Dallas Ebola Conundrum: Duncan Family Members and Emergency Room Staff Not Ill



Two nurses who were involved in treating Ebola virus victim Thomas Eric Duncan at Texas Health Presbyterian Hospital (THPH) in Dallas, Texas have now fallen ill. They were evidently exposed to the infection through some failure in procedures or equipment.

In the meantime, the four people who lived for four days in the apartment where Duncan became progressively sicker after being turned away from the emergency department at the THPH on September 24, so far do not appear to have come down with disease. (Just checked for news.) The U.S. Centers for Disease Control and Prevention notes that " symptoms may appear anywhere from 2 to 21 days after exposure to Ebola but the average is 8 to 10 days."

The onset of Duncan's symptoms was September 24, which means that it has been 22 days since the folks in the apartment and the emergency room personnel could have been first exposed to the virus. The people from the apartment are currently quarantined and, if they show no symptoms, are expected to be released on Sunday, October 19.

Is there a signficant difference in the infectivity of early stage Ebola patients compared to later stages when symptoms are more severe? If so, this could bode well for the folks whose contacts with Duncan and the ill nurses were early and fleeting. Here's hoping.

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      1. The Keystone Disease Kops probably accidentally shipped it there.

    2. I lol’d.

    3. It’s not really a surprise that a lot of disease is transmitted inside a hospital.

      If there was a God there would be a fatal disease that is only transmitted from inside courtrooms.

  2. Are you trying to start a shadow CDC?

  3. 1) Is the Ebola virus genome infectious?

    2) Does route of infection have an impact on pathogenesis and clinical outcome?

    1. Excellent questions. To repeat from below:

      I hate to say it, but things like this make me wish we had a, wait for it, government agency that could really land on infectious disease outbreaks with expertise and authority. Perhaps a Disease Control Center, something like that?

      1. We don’t have that already? Don’t they always get to the crisis immediately, have the best equipment, and are comprised of the world’s greatest experts. They jump right in and solve every problem, every time.

        Sure we do….I have seen them in the movies lots of times.

        1. Unfortunately Dustin Hoffman appears to currently be busy voicing Kung Fu Panda 3 (rumored).

          1. Good. I don’t want to seem him in any more shitty movies like Outbreak.

        2. They’re busy trying to figure out why lesbians are so often fat.

          1. Carpet is fattening?

  4. That’s what baffles me.

    Apparently, the most residual contact from improper removal of a hazmat suit can transmit the virus. You would think this would mean that unprotected contact with the patient would be nearly guaranteed to transmit the virus, but if anything, the infection rate with patient zero is higher if you were hazmatted than if you weren’t.

    Its the same damn virus whether you are early stage or late stage. The viral load gets pretty huge at some point, so maybe that’s the difference? Here’s hoping.

    1. In the limited training I have had with PPE designed to protect against hazardous chemical exposure, it was emphasized that removing PPE is often a very risky element and can result in exposure. I would assume similar for biohazards. The contaminant is already very close to your body and can easily be disturbed during the removal process.

      1. I wonder if the hazmat suits aren’t, on net, increasing the risk because of cross-contamination during removal?

        1. I doubt that, but if you use a tool, you have to use it properly.

        2. Provided that they are well-designed and used properly, they are the best thing we have.

          Now would be a good time to get to work on fully waterproof, positive air-pressure suits (ie, hose or tank fed). Waterproof so they and their occupant can go through a bleach shower.

          1. Provided that they are well-designed and used properly, they are the best thing we have.

            This is prototypical engineer head-in-ass syndrome.

            Visible safety and actual safety are not the same thing.

            It sounds like there are two classes of threats here. The first class is casual contact, and that is what the PPE protects against. The other class is “extreme” or “abnormal” contact, and not only is the PPE not capable of protecting against it, people wearing the PPE are more likely to expose themselves to this class of threat.

            You may be able to resolve some of this with “training”, but the incentives are already there for people to be extremely fucking careful and yet transmission is still occurring. It is entirely possible and indeed very likely that these procedures are wholly inadequate in the real world.

            It is the goddamn job of the CDC to find out how this is happening, not shove their fingers in their eyes and shout “la la la you aren’t following the rules”.

      2. This is a simple, simple problem to solve. You come out of the quarantined area and stand still, arms up. I take a simple garden sprayer with a 7-10 percent solution of sodium hypochlorite/sodium hydroxide and spray your suit head to toe, every fold and crevice. Wait 5 minutes and step under a shower.

        For biohazards of this magnitude the full hazmat suit is warranted, and with that procedure before removing the suit there would be zero chance of infection.

        1. I like the way you think.

        2. Are you telling me that don’t already do that??? That shocks me in some ways, and not in other ways.

    2. My guess would be the viral load since that presumably increases as the infection progresses.

    3. MM: It may be that at earlier stages the bodily fluids through which the virus is passed are way less copious and contain many fewer infectious particles than at later stages. But your comment captured my puzzlement exactly.

      1. Ron, the viral load is the number of critters per ml of bodily fluid.

        1. I wonder if the load varies by type of bodily fluid as the disease progresses?

          Maybe: early stage, mostly in blood, little to none in excreta or vomit.

          Later stage, viral load in all fluids are elevated?

          I hate to say it, but things like this make me wish we had a, wait for it, government agency that could really land on infectious disease outbreaks with expertise and authority. Perhaps a Disease Control Center, something like that?

          1. You left out “competent”, RC. That’s the problem here. And I don’t know whether the incompetence is an inherent byproduct of being a government agency.

            1. “And I don’t know whether the incompetence is an inherent byproduct of being a government agency.”

              I do.

          2. I hate to say it, but do we really have reason to think at this point that the CDC isn’t doing at least an adequate job of staying on top of this?

            1. Yes. Yes we do.

              Tom Frieden has stated that the only way any of the health care workers could become infected is if they broke protocol. A protocol designed for pathogens passed only through bodily fluids implemented for a pathogen we know next to nothing about.

              1. At this point it looks like they did breach protocol, but through no fault of their own. It appears they were not given proper training, nor given proper equipment.

                1. Protocol: is there anything it can’t do?

                  1. I thought it was Goldie Hawn who broke Protocol.

            2. Telling then-exposed (now infected) Nurse #2 that she could fly was not a prudent move.

          3. 2011 paper on Ebola sudan outbreak, with quantitative PCR results. Rapid Diagnosis of Ebola Hemorrhagic Fever by Reverse Transcription-PCR in an Outbreak Setting and Assessment of Patient Viral Load as a Predictor of Outcome

            The clinically trained—I am not one—will no doubt find it interesting. They mention log 8 viral RNA/ml, by which I am assuming 10^8 copies, as an indicator of a 90% prob of a fatal outcome. Anyway, I don’t know if that paper answers some of your questions, Mega.

            I would be really interested in hearing, live, from Duncan’s family around now, just to dispel the rumors if nothing else. My own, ex rectum, guess is that E. zaire in this country is not very contagious—until the carrier is vomiting and suffering diarrhea. And the recipient is involved with contacting that fluid or coming closer than 1-5 m to the vomiting/explosive diarrhea/blood gushing out the eyeballs event.

            So, I personally, (several hundred miles from Dallas) think the risk to the passengers on the Cleveland/Dallas flight was minimal, but I am wondering how the ambulance drivers on Duncan visit #2 have managed to skate so far. And I would like to know whether the nurses picked up the bug during the two days of admission where they didn’t have full isolation/provider PPE, or at the end of Duncan’s stay.

            1. I’d guess they picked it up towards the end of Duncan’s life. It’s well-known that the infected continue to become more contagious as time goes on.

              Even if the nurses had full hazmat protection after Duncan’s diagnosis, that doesn’t mean they went through the proper procedures of removing and disposing of those items after each visit. That may be the vague “protocol breach” that the CDC has been mentioning. Also, the nurses were supposedly adding additional layers beyond what they were issued, which apparently is a big no-no.

              1. And let’s unpack that “more contagious” a bit. I’m assuming the viral load (number of virii per milliliter of bodily fluid) increases as the infection progresses as happens with HIV. And as the patient becomes sicker they produce more fluids and in a more explosive fashion. FWIW, viral load may vary between various fluids.

            2. Ambulance crew, please, GG. Some of the drivers are just that – drivers. The EMT’s are the caregivers. It is possible to be certified in both. Who does what at what time depends on staffing resources.

              1. Whoops, thanks for the catch Tonio. The question still holds. We know that Duncan was at the shitting and puking himself stage while he was still at the apartment. Therefore, he was at that stage while he was being transported. Perhaps he didn’t appreciable secrete during the transport.

                As to viral loads and titres etc… I do not know, but do loads follow an ever-increasing concentration until patient death, or do they increase to a given max at some point in the disease progression and then decrease their rate of concentration acceleration to nearly zero until death? I’m just trying to get a handle on how long a patient like Duncan would be spewing max concentrations of virus everywhere.

                Thankfully we seem to be heading out of the incubation zone for a hypothetical carrier during the Hajj, with no reports of global Ebola cases from countries like Indonesia, Pakistan, or other Sunni Muslim countries.

                1. And I wasn’t trying to make the question go away in any fashion, GG, but rather to show some respect for the ambulance crew who probably shat themselves when they learned that they’d transported an Ebola patient. Ambulances, even ALS units, do not carry full biohazard gear.

                  Now, that does raise a question – if ambulance crewmembers are

                  Viral load – it’s called “going viral” for a reason. The loading increases until the host dies (at least with the viral course with which I’m most familiar). Natural selection dictates that the best thing the virus can do to move to a new host is to keep increasing output in hopes that it will infect something. Virus production only ends when the host experiences cellular death.

                  1. Yeah, ignore that incomplete paragraph.

            3. Thank you that is very interesting. Your right about it being 10^8.

              1. Cyto, could you speak or link-to how long droplets, such as from a sneeze, remain airborne?

                1. I don’t know. I’m too lazy to look it up, which might account for my current inability to find a job in my field.

                2. An ’05 paper on “the state of knowledge regarding the mechanisms of droplet spread in indoor environments and the solutions available to minimize the spread and prevent infections.” Proceedings of the Indoor Air 2005 Conference Beijing, China, 4-9 September 2005
                  Lidia Morawska
                  International Laboratory for Air Quality and Health, Queensland University of Technology

                  A very interesting blog by an infectious disease specialist at the University of New South Wales. She’s one of the two researchers who authored the post db cites below on ebola and aerosol transmission. In this post, she adds commentary to her post

                  1. As to your question on droplets and airborne times, I don’t know, and from the first paper I linked above, I’m not sure they know either. At page 9-10, ”

                    The understanding of size distribution of droplets and droplet residue related to various release mechanisms and their subsequent transport is still limited, and perception of the droplet dynamics, not free of misconceptions…From the above discussion it can be concluded that droplets do not remain in the air for any considerable periods of time as they evaporate very quickly. However, both these size ranges result in solid airborne residue and can be suspended in the air for prolonged periods of time.”

                    As to distances, times, etc… you’ve got me.

                    But see this 2003 paper on an 2000-2001 outbreak in Uganda. Ebola Hemorrhagic Fever Transmission and Risk Factors of Contacts, Uganda. From their findings: Among the postprimary case-patients, the most important risk factor was direct repeated contact with a sick person’s body fluids, as occurs during the provision of care. As expected, the risk was higher when the exposure took place during the late stage of the disease at home. The risk was reduced when the patient stayed in a hospitals, probably because of the use of gloves, even before strict barrier nursing was implemented (6,7). [Cont.]

                    1. By contrast, simple physical contact with a sick person appears to be neither necessary nor sufficient for contracting EHF. In fact, one person in whom the disease developed was probably infected by contact with heavily contaminated fomites (patient 7), and many persons who had had a simple physical contact with a sick person did not become infected.

                      Transmission through contaminated fomites is apparently possible. In fact, the association found for having slept on the same mat or having shared meals with a sick person or with funeral participants remained after controlling for direct contact. However, having washed the clothes of a sick person and having participated in the ritual handwashing during the funeral ceremony were not significant risk factors.

                      Finally, although we cannot exclude the possibility of airborne transmission, this mode probably plays a minor role, if any. In fact, the association between having slept in the same hut and acquiring the disease was weak and could have been produced by some unidentified confounding variables. Furthermore, the reported Ebola virus aerosol transmission among nonhuman primates (17,18) has been demonstrated in laboratory experiments, which may be irrelevant in the natural context.

                      So, I’ll go with aerosol transmission is unlikely, but don’t rely on an N95 mask to protect you when the guy’s projectile vomiting next to you.

                  2. Thanks, GG, I’m working through those.

        2. I think viral titre is the number of infectious units/unit of whatever. Viral load is the number of viral genome copies detected/unit of whatever. /nitpicking

          1. Is the difference, Cyto, just the number of viral particles suspected to cause infection? So the titre would be 1/(1-10) the load? 1-10 is the number of E. zaire particles suspected of causing infection in one primate study. Franz, D. R., Jahrling, P. B., Friedlander, A. M., McClain, D. J., Hoover, D. L., Bryne, W. R., Pavlin, J. A., Christopher, G. W., & Eitzen, E. M. (1997). Clinical recognition and management of patients exposed to biological warfare agents. Jama, 278(5), 399-411.

            1. Viral load will detect all those genomes by PCR (assuming the primers detect all the strains). But genomes =/= virion =/= infectious unit. A genome by itself may not be infectious, or even if it is it could be physically fragmented (but not in the amplified area for it to be detected by qPCR). You could also ascertain a sort of viral load by electron microscopy to visually see only intact virions which is way more work than qPCR but not nearly as much as I thought it was before a colleague did it. Even this will over-estimate the infectious titre because not all those virions are infectious. In some viruses, only 1/100 of the virions are infectious! (The virions go in and out of infectious state according to steady-state mechanics). This is why the gold standard of determining the actual number of infectious particles per unit of whatever is derived from infetivity titration: take whatever tissue you’re measuring, pull out the virus in a manner that hopefully doesn’t alter its infectivity, and apply in 1/10 serial dilutions to tissue culture. Fix, stain. Count. Do math stuff.

              Infectious dose is the number of infectious particles required to infect 50% of those exposed to that number . I am pretty sure that it’s always 50% and I’m pretty sure that can only be used to describe one route of infection. The ID50 will vary for say oral exposure versus skin exposure.

              By the way if anyone is hiring virologists/microbioloigsts/stuff like that I could use a job right now.

              1. I suspect it’s a growth industry, Cyto.

                But seriously, best of luck.

          2. No tittering.

    4. Maybe exposure to other nasty stuff weakens the ebola virus but sterile environments allow it the thrive.

  5. The virus can live outside the human host, but only on Latex.

    1. Healthcare has pretty much abandoned latex and gone with all nitrile gloves (the blue ones) because of common latex allergies among patients and staff.

      1. Healthcare has pretty much abandoned latex

        Well, during working hours, sure.

        Off-hours recreational activities? Who can say?

        1. The sex toy industry has mostly abandoned latex, too. Silicone, baby.

      2. No, Tonio, it was because the organism mutated and started to eat rubber and latex. I should probably stop reading The Andromeda Strain now.

        1. Latex is rubber, Epi. Specifically “natural” (plant-derived) rubber. Compare to silicone (synthetic) rubber.

    1. The Roll Out of the Hitler Youth Movement Through the Common Core Invasive Data Mining of Our Children

      Sounds credible.

      1. Yeah, and it sources Natural News, which is not a positive. But here’s the WHO report they are quoting:

        The period of 42 days, with active case-finding in place, is twice the maximum incubation period for Ebola virus disease and is considered by WHO as sufficient to generate confidence in a declaration that an Ebola outbreak has ended.

        Recent studies conducted in West Africa have demonstrated that 95% of confirmed cases have an incubation period in the range of 1 to 21 days; 98% have an incubation period that falls within the 1 to 42 day interval. WHO is therefore confident that detection of no new cases, with active surveillance in place, throughout this 42-day period means that an Ebola outbreak is indeed over.

        In other words the “21-day incubation period” everyone has been relying on is only good for 95% of cases. If 5% of cases have longer incubation periods, that’s rather significant, no?

        1. It’s all a numbers game, Papaya. Theoretically there might be .01% of cases where the incubation period is far longer.

          1. Well, yes, that’s part of my point. Too much of the “calm the masses” blather we are getting is treating biology as if it were mechanics, all known measurements and equations. But humans vary greatly. E.g. not everyone is normally 98.6: some have higher or lower average temperature. So it’s stupid for the CDC to say: “Oh, you’re an Ebola nurse with a 99.5 temperature? No problem! The Ebola marker is 100.4, and since you are .9 degrees under that, go ahead and fly!” They are picking arbitrary markers and acting as if they are based in science and set in stone. They aren’t.

    2. Ebola Bombs: ISIL’s new weapon?
      Film at 11.

    3. Interesting, but the author of that article misunderstands, perhaps deliberately so, the definition of “airborne”.

      1. Perhaps? You’re far too kind.

      2. There has been some legit discussion among epidemiologists that I saw that perhaps even though it may not be “airborne” that is may be aerosol borne, that is, an airborne virus would just float around where an aerosol borne o.e would need tiny droplets of liquid to sustain it. The.difference may be minimal when considering that you can easily inhale an aerosol from someone’s cough.or sneeze many minutes after the have.left the area.

        1. I’d like to see some good data on how long those droplets remain in the air. Even a small droplet is heavier than the air surrounding it. Now, the droplets do contaminate surfaces when they land which is a whole other problem.

            1. Thank you, db.

  6. This is just more evidence of the need to CLOSE THE BORDERS and why the COSMOTARIANZZZ are Teh EEEEEEEEVUUUUUUL!!!111!!!

    1. Believe it or not, I think that our obvious lack of understanding of how this thing transmits/infects IS the reason to restrict travel. Until we do have a much better handle on it.

      1. I think there is plenty of data out there on how it is transmitted. The disconnect is in the CDC’s inability to honestly communicate risk effectively to the general public out of fear of sparking a panic. Ironically the misinformation leads to.more panic.

      2. We understand it quite well enough and have a perfectly fine handle on it.

        Ebola is not a threat to America, end of story.

      3. The funny thing is, I would be bothered by a temporary ban on visas for people from the affected countries, but the way in which some people seem to want to use the ebola cases to go on about the wrongess of the open borders people comes across as unseemly.

        1. Er, wouldn’t be bothered.

        2. *cough* PapayaSF *cough*

          It is no different from the hoplophobe’s ability to turn every massacre into the reason we have to have more gun control now, and we should be treating it the same way.

          1. Well, I did have certain posters here in mind. Just like over on the thread about the guy running for governor in Illinois on the Libertarian ticket.

          2. And kindly turn your head when you cough.

          3. Current events are merely proving me correct. You open borders types simply refuse to see any costs associated with your beliefs. And gee, “immigrants carry disease” is a stereotype, and so it must be untrue. It must be, because it’s a stereotype, and by definition stereotypes are never true. Right?

            EV-D68 couldn’t possible be all over the US just because a bunch of immigrants from countries where it’s common were sent all over the US a few months earlier. Immigrants already proven to carry other diseases (TB, scabies, chicken pox) and who often don’t know how to use modern bathrooms.

            The analogy with gun control is inapt. We all agree that restrictions on guns won’t work. However, history and science show that quarantines do work.

            1. EV-D68 couldn’t possible be all over the US just because a bunch of immigrants from countries where it’s common were sent all over the US a few months earlier.

              Just shut up. You have no evidence or expertise for this horseshit. You’re like every xenophobic racist asshole screaming about the Yellow Peril almost 100 years ago. You’re good for nothing but ridicule.

              1. Here you go. Boy, you can really be a rude jerk when someone disagrees with you.

                1. It’s cute when you pretend you can science. You know that article does nothing to back your point up right?

                  1. It says EV-D68 is prevalent in Latin America. EV-D68 was rare in the US. Suddenly, after thousands of Latin Americans are spread around the country, EV-D68 is all over the US. If this isn’t 2+2=4, you explain it to me.

    2. You kid, but the area nativists are slavering for an excuse to keep out dirty furriners.

      1. “I hereby invalidate this evidence, because it supports my opponent’s point of view!”

        1. There would have to be evidence to invalidate in the first place. Your hysteria and disgusting lust for anything to jump on do not constitute evidence.

  7. It’s quite possible that those of African decent have some genetic immunity, while other races do not. Think Native Americans and small pox. It’s called the “virgin ground phenomena”.

    1. Then why are so many people in Africa dying of ebola?

      1. Plenty of Europeans died of smallpox too. It’s not a totally crazy idea. The entire reason West Africans were brought over as slaves is because large parts of the South were uninhabitable to othe races after malaria became endemic, after all.

  8. I think I might know why this is happening: they were all exposed to the virus, but only some progressed due to different innate immune states of the hosts.

    The guys in contact with the patient in his home were highly immunocompetent. Their innate immune system-which is what is most important in Ebola clinical outcome because Ebola moves too fast for the adaptive immune system to control-was running at full. *Maybe* something was even spinning it up to be more active than normal, like another pathogen or other immunogen. There is an experimental Ebola ‘vaccine’ that isn’t a vaccine at all but actually just acts by revving up the innate immune system.

    The nurse was stressed out physically and mentally. Maybe she didn’t sleep well. This is very bad for innate immune system. This immunosupression is why not sleeping or exposure to cold can lead to developing The Cold. Normally the innate immune system swats that down but in an depressed state it doesn’t.

    What is Ebola’s ID50? Does contact/exposure with any number of virus always result in infection? Does that infection always progress to clinical disease?

    1. Could be, but the far more likely explanation is the dates on which they were exposed.

      Duncan was more contagious and emitting many more fluids at the end of his life than when he first landed in the USA or even when he went to the hospital for the second (and last) time.

      If you look at the current outbreak in Africa, a huge percentage of the infected have been health care workers. If we were really talking about aerosol transmission or high degree of contagion during the entire life cycle of the disease, then Monrovia would be a ghost town now.

    2. I suspect that’s part of it, which does not bode well for average Americans slightly exposed to Ebola. I have read that Ebola is very infectious, in the sense that just a few virus particles can transmit it.

      One thing that some people were saying early on seems untrue: that Ebola has to get in your eyes or mouth or an open wound in order to infect. Now, it looks like if you even touch something with a heavy viral load, you can get it. I really don’t think both those nurses who attended Duncan picked their noses or their teeth afterwards. I suspect some tiny droplet hit some exposed skin, and that was enough.

      1. It is still entirely possible that they rubbed their eyes or nose. There’s no hard evidence showing through the skin Ebola transmission.

        1. Yes, it’s still possible. I’m just saying that the “you can’t get it if it simply touches your skin” may be incorrect. Clearly, the evidence in Africa is that it’s not usually that contagious. However, I’m not willing to say that all the dead doctors and nurses simply “did it wrong” and rubbed their eyes or mouth. In other words, I think that in the late stages of illness, it may be more contagious than they think.

  9. We should weaponize Ebola, and drop the warhead on ISIS from a plane named the Ebola Gay. Piloted, of course, by a homosexual.* Just to rub it in that they were killed by fags.

    *eating pork rinds or bacon in the cockpit while piloting would net additional points.

    1. I categorically deny writing the above comment. Obviously my account was hacked by one of the Koch Brothers, or possibly Mike Huckabee.

  10. I’ve been wondering the same thing about the family. The girlfriend, especially, since I remember her saying that he was shaking and sweating in bed next to her. So, if anyone was going to come down with it, I thought it would be her.

    I have read from a few epidemiologists that a person is most infectious when they are in the advanced stages or near death, so that could explain why the nurses caring for him it got it and why the family members and emergency room personnel did not.

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