By Zach Segal, Published Nov 18, 2020, 11:50am EST
(Info+)
Fever cameras have emerged as an indirect and flawed way to test for coronavirus. But what about actual coronavirus tests that directly test for the disease?
Inside this note, IPVM examines the 5 main types of coronavirus testing options:
PCR/Molecular
Rapid PCR
Saliva Based Molecular
Antigen
Antibody
We explain how they work, how long it takes to get results, how much they cost, how widely available they are, and what the projections are for improvements in such testing.
Can actual coronavirus testing provide a better solution than fever cameras? We examine inside.
I understand the chart lists diagnostic tests only. Meanwhile the article opens with the statement that fever cameras are an indirect and flawed way to test for coronavirus.
It would still be useful to include fever cameras and non-contact thermometer in a chart versus diagnostic testing that expresses the differences. It would be an eye opener for many decision makers.
Perhaps your Unhelpful clicker can be found in a deeper analysis of corona virus testing that may be pertinent to a brown eye opener? Hint: trying to make a pun here.
Great post, Zach! Quite a few countries (including Russia, but not Mexico, for example) are currently requiring travelers to present negative PCR tests to gain admission. (Here is a great CNN article on the topic as it relates to U.S. citizens, it was updated at least once in July but has not been revised in over two weeks.)
The time lag that you have mentioned is a hindrance to would-be travelers, with border officials requesting test results not older than 72 or in some cases 48 hours upon arrival.
If this is true, and I must admit I have seen other studies that say similar, then this makes 'fever cameras' one of the greatest cons of the century.
Assume that 80% of infected people do not have a sufficiently raised temperature to trigger a 'fever camera'. That leaves at most 20% who could be detected.
The incorrect implementation of many (most?) 'fever cameras' means their efficiency is further reduced, as a guess by 50% or more. This leaves at best a 10% catch rate. This is further reduced because some people have a naturally lower body temperature & when they have a fever their temp just goes up to what is considered to be the normal range.
As an industry would we accept video analytics that only works 10% of the time? Would we accept a camera install that only records 10% of the time?
As a workplace safety scenario, would we accept a safety barrier that only stopped 10% of people falling in a hole?
John and I have had this conversation several times. Applying the reasoning stated above, if there are 100 people in a group of 1,000 who have coronavirus and you have the option of catching 10 of them or none of them at all, which option would you choose?
Unfortunately, given the nature of the virus, many people are more than happy to invest thousands of dollars into a solution such as 'fever' cameras just for the sake of possibly catching those 10 infected individuals.
Actually I agree with you Robert, it is better to catch those 10. However the marketing BS with 'fever cameras' implies a match greater success rate than can possibly be attained in the real world.
Thus I feel almost every person marketing or selling fever cameras is lying to the end users, either by omitting to tell the full story, or by making outright fraudulent claims.
I completely agree with you. If a large private company wanted to buy 100 'fever' cameras and aim them at the ceiling or floor, then that would not be too newsworthy.
The public is being sold the myth that these cameras will catch anyone who ventures outside with even a slight fever, where in reality the odds are probably closer to the 1/10 that you mention above, if that.
On the serious side - this is a really great article Zach. The stories out there make some tests seem highly inaccurate (via false positives and negatives). It is good to have some useful to context to which tests are accurate and which are hygiene theater.
I think the key is rapid results, cheap, and easy to admin. I have two friends who may have been exposed, they had to wait for the possible carrier to get results before they got tested, so several days of lost time.
We have a customer locally working on the saliva test for that past few months. They used their own employees on a weekly basis for testing the "test". From what I hear it looks promising. The one issue I heard from someone who has done the saliva test is being able to actually produce enough saliva for the test. You have to not eat or drink anything for 30 minutes before you give the sample.
I got the traditional, "Let's Probe Your Brain Test", last week as I had several symptoms for a few of days and had attended a wedding the week prior. I wore a mask the whole time except to eat or drink. The venue IMO was way too small for the amount of people. I also have a new grandbaby coming any day now so it made sense to go ahead with the test. Fortunately the test came back negative.
Good news is that all these tests will get better and better as more testing is done and more samples are generated and evaluated.
Each attendee stopped at a security desk at the front entrance to hand over various waivers and medical declarations. Then we proceeded into a testing room for the coronavirus nasal swab. My results came back -- negative -- in 23 minutes. This was apparently an antigen test -- slightly less accurate than the more common PCR molecular test, prone to a few false negative results, but obviously much faster. We all wore masks for the remainder of our time in the drawing room.
Another Update, Abbott announced a fast (15 minutes) - $5 antigen test, that doesn't require lab equipment. They are currently ramping up production to produce 50 million tests a month and have Emergency Use Authorization from the FDA.
It is nasal swab based, so for accurate testing a medical professional will need to take the swab. This could be used at airports, drs offices, etc. You could also have a nurse go door to door through a university dorm or large apartment complex as well.The cost and lack of lab equiptment is very helpful.
I've updated the article to include information on the Debate over what should count as a positive PCR result. Many argue that the threshold is too low, and no-longer contagious individuals are getting positive test results.
I have updated the article because the U.S. Government has purchased 150 million rapid antigen tests to increase the coronavirus testing capabilities of the United States. According to Abbot, the manufacturer, they take 15 minutes, agree with PCRT tests 97% of the time, and require a shallow nose swab. These tests are only approved on people with symptoms.
This is kind of funny because back in March, fake detection apps were one of the first types of coronavirus-related malware. I actually warned all my coworkers to avoid coronavirus detection apps because phones are just phones, duh. Of course that was back when fever detection seemed viable. Amazing how things change.
It would be really nice if this audio test works out. Still almost seems too good to be true.
Update: We have added an explanation of how someone would be tested in Bethlehem, PA, USA; where IPVM's testing facilities are located; as an example of how someone could find out how to be tested.
We have updated the article to add that the FDA has authorized the first at-home rapid test from Lucira Health. Lucira says results should take 30 minutes once the test arrives, but it needs to be prescribed by a doctor and delivered, both of which take time. Also, it is a nasal swab test, and while lab accuracy was high, self-collected nasal swabs have been found to be less accurate than professionally collected swabs due to improper techniques.
In a new Times article, a Harvard epidemiologist is arguing for mass distribution of antigen testing, key quotes:
To win the war on COVID-19, we need a multi-pronged public health strategy that includes a national testing plan that utilizes widespread frequent rapid antigen tests to stop the spread of the virus.
Paper-strip antigen tests are inexpensive, simple to manufacture, give results within minutes, and can be used within the privacy of our own home
If only 50% of the population tested themselves in this way every 4 days, we can achieve vaccine-like “herd effects” (which is when onward transmission of the virus across the population cannot sustain itself—like taking fuel from a fire—and the outbreak collapses). Unlike vaccines, which stop onward transmission through immunity, testing can do this by giving people the tools to know, in real-time, that they are contagious and thus stop themselves from unknowingly spreading to others.
He also argues that the FDA is having difficulty approving / clearing it:
However, in the U.S., the FDA hasn’t figured out a way to authorize the at-home rapid antigen tests because the FDA is used to regulating medical devices, not public health screening tools.
Interestingly, in a CNN interview earlier this year, he compared antigen testing to temperature measurement as a better alternative to rapid, accurate screening:
All this noted, evidently, despite his advocacy, I don't see signs of widespread antigen testing being close.
Each kit, which tests a single swab sample, is expected to cost about $30 or less
Ellume’s test starts with a self-collected nasal swab. (Children younger than 16 must be swabbed by an adult.) Plugged into a cartridge, the sample is analyzed, then the data is pinged to a smartphone via Bluetooth. The results go to the person taking the test, and can be shared with health care providers and public health authorities.
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Comments (32)
Dwayne Cooney
I understand the chart lists diagnostic tests only. Meanwhile the article opens with the statement that fever cameras are an indirect and flawed way to test for coronavirus.
It would still be useful to include fever cameras and non-contact thermometer in a chart versus diagnostic testing that expresses the differences. It would be an eye opener for many decision makers.
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Robert Wren Gordon
Great post, Zach! Quite a few countries (including Russia, but not Mexico, for example) are currently requiring travelers to present negative PCR tests to gain admission. (Here is a great CNN article on the topic as it relates to U.S. citizens, it was updated at least once in July but has not been revised in over two weeks.)
These international destinations are still open to US tourists | CNN Travel
The time lag that you have mentioned is a hindrance to would-be travelers, with border officials requesting test results not older than 72 or in some cases 48 hours upon arrival.
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Undisclosed Distributor #1
"And the WHO estimates that roughly 80% of people have mild cases or are asymptomatic."
If this is true, and I must admit I have seen other studies that say similar, then this makes 'fever cameras' one of the greatest cons of the century.
Assume that 80% of infected people do not have a sufficiently raised temperature to trigger a 'fever camera'. That leaves at most 20% who could be detected.
The incorrect implementation of many (most?) 'fever cameras' means their efficiency is further reduced, as a guess by 50% or more. This leaves at best a 10% catch rate. This is further reduced because some people have a naturally lower body temperature & when they have a fever their temp just goes up to what is considered to be the normal range.
As an industry would we accept video analytics that only works 10% of the time? Would we accept a camera install that only records 10% of the time?
As a workplace safety scenario, would we accept a safety barrier that only stopped 10% of people falling in a hole?
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Undisclosed Integrator #2
I'm going to wait to see what Theranos brings to the table.
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Jerome Miller
I think the key is rapid results, cheap, and easy to admin. I have two friends who may have been exposed, they had to wait for the possible carrier to get results before they got tested, so several days of lost time.
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Zach Segal
We've updated the post to include a paragraph on SalivaDirect's emergency reauthorization by the FDA and how it's being tested further by the NBA.
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Shannon Davis
We have a customer locally working on the saliva test for that past few months. They used their own employees on a weekly basis for testing the "test". From what I hear it looks promising. The one issue I heard from someone who has done the saliva test is being able to actually produce enough saliva for the test. You have to not eat or drink anything for 30 minutes before you give the sample.
I got the traditional, "Let's Probe Your Brain Test", last week as I had several symptoms for a few of days and had attended a wedding the week prior. I wore a mask the whole time except to eat or drink. The venue IMO was way too small for the amount of people. I also have a new grandbaby coming any day now so it made sense to go ahead with the test. Fortunately the test came back negative.
Good news is that all these tests will get better and better as more testing is done and more samples are generated and evaluated.
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Zach Segal
The NBA used Antigen tests for participants in the NBA draft. We did not reach out to the NBA to ask why they went with Antigen testing instead of saliva-based molecular testing, but it is interesting to note.
The author described the process:
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Zach Segal
Another Update, Abbott announced a fast (15 minutes) - $5 antigen test, that doesn't require lab equipment. They are currently ramping up production to produce 50 million tests a month and have Emergency Use Authorization from the FDA.
Create New Topic
Zach Segal
I've updated the article to include information on the Debate over what should count as a positive PCR result. Many argue that the threshold is too low, and no-longer contagious individuals are getting positive test results.
Create New Topic
Zach Segal
I have updated the article because the U.S. Government has purchased 150 million rapid antigen tests to increase the coronavirus testing capabilities of the United States. According to Abbot, the manufacturer, they take 15 minutes, agree with PCRT tests 97% of the time, and require a shallow nose swab. These tests are only approved on people with symptoms.
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Zach Segal
Update: An MIT team has created a cough based test that has achieved ~97% accuracy at diagnosing cases and works on asymptomatic carriers. The test uses audio of a forced cough and can be collected remotely without trained experts.
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Zach Segal
Update November 9th, 2020: More at-home tests are available in the U.S., 9 companies, up from 8 in August. And more tests of various kinds have received FDA emergency use authorization. There are currently 7 antigen tests with FDA Emergency Use Authorization. 3 of which were approved in October. The FDA has approved test pooling, where samples are combined and only tested individually if the combined test comes back positive, to increase testing capabilities. However, high positive rates have made this practice counterproductive as too many pools have to be retested individually. Slovakia and the UK are using rapid antigen tests for mass testing. And airports around the world are offering coronavirus testing for safety, passenger peace of mind, and to help passengers meet entry requirements.
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Zach Segal
Update: We have added an explanation of how someone would be tested in Bethlehem, PA, USA; where IPVM's testing facilities are located; as an example of how someone could find out how to be tested.
Create New Topic
Zach Segal
We have updated the article to add that the FDA has authorized the first at-home rapid test from Lucira Health. Lucira says results should take 30 minutes once the test arrives, but it needs to be prescribed by a doctor and delivered, both of which take time. Also, it is a nasal swab test, and while lab accuracy was high, self-collected nasal swabs have been found to be less accurate than professionally collected swabs due to improper techniques.
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John Honovich
In a new Times article, a Harvard epidemiologist is arguing for mass distribution of antigen testing, key quotes:
He also argues that the FDA is having difficulty approving / clearing it:
Interestingly, in a CNN interview earlier this year, he compared antigen testing to temperature measurement as a better alternative to rapid, accurate screening:
All this noted, evidently, despite his advocacy, I don't see signs of widespread antigen testing being close.
Create New Topic
John Honovich
Update: Coronavirus (COVID-19) Update: FDA Authorizes Antigen Test as First Over-the-Counter Fully At-Home Diagnostic Test for COVID-19 | FDA
Company press release: FDA authorizes Ellume COVID-19 Home Test as First Over-the-Counter Fully At-Home Diagnostic Test | Ellume
NY Times coverage: New At-Home Covid Test Gets Green Light From F.D.A. - The New York Times, excerpt:
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