The worst Ebola outbreak in history is spreading throughout the West African nations of Guinea, Liberia and Sierra Leone, infecting more than 1,200 and killing more than 600 since early this year.
The virus, which has also infected two American aid workers and killed the top Ebola doctor in Sierra Leone, is extremely contagious, and can be passed from person to person via bodily fluids (such as blood, sweat and urine), as well as contaminated objects. It's marked by flu-like symptoms, as well as bleeding from the eyes, ears, mouth, nose and rectum.
The virus is known to kill up to 90 percent of people who are infected by it, though the fatality rate for this current outbreak is 60 percent, NBC News reported.
Note: Readers may find some of the following images disturbing in nature.
In this March 28, 2014 photo provided by Medecins Sans Frontieres (Doctors Without Borders), healthcare workers from the organization prepare isolation and treatment areas for their Ebola virus operations in Gueckedou, Guinea. One preacher advocated fasting and prayer to spare people from a virus that usually leads to a horrible death. Some people pray that the Ebola virus stays confined to a rural district. Others are unruffled and say the outbreak will blow over. (Kjell Gunnar Beraas/MSF/AP)
Workers from Doctors Without Borders prepare isolation and treatment areas for their Ebola virus operations in Gueckedou, Guinea. (Kjell Gunnar Beraas/MSF/AP)
A member of Doctors Without Borders puts on protective gear at the isolation ward of the Donka Hospital in Conakry, where people infected with the Ebola virus are being treated. (Cellou Binani/AFP/Getty Images)
Health specialists work at an isolation ward for patients at the Doctors Without Borders facility in Gueckedou, southern Guinea. (Seyllou/AFP/Getty Images)
Dr. Kent Brantly, left, treats an Ebola patient at the Samaritan's Purse Ebola Case Management Center in Monrovia, Liberia. On Saturday, July 26, 2014, the North Carolina-based aid organization said Brantly tested positive for the disease. (Samaritan's Purse/AP)
Doctors Without Borders staff members carry the body of a person killed by viral haemorrhagic fever at a center for victims of the Ebola virus in Gueckedou, on April 1, 2014. (Seyllou/AFP/Getty Images)
Health specialists work in an isolation ward for patients at the Doctors Without Borders facility in Gueckedou, southern Guinea. (Seyllou/AFP/Getty Images)
A view of gloves and boots used by medical staff, drying in the sun, at a center for victims of the Ebola virus in Gueckedou, on April 1, 2014. (Seyllou/AFP/Getty Images)
A 10-year-old boy is showered after being taken out of quarantine following his mother's death caused by the Ebola virus, in the Christian charity Samaritan's Purse Ebola treatment center at the ELWA hospital in the Liberian capital Monrovia, on July 24, 2014. (Zoom Dosso/AFP/Getty Images)
A health specialist works in a laboratory set up in a tent at an isolation ward for patients at the Doctors Without Borders facility in Gueckedou, southern Guinea. (Seyllou/AFP/Getty Images)
View of an isolation center for people infected with Ebola at Donka Hospital in Conakry. (Cellou Binani/AFP/Getty Images)
A worker loads material including protection gear for Doctors Without Borders at the airport of Conakry on March 29, 2014. (Cellou Binani/AFP/Getty Images)
The owners of a "maquis," a small African restaurant in Kobakro, outside Abidjan, which used to serve bush meat, hold up the different types of meat and fish they now offer to their clients. The Ministry of Health has asked Ivorians, "particularly fond of porcupine and agouti," a small rodent, to avoid consuming or handling bushmeat, as an unprecedented Ebola epidemic hit West Africa. The virus can spread to animal primates and humans who handle infected meat -- a risk given the informal trade in "bushmeat" in forested central and west Africa. (Issouf Sanogo/AFP/Getty Images)
A pharmacist searches for drugs in a pharmacy in Lagos on July 26, 2014. Nigeria was on alert against the possible spread of Ebola on July 26, a day after the first confirmed death from the virus in Lagos, the country's financial capital and Africa's biggest city. The health ministry said Friday that a 40-year-old Liberian man died at a private hospital in Lagos from the disease, which has now killed more than 650 people in four west African countries since January. (Pius Utomi Ekpei/AFP/Getty Images)
The Arwa clinic (center) that was closed after the clinic doctor was infected by the Ebola virus in the capital city of Freetown, Sierra Leone. Ebola had never before been seen in this part of West Africa. (Youssouf Bah/AP)
In this photo taken July 27, 2014, medical personnel are pictured inside a clinic taking care of Ebola patients in the Kenema District on the outskirts of Kenema, Sierra Leone. Liberia President Ellen Johnson Sirleaf has closed some border crossings and ordered strict quarantines of communities affected by the Ebola outbreak. The announcement late Sunday came a day after Sirleaf formed a new taskforce charged with containing the disease, which has killed 129 people in the country and more than 670 across the region. (Youssouf Bah/AP)
Health workers teach people about the Ebola virus and how to prevent infection, in Conakry, Guinea, on March 31, 2014. (Youssouf Bah/AP)
This photo provided by the CDC shows an Ebola virus. U.S. health officials are monitoring the Ebola outbreak in Africa but say the risk of the deadly germ spreading to the United States is remote. (CDC/AP)
Dr. David McRay speaks about his friend and colleague Dr. Kent Brantly during a news conference on Monday, July 28, 2014, in Fort Worth, Texas. Brantly is one of two American aid workers that have tested positive for the Ebola virus while working to combat an outbreak of the deadly disease at a hospital in Liberia. (LM Otero/AP)