Evening Ebola Update, Tues, 11/11: NPR Interview with Quammen/Dr. Bob’s Sel. Statements from ‘Ebola’   Leave a comment

11/11/14

Dear Colleagues:  Today is Veterans’ Day in the United States, a legal holiday, so many businesses are closed as well as all federal buildings.  Few new postings appear on the websites I scan and read each evening.  But the following items are posted for your reading:

l.  NPR interviewed David Quammen, author of ‘Spillover…’ and his September, 214 update and condensation of ‘Spillover’ titled ‘Ebola’.  See the transcript of the interview at: http://www.npr.org/blogs/goatsandsoda/2014/11/11/362379449/how-the-hot-zone-got-it-wrong-and-other-tales-of-ebolas-history

2.  Dr. Bob completed reading ‘Ebola’ by David Quammen and has selected statements from the book which impressed Dr. Bob.  See the selected statements below:

   Selected Statements from ‘Ebola’ by D. Quammen (ISBN 978-0-393-35155-2) Published September, 2014

A zoonosis is an animal infection that’s transmissible to humans. …Each of them reflects the action of a pathogen that can cross into people from other species. This form of interspecies leap is common, not rare; about 60% of all infectious disease currently known either cross routinely or have recently crossed between other animals and us.

Any spillover in the reverse direction-from human to nonhuman animals-is known as an anthroponosis. The famous mountain gorillas, for instance, have been threatened by anthroponotic infections such as measles, carried by ecotourists who come to dote upon them.

…Third, they (the Kikwit team) noted that Ebola outbreaks had been sporadic in time-with years sometimes passing between one episode and the next. Those gaps implied that infection of humans from the reservoir is a rare occurrence. Rarity of spillover in turn suggested two possibilities: that either the reservoir itself is a rare animal or that it’s an animal only rarely in contact with humans.

The case fatality rate (in Uganda 2000 spillover with Sudan virus) was again ‘only’ 53%, exactly what it had been in the first Sudanese outbreak, back in 1976. This precise coincidence seemed to reflect a significant difference in virulence between Sudan and Ebola viruses. Their difference, in turn, might reflect different evolutionary adjustments to humans as a secondary host.

Like other zoonotic viruses, ebolaviruses have probably adapted to living tranquilly within their reservoir(s), replicating steadily but not abundantly and causing little or no trouble. Spilling over into humans, they encounter a new environment, a new set of circumstances, often causing fatal devastation. 

He (Hewlett) found that the predominant ethnic group there (Gulu, Uganda) was the Acholi who were also inclined to attribute Ebola virus disease to supernatural forces. They believed in a form of malign spirit call gemo that sometimes swept in like the wind to cause waves if sickness and death. Ebola was not their first gemo. The Acholi previously suffered epidemics of measles and smallpox.

Once a true gemo was recognized, Acholi cultural knowledge dictated a program of special behaviors, some of which (isolation, limited caregivers, no sex, no rotten or smoked meat, no usual burial practices) were quite appropriate for controlling infectious disease.

The identity of Ebola’s reservoir host (or hosts) remains unknown, as of this writing, although suspects have been implicated bats (especially the hammer-headed fruit bat).

Two views of spread of Ebola across Africa; the particle view in which each human outbreak is seen as an independent event and Ebola is a old and ubiquitous virus in Africa, and the wave view in which the Ebola virus is a new virus descended from a viral ancestor, and the virus moves like a wave across Africa.

The key between animal hosts and humans is ‘connectivity’. …A large fraction of all the scary new viruses known to be zoonoses, and for which reservoir hosts have been identified, come jumping at us from bats.

…Bats come in many, many forms. The order Chiroptera encompasses 1.116 species, which amounts to 25% of all the recognized species of mammals. One in every 4 species of mammal is a bat.

Marburg, SARS coronavirus, and Nipah have bats as reservoirs. But Ebola has not been proven to have a bat reservoir. No live Ebola has been found in a bat.

The article by Gire, et. al. in Science Express reported three notable results: the virus was mutating prolifically; the 78 samples were sufficiently similar to suggest they had all descended from a single recent ancestor implying just one spillover from a reservoir host, this Ebola virus was different from The DRC Ebola virus by about 10 years worth of mutational differences.

END

3.  Google reports that Google will contribute $2 for every $1 donation to Ebola relief made on its Google site.

4.  ABC News reports that Nurses United have struck Kaiser Permanente in California over whether nurses have received enough education on EBOV by Kaiser and whether all HCW will be provided PPEs of the variety needed when in the ‘hot zone’.  Kaiser responded to ABC News that it has provided education and PPEs to nurses, and Nurses United has not joined Kaiser in developing guidelines for nurses despite Kaiser’s request/invitation to do so.

5.  ABC News reports that another Sierra Leone physician treating EBOV patients has become infected with EBOV.  He will be treated in country.  No details of his treatment have yet been released.

RGL, MD

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Posted November 11, 2014 by levittrg in Uncategorized

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