To Quarantine or not to Quarantine?: Science & Policy in the time of Ebola



 Bioethicist Arthur Caplan gives “7 Reasons Ebola Quarantine Is a Bad, Bad Idea”. I’m interested to know what readers think (I claim no expertise in this area.) My occasional comments are in maroon.

“Bioethicist: 7 Reasons Ebola Quarantine Is a Bad, Bad Idea”

In the fight against Ebola some government officials in the U.S. are now managing fear, not the virus. Quarantines have been declared in New York, New Jersey and Illinois. In Connecticut, nine people are in quarantine: two students at Yale; a worker from AmeriCARES; and a West African family.

Many others are or soon will be.

Quarantining those who do not have symptoms is not the way to combat Ebola. In fact it will only make matters worse. Far worse. Why?

  1. Quarantining people without symptoms makes no scientific sense.

They are not infectious. The only way to get Ebola is to have someone vomit on you, bleed on you, share spit with you, have sex with you or get fecal matter on you when they have a high viral load.

How do we know this?

Because there is data going back to 1975 from outbreaks in the Congo, Uganda, Sudan, Gabon, Ivory Coast, South Africa, not to mention current experience in the United States, Spain and other nations.

The list of “the only way to get Ebola” does not suggest it is so extraordinarily difficult to transmit as to imply the policy “makes no scientific sense”. That there is “data going back to 1975” doesn’t tell us how it was analyzed. They may not be infectious today, but…

  1. Quarantine is next to impossible to enforce.

If you don’t want to stay in your home or wherever you are supposed to stay for three weeks, then what? Do we shoot you, Taser you, drag you back into your house in a protective suit, or what?

And who is responsible for watching you 24-7? Quarantine relies on the honor system. That essentially is what we count on when we tell people with symptoms to call 911 or the health department.

It does appear that this hasn’t been well thought through yet. NY Governor Cuomo said that “Doctors Without Borders”, the group that sponsors many of the volunteers, already requires volunteers to “decompress” for three weeks upon return from Africa, and they compensate their doctors during this time (see the above link). The state of NY would fill in for those sponsoring groups that do not offer compensation (at least in NY). Is the existing 3 week decompression period already a clue that they want people cleared before they return to work?

  1. Quarantine is likely to be challenged in court.

And those challenging it are likely to win. Science does not support it.

Maybe so. I’m fairly sure that future volunteers will have to agree in advance. For those who haven’t agreed, I have no clue about legal precedence.

  1. Large-scale quarantine has not been thought through, in terms of making it bearable for those confined.

If government does not make it tolerable — and they show no signs of doing so, other than succeeding in stigmatizing people who are not dangerous — then people will not honor quarantine.

It isn’t clear it couldn’t be made tolerable. I think maybe people should be compensated if they are required to be quarantined.

  1. Health care workers who take care of those who really do have Ebola at big hospitals, such as Bellevue or Emory, are at the greatest risk.

If you quarantine them you are taking your best professionals offline for three weeks — and there are not a lot of replacements.

  1. Who will volunteer to go to West Africa to stamp out the epidemic, if they know they face three weeks of confinement upon their return?

Those who go are heroes who face hell on earth. Can’t they be trusted to do the right thing and self-monitor when they get back?

A serious worry is, indeed, that the new policy will kill off volunteers.

7. When officials respond to panic with quarantine they basically say they can’t trust public health officials, science and the ethics of doctors and nurses.

There is no substitute for that trust. None. If state and city officials undermine trust out of panic or politics, then they destroy the best weapon we have to control Ebola — good science implemented by heroes.

 I don”t see why elected officials imposing a quarantine means they can’t trust public health officials, although obviously it would be best if health officials are behind it.

It may be too late to reverse the leap to quarantine for those politicians deem at risk. But it is a leap into an unknown that we are likely to come to regret.

First published October 26th 2014, 6:11 pm


Arthur L. Caplan, Ph.D., is the Drs. William F. and Virginia Connolly Mitty Professor and founding head.

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50 thoughts on “To Quarantine or not to Quarantine?: Science & Policy in the time of Ebola

  1. Being forced to stay in a tent without a shower is pretty abysmal

    But Cuomo, “under pressure” is allowing people to stay at home instead.


  2. Sleepy

    Do they mean quarantining *at all*? I assume at least part of the practice is to account for the fact that people are not immediately symptomatic.

    • Sleepy: does who mean “at all”? Those against any quarantine?

      • Sleepy

        I’m referring to Caplan. (Sorry for the confusion – I picked up the singular ‘they’ from activist friends and never dropped the habit.)

        From the article I can’t tell whether Caplan is 1) against all forms of Ebola quarantine for the currently asymptomatic, even in cases where we know the individuals were exposed to the virus; 2) only against extended quarantines; or 3) against quarantining individuals based on whether they travel to infected areas.

        • Sleepy: Right, he’s not very clear as to what he’s against, or why.I’m glad they let that nurse go home, rather than be quarantined in a tent with no shower.

        • James T. Lee

          Language is powerful. In the present hornets’ nest atmosphere both precision and accuracy of speech need our closest attention. Dr. Caplan is a philosopher and brilliant thinker but he is neither a physician nor public health expert. He seems confused about both the meaning and medical importance of “Quarantine”.

          He betrays gross misunderstanding in his very first bullet point, “Quarantining people without symptoms makes no scientific sense”. What really makes no sense at all is Caplan’s very first sentence!

          Quarantine is a public health tool used for observing people who have had a credible exposure but NO SYMPTOMS. Caplan makes a layman’s mistake in getting confused by two facts: (1) quarantine involves isolating plausibly well people from society and (2) SICK people are also isolated during their treatment/recovery. Sick people with any contagious disease absolutely must be isolated from open society during their recovery period to prevent disease spread. Deep confusion about the meaning of “quarantine” is very widespread right now — watch CNN or MSNBC for 15 minutes and you can see for yourself.

          The utility of quarantine as a combined detection / prevention tool goes back many years in the history of public health and the term refers to the process of removing ASYMPTOMATIC people who have been credibly exposed from all contact with open society for a defined period of time (T) in order to observe these isolated people for reliable signs/symptoms of some disease X. Quarantine does reduce the spread of contagious diseases that are transmissible by human-to-human contact. The value of T is determined from empirical knowledge of the maximum incubation period for disease X as recorded for large numbers of past cases. Incubation period is defined as the number of days between exposure and the date of disease X development. Some exposed people develop a disease very quickly and obviously; others may not develop disease that promptly.

          For COVID19, T = 14 days and the median incubation period is known to be between 5 and 6 days. The nasty skunk at the picnic here is that people who have COVID19 disease can be highly contagious virus shedders, yet feel just peachy during their early incubation period. Not all contagious diseases are like that.

          In sum, if quarantined person Joe Smith does not become ill during T days of isolation from society, we can conclude with high confidence that Mr. Smith has not contracted disease X. On the other hand, if a quarantined person DOES develop findings that pin down the diagnosis of X during time T, the process of quarantine has not only allowed diagnosis of X at the earliest possible moment, but it has also prevented that person from exposing other people. Quarantine breaks the chain of transmission from persons who are asymptomatic but shedding dangerous pathogens during their incubation period.

          I understand that Dr. Caplan’s “points” were made in the context of a discussion about Ebola virus infections. Nonetheless, in the present COVID19 disaster it is absolutely certain that we are dealing with a new disease that is (a) Highly contagious, and (b) Definitely transmissible from persons who are carriers of the virus even though not yet symptomatic (they look well, feel well etc.). There is one more thing to note — Ebola is much more lethal than COVID19 and the irony here (or is it a paradox?) is that COVID19 arguably is far more insidious than Ebola because COVID19 victims can “stick around” much longer while shedding active SARS-CoV-2 virus.

          The lay public may be getting unwittingly hoodwinked in hearing from our government that “80 percent of you will be just fine if you get this illness”. Mr. Pence keeps sending that basic message although in not so many words. Well, yes maybe, contingent on the meaning of “just fine”. But persons who have “mild” COVID19 disease do also shed the active virus. COVID19 is a highly contagious disease that, unlike Ebola infection, does not incapacitate its victims rapidly. Quarantine is an absolutely essential tool in the present chaos.

  3. anonymous

    Military personnel returning (to Italy) from West Africa where they are helping to build medical units (and do not interact with ebola patients) are effectively under quarantine, even though they are calling it “controlled monitoring” “They will be monitored for 21 days at a “separate location” at the U.S. military installation at Vicenza Italy. Senior Pentagon officials say it is not a “quarantine,” but rather “controlled monitoring.” However, the troops are being housed in an access controlled location on base, and are not allowed to go home for the 21 day period while they undergo twice daily temperature checks.

  4. From a tweet by Nassim NicholنTaleb ‏‪@nntaleb‬ 9h
    9 hours ago
    The NECSI ‪@yaneerbaryam critique of the CDC response to ‪#Ebola (his approach explains why we collaborate on PP) ‪ …

    Y. Bar-Yam, Response to CDC Director Frieden’s Opposition to a Travel Ban. New England Complex Systems Institute (October 13, 2014).

    “While a waiting period might be considered a hardship for individuals, one should also recognize that the greatest risks are to the family, friends and business partners of those who travel from West Africa to other locations. In a recent report a message from a Liberian visitor to a U.S. resident friend was quoted “Why haven’t you visited me?” The friends response: “Hey, I love you, don’t get angry with me, you know? Give me the 21 days. You want me to live, you know?’ ”

  5. Steven McKinney

    What’s so wrong with a quarantine? Why not give healthcare workers who have served in the disease hotspots a two week break where they can relax, and have facilities to help them if the worst does happen to them? Why are we so averse to a paid break for the courageous souls who dig in and deal with this problem?

    A tent with no shower is not what I have in mind – perhaps a cruise ship circling the Azores. Time to read, relax and enjoy life after working on one of the most challenging epidemics for the planet.

    Front line doctors, nurses and other personnel are at higher risk. We’ve already had a New York doctor, and a cameraman for an NBC news crew treated in the USA, as well as the Texas hospital personnel. For well trained personnel who can return to a region with rapid access to Ebola-ready facilities, quarantine might not be necessary, but for others, what is the objection to a deck chair and some evening entertainment for a few days after weeks of hard work on a tough problem? I’m ready to donate to the cause already.

    • Steven: I don’t know about an ebola cruise ship. I do think it’s interesting how science and politics are getting blurred here. To say “it’s unscientific to impose a quarantine” and give as the reason “because quarantine turns heroes into pariahs” is a non sequitur.
      The bottom line is that there’s a lot of uncertainty–think of how little it would take for a major turnaround in opinion.

    • Cruise ships are basically floating petri dishes already — almost as bad as day-cares. Mexican or Cuban holiday resort with twice daily temperature checks would be nice…

      • Steven McKinney

        Sure – any such decent site, not Christie’s tent.

        My point is that the brave souls who go to Africa to help out are so worried about their job back in America, that they don’t want extra time tacked on to their time off for fear of losing their job. This is a sad state of affairs in America, that has consequences at times like this.

        Meanwhile, this “distraction” conveniently shifts the focus from where it should be. The epidemic in America at present is bullets, not virus particles. Death toll so far from Ebola: 5000 cases. “In 2010, the Centre for Disease Control and Prevention, which examines death certificates, counted 11,078 gun homicides in the U.S. for that year.” ( No legislation to deal with this epidemic since Sandyhook, but state governors are so quick to set up tents.

        • Couldn’t agree more about the bullets, but I would assert that loss of life due to gun suicide even worse than that due to homicide just by the numbers. A fascinating natural experiment took place in Britain (and elsewhere, I presume, but numbers for Britain are what was reported) when the gas sold to fuel gas ovens transitioned from highly toxic coal gas to non-toxic (albeit oxygen-free) natural gas. An oven running on coal gas makes a handy gas chamber, and it turns out that having a convenient death machine around the house is causal for (not merely associated with) suicide; a fair number of suicides simply ceased happening after the transition to natural gas, probably because a fair proportion of depressed people simply lack the motivation to carry out a less convenient form of suicide. (Curiously, even the overall suicide rate from all causes of death fell during the transition.) I crunched the numbers a while ago; under the assumption that “convenient death machine to hand” is causal for gun suicides in the US today to the same degree as it was for coal gas oven suicides in Britain, gun suicide is the cause of significantly greater loss of life than gun homicide, even accounting for those who would counterfactually complete a suicide attempt in the absense of readily available guns.

          • This discussion has taken a right angle turn, like we should be comparing U.S. deaths from ebola to car accidents and suicide? Right, ebola’s just a distraction from guns—give me A break. I really oppose such equating of risks, dismissing and blurring the issue at hand.

            • Policy is at least partly about where resources can be best put to use…

              • Corey: Resources? As if we can say we’re working on ebola because we’ve passed more gun laws. If they wanted to lower deaths by car accidents, why not go back to 55 MPH speed limit? You Canadians (or Canada inhabitants) have a very particular view of the U.S. The point is that this type of disease epidemic, many seem to think, is likely to become more common and will have to be worked on regardless of your favorite hobby horse.

                • “If they wanted to lower deaths by car accidents, why not go back to 55 MPH speed limit?”

                  Why not indeed? (Or better yet, why not legalize marijuana at the federal level?)

                  “As if we can say we’re working on ebola because we’ve passed more gun laws.”

                  I’m not taking your meaning here…

                  “regardless of your favorite hobby horse”

                  Not sure why this particular hobby horse is a bee in your bonnet (especially compared to my egregious Bayesian dressage all over your comment sections ever since you started blogging!). But for the record, my *favorite* hobby horse is AI safety.

                  • Corey: How could I forget your irrational fear of mean and nasty robots who will come back and torture their creators in the midst of obeying a command for more paperclips? Is it only Bayesians that imagine their computers will turn unfriendly? Seriously, it occurs to me that I haven’t heard of any frequentists claiming their main hobby fear is AI danger.*

                    *If you think I’m just in a foul mood, you’re right—academic and bureaucratic silliness.

                    • Mayo: And if *you* think it’s tiresome and irrational, imagine how it sounds to my buddy Dave with whom I’ve been friends since elementary school and who now works for IBM on Watson? (Incidentally, based on hints from Dave, I’m pretty sure Watson runs at least partially on Bayes.)

                      Sorry to hear bureaucratic bullshit has you down.

                    • Corey: Well I hear they’re building ebola robots, maybe Dave is juggling this among his other works.

                      Thanks for the empathy on my personal vexations.

                  • twitter
                    Ebola ‏@FollowEbola 1h1 hour ago
                    Canada imposes visa ban on three #Ebola-hit countries.

  6. State Dept. memo on helping to bring non-U.S. citizens to the U.S. for ebola treatment:

    It’s unclear whether this will be put in place.

    • Steven McKinney

      It’s unclear if the purported State Department memo is even real. This item appears on Fox “news” and other associated right wing tea party blogosphere sites. I see no discussion of it in any other media – no Reuters, McClatchy, large American city newspapers, foreign press. . .

      Will have to wait a few hours/days to find out if this is just another piece of swill out of these silly sites.

      • Steven: Right, all the controlled news stories coming out of the left-wing media are to be fully trusted as unbiased ‘truthiness’! Maybe you like USA today.

        • Steven McKinney

          I thoroughly vet any story coming out of any media source with a politically identifiable left or right leaning. Such media sources offer opinion and entertainment, not serious objective news feeds.

        • Steven McKinney

          That US News and World Report article appears in their “Opinion” section, not their “News” section. Notice the “/opinion” in the URL even. Author of the opinion piece is Peter Roff.

          “The memo, which the Washington Times says was authored by Robert Sorenson, deputy director of the Office of International Health and Biodefense at the State Department. . .”

          Washington Times – Sun Myung Moon’s media fiefdom. Vet carefully.

          “Peter Roff is a contributing editor at U.S. News & World Report. Formerly a senior political writer for United Press International, he’s now affiliated with several public policy organizations including Let Freedom Ring, and Frontiers of Freedom. His writing has appeared in National Review, Fox News’ opinion section, The Daily Caller, Politico and elsewhere.”

          Opinion piece offered by a contributor to multiple right-wingy thingies. Vet carefully, this is an opinion piece, not an objective scientific report or news item.

          After the deregulation of much of American media, and the transfer of News rooms to the entertainment divisions of large media conglomerates to turn them into profit centers, we Americans have to now do extra homework to verify items they disgorge.

          Severe testing! It’s not just for statistics any more.

  7. Fay Flam on Ebola and vaccines:(at Forbes)
    http://www.forbes com/sites/fayeflam/2014/10/28/in-ebola-crisis-new-vaccine-candidates-show-uncertain-promise/

  8. I’m getting a bit tired of hearing about nurse Hickox who is so keen to challenge the policy in her own state of Maine. Even if she’s perfectly fine and careful, she might consider the precedent for others.

  9. Seven patients treated for Ebola in the U.S. so far have survived (1 died, 1 still being treated):

    Kent Brantly, a doctor working for the aid group Samaritan’s Purse;
    Nancy Writebol, working as a missionary for SIM USA;
    Richard Sacra, physician, working for SIM USA;
    Ashoka Mukpo, freelance journalist and cameraman;
    an anonymous patient;
    Amber Vinson;
    Nina Phan.

    Two contracted ebola in the US––nurses Amber Vinson and Nina Phan – nurses for Eric Duncan at Texas Health Presbyterian Hospital. U.S. Duncan, a Liberian, died Oct. 8, but his treatment was delayed after arriving in the U.S. (he was first sent home with antibiotics.)

    Pham, Sacra and Mukpo all received donated blood plasma from Brantly, who had received a transfusion from a survivor before leaving Africa. Vinson received blood plasma from Ebola survivors Brantly and Writebol.

    Brantly, Writebol and Sacra were sick for several days before leaving Liberia, but the two nurses were treated as soon as they developed fevers.

    Craig Spencer, a physician, contracted Ebola in Guinea while working for Doctors Without Borders; he is hospitalized at Bellevue Hospital Center in New York, received a blood transfusion from Writebol. He showed no fever or other symptoms when passing through JFK airport, and remained symptom-free for days after returning to the U.S.

    Emory hospital treated Vinson, Brantly, Writebol and the unidentified patient. The Nebraska Medical Center in Omaha treated Sacra and Mukpo. Pham was treated at the National Institutes of Health.

    Duncan didn’t receive a blood donation — the Dallas hospital has said his blood type didn’t match — he did receive an experimental drug brincidofovir a few days before he died.

    Mukpo received brincidofovir.
    Sacra received an experimental drug, TKM-Ebola.
    Brantly and Writebol got an experimental drug, ZMapp.

    Emory has a substantial site summarizing their experience with ebola:

    Most of this info may be found at:

    Send corrections, additions.

  10. Nathan Schachtman


    I was forced by the current crisis to blog about it on my own site yesterday. Today, the NYT carried a story about a child barred from attending school in Connecticut, upon return from Nigeria, where there are no known cases. That’s crazy. It would make more sense to bar children who have been to the U.S., where there are known cases.

    I have great respect for Arthur, whom I met when he taught at Penn, but I think his 7 reasons don’t add up to much.

    1. He leaves out sweat. In the NYC subways, you may have “evidence-based” fears of touching poles and straps that have the residua of sweaty palms for the last hour or so. The self-monitoring regime is inadequate. A person take her temp twice a day, say at 7am and 7pm. At 6pm on the subway home, she begins to feel “hot,” and is a bit sweaty. Is she supposed to carry a plastic bag, jump in it, and call 911 for a HazMat team?

    2. Quarantine would be easier to enforce if our President engaged the military for something useful, like commissioning hospital ships and military cargo planes to be the sole transportation to and from West Africa. One protocol, for civiilans and military alike, with CDC oversight (for whatever that’s worth).

    3. Legal challenges. Arthur is an ethicist, not a lawyer, and his legal judgment here is faulty. The challenges will fail in court, and they will provoke a greater backlash against the do-gooders.

    4, 5, 6, 7. The ethics of healthcare workers? Well Dr. Spencer, per the NY Post, lied to authorities when he claimed to have stayed at home, when he was gallivanting around NYC. Nurse Hycock has announced her intention not to comply with Maine’s “softer” quarantine requirements. Arthur is simply incorrect to turn to this question into one of trust and respect. Some workers will be compliant, some will not.

    The situation cries out for a national, coordinated, policy, and I lay the blame for the failure at the feet of our President, who appointed a lawyer, political operative to head up his response.

    Further thoughts at



    • Sleepy

      I also found the appeals to trust surprising. He seems to reason that if a worker is ethical, then he or she will always be compliant with health regulations; therefore when we imply these “heroes” must be quarantined/tightly controlled we are casting aspersions on their character.

      I find this frustrating. It’s not a shock that some people tried to wiggle out of this for selfish purposes. People tend to be wigglers, consciously or unconsciously, regardless of stated concern for public health. I suspect that the doctors and nurses who lied weren’t thinking of this as an ethical conundrum at all – perhaps they thought the soft quarantine regulations were unnecessary, or just overly inconvenient in proportion to the threat. But Caplan seems to claim policy responding to this tendency (which is how I interpret the enforced quarantines) eliminates trust, to the effect of destroying “the best weapon we have to control Ebola — good science implemented by heroes.” I just don’t think that follows.

      I’m not sure how I feel about the quarantines. It will take me a bit to think about the contents of your post, but at the very least let me commend you on the phrase “Wild Nurse Hickox”.

    • Nate:
      Thank you so much for an insightful comment, I will read the one on your blog shortly. Why were you forced to write one?
      Here’s an interesting, somewhat disturbing, article

    • Compare to Hickox.
      REDWOOD CITY — Dr. Colin Bucks sits in his Redwood City home every day — completely alone. He sent his wife and dog to a hotel. The only time he goes out the front door is to retrieve food delivered into a cooler on his porch.
      He won’t even walk down the driveway to pick up the tossed fliers that are piling up.Bucks, 43, a Stanford emergency physician, is one week into a 21-day quarantine since his return from a jungle camp in Liberia, where he served for a month on the front lines of the Ebola epidemic that killed about half his patients whose stories “hit you right in the gut.”
      Bucks remained healthy in what he called an “enormously austere” environment. The medical teams covered themselves head to toe in sweltering, yellow Hazmat suits while treating patients, then hosed the suits down with a bleach solution as they undressed. He has no symptoms and believes he poses no health risk to his community.
      But unlike Maine nurse Kaci Hickox who has been making headlines by defying her quarantine order after returning from treating Ebola patients in Sierra Leone, Bucks has no quarrel with his required isolation. He knows that while unlikely, it’s possible he could develop symptoms within 21 days of his last exposure to the virus that has killed nearly 5,000 people. And even though San Mateo County health officials have given him the go-ahead for bike rides or jogs through the neighborhood by himself, he chooses to exercise in the confines of his house.

  11. Nathan Schachtman

    Mayo, I will look at the piece in Forbes. One other thought: I find it curious and fascinating that many of the precautionary principle folks, who want to ban some chemicals solely on animal evidence, or on dubious high-to-low dose extrapolations, are totally comfortable with the risk of spreading Ebola. But we have good evidence that Ebola can be spread by sweat and by airborne droplets of mucous from someone with symptoms or signs. I say “or” rather than “and” because people with low fever may not know it, and they already have an exponentially expanding virus load in their system.

    So this is very different from many of the environmental controversies where there is doubt where the chemical agent can cause the disease outcome in humans, and even more doubt whether it can do it by the mode of exposure at levels reasonably expected to be encountered.

    I was “forced” to write the blog piece by irresistable impulse. That’s my defense.

    • Nate: I too thought of this apparent inconsistent behavior with the PP folk. The answer, I spoze, is the Obama point that if we don’t fight it there, it’s coming here, coupled with the presumption that quarantines might diminish our fighting it there. (Maybe I’ll find out at the upcoming philosophy of science meeting.) If it got really bad there, Obama said, blocking all but essential flights would be appropriate. But then how does it come here?
      I think the PP is only supposed to apply to industries and companies (one doesn’t like), and not to people who want to take bike rides.

      The other interesting thing is that even the 21 day business is based on what occurs, supposedly, 95% of the time. So suddenly every is happy with 5% error. Also, WHO found that something like 13% never show a fever.

  12. anonymous

    The city is actively monitoring nearly 120 people who have recently returned from Ebola-stricken countries out of an abundance of caution as it seeks to prevent the spread of the deadly virus, Mayor de Blasio’s administration said Thursday.

  13. Ebola update: Maine judge rejects quarantine for nurse Kaci Hickox

  14. “Ebola survivors are immune to the virus for as long as three months. This means they can risk getting close to those with symptoms, and even touch them—something that’s especially helpful with children, a number of whom are separated from their families. ‘It’s kind of like a superpower,’ Portnoy says of the survivor’s immunity.

    What about the antibodies in the blood, enabling those transfusions to those with ebola. Do they disappear after 3 months too? Anyone know? Perhaps a survivor should store their own.

  15. Steven McKinney

    For organisms for which the human immune system can manufacture antibodies or related organism-fighting compounds, the immune system takes a few days to get production up to effective disease-fighting levels. The production will persist for several days to weeks, then start to tail off. Titration papers showing data on the rate of decrease of production of e.g. antibodies show this effect, though the scientific language used to describe the phenomenon is a bit difficult to deparse. See e.g.
    “Changes in antibody avidity after virus infections: detection by an immunosorbent assay in which a mild protein-denaturing agent is employed.”
    or an Ebola-specific paper

    A description in understandable English can be found at
    “IgG antibodies usually appear within 1 to 2 weeks of the infection, peak within 1 to 2 months, fall at variable rates, and usually persist for life.” This is specifically for a Toxoplasmosis infection, so Ebola characteristics will differ from this description. Only decent scientific investigation will establish these characteristics for Ebola. There is a decade’s worth of scientific review papers from which such information can be drawn. An example of description in English is shown at

    The human immune system has the ability to remember a recipe for an antibody, so that potential immunity against the pathogen is retained for years if not a lifetime. But months after an infection, a re-infection might cause uncomfortable symptoms before the immune system can crank up the recipe to fight the re-invasion of the pathogen.

    So current observations appear to be showing that infected humans who survive have enough antibody in their blood for up to three months post-recovery that allows them the ability to work with Ebola patients with little effect to themselves, as there is sufficient antibody in their blood to stifle the virus activity should they be re-infected.

    Ebola survivors can also donate blood serum, which will contain antibodies to Ebola, to other humans recently infected, as has already been done in recent treatment of cases in America.

    A survivor doesn’t need to save serum for themselves, as their own immune system will crank up production should they be re-infected. But Ebola survivors can share the serum with other cases newly infected, and the antibodies will help reduce viral activity while the newly infected patient’s own immune system tries to generate antibodies that work.

  16. Steven McKinney

    From a 1999 paper written by US Army medical researchers in the Journal of Infectious Diseases:

    ELISA for the Detection of Antibodies to Ebola Viruses

    Thomas G. Ksiazek, Cynthia P. West, Pierre E. Rollin, Peter B. Jahrling, and C. J. Peters

    Disease Assessment Division, US Army Medical Research Institute of
    Infectious Diseases, Fort Detrick, Frederick Maryland;
    Microbiological Associates Inc., Rockville, Maryland


    “EIAs for IgG and IgM antibodies directed against Ebola (EBO) viral antigens have been developed and evaluated using sera of animals and humans surviving infection with EBO viruses. The IgM capture assay detected anti-EBO (subtype Reston) antibodies in the sera of 5 of 5 experimentally infected animals at the time they succumbed to lethal infections. IgM antibodies were also detected in the serum of a human who was infected with EBO (subtype Reston) during a postmortem examination of an infected monkey. The antibody was detectable as early as day 6 after infection in experimentally infected animals and persisted for 400 days in 3 animals who survived infection, and it persisted for ∼10 years after infection in the sera of 2 humans. Although these data are limited by the number of sera available for verification, the IgM assay seems to have great promise as a diagnostic tool. Furthermore the long-term persistence of the IgG antibodies measured by this test strongly suggests that the ELISA will be useful in field investigations of EBO virus.”

    and further into the article

    “We also tested the sera of a number of humans who had been infected with strains of EBO virus isolated from the 1976 epidemic in the Democratic Republic of the Congo (DRC). The sera from 2 of these individuals were collected ∼ 10 years after they were infected with EBO. In both instances, the adjusted OD and titers were similar to those seen in the late convalescent sera of the experimental monkeys (table 1). Also shown in table 1 are ELISA data that were collected for other individuals in association with the 1976 epidemic in DRC, but specific time intervals for the collections were not known.”

    so this study found evidence that the ability to respond to the Ebola virus was still detectable in two humans ten years after their initial infection. Now if those humans were re-exposed, they might well feel sick for some period of time before their immune system ratchets up production of antibody from the old recipe it kept. Not all humans will show immune response ten years later, some might lose the recipe sooner than that.

    As I mentioned above, the amount of antibody produced increases after the initial infection in those individuals whose immune system figures out an effective antibody or two. If you monitor blood levels of antibody using titration techniques, you can graph the rise and then the fall of antibody production. So there will be a window of several days to weeks of elevated antibody production, after which continued production of large amounts of antibody becomes useless, as the disease pathogens have been cleaned up. At that point the immune system doesn’t keep up high level production of antibodies, but rather keeps some copies of the “recipe” for the antibody. But while the person is in that elevated production phase, which appears to be around three months post-infection for Ebola, they could be helping other Ebola victims without going hemorrhagic themselves.

    So the article you read may well have said “for three months”, but the whole story is more complex than can be explained in a brief news or other article as all these medical papers show.

  17. Nov. 10 ebola update:

    Dr. Craig Spencer – the patient diagnosed with Ebola and who has been treated in NYC at Bellevue since Oct. 23, has been declared cured after a “vigorous course of treatment”. He will be released from the hospital tomorrow, Nov. 11.
    “Spencer is the only confirmed case of Ebola in New York City. His fiancee, Morgan Dixon, is in quarantine at the couple’s Manhattan apartment. Quarantine has been lifted for friends who had socialized with the couple.
    As of last week, 357 people in New York City were being actively monitored for possible Ebola, most of them travelers who arrived within the past 21 days from Guinea, Liberia or Sierra Leone, the three Ebola-affected countries.
    The list also includes emergency medical staff who transported Spencer to Bellevue and those caring for him plus laboratory workers who conducted his blood test. The news of Spencer’s infection prompted New York Gov. Andrew Cuomo and New Jersey Gov. Chris Christie to announce a mandatory 21-day quarantine for travelers who have come in close contact with Ebola patients.”

  18. Nov. 14 A surgeon from Sierra Leone and a permanent resident of the United States who contracted Ebola while working in West Africa will be flown to the United States to receive treatment for the deadly virus, according to a government official. Dr. Martin Salia is expected to arrive in the United States on Saturday and will receive treatment at Nebraska Medical Center, the official told ABC News today. It is unclear how he contracted Ebola, but the official said he was in Sierra Leone at the time. …This comes two days after Dr. Craig Spencer, who contracted Ebola treating patients in West Africa, was discharged from a New York City hospital Ebola-free. Spencer, 33, who treated Ebola patients in Guinea for Doctors Without Borders, spent 20 days in isolation at Bellevue Hospital in Manhattan after testing positive for Ebola there on Oct. 23. Spencer was the fourth person to be diagnosed with Ebola in the United States and the ninth Ebola patient to be treated in this country. Only Thomas Eric Duncan, the Liberian national who was diagnosed in Dallas, Texas, in late September, has died of the virus in the United States. More than 5,000 people have died in the Ebola outbreak that is ravaging parts of West Africa, the World Health Organization reported on Wednesday. This is the largest Ebola outbreak ever recorded — the vast majority in the West African countries of Liberia, Guinea and Sierra Leone.

  19. Nov. 17:
    Surgeon flown in to Nebraska hospital dies. I could see it was too many days that he’d gone untreated. They said he’d has a false negative test for ebola a few days before testing positive. Now I wonder how many in Nebraska will have to be quarantined.

    “A statement released Monday by Nebraska Medical Center said Dr. Martin Salia “has passed away as a result of the advanced symptoms of the disease.” Hospital spokesman Taylor Wilson said Salia died shortly after 4 a.m. Monday.

    Salia, 44, was being treated in the medical center’s biocontainment unit after arriving Saturday by plane from West Africa. He was transported by ambulance to the hospital, where two other Ebola patients have been successfully treated. On Sunday officials had described his condition as “an hour-by-hour situation.”

    “Dr. Salia was extremely critical when he arrived here, and unfortunately, despite our best efforts, we weren’t able to save him,” said Dr. Phil Smith, medical director of the biocontainment unit. Salia was placed on dialysis, a ventilator and given several medications to support his organ systems. He was given the experimental drug ZMapp on Saturday. He also received a plasma transfusion from an Ebola survivor — a treatment that is believed to provide antibodies to fight the virus.”

    • I’m trying to figure out what test Salia was given. Apparently the indirect fluorescence assay has really high false positive rate?

  20. Jan 4, 2015

    A U.S. health-care worker who experienced “high-risk exposure” to Ebola in Sierra Leone is expected to arrive Sunday afternoon at a Nebraska hospital that has treated three people with the dangerous virus.
    The unnamed patient isn’t currently ill or contagious, but will be carefully monitored, said Phil Smith, medical director at the Nebraska Medical Center’s biocontainment unit in Omaha, in a statement. A hospital spokesman did not have any additional details on the patient Sunday morning.
    The patient, expected to arrive via private air ambulance, will be monitored in the same room used to treat the three confirmed Ebola patients. Among those three, missionary doctor Richard Sacra and freelance journalist Ashoka Mukpo were successfully treated and released, but surgeon Martin Salia died from the virus.

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