An Ebola survivor participates in a study in Monrovia, Liberia, on June 17, 2015. The country launched a five-year study to unravel the mystery of the long-term health effects that plague survivors of the viral disease. Since the epidemic started more than a year ago in a remote village in Guinea, more than 11,000 people have died, the vast majority in three West African nations, <a href="index.php?page=&url=http%3A%2F%2Fapps.who.int%2Febola%2Febola-situation-reports" target="_blank" target="_blank">according to the latest numbers from the World Health Organization</a>. And that number is believed to be low, since there was widespread under-reporting of cases, according to WHO.
An Ebola survivor participates in a study in Monrovia, Liberia, on June 17, 2015. The country launched a five-year study to unravel the mystery of the long-term health effects that plague survivors of the viral disease. Since the epidemic started more than a year ago in a remote village in Guinea, more than 11,000 people have died, the vast majority in three West African nations, according to the latest numbers from the World Health Organization. And that number is believed to be low, since there was widespread under-reporting of cases, according to WHO.
Stringer/Reuters/Landov
Women in Monrovia celebrate after the World Health Organization declared Liberia Ebola-free on May 9, 2015. Other cases have recurred since, however. Two people in Liberia have died of the disease since the end of June, just weeks after the WHO declared the nation free of the disease.
Women in Monrovia celebrate after the World Health Organization declared Liberia Ebola-free on May 9, 2015. Other cases have recurred since, however. Two people in Liberia have died of the disease since the end of June, just weeks after the WHO declared the nation free of the disease.
James Giahyue/Reuters/Landov
A man walks past an Ebola awareness painting in Monrovia on March 22, 2015.
A man walks past an Ebola awareness painting in Monrovia on March 22, 2015.
AHMED JALLANZO/EPA/Landov
Soldiers from the U.S. Army's 101st Airborne Division walk across the tarmac at Campbell Army Airfield before reuniting with their families at a homecoming ceremony March 21, 2015 in Fort Campbell, Kentucky. The 162 soldiers were deployed in Liberia, where they helped fight the spread of Ebola.
Soldiers from the U.S. Army's 101st Airborne Division walk across the tarmac at Campbell Army Airfield before reuniting with their families at a homecoming ceremony March 21, 2015 in Fort Campbell, Kentucky. The 162 soldiers were deployed in Liberia, where they helped fight the spread of Ebola.
Luke Sharrett/Getty Images
Relatives weep for a loved one who it was believed died from Ebola, at a graveyard on the outskirts of Monrovia on March 11, 2015.
Relatives weep for a loved one who it was believed died from Ebola, at a graveyard on the outskirts of Monrovia on March 11, 2015.
Abbas Dulleh/AP
Doctors Without Borders staffer Alex Eilert Paulsen watches as mattresses and bed frames burn at the Ebola Treatment Unit in Paynesville, Liberia, on January 31, 2015. The organization reduced its number of beds from 250 to 30 as gains were made in battling the virus.
Doctors Without Borders staffer Alex Eilert Paulsen watches as mattresses and bed frames burn at the Ebola Treatment Unit in Paynesville, Liberia, on January 31, 2015. The organization reduced its number of beds from 250 to 30 as gains were made in battling the virus.
John Moore/Getty Images
Pauline Cafferkey, a Scottish woman diagnosed with Ebola, is put on a plane in Glasgow, Scotland, on December 30, 2014. Cafferkey, a 39-year-old nurse who volunteered in Sierra Leone, <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2014%2F12%2F31%2Fworld%2Feurope%2Fuk-ebola%2Findex.html" target="_blank">was being transported to London</a> for treatment.
Pauline Cafferkey, a Scottish woman diagnosed with Ebola, is put on a plane in Glasgow, Scotland, on December 30, 2014. Cafferkey, a 39-year-old nurse who volunteered in Sierra Leone, was being transported to London for treatment.
stringer/AFP/Getty Images
A child who survived the Ebola virus is fed by another survivor at a treatment center on the outskirts of Freetown, Sierra Leone, on November 11, 2014.
A child who survived the Ebola virus is fed by another survivor at a treatment center on the outskirts of Freetown, Sierra Leone, on November 11, 2014.
FRANCISCO LEONG/AFP/Getty Images
Health workers in Monrovia cover the body of a man suspected of dying from the Ebola virus on October 31, 2014.
Health workers in Monrovia cover the body of a man suspected of dying from the Ebola virus on October 31, 2014.
Abbas Dulleh/AP
Kaci Hickox leaves her home in Fort Kent, Maine, to take a bike ride with her boyfriend on October 30, 2014. Hickox, a nurse, recently returned to the United States from West Africa, where she treated Ebola victims. State authorities wanted her to avoid public places for 21 days -- the virus' incubation period. But Hickox, who twice tested negative for Ebola,<a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2014%2F10%2F30%2Fhealth%2Fus-ebola%2Findex.html"> said she would defy efforts</a> to keep her quarantined at home.
Kaci Hickox leaves her home in Fort Kent, Maine, to take a bike ride with her boyfriend on October 30, 2014. Hickox, a nurse, recently returned to the United States from West Africa, where she treated Ebola victims. State authorities wanted her to avoid public places for 21 days -- the virus' incubation period. But Hickox, who twice tested negative for Ebola, said she would defy efforts to keep her quarantined at home.
Robert F. Bukaty/AP
Health officials in Nairobi, Kenya, prepare to screen passengers arriving at the Jomo Kenyatta International Airport on October 28, 2014.
Health officials in Nairobi, Kenya, prepare to screen passengers arriving at the Jomo Kenyatta International Airport on October 28, 2014.
TONY KARUMBA/AFP/Getty Images
U.S. President Barack Obama hugs Ebola survivor Nina Pham in the Oval Office of the White House on October 24, 2014. Pham, one of two Dallas nurses diagnosed with the virus, was declared Ebola-free after being treated at a hospital in Bethesda, Maryland. The other nurse, Amber Vinson (not pictured), was treated in Atlanta and also declared Ebola-free.
U.S. President Barack Obama hugs Ebola survivor Nina Pham in the Oval Office of the White House on October 24, 2014. Pham, one of two Dallas nurses diagnosed with the virus, was declared Ebola-free after being treated at a hospital in Bethesda, Maryland. The other nurse, Amber Vinson (not pictured), was treated in Atlanta and also declared Ebola-free.
Evan Vucci/AP
Health workers in Port Loko, Sierra Leone, transport the body of a person who is suspected to have died of Ebola on October 21, 2014.
Health workers in Port Loko, Sierra Leone, transport the body of a person who is suspected to have died of Ebola on October 21, 2014.
Michael Duff/AP
Health workers bury a body on the outskirts of Monrovia on October 20, 2014.
Health workers bury a body on the outskirts of Monrovia on October 20, 2014.
Abbas Dulleh/AP
Garteh Korkoryah, center, is comforted during a memorial service for her son, Thomas Eric Duncan, on October 18, 2014, in Salisbury, North Carolina. Duncan, a 42-year-old Liberian citizen, died October 8 in a Dallas hospital. He was in the country to visit his son and his son's mother, and he was the first person in the United States to be diagnosed with Ebola.
Garteh Korkoryah, center, is comforted during a memorial service for her son, Thomas Eric Duncan, on October 18, 2014, in Salisbury, North Carolina. Duncan, a 42-year-old Liberian citizen, died October 8 in a Dallas hospital. He was in the country to visit his son and his son's mother, and he was the first person in the United States to be diagnosed with Ebola.
Nell Redmond/AP
Boys run from blowing dust as a U.S. military aircraft leaves the construction site of an Ebola treatment center in Tubmanburg, Liberia, on October 15, 2014.
Boys run from blowing dust as a U.S. military aircraft leaves the construction site of an Ebola treatment center in Tubmanburg, Liberia, on October 15, 2014.
John Moore/Getty Images
Aid workers from the Liberian Medical Renaissance League stage an Ebola awareness event October 15, 2014, in Monrovia. The group performs street dramas throughout Monrovia to educate the public on Ebola symptoms and how to handle people who are infected with the virus.
Aid workers from the Liberian Medical Renaissance League stage an Ebola awareness event October 15, 2014, in Monrovia. The group performs street dramas throughout Monrovia to educate the public on Ebola symptoms and how to handle people who are infected with the virus.
John Moore/Getty Images
Ebola survivors prepare to leave a Doctors Without Borders treatment center after recovering from the virus in Paynesville, Liberia, on October 12, 2014.
Ebola survivors prepare to leave a Doctors Without Borders treatment center after recovering from the virus in Paynesville, Liberia, on October 12, 2014.
John Moore/Getty Images
A man dressed in protective clothing treats the front porch of a Dallas apartment on October 12, 2014. The apartment is home to one of the two nurses who were diagnosed with Ebola after treating Thomas Eric Duncan, a Liberian national who traveled to Dallas and later died from the virus.
A man dressed in protective clothing treats the front porch of a Dallas apartment on October 12, 2014. The apartment is home to one of the two nurses who were diagnosed with Ebola after treating Thomas Eric Duncan, a Liberian national who traveled to Dallas and later died from the virus.
Mike Stone/Getty Images
A woman crawls toward the body of her sister as a burial team takes her away for cremation October 10, 2014, in Monrovia. The sister had died from Ebola earlier in the morning while trying to walk to a treatment center, according to her relatives.
A woman crawls toward the body of her sister as a burial team takes her away for cremation October 10, 2014, in Monrovia. The sister had died from Ebola earlier in the morning while trying to walk to a treatment center, according to her relatives.
John Moore/Getty Images
A man digs a grave on October 7, 2014, outside an Ebola treatment center near Gbarnga, Liberia.
A man digs a grave on October 7, 2014, outside an Ebola treatment center near Gbarnga, Liberia.
John Moore/Getty Images
A person peeks out from the Dallas apartment where Thomas Eric Duncan, the first person diagnosed with the Ebola virus in the United States, was staying on October 3, 2014.
A person peeks out from the Dallas apartment where Thomas Eric Duncan, the first person diagnosed with the Ebola virus in the United States, was staying on October 3, 2014.
JIM YOUNG/REUTERS/LANDOV
A girl cries as community activists approach her outside her Monrovia home on October 2, 2014, a day after her mother was taken to an Ebola ward.
A girl cries as community activists approach her outside her Monrovia home on October 2, 2014, a day after her mother was taken to an Ebola ward.
Jerome Delay/AP
A health official uses a thermometer September 29, 2014, to screen a Ukrainian crew member on the deck of a cargo ship at the Apapa port in Lagos, Nigeria.
A health official uses a thermometer September 29, 2014, to screen a Ukrainian crew member on the deck of a cargo ship at the Apapa port in Lagos, Nigeria.
Sunday Alamba/AP
Workers move a building into place as part of a new Ebola treatment center in Monrovia on September 28, 2014.
Workers move a building into place as part of a new Ebola treatment center in Monrovia on September 28, 2014.
PASCAL GUYOT/AFP/Getty Images
Medics load an Ebola patient onto a plane at Sierra Leone's Freetown-Lungi International Airport on September 22, 2014.
Medics load an Ebola patient onto a plane at Sierra Leone's Freetown-Lungi International Airport on September 22, 2014.
Spain Ministry of Defense/Pool/Anadolu Agency/Getty Images
A few people are seen in Freetown during a three-day nationwide lockdown on September 21, 2014. In an attempt to curb the spread of the Ebola virus, people in Sierra Leone were told to stay in their homes.
A few people are seen in Freetown during a three-day nationwide lockdown on September 21, 2014. In an attempt to curb the spread of the Ebola virus, people in Sierra Leone were told to stay in their homes.
Michael Duff/AP
Supplies wait to be loaded onto an aircraft at New York's John F. Kennedy International Airport on September 20, 2014. It was the largest single shipment of aid to the Ebola zone to date, and it was coordinated by the Clinton Global Initiative and other U.S. aid organizations.
Supplies wait to be loaded onto an aircraft at New York's John F. Kennedy International Airport on September 20, 2014. It was the largest single shipment of aid to the Ebola zone to date, and it was coordinated by the Clinton Global Initiative and other U.S. aid organizations.
CARLO ALLEGRI/Reuters/Landov
A child stops on a Monrovia street September 12, 2014, to look at a man who is suspected of suffering from Ebola.
A child stops on a Monrovia street September 12, 2014, to look at a man who is suspected of suffering from Ebola.
Abbas Dulleh/Ap
After an Ebola case was confirmed in Senegal, people load cars with household items as they prepare to cross into Guinea from the border town of Diaobe, Senegal, on September 3, 2014.
After an Ebola case was confirmed in Senegal, people load cars with household items as they prepare to cross into Guinea from the border town of Diaobe, Senegal, on September 3, 2014.
SEYLLOU/AFP/Getty Images
A health worker wearing a protective suit conducts an Ebola prevention drill at the port in Monrovia on August 29, 2014.
A health worker wearing a protective suit conducts an Ebola prevention drill at the port in Monrovia on August 29, 2014.
DOMINIQUE FAGET/AFP/Getty Images
A burial team from the Liberian Ministry of Health unloads bodies of Ebola victims onto a funeral pyre at a crematorium in Marshall, Liberia, on August 22, 2014.
A burial team from the Liberian Ministry of Health unloads bodies of Ebola victims onto a funeral pyre at a crematorium in Marshall, Liberia, on August 22, 2014.
John Moore/Getty Images
Dr. Kent Brantly leaves Emory University Hospital on August 21, 2014, after being declared no longer infectious from the Ebola virus. Brantly was one of two American missionaries brought to Emory for treatment of the deadly virus.
Dr. Kent Brantly leaves Emory University Hospital on August 21, 2014, after being declared no longer infectious from the Ebola virus. Brantly was one of two American missionaries brought to Emory for treatment of the deadly virus.
David Morrison/Samaritan's Purse
An Ebola Task Force soldier beats a local resident while enforcing a quarantine on the West Point slum on August 20, 2014.
An Ebola Task Force soldier beats a local resident while enforcing a quarantine on the West Point slum on August 20, 2014.
John Moore/Getty Images
Local residents gather around a very sick Saah Exco, 10, in a back alley of the West Point slum on August 19, 2014. The boy was one of the patients that was pulled out of a holding center for suspected Ebola patients after the facility was overrun and closed by a mob on August 16. A local clinic then refused to treat Saah, according to residents, because of the danger of infection. Although he was never tested for Ebola, Saah's mother and brother died in the holding center.
Local residents gather around a very sick Saah Exco, 10, in a back alley of the West Point slum on August 19, 2014. The boy was one of the patients that was pulled out of a holding center for suspected Ebola patients after the facility was overrun and closed by a mob on August 16. A local clinic then refused to treat Saah, according to residents, because of the danger of infection. Although he was never tested for Ebola, Saah's mother and brother died in the holding center.
John Moore/Getty Images
Workers prepare the new Ebola treatment center on August 17, 2014.
Workers prepare the new Ebola treatment center on August 17, 2014.
John Moore/Getty Images
Liberian police depart after firing shots in the air while trying to protect an Ebola burial team in the West Point slum of Monrovia on August 16, 2014. A crowd of several hundred local residents reportedly drove away the burial team and their police escort. The mob then forced open an Ebola isolation ward and took patients out, saying the Ebola epidemic is a hoax.
Liberian police depart after firing shots in the air while trying to protect an Ebola burial team in the West Point slum of Monrovia on August 16, 2014. A crowd of several hundred local residents reportedly drove away the burial team and their police escort. The mob then forced open an Ebola isolation ward and took patients out, saying the Ebola epidemic is a hoax.
John Moore/Getty Images
A health worker disinfects a corpse after a man died in a classroom being used as an Ebola isolation ward August 15, 2014, in Monrovia.
A health worker disinfects a corpse after a man died in a classroom being used as an Ebola isolation ward August 15, 2014, in Monrovia.
John Moore/Getty Images
Aid worker Nancy Writebol, wearing a protective suit, gets wheeled on a gurney into Emory University Hospital in Atlanta on August 5, 2014. A medical plane flew Writebol from Liberia to the United States after she and her colleague Dr. Kent Brantly were infected with the Ebola virus in the West African country.
Aid worker Nancy Writebol, wearing a protective suit, gets wheeled on a gurney into Emory University Hospital in Atlanta on August 5, 2014. A medical plane flew Writebol from Liberia to the United States after she and her colleague Dr. Kent Brantly were infected with the Ebola virus in the West African country.
John Spink/AJC/AP
Members of Doctors Without Borders adjust tents in the isolation area in Kailahun on July 20, 2014.
Members of Doctors Without Borders adjust tents in the isolation area in Kailahun on July 20, 2014.
courtesy Tommy Trenchard
Boots dry in the Ebola treatment center in Kailahun on July 20, 2014.
Boots dry in the Ebola treatment center in Kailahun on July 20, 2014.
courtesy Tommy Trenchard
Dr. Jose Rovira of the World Health Organization takes a swab from a suspected Ebola victim in Pendembu, Sierra Leone, on July 18, 2014.
Dr. Jose Rovira of the World Health Organization takes a swab from a suspected Ebola victim in Pendembu, Sierra Leone, on July 18, 2014.
courtesy Tommy Trenchard
Red Cross volunteers disinfect each other with chlorine after removing the body of an Ebola victim from a house in Pendembu on July 18, 2014.
Red Cross volunteers disinfect each other with chlorine after removing the body of an Ebola victim from a house in Pendembu on July 18, 2014.
courtesy Tommy Trenchard
A scientist separates blood cells from plasma cells to isolate any Ebola RNA and test for the virus April 3, 2014, at the European Mobile Laboratory in Gueckedou, Guinea.
A scientist separates blood cells from plasma cells to isolate any Ebola RNA and test for the virus April 3, 2014, at the European Mobile Laboratory in Gueckedou, Guinea.
stringer/reuters/landov
Health specialists work March 31, 2014, at an isolation ward for patients at the facility in southern Guinea.
Health specialists work March 31, 2014, at an isolation ward for patients at the facility in southern Guinea.
SEYLLOU/AFP/Getty Images
The Ebola epidemic

Story highlights

Mali says it has three suspected Ebola cases

Ebola has sickened 178 people, killed more than 100, WHO says

More deaths are suspected or confirmed in Sierra Leone, Mali

CNN  — 

The Ebola outbreak in coastal West Africa is still contained to Guinea and Liberia, the World Health Organization announced Tuesday, despite rumors of the virus spreading to other countries.

Cases have been reported in Sierra Leone, Mali and Ghana, but the WHO says none has been confirmed. Rumored cases in Mali are still being investigated.

The number of suspected cases in Guinea has grown to 157, with 101 deaths. Sixty-seven have been confirmed as Ebola. In Liberia, 21 cases have been reported, including 10 deaths. Five of the cases have been confirmed as Ebola.

The outbreak has “rapidly evolved” since originating in the forests of southeastern Guinea. The city of Guekedou, near the borders with Sierra Leone and Liberia, has seen the majority of the deaths.

Twenty cases are believed to have occurred in Guinea’s capital, Conakry, according to WHO.

“This is one of the most challenging Ebola outbreaks that we have ever faced,” said Dr. Keiji Fukuda, WHO’s assistant director-general for health security.

What is Ebola and why does it kill?

It’s the first emergence of Ebola in western Africa, which means doctors and health officials in the region don’t have any experience with the virus. Outbreaks generate a lot of fear and anxiety, Fukuda said, which can lead to misinformation.

Health workers teach people about the Ebola virus and how to prevent infection, in Conakry, Guinea, Monday, March 31, 2014. Health authorities in Guinea are facing an "unprecedented epidemic" of Ebola, the international aid group Doctors Without Borders warned Monday as the death toll from the disease that causes severe bleeding reached 78. The outbreak of Ebola in Guinea poses challenges never seen in previous outbreaks that involved "more remote locations as opposed to urban areas," said Doctors Without Borders. (AP Photo/ Youssouf Bah)
Health workers teach people about the Ebola virus and how to prevent infection, in Conakry, Guinea, Monday, March 31, 2014. Health authorities in Guinea are facing an "unprecedented epidemic" of Ebola, the international aid group Doctors Without Borders warned Monday as the death toll from the disease that causes severe bleeding reached 78. The outbreak of Ebola in Guinea poses challenges never seen in previous outbreaks that involved "more remote locations as opposed to urban areas," said Doctors Without Borders. (AP Photo/ Youssouf Bah)
Youssouf Bah/AP
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A picture taken on July 28, 2012 shows officials from the World Health Organization wearing protective gear as they prepare to enter Kagadi Hospital in Uganda's western Kibale district, around 200 kilometres (125 miles) from Kampala.
A picture taken on July 28, 2012 shows officials from the World Health Organization wearing protective gear as they prepare to enter Kagadi Hospital in Uganda's western Kibale district, around 200 kilometres (125 miles) from Kampala.
ISAAC KASAMANI/AFP/Getty Images
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The U.N. agency is trying to track people who had encountered the victims and make sure “that all those who have been in contact with infected people are being checked upon,” spokesman Tarik Jasarevic told CNN last week.

There are about 50 staff currently deployed in the area and more are set to go shortly. They are working to prevent the spread of infection, primarily in health care facilities, and are sending personal protective equipment to surrounding countries.

“What is really important is to inform the population of Guinea and Conakry about this disease, as this is the first time they are facing Ebola,” Jasarevic said. “They need to know what it is and how they can protect themselves.”

The aid organization Doctors Without Borders has called the outbreak unprecedented, because previous cases have been limited to a small area.

Mali’s government reported on its Facebook page last week that biological samples tied to three suspected Ebola cases within its borders were being sent to the U.S. Centers for Disease Control and Prevention for analysis. WHO said two of the samples have come back negative; they are still waiting on the other. Nine Ebola cases total are suspected in the country.

Ebola is one of the world’s deadliest viruses, causing a hemorrhagic fever that kills up to 90% of those infected. It spreads in the blood and shuts down the immune system, causing high fever, headache and muscle pain, often accompanied by bleeding.

Close to 9 in 10 of the patients WHO health professionals are seeing with Ebola are dying, said Dr, Stephane Hugonnet, who returned from southeast Guinea last weekend.

“Ebola is clearly a severe disease,” Fukuda said. “It is also an infection that can be controlled. … We know very well how this virus is transmitted.”

The virus is named after the Ebola River in the Democratic Republic of Congo (formerly Zaire), where one of the first recorded outbreaks occurred in 1976.

CNN’s Miriam Falco, Jacque Wilson, Matt Smith and Anna Maja Rappard contributed to this report.