4 ms·

Part of the reason for that threshold is that Ebola is only transmissible (based on current evidence) when the patient is "symptomatic". If the threshold was s

Part of the reason for that threshold is that Ebola is only transmissible (based on current evidence) when the patient is "symptomatic". If the threshold was set too low, then the screening process would have too many false positives and potentially overburden it beyond being effective at all.

anigbrowl 12y ago
Cost of a false positive here would have been a nurse who was inconvenienced. Cost of a false negative is at a minimum the time and expense of contact-tracking 132 people who flew with her, the cost to the airline of taking the plane out of service (which they've already done), and a severe drop of public confidence in the CDC. The pane made 5 more flights before it was taken out of service: http://www.latimes.com/business/la-fi-frontier-airline-ebola-patient-20141015-story.html http://www.latimes.com/business/la-fi-frontier-airline-ebola... Now, the chances that anyone else on the same flight got infected is very very low, close to zero. That's even more true for the people who took other flights on the same plane, even the people who were sitting in the same seat that she sat in - though it's non-zero, as I doubt the airline disinfects the armrests and fold-down trays after every single flight. But just doing the contact tracking and being prepared to field telephone and email inquiries from all the other people who traveled on that plane with and after the nurse did is going to consume a bunch of CDC resources that could be better spent elsewhere. Meanwhile, it seems that staff at the hospital were not wearing adequate protective gear for the first 2 days after Duncan was admitted until they got a positive blood test for Ebola: http://thescoopblog.dallasnews.com/2014/10/presbyterian-workers-wore-no-protective-gear-for-two-days-while-treating-ebola-patient.html/ http://thescoopblog.dallasnews.com/2014/10/presbyterian-work... False positives are bad but IMHO they're a lot cheaper than false negatives. When dealing with the limited subset of people who had contact with known Ebola carrier at the Texas hospital (a total of 76 medical personnel AFAIK), the slight economic cost of limiting travel and monitoring all of them for a few weeks seems low compared to the new situation.
- JoeAltmaier 12y ago
  If its only one, sure. How many people on that plane had temperatures around 99? Half a dozen? From flu or hot coffee or too much sun? If half a dozen people are kept off of every plane and quarantined, that's thousand of people a day. That's an overburdened health care staff. I have more sympathy for the problem.
  - anigbrowl 12y ago
    You seem to be talking about airport screening for everyone boarding planes. I'm talking about a nurse who already knew she had spent days treating a patient who died from Ebola and who made several telephone calls to the CDC advising them that she felt feverish, who at a hospital that had already screwed up badly when that patient first presented, and whose administrators changed their story about this multiple times. How you manage to ignore these additional risk factors and conclude that I was talking about screen all fliers is just beyond me. I believe I made the context abundantly clear: When dealing with the limited subset of people who had contact with known Ebola carrier at the Texas hospital (a total of 76 medical personnel AFAIK), the slight economic cost of limiting travel and monitoring all of them for a few weeks seems low compared to the new situation.
    - itengelhardt 12y ago
      I'm not necessarily disagreeing with you, but taking away the freedom of movement (among others) of 76 people (potentially many more now) without proof is severe. I believe it to be a good sign for the republic that the government has not resorted to do so.
      - SapphireSun 12y ago
        Actually according to this article, the nurse was not supposed to be on public transit at all (cars / charter planes OK, commercial airlines no). It just seems that enforcement was lax. http://www.nytimes.com/2014/10/16/us/ebola-outbreak-texas.html?hp&action=click&pgtype=Homepage&version=LedeSum&module=first-column-region&region=top-news&WT.nav=top-news http://www.nytimes.com/2014/10/16/us/ebola-outbreak-texas.ht...
- baddox 12y ago
  > Cost of a false positive here would have been a nurse who was inconvenienced. Cost of a false negative is at a minimum the time and expense of contact-tracking 132 people who flew with her, the cost to the airline of taking the plane out of service (which they've already done), and a severe drop of public confidence in the CDC. Perhaps the cost of allowing a lot of personal discretion from the CDC workers who make these decisions would be even higher than either.
  - hga 12y ago
    Little "discretion" applied here, from reports. The drone at the CDC looked it up, 100.4 F is the official threshold, and gave her the all clear without taking a step back and saying, hey, let's be extra cautious for her class of close contact (can't quite say "exposed" at that time).
    - baddox 12y ago
      What's the distribution of human body temperatures? I don't know, but it's at least plausible that invoking the restrictive policies for body temperatures below the official threshold would, in the long term, be more costly than strictly enforcing the official threshold.
JamesSwift 12y ago
If the threshold was set too low, then the screening process would have too many false positives and potentially overburden it beyond being effective at all. While I completely understand where you are coming from, I have to completely disagree on the grounds that we are talking about a single person here. We literally only care about this single person at this point time, and their actions could significantly affect the entire US prognosis in the immediate term. When we are so laser focused, there is no excuse for not being absolutely 100% careful for 21 days.

anigbrowl 12y ago

Cost of a false positive here would have been a nurse who was inconvenienced. Cost of a false negative is at a minimum the time and expense of contact-tracking 132 people who flew with her, the cost to the airline of taking the plane out of service (which they've already done), and a severe drop of public confidence in the CDC. The pane made 5 more flights before it was taken out of service: http://www.latimes.com/business/la-fi-frontier-airline-ebola-patient-20141015-story.html http://www.latimes.com/business/la-fi-frontier-airline-ebola... Now, the chances that anyone else on the same flight got infected is very very low, close to zero. That's even more true for the people who took other flights on the same plane, even the people who were sitting in the same seat that she sat in - though it's non-zero, as I doubt the airline disinfects the armrests and fold-down trays after every single flight. But just doing the contact tracking and being prepared to field telephone and email inquiries from all the other people who traveled on that plane with and after the nurse did is going to consume a bunch of CDC resources that could be better spent elsewhere. Meanwhile, it seems that staff at the hospital were not wearing adequate protective gear for the first 2 days after Duncan was admitted until they got a positive blood test for Ebola: http://thescoopblog.dallasnews.com/2014/10/presbyterian-workers-wore-no-protective-gear-for-two-days-while-treating-ebola-patient.html/ http://thescoopblog.dallasnews.com/2014/10/presbyterian-work... False positives are bad but IMHO they're a lot cheaper than false negatives. When dealing with the limited subset of people who had contact with known Ebola carrier at the Texas hospital (a total of 76 medical personnel AFAIK), the slight economic cost of limiting travel and monitoring all of them for a few weeks seems low compared to the new situation.

JoeAltmaier 12y ago
If its only one, sure. How many people on that plane had temperatures around 99? Half a dozen? From flu or hot coffee or too much sun? If half a dozen people are kept off of every plane and quarantined, that's thousand of people a day. That's an overburdened health care staff. I have more sympathy for the problem.
- anigbrowl 12y ago
  You seem to be talking about airport screening for everyone boarding planes. I'm talking about a nurse who already knew she had spent days treating a patient who died from Ebola and who made several telephone calls to the CDC advising them that she felt feverish, who at a hospital that had already screwed up badly when that patient first presented, and whose administrators changed their story about this multiple times. How you manage to ignore these additional risk factors and conclude that I was talking about screen all fliers is just beyond me. I believe I made the context abundantly clear: When dealing with the limited subset of people who had contact with known Ebola carrier at the Texas hospital (a total of 76 medical personnel AFAIK), the slight economic cost of limiting travel and monitoring all of them for a few weeks seems low compared to the new situation.
  - itengelhardt 12y ago
    I'm not necessarily disagreeing with you, but taking away the freedom of movement (among others) of 76 people (potentially many more now) without proof is severe. I believe it to be a good sign for the republic that the government has not resorted to do so.
    - SapphireSun 12y ago
      Actually according to this article, the nurse was not supposed to be on public transit at all (cars / charter planes OK, commercial airlines no). It just seems that enforcement was lax. http://www.nytimes.com/2014/10/16/us/ebola-outbreak-texas.html?hp&action=click&pgtype=Homepage&version=LedeSum&module=first-column-region&region=top-news&WT.nav=top-news http://www.nytimes.com/2014/10/16/us/ebola-outbreak-texas.ht...
baddox 12y ago
> Cost of a false positive here would have been a nurse who was inconvenienced. Cost of a false negative is at a minimum the time and expense of contact-tracking 132 people who flew with her, the cost to the airline of taking the plane out of service (which they've already done), and a severe drop of public confidence in the CDC. Perhaps the cost of allowing a lot of personal discretion from the CDC workers who make these decisions would be even higher than either.
- hga 12y ago
  Little "discretion" applied here, from reports. The drone at the CDC looked it up, 100.4 F is the official threshold, and gave her the all clear without taking a step back and saying, hey, let's be extra cautious for her class of close contact (can't quite say "exposed" at that time).
  - baddox 12y ago
    What's the distribution of human body temperatures? I don't know, but it's at least plausible that invoking the restrictive policies for body temperatures below the official threshold would, in the long term, be more costly than strictly enforcing the official threshold.

JamesSwift 12y ago

If the threshold was set too low, then the screening process would have too many false positives and potentially overburden it beyond being effective at all. While I completely understand where you are coming from, I have to completely disagree on the grounds that we are talking about a single person here. We literally only care about this single person at this point time, and their actions could significantly affect the entire US prognosis in the immediate term. When we are so laser focused, there is no excuse for not being absolutely 100% careful for 21 days.