They wave from-a-distance thermometers, which don’t work well, I’ve heard, at people in the airport, but so what. I’m trying to decide how mad I should be at the bowling doctor; possible legal actions against him will be for another thread.
Anyway, that’s NOT this OP.
Will a person’s blood show immediate confirmation of whether the person is infected?
Spit? Excreta?
No, the earliest indicator we have is body temperature (at least according to the latest article I read on the issue). The virus doesn’t become detectable in bodily fluids until later - which is also why they’re not contagious. No virus in the fluids.
I don’t know the accuracy of the thermometers or technique they’re using in the airports. I use an Exergen Temporal Thermometer, and I use it about 23-25 times a week, on 20-22 different people. I’d say that two or three times a week I get a number I don’t believe, and I take it again, and get a number that makes more sense. If it says 93.1 and the person is talking to me, I’m pretty sure I need to recheck that one. (That’s the temperature of a fairly recently deceased body.) So, it’s pretty accurate, when coupled with come common nursing sense.
Now, I’m often distracted, talking and listening while I take vitals, so I’m sure my technique is at fault when I get a number like that, not the instrument. Those things are designed and tested and retested to be accurate “within the range of 0.2 C, resulting in correlation coefficient of 0.99 in the febrile group and 0.91 in the afebrile group, the highest scores of any of the thermometry methods.” In other words, if you’ve got a fever, it’s going to tell me you’ve got a fever. If you don’t have a fever, it might tell me you do, but probably not.
You shouldn’t be mad at him at all. He followed the correct procedures and didn’t put anyone at risk. Read this:
especially this quote:
“When Spencer did record a fever on Thursday morning, running a temperature of 100.3 degrees, he contacted Doctors Without Borders. He was in quarantine at Bellevue Hospital within two hours.”
The problem is that there is no reason to believe that fever must be present for a patient to be infectious. Or that fever must somehow be the first symptom of the disease.
He reported symptoms of fatigue TWO DAYS prior to his fever. Fatigue is a well known symptom of Ebola Virus Disease. Of course fatigue could have arisen due to excessive physical activity. Hard to say.
To answer the OP’s question… it depends on how rigorously you want to test. Viral isolation with PCR amplification is extremely sensitive and could detect just a few viral particles. But early in the viral life cycle there is not much free floating virus in the bloodstream. The virus is busy invading an array of tissues. Wait a few days and its in the blood, if there is an infection at all.
So returning medical workers or travelers from West Africa may be very reluctant to undergo lung biopsies or biopsies of other tissues just to be able to test a few days sooner.
You have promoted this view frequently and have made statements that are not accurate. But there are many reasons to have the view that fever is the primary point to know, because of the observations of actual transmissions and the non-transmissions to persons living closely with the eventual Ebola patients and this over many years.
To make this statement is false. There are many reason to believe this and no thing more than suspicions to believe otherwise. It is not a certainty, but it is a strong and good presumption.
Or a bad night of sleep or many things. The idea that “fatigue” is something you are to use as a trigger is ridiculous, it is not a clear or a quantifiable indicator. A fever is and the history of the Ebola transmissions, which is not new, strongly supports this as the earliest sign of the potential, and even then it is not strongly transmissable.
Except for 30 years of experience of treating Ebola. Can you provide a cite from any medical expert that Ebola might be transmissible without showing any symptoms?
Yes, there is good reason to believe that Ebola is not transmissible until the fever presents. There has been a fair amount of study into the lifecycle of the disease over the last 38 years, and the virus stays in the internal organs for a time before it enters fluids (which is when it can be tranmitted-- you can’t catch something that’s locked up in someone’s spleen). The fever coincides with the process by which the virus migrates to fluids.
It is not new for him to make this kind of claim, as http://boards.straightdope.com/sdmb/showpost.php?p=17731918&postcount=14
Cite?
CDC guidelines have been that a fever of 101.5°F (38.6°C) was indicative of Ebola. That has been revised to 100.4°F (38°C). Why? Because we are still learning.
Prior to the current outbreak one of the most comprehensive summaries of current knowledge about filoviral illness (Marburg and Ebola) was published in The Journal of Infectious Diseases in 2011.
With regard to fever, Kortepeter et al note
Internal citations omitted. Emphasis added
The variability of fever as a symptom of filoviral illness is illustrated by an early case of a lab worker infected by needle stick injury. In that case study included with the above referenced report the patient presented with initial fever of 37.4°C (99.3°F) reported around midnight six days after initial exposure. That is below even the recently revised CDC guidelines. The next morning subsequently complained of abdominal pain and nausea. And is temperature was normal. His temperature proceeded to swing widely through the course of his illness.
His case is certainly not unique in having wide swings in the patient’s temperature. Another lab worker was infected with Ebola subtype Tai Forest while conducting a necropsy of a chimpanzee. She complained of multiple symptoms initially including fever, chills, headache, and myalgia. Throughout the course of her illness her fever faded to below normal levels before spiking again.
Why do I focus on lab worker infections? Because those are the best studied.
But there is data from the initial 1976 Ebola outbreak. And while fever is a very common symptom of Ebola, it was not present in all patients. Cite (long PDF. Literally “the book” on Ebola. See table page 18) Fever was present in 98.1% of fatal cases and only in 58.8% of non-fatal cases with positive titers)
Iggy none of that is relevant, because even if the fever goes away for a short time there are still other symptoms presenting before the patient is infectious.
MSF guidelines for returning medical workers involve them going into quarantine if they show any symptoms, not just fever. Again do you have any cite to show that someone can be infectious WITHOUT SHOWING ANY SYMPTOMS ?
My issue is the focus on fever as a symptom to exclusion of recognizing the importance of other symptoms.
A patient with a cough, runny nose, headahces, and bodyaches might very well be diagnosed with influenza even in the absence of fever. That is not surprising, even though fever is a well accepted symptom of influenza.
Not every patient has every symptom of a disease. And when a new disease presents itself doctors are not always certain what are symptoms caused by the disease and what is just normal variation across a patient population.
Fever is, of course, an important and well recognized symptom of Ebola Virus Disease. But if you are going to set up screening questions to try to detect potential patients I do think it would be improper to dismiss consideration of any person with various symptoms and travel history indicative of Ebola risk but who is afebrile. The returning medical worker just coming back from Guinea who complains of headache and muscle pain but who lacks a fever should, IMHO, be evaluated clinically.
Agreed. And they are. Everyone is screened for contact and the symptoms you mention - which are imperfect tests, because people are lying liars who lie - as well as being tested for fever, which is harder (but not impossible) to conceal. There is no “exclusion of other symptoms.” There’s exposure risk, other symptoms AND fever. At the end of the day, there is no perfect system; but the fever rubric is the best sign, as opposed to symptom. It’s the least prone to error and false positive sign *or *symptom that we have for mass screening right now, but we are still looking for symptoms.
Hopefully that will change in the near future and we’ll have something better. Changing rubrics is not a bad thing; it’s not a sign that we didn’t have a clue last week, it’s a sign that we’ve learned more and have a better clue this week. Surely you don’t want us to keep the cutoff at 101.5 just to save face, when we learn new important information, do you?
The latest nurse didn’t even have *any *of the symptoms you mentioned and she found herself locked up. Just being in contact with Ebola patients was enough to trigger the quarantine protocol, which is ridiculous and counter productive. How are we supposed to get health care workers to volunteer to go over there and fight this thing if we treat them like criminals and destroy their ability to make a paycheck when they get home?
To quote myself:
I surmise that, based upon the literature, that fever need not be the first symptom of Ebola Virus Disease. That is supported clearly in the literature by documented cases of patients who tested positive, became ill, but remained afebrile. Rare, but it happens.
I have no reason to believe such patients can (or cannot) be infectious to others. Lack of data. Safer to assume they might be infectious. I certainly would assume any patient who is currently ill and has tested positive is potentially infectious even if they do not have a fever at the moment.
As the LA Times article discussed, being asymptomatic is a bit of a touchy line. We just don’t have definitive data. We have lots of observations indicating something is unlikely. But impossible?
As Dr Philip Russel stated, “Being dogmatic is, I think, ill-advised, because there are too many unknowns here.”
Taking the case of Dr. Spencer in NYC. Various news outlets have reported he “felt sluggish” or “fatigue” or “fatigue and exhaustion” in the two days prior to having a 100.3°F fever.
How do we know he was not infectious prior to having that low grade fever? He went on a three mile jog during that time. I know I would be sweating. Was he shedding viral particles in his sweat? Or maybe he wasn’t yet. No test. No data.
As you say there is no data, which means there is no recorded case of an asymptomatic person transmitting Ebola.
In this case too much caution is a bad thing, because its not free. The price for locking up all medical staff who return from West Africa is the thousands of lives that won’t be saved. Put that up against the minuscule chance of an asymptomatic medical worker transmitting the disease to one or two people.
I assume you are referring to the Newark, NJ incident. A report I read indicated one reading of a “fever” well after she had been pulled aside for questioning. She asked to be checked with an oral thermometer but that didn’t happen. She argued, quite correctly it seems, that the thermal thermometer reading may have been off due to her feeling flushed (and possibly rather aggravated?) with the whole experience.
Yes, we need concise protocols. Front line personnel should be trained. But I do recognize that not every front line immigration of customs officer may fully understand the nuances of Ebola. Passing such cases on to a supervisor or CDC representative for secondary screening is reasonable. Unfortunately it seems the secondary screening was also conducted by those who don’t seem to have a good grasp on things.
But there is no good reason why that secondary screening should last for hours. A few questions and a temperature check with a decent thermometer along with some basic observations skills (Gee… is the traveler vomiting now? Any signs of bleeding?). If all is well, then on your way in 5 minutes tops.
I’m saying there is no data that tells us when exactly a person contracted Ebola* and the symptoms, if any, the transmitting party may have had at the time. Absence of evidence is not evidence of absence.
Absent a recent known exposure there just isn’t a good enough reason to impose the inconvenience and expense of intrusive monitoring.
So what to do for retuning medical workers and travelers from the affected region?
Take their temperature? Sure. Temporarily bar them from donating blood? Sure. Monitor for signs/symptoms of illness? OK. Periodic blood test? Maybe. Biopsy a lung for PCR viral analysis? No way. The response has to be rationale and proportionate to the risk.
Indeed, there is a societal cost to any approach taken. And MSF is desperate for qualified medical personnel to treat patients. As I understand it many of their volunteers travel for a relatively short time. Expecting them to add a three week quarantine to their commitment may indeed be asking too much. But perhaps a three week monitoring regimen that does not impose quarantine unless/until symptoms appear?
There is new test; any thoughts?
http://www.reuters.com/article/2014/10/25/health-ebola-usa-fda-idUSL2N0SK0US20141025
I can’t get the link to open on my phone. Does it say how early in the infectious process it can be used with accurate results?
That’s pretty much a crap cite.
ok then give me a cite that gives some evidence that Craig Spencer was at risk of infecting anyone before he had any symptoms.