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.)
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.
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.
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.