoms of Ebola. He immediately sought treatment and was placed in isolation at New York City's Bellevue Hospital, one of the eight hospitals that are part of New York state's Ebola preparedness plan. On Oct. 27, New York City health officials said Spencer was in serious but stable condition.
Patients Under Watch
On Oct. 20 — the same day the World Health Organization declared Nigeria to be Ebola-free — 43 people were taken off the Ebola watch list. They had had possible contact with Duncan and self-monitored and reported to health officials for 21 days. Ebola has an incubation period of 21 days, meaning that patients who go for longer than 21 days after possible exposure without developing symptoms are not likely to have the virus.
Still, more than 70 health workers who had contact with Duncan remained under watch for possible Ebola exposure.
More people were also being closely monitored. In Ohio, 163 people who had contact with Vinson were under watch for Ebola symptoms. None were sick, but eight had placed themselves under voluntary quarantine. Also, several passengers on each flight Vinson took to get from Ohio to Dallas were asked to monitor themselves for symptoms.
Symptoms of Ebola include a high fever, nausea, vomiting and unexplained bleeding. People with Ebola are only contagious when they are displaying symptoms. The virus can only be spread through blood and other infected bodily fluids.
As of Oct. 24, health officials were monitoring three people who had contact with Craig Spencer after he showed symptoms. These three people — his fiancée and two friends — were placed under quarantine.
Patients Brought to the US for Treatment
Several US health and aid workers have become infected with Ebola while trying to fight the outbreak in West Africa. The outbreak has hit Liberia, Guinea and Sierra Leone the hardest.
Some of those workers have been evacuated to the US for treatment. The first was Kent Brantly, a missionary doctor fighting Ebola in Liberia. He was flown to Atlanta Aug. 2 for treatment at Emory.
Dr. Brantly recovered and was released from treatment Aug. 21.
Also evacuated from Liberia and treated at Emory in Atlanta was Nancy Writebol, a missionary. She was flown to the hospital Aug. 5 and released, fully recovered, Aug. 19.
Dr. Rick Sacra was treated in Omaha at the Nebraska Medical Center. He had contracted Ebola while working in Liberia on a religious mission. After a 20-day stay — from Sept. 5 to Sept. 25 — he recovered and was released from the hospital.
A cameraman working as a freelancer in Liberia was also infected and flown to Nebraska Medical Center Oct. 5. Ashoka Mukpo recovered and left the hospital Oct. 22.