West Africa is struggling with the worst Ebola outbreak since the disease was identified in 1976, and the first case has been diagnosed in the United States.

Below are some facts regarding the outbreak:

- The outbreak has killed 3,338 people, or 47 percent of the 7,178 known to have been infected as of Sept. 28, predominantly in Liberia, Sierra Leone and Senegal. The disease - which emerged in a remote forest region of Guinea in March - has also turned up in Nigeria and Senegal, but officials say the disease has been contained in those two countries.

- There is no vaccine or cure for Ebola, a hemorrhagic fever. In past outbreaks, fatality rates have reached up to 90 percent. Ebola causes fever, flu-like pains, bleeding, vomiting and diarrhea.


- Pharmaceutical companies are working on experimental Ebola vaccines and antiviral drugs, but a significant number of doses will not be available until at least the first quarter of 2015.

- Ebola is not airborne. It is transmitted through blood, vomit, diarrhea and other bodily fluids. Healthcare workers in West Africa have been among the hardest hit by the outbreak.

- Ebola symptoms generally appear between two and 21 days after infection, meaning there is a significant window during which an infected person can escape detection, allowing them to travel. However, they are not considered contagious until they start showing symptoms.

- Recovery from Ebola depends on the patient’s immune response. People who recover from Ebola infection develop antibodies that last for at least 10 years.

- The U.S. Centers for Disease Control and Prevention (CDC) has estimated that the number of infections could rise to up to 1.4 million people by early next year without a massive global intervention to contain the virus.

- The United States, Britain, France, China, Cuba and international organizations are pouring funds, supplies and personnel into the affected parts of West Africa.

- Ebola's suspected origin is forest bats. The virus was first identified in 1976 in what is now known as Democratic Republic of the Congo.