| Posted October 24, 2014 | By Shaefer Spires, M.D. | Categorized under Families, Men's Health, Women's Health |

What happens when someone is infected with Ebola virus?

Infected persons will develop a range of symptoms including fever (≥ 38.5°C or 101.5°F), severe headache, muscle pain, weakness, diarrhea, vomiting, abdominal (stomach) pain and unexplained hemorrhage (bleeding or bruising).

How is Ebola virus spread?

Ebola virus is a blood-borne virus that is spread by exposure to the blood or body fluids (including but not limited to sweat, urine, saliva, feces, vomit and semen) of a person who is sick with Ebola or to objects (like needles and syringes) that have been contaminated with the body fluids containing the virus. Importantly it is not spread through the air, by water, or by food.

When can an infected person spread Ebola virus to others?

Ebola is actually quite difficult to spread to others because it requires the person to exhibit symptoms of Ebola. They do not transmit the virus if asymptomatic.  Also for spread to occur, a susceptible person must be exposed to body fluids, especially blood.

Can Ebola be spread by coughing? By sneezing?

Unlike respiratory illnesses like measles or chickenpox, which can be transmitted by virus particles that remain suspended in the air after an infected person coughs or sneezes, Ebola is transmitted by direct contact with body fluids of a person who has symptoms of Ebola disease. While a symptomatic patient with Ebola who coughs or sneezes on someone (and then his or her saliva or mucus come into contact with that person's eyes, nose or mouth) may transmit the disease, this is a very rare event. In addition, coughing and sneezing are unusual symptoms of Ebola that would be expected to occur in an already sick patient already in the hospital (and not early on in the illness).  In that instance, the personal protective equipment used would protect from this type of spread.

What does "direct contact" mean?

Direct contact means that body fluids (blood, saliva, mucus, vomit, urine, or feces) from an infected person (alive or dead) have touched someone's eyes, nose, or mouth or an open cut, wound, or abrasion.  Intact skin is only a risk when then transferred to either open wound or mucous membranes.

Can Ebola be spread through mosquitos?

No.

How long does Ebola live outside the body?

Ebola is difficult to recover from surfaces. Once it leaves the body, it starts to die off very quickly.  The environment has also not been noted to be a source of transmitted virus in prior Ebola outbreaks. Reassuringly, the team at Emory could not detect Ebola virus in the rooms of the Ebola patients they recently treated. Ebola is also killed with routine hospital-grade disinfectants (such as household bleach) that we use for our environmental cleaning at WMC.

Are patients who recover from Ebola immune for life? Can they get it again? If so, will it be the same or a different strain?  

Recovery from Ebola depends on good supportive clinical care and a patient's immune response. Available evidence shows that people who recover from Ebola infection develop antibodies that last for at least 10 years, possibly longer. Currently we don't know if people who recover are immune for life or if they can become infected with a different species of Ebola.

If someone survives Ebola, can he or she still spread the virus?

Once someone clinically recovers from Ebola, they can no longer spread the virus.  However, Ebola virus has been found in semen for up to 3 months. People who recover from Ebola are advised to abstain from sex or use condoms for 3 months.

Why are health care workers in Africa getting infected?  

The data coming out from CDC indicate that those workers were not able to wear the recommended PPE (due to the high heat, fatigue, etc.) and may have had other non-healthcare-related exposures to the virus. Recall that Africa has a tropical climate and PPEs make the user hot, leading some healthcare workers to not wear all pieces of the recommended PPE. In addition, running water and water sources are scarce making hand hygiene difficult if not impossible in these areas.

Is it safe for health care workers who have cared for an Ebola patient to go to their home and be around their loved ones?

As long as no unprotected exposure has occurred and the worker is monitoring their symptoms and temperature and has no symptoms or fever, it is safe to go about normal activities and to be around friends and family. Should an unprotected exposure occur, supervised isolation is recommended to ensure the safety of others.

How long does Ebola live on surfaces?

One study could not recover any Ebola virus from experimentally contaminated surfaces (plastic, metal or glass) at room temperature. In another study, Ebola virus dried onto glass, polymeric silicone rubber, or painted aluminum alloy is able to survive in the dark for several hours under ambient conditions (between 20 and 25⁰C and 30-40% relative humidity) (amount of virus reduced to 37% after 15.4 hours), but is less stable than some other viral hemorrhagic fevers (e.g. Lassa). Also, a study was done in an African hospital under "real world conditions" to assess contamination of the patient care environment during an outbreak. Using nucleic acid amplification and culture to look for virus,  researchers did not find virus in any of 33 samples collected from sites that were not visibly bloody. Virus was only detected on a blood-stained glove and bloody intravenous insertion site by nucleic acid amplification.

What is the treatment for Ebola?

Right now, the only treatment is supportive care.  No specific vaccine or medicine (e.g., antiviral drugs) has been proven to be effective against Ebola. It is believed that the survival rate for Ebola infection will be much higher in the United States due to the ability to better support the volume and electrolyte abnormalities seen with this disease. This is the type of supportive care that ICUs are very familiar with and provide daily to critically ill patients.

What are these experimental treatments that patients have been receiving?

There are two experimental drugs (Zmapp and brincidofovir (CMX001)). ZMapp, developed by Mapp Biopharmaceutical Inc., is an experimental treatment, for use with individuals infected with Ebola virus. It has not yet been tested in humans for safety or effectiveness. The product is a combination of three different monoclonal antibodies that bind to the protein of the Ebola virus. Brincidofovir, developed by the biopharmaceutical company Chimerix Inc., is a broad-spectrum antiviral that has appeared promising against Ebola in test tube studies.

How effective is the experimental treatment?

It is too early to know whether ZMapp or brincidofovir are effective, since they are in experimental stages and have not been tested in humans for safety or effectiveness. Some patients infected with Ebola virus do get better spontaneously or with supportive care. However, the best way to know if treatment with the product is efficacious is to conduct a randomized controlled clinical trial in people to compare outcomes of patients who receive the treatment to untreated patients. No such studies have been conducted. It's important to note that the standard treatment for Ebola remains supportive therapy. Most public health officials believe that the current outbreak in West Africa will be stopped by supportive care and public health measures (contact tracing, isolation, quarantine).

Why aren't more people getting ZMapp?

At this time, very few courses of this experimental treatment have been manufactured. The manufacturer doesn't have any doses available to be distributed. Since the product is still in an experimental stage, it is too early to know whether ZMapp is effective. The manufacturer of this experimental treatment continues to research and evaluate the product's safety and effectiveness. It has not yet been tested in humans for safety or effectiveness and much more study is needed.

How much supply is there?

The product is still in an experimental stage, and the manufacturer reports that there is a very limited supply, so it cannot be purchased and is not available for general use. The manufacturer has been planning for phase 1 clinical trials and does not have the capacity to manufacture large quantities of the treatment. The drug has not gone through clinical trials, and we do not know if this medication works or if it is of any benefit to Ebola-infected patients.  We also do not know if it has any serious side effects. The most effective way to stop the current Ebola outbreak in West Africa is meticulous work in finding Ebola cases, isolating and caring for those patients, and tracing contacts to stop the chains of transmission. It means educating people about safe burial practices and having health care workers strictly follow infection control in hospitals. This is how all previous Ebola outbreaks have been stopped.

Is ZMapp available under the Food and Drug Administration's expanded access to investigational drugs?

 Currently there are only experimental treatments for Ebola virus infection in the earliest stages of development. When a drug is not approved, the FDA can authorize access to potentially promising products through other mechanisms, such as through an emergency Investigational New Drug (IND) application.  No current IND applications are available for US hospitals.

Is the U.S. government involved in the development of ZMapp?

The U.S. government, specifically, the NIH's National Institute of Allergy and Infectious Diseases, the Department of Defense's Defense Threat Reduction Agency (DTRA), and the HHS' Biomedical Advanced Research and Development Authority (BARDA), has provided support for the development of this experimental treatment.

Is ZMapp a vaccine?

No. ZMapp is being developed as a therapeutic product for treatment of people infected with Ebola virus, but not to prevent infection in the same manner as a vaccine. The best way to prevent infection currently is with stringent infection control measures.

What's the difference between therapy and vaccine?

Vaccines are usually given to people before they are exposed to a virus or bacteria that causes a disease. A vaccine stimulates the immune system to generate antibodies and cellular immunity that can fight off an infection if it were to occur. Typically, therapeutics are provided to people who are already infected with the virus. With the experimental ZMapp treatment, the monoclonal antibodies bind to the virus, so that the human immune system can eliminate the virus.

Are there Ebola vaccines available for use or in development?

There are currently no FDA approved vaccines for Ebola. The NIH's National Institute of Allergy and Infectious Diseases is working on developing an Ebola vaccine. NIH recently announced they are expediting their work and are launching phase 1 clinical trials of an Ebola vaccine.

Are there other companies developing experimental treatments or vaccines?

Two other companies, Tekmira and Biocryst Pharmaceuticals, receive funding from the Department of Defense's Defense Threat Reduction Agency and have therapeutic candidates for Ebola in early development. The Department of Defense is working with a company called Newlink to develop an Ebola vaccine candidate. BioCryst, with NIH support, is working to develop an antiviral drug to treat Ebola virus that is expected to begin Phase 1 testing later this year.