What is Ebola?
Ebola virus disease is a severe illness that was first discovered in humans in 1976 in South Sudan and the Democratic Republic of Congo, formerly Zaire.1,2 Since then, a number of outbreaks have occurred in central and western Africa.
Symptoms
Symptoms can occur abruptly and include fever, severe headache, muscle pain, weakness, fatigue, diarrhea, vomiting, stomach pain and bleeding or bruising.3 Without prompt and appropriate treatment as many as 90% of people who become sick with Ebola virus disease die.2 The fatality rate is much lower among those who receive immediate medical treatment including optimal full supportive care including fluids, oxygen and medications to manage symptoms ranging from vomiting to fever.1,2
Is Ebola contagious?
Ebola is highly contagious, but it is transmitted only through direct contact with bodily fluids.4 It is not spread through the air or casual contact. The incubation period for Ebola – meaning the time after infection and before symptoms appear – is 2 to 21 days.3 People with Ebola are not contagious until they begin having symptoms. People who have died from Ebola remain contagious.4
Who is at risk?
Health workers who do not use proper infection control while caring for Ebola patients, and family and friends in close contact with Ebola patients, are at the highest risk of getting sick.1 Ebola poses little risk to travelers or the general public who have not cared for or been in close contact with someone sick with Ebola.1
Where does Ebola come from?
Scientists aren’t positive but believe outbreaks begin when the virus is transmitted from bats (which aren’t affected by the virus) to other animals, such as gorillas, chimpanzees and antelope (which are affected). People can become infected by hunting and handling or eating the meat of infected wild animals (bushmeat). It then spreads from person to person.2
Treatment
There is no cure for Ebola, but there are currently two treatments that have been approved by the Food and Drug Administration to treat disease caused by the Zaire ebolavirus species of Ebola in adults and children. Inmazeb, a drug approved in October 2020, is a combination of three monoclonal antibodies; another drug, Ebanga, is a single monoclonal antibody and was approved in December 2020.1 Neither treatment has been evaluated for efficacy against types of Ebola other than Zaire ebolavirus. While research on treatments is ongoing, people who become infected are also given supportive therapy, including fluids and oxygen as well as medications to manage vomiting, diarrhea, pain, fever and blood pressure.1,2
Prevention
Avoid traveling to areas where there is an Ebola outbreak. If you do travel to such an area, avoid contact with people who are sick or have died of Ebola, particularly their bodily fluids or objects their fluids have touched.1 FDA approved an Ebola vaccine, rVSV-ZEBOV (Ervebo), in 2019 that has been found to be safe and protective against Zaire ebolavirus, the type of the virus that has caused the largest and most deadly Ebola outbreaks to date.1 CDC recommends pre-exposure prophylaxis vaccination with this vaccine for adults in the U.S. population who are at potential occupational risk of exposure to the virus.1
EBOLA HISTORY AND RISK TO THE U.S.
Ebola Outbreaks
There have been many Ebola outbreaks since the first known outbreak in 1976, all in sub-Saharan (west, east and central) Africa. By far the deadliest outbreak occurred in 2014-2016 when more than 11,000 people died (most in west African Guinea, Liberia and Sierra Leone).5 More than 2,000 people died during the second largest outbreak to date, from 2018 to 2020, in the Democratic Republic of Congo.2
Is Ebola a threat to the United States?
Currently Ebola is not considered a threat outside of certain countries in sub-Saharan Africa. Very few people with Ebola have been outside of that area. During the 2014-2016 outbreak, 11 people with Ebola were treated in the United States, nine of whom had contracted it in western Africa, most as health care workers. Two died – a Liberian visiting the United States and a doctor who had treated Ebola patients in Sierra Leone. Two American nurses contracted the disease while treating the Liberian patient, but both recovered. In other words, only two people have ever been infected with Ebola while on American soil, and neither died. By comparison, CDC estimated 51,000 Americans died from influenza during the 2017-2018 flu season.6
What happens if a person with Ebola comes to the United States?
CDC provides guidance for U.S. health care providers, public health departments and laboratories to help them identify and safely manage potential cases of Ebola in the U.S. Several people with Ebola received treatment in the U.S. during the 2014-2016 outbreak, leading to increased awareness of the disease and its symptoms. Protocols, resources and training for health care providers and health care facilities have been developed, as part of the National Emerging Special Pathogens Training and Education Center, to support safe care for patients in the U.S. and to help prevent the spread of Ebola.7
How can we decrease the risk that a person with Ebola comes to the United States?
Stopping an outbreak where it starts remains the most effective way to prevent it from spreading to other countries. Restricting trade and travel may seem like a protective response, but these steps are more likely to cause more harm than good for affected communities, individuals and the effective response needed to end the outbreak. The United States’ help and expertise is critical in supporting the response to Ebola outbreaks globally and to protecting public health at home. This includes improving the capacity of other countries and partners to identify and respond to emerging public health threats where they start.