Q&A: Ebola outbreak, treatment, prevention
Posted October 15, 2014
Updated October 25, 2014
Ebola, previously known as Ebola hemorrhagic fever, is a rare and deadly disease caused by infection with one of the Ebola virus strains. Ebola can cause disease in humans and nonhuman primates (monkeys, gorillas, and chimpanzees), according to the U.S. Centers for Disease Control and Prevention.
Ebola viruses are found in several African countries. Ebola was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, outbreaks have appeared sporadically in Africa.
The natural reservoir host of Ebola virus remains unknown. However, on the basis of evidence and the nature of similar viruses, researchers believe that the virus is animal-borne and that bats are the most likely reservoir. Four of the five virus strains occur in an animal host native to Africa, according to the CDC.
As of Oct. 25, 2014, there have been more than 10,000 cases of Ebola and 4,877 deaths, according to the CDC and the World Health Organization.
- Fever greater than 101.5°F
- Severe headache
- Muscle pain
- Stomach pain
- Unexplained bleeding or bruising
Symptoms may appear anywhere from two to 21 days after exposure to Ebola, but the average is eight to 10 days, according to the CDC. Recovery from Ebola depends on good, supportive clinical care and the patient’s immune response. People who recover from Ebola infection develop antibodies that last for at least 10 years.
The 2014 Ebola epidemic is the largest in history, according to the CDC. West Africa has been hardest hit. The World Health Organization projects the pace of infections will accelerate in West Africa to as many as 10,000 new cases a week within two months.
Only when someone is showing symptoms, which can start with vague symptoms including a fever, flu-like body aches and abdominal pain, and then vomiting and diarrhea.
When an infection occurs in humans, the virus can be spread in several ways to others. Ebola is spread through direct contact (through broken skin or mucous membranes in the eyes, nose, or mouth, for example) with:
- Blood or body fluids (including urine, saliva, sweat, feces, vomit, breast milk and semen) of a person who is sick with Ebola. Those fluids must have an entry point, like a cut or scrape or someone touching the nose, mouth or eyes with contaminated hands, or being splashed. That's why health care workers wear protective gloves and other equipment.
- Objects (such as needles and syringes) that have been contaminated with the virus
- Infected animals
- Ebola is not spread through the air or by water, or in general, by food. However, in Africa, Ebola may be spread as a result of handling bushmeat (wild animals hunted for food) and contact with infected bats. There is no evidence that mosquitoes or other insects can transmit Ebola. Only mammals (for example, humans, bats, monkeys and apes) have shown the ability to become infected with and spread Ebola virus.
The World Health Organization says blood, feces and vomit are the most infectious fluids, while the virus is found in saliva mostly once patients are severely ill and the whole live virus has never been culled from sweat.
Ebola isn't airborne. CDC Director Dr. Tom Frieden says people don't get exposed by sitting next to someone on the bus.
"This is not like flu. It's not like measles, not like the common cold. It's not as spreadable, it's not as infectious as those conditions," he added.
Diagnosing Ebola in an person who has been infected for only a few days is difficult, according to the CDC, because the early symptoms, such as fever, are nonspecific to Ebola infection and are seen often in patients with more commonly occurring diseases, such as malaria and typhoid fever.
However, if a person has the early symptoms of Ebola and has had contact with the blood or body fluids of a person sick with Ebola, contact with objects that have been contaminated with the blood or body fluids of a person sick with Ebola, or contact with infected animals, they should be isolated and public health professionals notified. Samples from the patient can then be collected and tested to confirm infection.
The average Ebola fatality rate is around 50 percent, according to the World Health Organization. Case fatality rates have varied from 25 percent to 90 percent in past outbreaks.
The government will send a rapid response team to any hospital in the country that diagnoses another Ebola patient, to make sure the local health workers can provide care safely. The Centers for Disease Control and Prevention has specialists implementing changes to protect health workers at Texas Health Presbyterian Hospital in Dallas as it cares for a nurse who became infected.
No FDA-approved vaccine or medicine is available for Ebola. Symptoms are treated as they appear. The following basic interventions, when used early, can significantly improve the chances of survival:
- Providing intravenous fluids (IV) and balancing electrolytes (body salts)
- Maintaining oxygen status and blood pressure
- Treating other infections if they occur
Experimental vaccines and treatments for Ebola are under development, but they have not yet been fully tested for safety or effectiveness, according to the CDC.
Recovery from Ebola depends on good care and the patient’s immune response. People who recover from Ebola infection develop antibodies that last for at least 10 years and possibly longer.
It isn't known if people who recover are immune for life or if they can become infected with a different species of Ebola. Some people who have recovered from Ebola have developed long-term complications, such as joint and vision problems.
A Dallas nurse being treated for Ebola received a plasma transfusion from a doctor who beat his own infection with the deadly virus after getting a similar treatment. The reason is because antibodies in the blood of a survivor may help a patient fight off the germ.
Dr. Kent Brantly went to Texas Health Presbyterian Hospital in Dallas to donate the plasma to nurse Nina Pham. Brantly got Ebola while caring for patients in Africa, and received plasma from a 14-year-old boy who recovered under his care there.
Brantly also received ZMapp, an experimental drug that contains antibodies against Ebola. Its maker says supplies are now exhausted, leading doctors to look at plasma transfusions as an alternative.
Antibodies have helped many people battle other infectious diseases, but their use against Ebola is too new to establish a track record. So, many things affect whether an Ebola patient recovers – how quickly the disease was diagnosed, whether intravenous fluids and other supportive care were given – that it's impossible to know whether plasma or an antibody drug made a difference.
"It's believed you can replace your antibodies in about two days," so it's not uncommon for people to donate twice a week, said Dr. James Crowe, an immunologist and director of the Vanderbilt Vaccine Center in Nashville.
There is no FDA-approved vaccine available for Ebola. If you travel to or are in an area affected by an Ebola outbreak, make sure to do the following:
- Practice careful hygiene. For example, wash your hands with soap and water or an alcohol-based hand sanitizer and avoid contact with blood and body fluids.
- Do not handle items that may have come in contact with an infected person’s blood or body fluids (such as clothes, bedding, needles, and medical equipment).
- Avoid funeral or burial rituals that require handling the body of someone who has died from Ebola.
- Avoid contact with bats and nonhuman primates or blood, fluids and raw meat prepared from these animals.
- Avoid hospitals in West Africa where Ebola patients are being treated. The U.S. embassy or consulate is often able to provide advice on facilities.
- After you return, monitor your health for 21 days and seek medical care immediately if you develop symptoms of Ebola.
Health care workers who may be exposed to people with Ebola should follow these steps:
- Wear protective clothing, including masks, gloves, gowns, and eye protection.
- Practice proper infection control and sterilization measures.
- Isolate patients with Ebola from other patients.
- Avoid direct contact with the bodies of people who have died from Ebola.
- Notify health officials if you have had direct contact with the blood or body fluids, such as but not limited to, feces, saliva, urine, vomit, and semen of a person who is sick with Ebola. The virus can enter the body through broken skin or unprotected mucous membranes in, for example, the eyes, nose, or mouth
Hospitals with a suspected case call their health department or the CDC to go through a checklist to determine the person's level of risk. Among the questions are whether the person reports a risky contact with a known Ebola patient, how sick they are and whether an alternative diagnosis is more likely. Most initially suspicious cases in the U.S. haven't met the criteria for testing.
The CDC says bleach and other hospital disinfectants kill Ebola. Dried virus on surfaces survives only for several hours.
Due to the outbreak in the west African nations of Liberia, Guinea and Sierra Leone, the CDC has issued health travel warnings for those three countries advising against nonessential travel and has provided guidance to reduce the potential for spread of Ebola. A CDC Level 2 travel alert has been issued for Nigeria, recommending that travelers practice enhanced precautions. The Department of State has issued travel warnings for Liberia, Sierra Leone and Nigeria.
Carolinas Poison Center has established an Ebola hotline. The number is 1-800-222-1222, and callers should press 6 for questions about Ebola.