Over the last several months, the deadliest-ever outbreak of the Ebola virus has torn through West Africa, claiming hundreds of lives and leaving hundreds more infected. If you're just catching up with the news, here's some of what we know about the disease, its spread, and how it might be stopped.

What is the Ebola virus, exactly, and what does it do?

First documented in 1976, Ebola is a deadly virus that's contracted through contact with the blood or bodily fluids of another infected person or animal. Because fruit bats can seemingly carry the virus without without falling sick, they are thought to be its primary carriers. Symptoms, at first, are flu-like—fever, chills, headache, sore throat, diarrhea, vomiting—and most commonly occur 8-10 days after infection, according to the Centers for Disease Control and Prevention. The prognosis for patients is not good: The World Health Organization estimates a fatality rate of up to 90 percent.

Why is it suddenly in the news?

West Africa is currently in the throes of the deadliest Ebola outbreak in history. Over 700 people have died of the virus since it reared its head in Guinea in March—339 in Guinea, 233 in Sierra Leone, 156 in Liberia, and one in Nigeria, the Associated Press reports. Among the dead are Sheik Umar Khan, a prominent Ebola doctor in Sierra Leone who treated dozens of patients before his death, and over 6o health workers.

A graphic from the New York Times shows the geographic scope of the outbreak.

Some recent updates: Sierra Leone declared a state of emergency, its soccer team was blocked from traveling to Kenya and the Seychelles, a man died of Ebola in Nigeria after flying from Liberia (the people he came into contact with are being monitored and/or isolated), aid organizations pulled workers out out from the affected countries, and two American citizens were infected (we'll get to them in a second).

Is there a cure, or a vaccine, or anything?

The short answer is no. No licensed drugs proven to eradicate the Ebola virus from a body or prevent its spread exist, though some unproven treatments are available, including an "experimental serum" that's been used on some cases in the current outbreak and the transfusion of blood from an Ebola survivor to an infected patient. Some people are able to withstand the virus and live, though it's unclear how their bodies deal with the infection when so many others can't. According to the AP, most patients "can only be given supportive care to keep them hydrated."

And the infected Americans?

This week brought the news that Americans Dr. Kent Brantly and Nancy Writebol, a missionary, were infected with the Ebola virus in Liberia. Both are still alive and receiving treatment: Writebol with the experimental serum and Brantly with blood transfusions from a 14-year-old boy who survived the disease in his care, the AP reports. Only enough serum arrived in Liberia for one person, and Brantly asked that it be given to Writebol. According to Franklin Graham, head of Samaritan's Purse, a religious aid organization working in Liberia, the boy giving blood to Brantly "wanted to be able to help the doctor who saved his life."

One of the American patients, though it is unclear which, will be transported to the United States to receive treatment at Atlanta's Emory University hospital, which has a specialized unit where Ebola can be treated in isolation. Though the prospect of putting people infected with a deadly, contagious disease on American soil may be frightening to some, CDC director Dr. Thomas Frieden said a spread of the virus in the U.S. is "not in the cards."

State Department spokespeople say protective measures will be taken when transporting patients home. From NBC:

'Every precaution will be taken to move the patients safety and securely to provide critical care en route and to maintain strict isolation upon arrival in the United States," [State Department spokeswoman Marie Harf said].

"The State Department office of medical services has deployed its chief of infectious disease to West Africa in order to provide on the ground consultation and guidance to health unit staff regarding protective measures and case recognition."


"This would be done through non-commercial air travel in very controlled steps," another spokesman added. "The CDC has devised plans and equipment to do it safely. Patients were evacuated in similar ways during the SARS outbreak in 2003 and in cases involving drug resistant tuberculosis in 2007."

What happens next?

No one really knows. The disease's quick spread was aided in part by mistrust of doctors and hospitals among citizens of Guinea, Sierra Leone, and Liberia, as well as sluggish responses from local and international governments, and it shows no sign of slowing down. Dr. Jonathan LaPook discussed that mistrust on CBS This Morning this week: "You can understand why. People come into the hospitals and they don't leave, and so they're thinking maybe something bad is going on there; maybe the care is not optimal."

That means lots of patients are in their homes or churches instead of quarantined, and friends and family members tending to them face risk of infection. Last month, Sierra Leonean Ebola patient Saudatu Koroma was forcibly removed from a hospital in Freetown, the country's capital, by her family. Koroma was the first documented patient in Freetown, and it was feared that her escape would lead to a larger outbreak there. She later returned to the hospital, where she died.

The leaders of each affected country met with the head of the WHO in Conakry, Guinea today, the New York Times reports, where they discussed a proposed $100 million plan to help treat and contain the virus. A WHO statement describes the plan, which will deploy hundreds of additional aid workers to the west African nations:

Key elements of the new plan, which draws on lessons learnt from other outbreaks, include strategies to:

  • stop transmission of Ebola virus disease in the affected countries through scaling up effective, evidence-based outbreak control measures; and
  • prevent the spread of Ebola virus disease to the neighbouring at-risk countries through strengthening epidemic preparedness and response measures.

WHO and affected and neighbouring countries will renew efforts to mobilize communities and strengthen communication so that people know how to avoid infection and what to do if they fear they may have come into contact with the virus.

Improving prevention, detecting and reporting suspected cases, referring people infected with the disease for medical care, as well as psychosocial support, are key. The plan also emphasizes the importance of surveillance, particularly in border areas, of risk assessments and of laboratory-based diagnostic testing of suspected cases. Also highlighted is the need to improve ways to protect health workers, a scarce resource in all three countries, from infection.

In addition to those who have died, the Times reports, there are 1,323 confirmed or suspected cases of Ebola in west Africa to date.

[Image via AP]