Ebola Updates

I don’t want this to become an Ebola blog. Even with Danzig quotes, there’s just so much else out there to write about. However, a few things have happened over the weekend. A nurse in Texas has been reported infected, after serving on the care team for Mr. Duncan, the Liberian man who died last week, and Emory has released a “lessons learned” document relating to the care of two individuals infected in West Africa in July and August who were transported there for treatment.

How the Gods Kill

Emory first. Their hospital works closely with the CDC, and hence has some of the best isolation facilities in the world. The clinical care section of the document is the single best description of the course of the disease I have ever seen- 5-10L of fluid loss per day, largely by third-spacing (leaking into tissue outside the bloodstream) due to loss of albumin (the protein that keeps fluid in the blood.) The disease also depletes electrolytes, which we all know and love from gatorade commercials. As well as facilitating muscle contraction, electrolytes are the electrical “juice” for nerve and heart cells, and screwed up electrolytes (from, say, prolonged vomiting) can lead to heart arrhythmias and death.

Albumin, for the record, is produced by the liver, and is one of the first proteins “economised” in a starvation situation. This is why the typical image of kwashiorkor starvation is a skeleton with a pot-belly: that belly is actually fluid that has leaked out of the bloodstream because there isn’t enough protein to hold it in. Not blood, not bleeding, just fluid. I’m not clear why Ebola patients would lose albumin during the illness, the document mentions “nutritional depletion” but there may be more liver-specific reasons as well. I’m speculating; don’t quote me.

Clinical care seems to be crap-tons of electrolyte replacement, nutritional support, and fluid. The Emory team “engaged the FDA, CDC and pharmaceutical manufacturers in active discussions” about experimental therapies, but its not clear what was used and without more data points we can’t know if anything helped.

Still Not Airborne

On the question of airborne transmission, I mentioned in the last post that testing was by reverse-transcriptase PCR which means looking for viral RNA. The Emory team tested every fluid and (it seems like) every surface the patients were exposed to, and found virions only in the fluid samples. That makes a dry airborne transmission less likely. However, its also worth noting that, again as I mentioned before, wearing PPE consistently and constantly is grueling and in some climates impossible for the human body. Staff at Emory switched to using battery Powered Air Purifying Respirators or PAPRs (see the cartoon at the top of this article, from the Ontario Ministry of Labour) for their own comfort, as these are cooled by airflow. Whether they become the standard of care for comfort reasons, compliance reasons, or as a hedge against fear of “airborne” viruses, they seem to be acceptable for use in a hospital setting at least.

I imagine we’ll see discussion of PAPRs in the future. The CDC is already sparring with the coworkers of the nurse infected in Texas about whether she was compliant with PPE regulations, and nurses in Madrid are walking off the job over (previously reported) complaints about poor support for working with the virus. Given that PAPRs are simpler and easier to use, if I were a hospital administrator, I’d be on the phone to purchasing right now.

(okay, they also cost a lot)

Everyone Freaking Out

Another interesting not in the Emory report is that shippers and sewage contractors are being chary about working near Ebola. For decades the virus has been shipped as a “Class A” biohazard, which means significant protections must be in place. However, even with those protections, class-A licensed shippers are refusing to send samples (compare to Peter Piot in 1976: “When we opened the thermos, the ice inside had largely melted and one of the vials had broken. Blood and glass shards were floating in the ice water. We fished the other, intact test tube out of the slop and began examining the blood for pathogens.”). Similarly, the water authority required specific disinfection of any materials that were flushed (no standards exist) and lab techs preferred to move their equipment into the patient-care area, rather than trusting the isolation kit to prevent a costly spill in the main hospital lab. It sounds like an abundance of caution, whether helpful or annoying, prevails in Atlanta.

In Other News

OIE says “There is no evidence that domestic animals play an active epidemiological role in the transmission of the disease to humans.” Although they are writing in the context of swine (pigs) this has been interpreted to mean that Excalibur, the Spanish nurse’s dog,

5 thoughts on “Ebola Updates

    • Those are very different questions! Why rule it out? Because its a really, really important piece of data to know one way or the other, hence the extensive viral swabbing! It has been pointed out by sharper minds than mine that human-to-human dry airborne transmission is not testable, experimentally, for obvious ethical reasons, but accumulating as much data as possible by indirect means is critical. As for the taking precautions, that’s a different issue. Effectively, that’s what the Emory U team did, though for other reasons. At some point that becomes a fruitless endeavour, and you start to run into human rights problems (as happened with HIV in the 80s, when “taking precautions” started to mean some fairly brutal medical abuse), but for now sure. Whatever. As I’ve said, PPE in hot climates is a total beast without positive pressure ventilation anyway.

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  1. Thanks for the response. You are certainly correct that more knowledge is for the better. I should have finished the sentence as “Why rule it out as a possibility when we do not know the answer ?” So little data, so much mis(sing)-information. The respirator (esp PAPR) vs N95 mask would seemingly not add all that much to the existing ‘beastly’ PPE in use. In any case, the staff of western medical systems themselves will force the issue as was the case for the 1918 flu outbreak with strikes. CDC seems to be behind the curve in any case with their minimal facemask requirement.

    You baffle me by raising the human rights stuff…too much info there, perhaps, when my point was only to treat Ebola as if it DID spread as an aerosol since the indications are that it might be so.

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  2. Anne,
    Do you know if the virus can infect trans-dermally? If not, does this open up a possibility for headgear and glove only PPE which would be cheaper and could be worn for longer periods?

    And the big news this morning of course is that a second Texas health care worker has tested positive.

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    • Cuts and scrapes are vectors for infection for certain. I think the concern about intact skin is that even if you can’t get infected that way, one wipe of your face, or one inopportune collision with, say, the side of an elevator, and you’ve spread the virions somewhere they shouldn’t be. PPE is easier to remove, bag and burn than human bodies are to clean. I believe that for BSL-4 you do both (though I’ve never done the training), but hospitals have a bit more leeway. In a hospital context, “Isolation PPE” can mean anything from this:

      to this:

      Both take a good deal of training to use effectively. This one I have done!

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