The outbreak of Ebola virus centered in West Africa is frightening for many reasons. It was the largest Ebola outbreak ever, claimed thousands of lives; and showed that the deadly infectious disease could travel easily from person to person in the later stages.
Most recently, an American healthcare worker with Ebola was brought to Bethesda, Maryland, on March 13, 2015, and admitted for treatment at the National Institutes of Health (NIH), where there is a high-security containment for infectious disease cases. The patient's clinical status went from serious to critical on March 16th.
Earlier confirmed U.S. Ebola cases included two Americans who returned already ill from West Africa for treatment at Emory University Hospital in Atlanta. They were treated and released, virus free on Aug. 21, 2014.
The first Ebola case that was diagnosed in the United States was on Sept. 30, 2014; the patient died on Oct. 8. It was in Dallas, at the Texas Health Presbyterian Hospital, confirms the U.S. Centers for Disease Control and Prevention (CDC).
On Oct. 11, a second U.S. case was diagnosed, a nurse who cared for the first patient at the same hospital, and she was released virus-free Oct. 24. A third case at the same site, another healthcare worker caring for the patient, was diagnosed Oct. 15, released virus-free on Oct. 28.
A volunteer medical worker who returned to the United States from Guinea, West Africa tested positive for Ebola, in Bellevue Hospital, New York City on Oct. 24, where he was cared for in isolation, and released virus-free on Nov 11.
But on Nov. 17, 2014, a U.S. surgeon died of Ebola in at the Nebraska Medical Center in Omaha, where he was brought from Sierra Leone already in the later stages of Ebola disease.
Controlling Ebola's Spread
In a Gallup poll of over 1,000 Americans, one fifth were worried about contracting Ebola. Still, the chances you'll be exposed to Ebola in the United States are very low because of the tight infection-control practices of public health workers here.
CDC workers are taking steps to identify anyone who may have been in contact with the U.S. patients with Ebola. Health workers are stepping up infection-control practices that will include isolating any of the patients' contacts who may become ill.
In two of the previous cases in the United States, patients were kept at a unit at Emory that has very high security for infectious disease, says Amar Safdar, MD, an associate professor in the division of infectious diseases and immunology at NYU Langone Medical Center in New York. “Only people who are allowed to see them could be potentially exposed,” says Dr. Safdar. Those people are using protective gear and procedures that are effectively fail-proof, he says.
Tom Frieden, MD, director of the CDC, stressed in a public statement that the situation here in the United States, where healthcare systems are strong, will be far different from the experience in West Africa. He noted that he has no doubts about the ability to contain Ebola here.
Meanwhile, public health officials are working hard in West Africa to prevent spread of Ebola. Researchers around the world are looking for ways to prevent and treat Ebola by searching for a vaccine and a cure. The first human safety tests of a new trial vaccine are underway, developed with the U.S. National Institutes of Health.
Ebola Facts
Here are 10 essential facts about Ebola that may ease your fears:
1. The current Ebola outbreak is most widespread and intense in West Africa.
The countries of Guinea, Sierra Leone, and Liberia have reported the most infections, with an additional 20 cases in Nigeria, one each in Senegal, the United Kingdom, and Spain, four in the United States, and eight in Mali. To date, the current outbreak includes 24,282 cases of Ebola as of March 11, 2015, of whom 9,976 have died, according to the World Health Organization (WHO).
People who are most at risk are those in close physical contact with an infected person, like family members and the healthcare workers taking care of the patient.
2. Travel warnings have been issued for Guinea, Liberia, and Sierra Leone.
Because of the increasing numbers of Ebola cases in these West African countries,the CDC advises against all “nonessential” travel to these countries while the Ebola outbreak is ongoing. In addition, the CDC says that anyone who does travel to Guinea, Liberia, or Sierra Leone should avoid touching blood or bodily fluids from anyone who is sick, as it could possibly be Ebola disease.
3. Main entry points to the United States from West Africa screened for Ebola cases.
Five major U.S. international airports began to screen patients coming from Guinea, Liberia, and Sierra Leone for fever and possible Ebola exposure, announced by the CDC and Department of Homeland Security, Oct 8. Screening began at New York's JFK International Airport, followed by Washington-Dulles, Newark, Chicago-O'Hare, and Atlanta.
After arrival, public health workers will monitor all of these travelers daily for 21 days for any signs of fever or other symptoms, and any intent to travel, the CDC announced.
The first U.S. case of Ebola was not apparent during travel, because the patient did not have symptoms until several days after arriving in the United States from West Africa, the CDC notes.
Screening could be implemented by checking for fever in any passengers to airports whose flights began in West Africa, says David C. Pigott, MD, professor of emergency medicine at the University of Alabama, Birmingham (UAB). Dr. Pigott published a 2005 review of the virus in Critical Care Clinics journal.
Quarantine has been imposed on journalists covering the Ebola crisis as well, and on March 12, 2015, chief medical editor for NBC News, Nancy Snyderman, MD. resigned her position after failing to keep to quarantine, the Associated Press reported.
4. Ebola is caused by an RNA virus.
This emerging health threat is the result of an RNA (ribonucleic acid) virus that infects wild animals — like fruit bats, monkeys, gorillas, and chimpanzees — as well as people. It is very unlikely to affect pets like dogs or cats. Contact with an infected wild animal’s blood or body fluids is probably the original source of the infectious disease. Outbreaks of Ebola began in 1976 in the Democratic Republic of Congo on the Ebola River, and Sudan, with later outbreaks in Uganda and other African nations, according to World Health Organization data.
“It is not a casual contact-acquired infection,” notes Safdar. Rather, in its later stages, the Ebola virus is passed from person to person via bodily fluids. "There is no known Ebola transmission through coughing or sneezing, like with influenza or tuberculosis," he says. The virus can live on surfaces that are soiled with blood or other body fluids, but sterilizing hospital equipment with bleach kills Ebola.
5. Early Ebola symptoms are also symptoms of other viral infections.
Early Ebola symptoms include fever, headache, body aches, cough, stomach pain, vomiting, and diarrhea. Because these could be symptoms of other diseases, it's difficult to diagnose Ebola early on. The time it takes from exposure to Ebola to actually getting sick, known as the incubation period, is anywhere from 2 to 21 days, says UAB's Pigott. Most people who are infected with Ebola will develop early symptoms eight to nine days after exposure to the virus, according to the CDC. Specific tests for antibodies against Ebola and viral DNA help doctors make a conclusive diagnosis.
6. Bleeding is common in the later stages of Ebola.
Later symptoms of Ebola can appear quickly, within a few days after onset of early symptoms. Due to internal and external bleeding, the patient's eyes may become red, and they may vomit blood, have bloody diarrhea, and suffer cardiovascular collapse and death, explains Pigott. The only treatment doctors can provide is supportive care — they give the patient fluids and oxygen, and keep their blood pressure steady.
7. Ebola is often fatal.
Almost half of the cases of Ebola viral infection in West Africa have resulted in death, based on WHO data. Of the 24,282 cases in the current outbreak, 9,976 deaths were reported as of March 11, according to WHO statistics.
Health workers often succumb to the disease because of close contact with sick patients. Among those infected with Ebola was the doctor who was the head ofEbola virus treatment in Sierra Leone, Dr. Sheik Umar Khan, who died on July 29. The head doctor for Ebola treatments in Liberia, Dr. Samuel Brisbane, died from the disease three days earlier.
RELATED: Beyond Ebola: Disease Outbreaks That Shook the World
8. New Ebola medications are in development.
The U.S. Food and Drug Administration has not approved any treatments for Ebola, notes Pigott. But two American health workers who were infected in Liberia, Kent Brantly, MD, and Nancy Writebol, were treated with a drug that’s still under study.
The drug is called ZMapp, and it's made by Mapp Biopharmacuetical Inc. “It’s an experimental, antibody-based medication,” explains Pigott, but it has not been tested in human trials for effectiveness. Developed in early 2014, ZMapp is produced in plants and has not yet been found to be safe for use in people, according to the manufacturer.
9. There is no vaccine to prevent Ebola.
Vaccines in development have been effective at preventing Ebola infections in animal studies, researchers from the National Institutes of Health (NIH) report. The research, on apes in particular, is controversial because ape populations are dwindling and in danger of extinction. It is very difficult to test effectiveness of an experimental vaccine in people, Pigott says, because it's unlikely anyone is going to let you inject them with Ebola and later see whether or not they get the infection. However, safety testing of new vaccines in people where the infections are ongoing is now underway.
10. Ebola is not a risk to the general public in the United States.
You are not at risk for Ebola infection unless you are in direct contact with blood or other bodily fluids of someone with Ebola while they have viral symptoms such as fever, vomiting, and cough. “If you don’t have early viral symptoms, you’re probably not contagious,” says Pigott. New infections come from close contact with an infected person, especially with blood, body fluids, or contaminated needles, late in the disease when viral levels are high.
To protect the U.S. public health, the CDC is building up their capacity for testing and surveillance, and getting infection-control information out to health workers. They are training medical res ponders, flight crews, and airport workers on how to report a sick passenger to the CDC in case isolation becomes necessary.
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