What is the point of COVID testing?

[mountainsoft]

I keep hearing how more testing is needed before life can return to normal. But I don't understand what the point of more testing is?

If I'm tested and discover I'm infected (either with no symptoms, or obvious because I've already been sick) what does that mean? Am I free to roam the streets because I can't get it again. That has yet to be proven. Am I labeled "infected" and banned from places that have no infections, such as visiting someone in an assisted living home? Will we have a segregated society, one restaurant for infected individuals, and one for the uninfected? We don't serve your kind here?

If I'm tested and it comes back negative, who's to say I won't be infected tomorrow or next week?

Sorry, I'm not trying to be dense, I just don't see what more testing is supposed to achieve. Common sense would say that until there's a vaccine, or the majority of people have already had the virus, someone will always be at risk.

Somewhere I am missing the goal of increased testing...

 

[martyp]

If you get an rtPCR test and it is positive then it means you are currently infectious. This is a very accurate test.

I think the antibody tests are useful for epidemiologists to understand the spread of the disease in the greater population. That could be useful for general policy decisions. The error rates of the current tests may be too great to confidently provide an individual knowledge of whether they have previously been infected and whether they are at risk for subsequent infection.

The question for you is what would you do if you knew the test had a 5% error rate? Would you visit your 90 year old mother? Plan a wedding? Go back to work as a teacher? Go get your teeth cleaned at the dentist?

A huge issue is what will government and businesses do with that information? If they say you can go back to work will that affect your unemployment benefits? What if you don’t feel safe to return to work? Who is liable if you do get sick when returning to work?

 

[Alan]

The UK has started a trial which I expect other countries will also be doing, if not the same, but similar trials. They have written to 20,000 households and asked if they would be willing to join a scheme where some of the households will be blood tested for the presence of Covid every week for a month while the rest will be tested for Covid every month for a year. The data collected will be analyzed by epidemiologists.

There is still so much to be learned about who has it, who catches it, symptoms, no symptoms, reinfection rates etc.

 

[Amethyst]

This. Plus data collection's potential usefulness for understanding this previously unknown disease. Data can often be the mother of discovery.

But day-to-day usefulness is, as OP says, rather elusive.

A huge issue is what will government and businesses do with that information? If they say you can go back to work will that affect your unemployment benefits? What if you don’t feel safe to return to work? Who is liable if you do get sick when returning to work?

 

[audreyh1]

The reason testing is so important is because it’s used along with contact tracing to manage outbreaks as society tries to get back to normal - “open back up”, get back to work, etc. We need to keep workplaces safe, and know if health care workers and first responders have been exposed so that they don’t expose others. We need to know when an infection occurs in a nursing home or elder care home. Without this we are faced with rampant spread and we already know it can be fast.

If outbreaks get out of control again, we might have to shut things down again or face hospitals being overwhelmed. I guess some folks really have trouble understanding that last point.

 

[donheff]

The antibody tests are of use in estimating spread but may be limited as "go to work free" cards since they can toss off significant numbers of false reports. The DNA tests used to confirm active infections are very accurate. The "testing. testing, testing" mantra is always combined with tracing, and containment. The idea is that once community spread is tamped down to a trickle by isolation we can start going back to work. When an active infection is detected, quick contact tracing could identify others that are infected (including contacts that show no symptoms). With enough rapid testing available, and with decent contact tracing by people and/or technology. this would catch clusters of infection before they become raging fires.

Or so the theory goes. The impression I have gotten from media reports (subject to correction by others who have better info) is that countries who have been successful in holding rates down are doing this.

 

[martyp]

The reason testing is so important is because it’s used along with contact tracing to manage outbreaks as society tries to get back to normal - “open back up”, get back to work, etc. We need to keep workplaces safe, and know if health care workers and first responders have been exposed so that they don’t expose others. We need to know when an infection occurs in a nursing home or elder care home. Without this we are faced with rampant spread and we already know it can be fast.

If outbreaks get out of control again, we might have to shut things down again or face hospitals being overwhelmed. I guess some folks really have trouble understanding that last point.

The problem right now is that you can’t do rtPCR tests to test the general population. There are not enough tests. In addition, an rtPCR test only tests to see if you are actively infectious which is about a 1-4 week window while you are sick. It is the test they will use to monitor patients and those identified as contacts through contact tracing.

An antibody test should tell you if you had been previously infected. This would be great news for those who were infected but didn’t know it at the time. These tests should be fast and cheap. Everyone would like to think that if they have antibodies then they have a passport to work and to rejoin society. However, no one knows if having antibodies will give you immunity and for how long. In addition, there are dozens of unregulated tests on the market and most of them have pretty high error rates of false positives and false negatives. It is not clear how an individual or a business can make decisions based on error prone tests for a highly infectious, often asymptomatic, disease.

 

[audreyh1]

Tests are being used for health care workers and in nursing homes. Seems like efforts are being made to get as many tests available as possible. Identifying who is currently sick is still very important to control the spread. That’s why the goal is to keep increasing the tests available so that contact tracing is viable.

 

[Aerides]

But I don't understand what the point of more testing is?

Testing isn't about you, or me, but us. It's about knowing if there are 3 cases in your state, or 30,000. About whether we need more medical capacity or less, and whether we can ease social distancing or not. Is it growing or subsiding?

Testing is almost meaningless to a person, but it's incredibly meaningful to a community.

And as far as this part...

Am I labeled "infected" and banned from places that have no infections, such as visiting someone in an assisted living home? Will we have a segregated society, one restaurant for infected individuals, and one for the uninfected? We don't serve your kind here?

What? Why would you think that - is anybody labeled or banned now? Of course if you are sick you should stay home, period, test or no test. But if you are healthy, either never sick or recovered, you go about your life as it best makes sense for you.

 

[easysurfer]

The more pressing question I have is where is the push to get everyone (well, as close as possible to everyone) tested?

Saw on the evening news last night that NY is hoping to get testing available at places like CVS. Had me asking, what took so long as I'd think that should've been the very first strategy.

 

[audreyh1]

Saw on the evening news last night that NY is hoping to get testing available at places like CVS. Had me asking, what took so long as I'd think that should've been the very first strategy.

I think that simply reflects how difficult a problem this has been for the US to solve, and yes, I suspect it wasn’t taken seriously early enough to make an all out effort and we are now desperately trying to catch up.

 

[LOL!]

To the OP:

If you were tested and shown to be an asymptomatic person infected with coronavirus, then would you change your behavior at all?

Also do you live with anyone else in the same household?

If you found out that half (10%, 25%, 50%, 90%?) of the people that were in the grocery store or at work with you were infected with coronavirus, then what would you do?

If you found out that no one within 200 (5, 25, 100?) miles of you was infected, then what would you do?

 

[Independent]

I keep hearing how more testing is needed before life can return to normal. But I don't understand what the point of more testing is?

You seem to be conflating two different types of tests.

The nasal swabs tests labs are running today look for virus RNA. A positive tells you that you're currently infected and probably contagious. The definite result is that you need to get away from other people, even if you don't feel symptoms.

The blood antibody tests that we hope to have in the near future say that you've had the virus and your immune system built antibodies that are specific to this virus. Ideally, they tell you that you have at least temporary practical immunity. You don't need to worry about catching it again or about infecting other people.

 

[eytonxav]

One thing that is interesting to note, is looking at two neighboring countries, Sweden and Norway. Sweden never did any lockdowns, while Norway did. Both have similar results in terms of deaths and hospitalizations as a percent of the total population. Sweden's economy kept going strong, while Norway's took a big hit. Looking at California, the % of hospitalizations and deaths based on the total population is very low after they did some antibody testing and extrapolation. Nothing like what Fauci and Birks were originally projecting. Therefore, some Drs have suggested based on antibody testing that a large % of the population has already been infected without much impact, and that the current strategy should be shifted to allow the elderly and those with comorbitities to continue sheltering in place while everyone else returns to work. If everyone remains sheltered, our immune systems will suffer, as being out in the world and exposed helps build ones immunity to many of the bad bacterias and viruses that are out there. I can definitely see more antibody testing making the experts more comfortable with a much more relaxed sheltering strategy and getting our economy back.

 

[mountainsoft]

Testing isn't about you, or me, but us. It's about knowing if there are 3 cases in your state, or 30,000. About whether we need more medical capacity or less, and whether we can ease social distancing or not. Is it growing or subsiding? Testing is almost meaningless to a person, but it's incredibly meaningful to a community.

That's probably the best reasoning I've read so far. Thanks.

What? Why would you think that - is anybody labeled or banned now?

I've seen too many science fiction movies...

 

[Independent]

For people interested in the accuracy of antibody tests, a group of researchers in San Francisco have been testing the tests -- running a dozen tests against the same blood samples.

Unfortunately, none are perfect. Encouragingly, some are pretty good.

NYT article: https://www.nytimes.com/2020/04/24/health/coronavirus-antibody-tests.html
Pre-print paper: https://covidtestingproject.org/

One test had no false positives on 108 blood samples known to be negative.

The project itself is a fascinating example of working under time pressure.

For the past few weeks, more than 50 scientists have been working diligently to do something that the Food and Drug Administration mostly has not: Verifying that 14 coronavirus antibody tests now on the market actually deliver accurate results.

... The new research, completed just days ago and posted online Friday, confirmed some of those fears: Of the 14 tests, only three delivered consistently reliable results. Even the best had some flaws.

... The researchers worked around the clock, in shifts of three to five hours, hoping to stave off weariness and keep their minds sharp for the delicate task.

They set up lines of laboratory volunteers: medical residents, postdoctoral students, even experienced veterans of science, each handling a specific task.

The researchers created a biosafety-certified space, obtained the needed approvals and procured hundreds of blood samples from two Bay Area hospitals.

They also purchased tests from Chinese manufacturers, clearing customs regulations and sometimes accepting Uber deliveries in the middle of the night

.

The paper has some neat graphics for the analytical types here.

 

[Rianne]

If everyone remains sheltered, our immune systems will suffer, as being out in the world and exposed helps build ones immunity to many of the bad bacterias and viruses that are out there.

That's the conundrum. I believe it is necessary to develop strong immune system, one must be exposed to a variety of bacteria, virus, germs etc. This virus makes me uncomfortable because it is so contagious. And we have 0 antibodies to fight it. I don't know if gradual exposure is possible. It replicates quickly to not only the lungs, but organs and the brain. We're just beginning to understand how/why it affects people differently. And if antibodies protect us. We don't know that yet.

 

[eytonxav]

That's the conundrum. I believe it is necessary to develop strong immune system, one must be exposed to a variety of bacteria, virus, germs etc. This virus makes me uncomfortable because it is so contagious. And we have 0 antibodies to fight it. I don't know if gradual exposure is possible. It replicates quickly to not only the lungs, but organs and the brain. We're just beginning to understand how/why it affects people differently. And if antibodies protect us. We don't know that yet.

You need to look at Sweden and Norway. Given their results, I think the initial response to the virus was correct, but now we need everyone to understand the data and end the panic. Time to get our economy back.

 

[Amethyst]

There, that's what I was trying to get at with my comment about data being useful in ways we may not even realize - until we have sufficient data to do meaningful analyses.

Testing isn't about you, or me, but us. It's about knowing if there are 3 cases in your state, or 30,000. About whether we need more medical capacity or less, and whether we can ease social distancing or not. Is it growing or subsiding?

Testing is almost meaningless to a person, but it's incredibly meaningful to a community.
.

 

[anethum]

One thing that is interesting to note, is looking at two neighboring countries, Sweden and Norway. Sweden never did any lockdowns, while Norway did. Both have similar results in terms of deaths and hospitalizations as a percent of the total population. Sweden's economy kept going strong, while Norway's took a big hit. Looking at California, the % of hospitalizations and deaths based on the total population is very low after they did some antibody testing and extrapolation. Nothing like what Fauci and Birks were originally projecting. Therefore, some Drs have suggested based on antibody testing that a large % of the population has already been infected without much impact, and that the current strategy should be shifted to allow the elderly and those with comorbitities to continue sheltering in place while everyone else returns to work. If everyone remains sheltered, our immune systems will suffer, as being out in the world and exposed helps build ones immunity to many of the bad bacterias and viruses that are out there. I can definitely see more antibody testing making the experts more comfortable with a much more relaxed sheltering strategy and getting our economy back.

No, Sweden & Norway do NOT have similar results in terms of deaths and infection rates, according to data updated in real-time in the Washington Post. Their results are not even remotely similar. The article below is free; no subscription is required. It has been on The Post's homepage every day for weeks.

https://www.washingtonpost.com/grap...-low_web-gfx-death-tracker:homepage/story-ans

In the article, if you scroll down and roll your mouse over a country on the map, the data for that country will appear. There's also a table if you scroll down.

As of midday today, April 27, the data for Norway & Sweden are as follows:

Norway: Total deaths: 205; Deaths per 100,000 population: 3.9
Infection rate per 100,000 population: 142.1

Sweden: Total deaths: 2,274; Deaths per 100,000 population: 22.3
Infection rate per 100,000 population: 185.9

The per capita death rate from Covid-19 is a whopping 572% higher in Sweden than in Norway. I don't know how widespread testing is in either country, but I have faith that the death figures are accurate for both countries.

 

[copyright1997reloaded]

For people interested in the accuracy of antibody tests, a group of researchers in San Francisco have been testing the tests -- running a dozen tests against the same blood samples.

Not tested, the Abbott anti-body test has a sensitivity of 100% and specificity of 99.5%.

One negative on the Abbott test is that it is for the IgG antibody, which is produced late in the infection. So, the above measurements are assuming 2 weeks from first infection. The good news is they think it may remain in the bloodstream for months (perhaps years).

https://www.abbott.com/corpnewsroom/product-and-innovation/an-update-on-abbotts-work-on-COVID-19-testing.html

 

[eytonxav]

No, Sweden & Norway do NOT have similar results in terms of deaths and infection rates, according to data updated in real-time in the Washington Post. Their results are not even remotely similar. The article below is free; no subscription is required. It has been on The Post's homepage every day for weeks.

https://www.washingtonpost.com/grap...-low_web-gfx-death-tracker:homepage/story-ans

In the article, if you scroll down and roll your mouse over a country on the map, the data for that country will appear. There's also a table if you scroll down.

As of midday today, April 27, the data for Norway & Sweden are as follows:

Norway: Total deaths: 205; Deaths per 100,000 population: 3.9
Infection rate per 100,000 population: 142.1

Sweden: Total deaths: 2,274; Deaths per 100,000 population: 22.3
Infection rate per 100,000 population: 185.9

The per capita death rate from Covid-19 is a whopping 572% higher in Sweden than in Norway. I don't know how widespread testing is in either country, but I have faith that the death figures are accurate for both countries.

You are right. I should have said #confirmed cases when comparing the two vs deaths and hospitalizations. When comparing #cases to total population, Sweden is ~ .18% infected, while Norway is .14% and both have relatively low number of deaths based on their populations.

 

[audreyh1]

One thing that is interesting to note, is looking at two neighboring countries, Sweden and Norway. Sweden never did any lockdowns, while Norway did. Both have similar results in terms of deaths and hospitalizations as a percent of the total population. Sweden's economy kept going strong, while Norway's took a big hit. Looking at California, the % of hospitalizations and deaths based on the total population is very low after they did some antibody testing and extrapolation. Nothing like what Fauci and Birks were originally projecting. Therefore, some Drs have suggested based on antibody testing that a large % of the population has already been infected without much impact, and that the current strategy should be shifted to allow the elderly and those with comorbitities to continue sheltering in place while everyone else returns to work. If everyone remains sheltered, our immune systems will suffer, as being out in the world and exposed helps build ones immunity to many of the bad bacterias and viruses that are out there. I can definitely see more antibody testing making the experts more comfortable with a much more relaxed sheltering strategy and getting our economy back.

What is your idea of similar results? Sweden's death rate has been rather high for the size of its country. It has a death rate of 225 people per 1M population whereas Norway has a death rate of only 38 people per 1M population. Sweden has about 2.5 times the number of cases, and a much, much higher relative death rate.

Who claims they are having similar results?

 

[aiken]

The antibody tests aren't perfect, so maybe the solution is having them done 2 times if you're positive. So, at a 5% false positive rate, the odds of getting two false positives in a row is .0025% (.05x.05) ...assuming there were enough tests to do multiple observations.

 

[copyright1997reloaded]

The antibody tests aren't perfect, so maybe the solution is having them done 2 times if you're positive. So, at a 5% false positive rate, the odds of getting two false positives in a row is .0025% (.05x.05) ...assuming there were enough tests to do multiple observations.

This assumes no/minimal correlation in errors.