WHO Chief Warns Of Ebola Mutation Risk

Note (added 11 October 2014): a more up to date article reviewing these issues appears here.

Please see important note at the foot of this report.

Evidence of airborne transmission of Ebola between animals presented in a scientific paper in 2012. The authors wrote that "Segmental attenuation and loss of respiratory epithelium in the bronchiolar wall (large arrow) with some areas of the lungs relatively unaffected (arrowhead). Immunostaining for Ebola virus antigen was detected in occasional respiratory epithelial cells (small arrow) as well as within alveolar and septal macrophages. Bar = 50 μm." Courtesy: authors and Scientific Reports.

Evidence of airborne transmission of Ebola Zaire between animals presented in a scientific paper in 2012. The authors wrote that “Segmental attenuation and loss of respiratory epithelium in the bronchiolar wall (large arrow) with some areas of the lungs relatively unaffected (arrowhead). Immunostaining for Ebola virus antigen was detected in occasional respiratory epithelial cells (small arrow) as well as within alveolar and septal macrophages. Bar = 50 μm.” Courtesy: authors and Scientific Reports.

The longer that Ebola is allowed to circulate in West Africa then the greater the risk that the virus will evolve into an even more virulent form.

This unprecedented crisis, caused by the most lethal strain in the family of Ebola viruses (Ebola Zaire), is the largest outbreak of disease ever recorded, and it provides this frightening organism with a chance to adapt itself to human hosts – that is, to spread.

The outbreak “is moving faster than our efforts to control it,” warned Dr Margaret Chan, Director-General of the World Health Organization (WHO), earlier today (Friday 1 August 2014). “If the situation continues to deteriorate, the consequences can be catastrophic,” Chan told the Presidents of Guinea, Liberia, and Sierra Leone – the three countries hardest hit by the current Ebola outbreak.

Constant mutation

“This is not an airborne virus. Transmission requires close contact with the bodily fluids of an infected person, also after death. Apart from this specific situation, the general public is not at high risk of infection by the Ebola virus,” explained Chan. “At the same time, it would be extremely unwise for national authorities and the international community to allow an Ebola virus to circulate widely and over a long period of time in human populations… Constant mutation and adaptation are the survival mechanisms of viruses and other microbes. We must not give this virus opportunities to deliver more surprises.”

Make no mistake about it, Chan is warning about the threat that left unchecked the virus will evolve into an even more dangerous form and, possibly, that it may go airborne. Chan will know that research published in 2012 in a sister publication to the prestigious scientific journal Nature showed that the Ebola Zaire (ZEBOV) can spread through the air between infected pigs and macaque monkeys, raising the scary possibility that it might manage to spread through the air between humans – like ‘flu.

Airborne transmission

The authors of the 2012 study wrote: “Under conditions of the current study, transmission of ZEBOV could have occurred either by inhalation (of aerosol or larger droplets), and/or droplet inoculation of eyes and mucosal surfaces and/or by fomites due to droplets generated during the cleaning of the room. Infection of all four macaques in an environment, preventing direct contact between the two species and between the macaques themselves, supports the concept of airborne transmission”.

Now there is an issue here around whether or not the transmission they observed was via droplets of bodily fluid that were suspended in the air, which is not technically defined as airborne transmission, or whether the virus was actually spread through the air without the help of droplets. But this is semantics. Ebola has been shown to spread through the air between animals although it has not been seen to spread though the air between humans – so far.

But that has not stopped the US Centers for Disease Control and Prevention (CDC) from implicitly acknowledging the risk of airborne transmission between humans in its latest guidance to US passenger plane air crew, who may have to deal with sick passengers. “Provide the sick person with a surgical mask (if the sick person can tolerate wearing one) to reduce the number of droplets expelled into the air by talking, sneezing, or coughing,” the guidance, updated this week on 31 July 2014, states.

Ebolagraph2

The outbreak “is moving faster than our efforts to control it,” warned Dr Margaret Chan, Director-General of the World Health Organization. You can see what she means. Data courtesy: WHO.

Doomsday scenario

The number of cases of Ebola in West Africa is growing rapidly and it appears to be accelerating. This supports the contention that the disease is spreading more easily in this outbreak than in previous outbreaks. This does not in itself mean that the disease is spreading through the air in Africa at the moment but it does indicate how contagious this virus already is when spread through close contact.

The risk to countries outside of Africa remains low so long as Ebola can be spread only through direct physical contact. You will hear a lot of reassuring words from politicians and pubic health officials in Europe, the Americas and Asia about how Ebola does not spread through the air and about how confident they are that effective infection control measures will limit the spread of the disease should it ever cross their borders.

Viruses mutate and evolve fast to adapt to their hosts. Ebola will be doing just that right now. The longer this current outbreak is allowed to continue then the greater the risk that this particular virus will develop its nascent ability to spread through the air.

Airborne transmission between humans of Ebola, a disease with a death rate of more than 50 per cent, is a doomsday scenario.

The world must act to contain this outbreak now. Before it is too late.

IMPORTANT NOTE: This report quotes the text of a pre-publicised speech written for WHO DG Margaret Chan. The text was issued issued by WHO and placed on its website. The quotes attributed to Chan come from that text and were widely quoted in the media including on this blog. WHO subsequently reported that this speech was not delivered and WHO has withdrawn the text from its website. The text of the speech is presented in the images below.

Chan speech 1

Page 1

Chan speech 2

Page 2

Chan speech 3

Page 3

This is what WHO now say about the speech that was written for Chan to deliver in Africa.

This is what WHO now says about the speech that was written for Chan to deliver in Africa.

Sources

The speech Chan was expected to make here.

This is where WHO had originally placed the text for Chan’s speech which WHO now says was not delivered: here.

Scientific paper on airborne Ebola transmission: Transmission of Ebola virus from pigs to non-human primates by Hana M. Weingartl, Carissa Embury-Hyatt, Charles Nfon, Anders Leung, Greg Smith & Gary Kobinger published in Scientific Reports 2,Article number:811 doi:10.1038/srep00811 here.

CDC advice to aircrew updated 29 July 2014 here.

WHO case and death data here.

Spare a moment…

If you found this article thought provoking or informative then please take a second to Like it and share it with friends and colleagues via social networking using the buttons below.  And if you enjoy reading this kind of article then press the follow button!

Advertisements
Comments
7 Responses to “WHO Chief Warns Of Ebola Mutation Risk”
  1. Winston says:

    If Ebola can’t be transmitted by airborne droplets, then why does the CDC requirement stipulate droplet protection methods?

    Infection Prevention and Control Recommendations for Hospitalized Patients with Known or Suspected Ebola Hemorrhagic Fever in U.S. Hospitals

    http://www.cdc.gov/vhf/ebola/hcp/infection-prevention-and-control-recommendations.html

    First paragraph:

    Standard, contact, and droplet precautions are recommended for management of hospitalized patients with known or suspected Ebola hemorrhagic fever (Ebola HF), also referred to as Ebola Viral Disease (EVD)

    The Most Common Droplet Transmission Diseases

    http://ent.answers.com/ent-treatments/the-most-common-droplet-transmission-diseases

    In that list, influenza and the common cold.

    • Biologist says:

      The take extra measurements to contain it. Also people sneeze and it’s not always a dry sneeze.

    • Samantha says:

      The CDC requires droplet protection methods in order to prevent spreading of the disease through bodily fluid contact with mucous membranes in your mouth and eyes. The Ebola virus can cause patients to projectile vomit, and those fluids can result in infection if particles of the fluid make contact with another person’s mouth or eyes. Droplet transmission protection protocol is used as a general precaution to prevent the transfer of particles of bodily fluids making their way to areas of another human’s body that could result in the transfer of the infection.

  2. Gilberto says:

    Great and accurate information was found in this article. We have to get the Ebola outbreak contained and under control. Testing and research has shown us that Ebola can jump from pigs to monkeys without physical contact meaning that it has the potential to become airborne if we give this Ebola a chance its only a matter before this virus mutates and becomes transmittable from human to human airborne Ebola would be catastrophic. Again kudos on this great article.

  3. Realist says:

    We should allow it to travel uncontained. An outbreak is humanities only chance now to get the population to below a sustainable 4 billion.

  4. bigD97 says:

    outstanding article, especially the screen shots of Chan’s original report– before it mysteriously disappeared from WHO’s website. that level of irony may literally kill me.

Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

  • Copyright © 2014. iExpon Limited
  • Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 81,676 other followers

%d bloggers like this: