10 Things to Know About Ebola

The current outbreak of Ebola virus disease (EVD) is the deadliest on record but it is important to understand key elements of this virus. Lee Norman, MD, chief medical officer for the University of Kansas Hospital offers these 10 things to know about Ebola:

1. Cases Are Out-Migrating From Africa: This is happening due to the fact that infected or ill people are traveling out of those countries in Africa with Ebola outbreaks.  Cases found outside of Africa may likely go up as the number of people leaving outbreak areas increases when aid-workers and others return to their home countries.

2. No Cases of Human-to-Human Transmission Outside of Africa: There has been no human-to-human or other transmission to humans outside of Africa.

3. Ebola Is Not Transmitted By Air, Only Via Bodily Secretions: Ebola is not respiratory, so it is not transmitted through coughing or breathing. These infections are occurring because of people who are exposed to bodily fluids of infected individuals.

4. Ebola Is Not The Most Infectious Disease: As infectious diseases go, Ebola virus isn't inherently the most infectious nor is it the least infective from person-to-person.  Measles and chickenpox, for example, are easier to spread. So are influenza and MERS.

5. High Mortality Rates Due to Geography: The mortality rate is quite high in Africa Ebola cases, partly because of the chaos, instability, and unrest of the governments there, and very directly related to the fact that their access to standard treatment supplies (IV solution, tubing, syringes, and protective equipment) is not universally available. Ebola cases identified and treated in westernized nations, and those with modern infection control practices, will have a much lower rate than those seen in most African regions.

6. Likelihood of Breakouts In Areas Outside of Africa: Meticulous infection control practices in modern hospitals will make it more unlikely that human-to-human transmission will occur in these settings. While expensive and advanced bio-containment units provide the highest level of infection control, it is unlikely that these units will be widespread throughout the world.

7. No Approved Immunizations and Treatments: There are no approved immunizations to prevent Ebola virus infection. There are no approved treatments for Ebola virus infection.  There are experimental antibody treatments, as well as an antiviral medication not approved for Ebola.  But whether either or both are safe or effective for widespread use is not known. "Compassionate use" or "experimental use" of the above treatments is tempting, because no targeted, specific "conventional treatment" exists. But widely adopting experimental, unproven medications as "the new conventional therapy" has its own difficulties: Is it safe? Is it effective? Is it costly? Are there unanticipated "down-sides" to using them? A WHO ethics panel has given the go-ahead for this, something it has never done before.

8. How Animals Play a Role: The non-human vectors that can harbor Ebola virus (fruit bats, non-human primates) are widespread in areas far removed from Africa. As such, it bears watching whether those vectors begin to harbor the virus. The WHO has an excellent map showing the parts of the world with these vectors.

9. Alert Levels: The WHO and CDC both recently increased their respective alert levels. State and local health departments throughout the U.S. and world will certainly seek guidance as to the adoption of best "local practices" to guide hospital and care providers. The guidance by the CDC as to how to manage exposed individuals and those who might be incubating the infection are quite specific and helpful. They will certainly change as time goes on.

10. What We Don't Know About Ebola: There are things unknown about Ebola. For example:
- Can a person have had a low-level infection and not know they ever had it?  Probably, based on serum testing.
- Does a person who has had it and survived develop lifelong immunity?  That is unknown at this point.  The various strains of Ebola are enough different antigenically that there may not be cross-immunity.
- Is there such a thing as a "chronic carrier state" in humans where a person can shed the virus and be infectious for a long period of time, even when they themselves have no illness or symptoms? That is also unknown at this point.

Source: University of Kansas Hospital