As it happens, I currently have COVID. When I first noticed I was getting sick, I was scheduled to fly in the near future, so I got a rapid COVID test that delivers results in 15 minutes.
It was negative. I got another one, and it was negative too. I had thus intended to go ahead with the trip under the assumption I had a minor cold.
Later, a few days before I was to fly, I lost all smell and taste. Now I didn’t know what to think. I wasn’t particularly congested, and the loss of smell was total. I’d never experienced this before. Could both tests have been false negatives?
I delayed the flight (free of charge luckily, so no big deal) and got a test that had to be sent to a lab for analysis. A week later, the positive test result came back.
Take from this what you will. I'm not a scientist or a doctor and frankly there's nothing remotely intelligent I can say about the various tests out there for COVID. But if the rapid tests are as unreliable in general as they were for me, it’s sort of no wonder COVID is spreading like wildfire. I was very, very close to boarding a plane with an active case of COVID, and I would have if I hadn’t acted out of an abundance of caution.
Rapid tests are known to be unreliable and particularly have a high false negative rate. That's why all the guidance has been that rapid tests can be used to indicate infection but not rule one out, and none of the screening processes based on exposure and symptoms accept “but I also had a negative rapid test” as neutralizing a flag on any screening factor.
> I would have if I hadn’t acted out of an abundance of caution.
The bare minimum of caution with a rapid test is treating a positive as a true positive and a negative as an indicator that you need a regular test. That you understood your actions to be an abundance of caution demonstrates a failure to effectively communicate on some level (I'm not saying that you are culpable; the information is out there's but delivery is...mixed, even before considering how it is muddled by misinformation from various sources.)
I'm glad the OP made the correct decision in this case and hope they get well soon.
> the assumption I had a minor cold
> the loss of smell was total
Since there does seem to be a messaging problem about the reliability of testing, I think it's worth emphasizing: if someone has symptoms of COVID, they should proceed as-if they have COVID. CDC guidance[1] is to isolate if you have a positive test OR if you have symptoms.
To do otherwise is to gamble with the health and lives of the people they meet, and the people those people meet, and so on. It may prove almost impossible to show who caught COVID from whom, but that doesn't mean that ignoring guidance won't lead to deaths. A statistical death is still the death of a real person, even if we can't put a name to them.
Whether a test is positive or not depends highly on what type of test it is, and when you are tested relative to symptom onset. You can absolutely be carrying the COVID virus but still test negative. Heres a paper with a handy chart: https://jamanetwork.com/journals/jama/fullarticle/2765837
I think you testing negative was a combination of the rapid test being unreliable, as well as getting tested early with respect to symptoms.
Thanks for your anecdote. When SF was doing better and the possibility of big outdoor events with testing on the door were something that was being discussed, I looked at rapid tests together with some friends and the accuracy is really appalling. People relying on this to "safety socialize" may be one of the issues making cases rise in California, the math adds up. Many people reached to the government saying they should stop sponsoring and advertising rapid test sites because the false sense of security may be really doing more harm than good.
One of the rapid tests that we considered has, as advertised by its own manufacturer, a 10% false positive rate on basically all the population, and a 50% false negative rate even on symptomatic individuals with high viral load. Do the math, but using that type of test in something like for example a 100 person event or a restaurant will result in people being turned out of the door daily even if they were not symptomatic, and at least one or two people with high viral load being admitted into your place. I can't find the link of the test now, but there's better data about how harmful rapid tests are when not used together with PCR testing, for example here: https://www.bmj.com/content/371/bmj.m4941 and here: https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Se...
That's why most countries that really thought this through require a recent PCR test result for admittance.
It's really not clear what benefits rapid tests have if you don't have a model for population behavior. I think at lest the SF government is only doing them to save face now that the cat is out of the bag.
> But if the rapid tests are as unreliable in general as they were for me, it’s sort of no wonder COVID is spreading like wildfire.
Many rapid tests are indeed not accurate[1] but they still serve a purpose, depending on the sensitivity and specificity of the tests[2].
For the rapid tests with high sensitivity and you get a positive result, it's highly likely you have COVID.
For the rapid tests with high specificity and you get a negative result, it's highly likely that you don't have COVID.
And the public health measures of testing / contact tracing ONLY works if testing results come back quick. PCR tests are neither fast nor cheap, so those are not as effective in prevention of spreading because you don't do those all the time (slow + expensive).
This rapid tests have a very high false negative rate. The result you get back should really be "You have COVID" or "You may have COVID, get a PCR test".
Most countries which require a test for entry stipulate it must be a PCR test rather than a rapid (antigen) test. I’m currently in Lisbon waiting for the results of a 24h PCR test in order to board a flight to Azores, for example.
Rapid tests are at their most accurate when someone is at their peak infectiousness. Accuracy declines swiftly before or after that.
So the use you made of them didn’t fit their ideal use case, as you used them several days before travel.
Even then, with symptoms, I am not sure they would be enough to rule out a positive. The biggest use of rapid tests is finding additional positives that would not otherwise have been found.
> A week later, the positive test result came back
Which country do you live in that it takes a week for the PCR test to come back? It's around 24 hours here and I thought that was the case in all developed countries.
They've been using these lateral flow tests in the UK quite a bit - particularly for university students returning home/to campus (or at least, that was the plan!).
There is enough knowledge out there about the various kinds of tests (PCR, antibody, antigene) and what they're good for and what they're not. It's perfectly understood that while rapid tests are, well, rapid, they're much less precise than PCR testing. However, they are often better than nothing (you can't give a PCR test to everyone who wants to visit relatives in a nursing home), so they serve to minimise risk, not to remove it. (They also have a tendency to be more likely to be positive while you're actually infectious, which is not the same thing as having symptoms.)
I really don't think we should be discussing personal anecdotes during a health crisis, when there's enough data around that we can actually look at.
You were probably not contagious during those first days (at least for everyone except your partner).The threshold for the rapid test is higher than what the PCR detects. The antigen test is highly reliable for catching contagiousness, not just any viral load. Michael Mina (Harvard Biologist) presents the data in a great way if you want to check.
There are many different rapid tests. Some are reliable and some are unreliable.
For the ones that are reliable (like Abbott's test), they are highly accurate at determining whether someone is currently infectious. So you could have been infected but not capable of transmitting to others yet. These tests would be highly useful for onsite testing, such as if airlines required a rapid test right at the airport.
The most common error with these tests is false application. Did you have someone else doing the swab? It has to feel like someone is poking at your brain.
If you still have yet to test positive for COVID you may not have COVID. A loss of sense of smell and taste is a common symptom of a viral infection.˜ [1]
I don't understand why we don't implement the isolation procedures of countries that have gotten this under control, following these procedures for both foreign citizens AND US citizens:
- When you arrive in the US, you either spend two weeks at a government approved hotel, at your expense, which is monitored by federal agents to make sure you don't leave your room. You pay for room service for two weeks to get food. This is what Singapore does.
- If you don't want to stay at the government hotel, you agree to let the government track your cell phone for two weeks to make sure you stay in your home, and randomly call you twice a day to make sure you didn't ditch your phone. This is what Taiwan does.
As a plus, all the hotels near airports would be so thankful for all the forced business to make up for the loss of travel business.
They should have been doing this for the last nine months.
Edit: And obviously combine these rules with a relief bill that helps the industries that are hurt by these rules, or you know, everyone.
A similar requirement has been enacted in Canada and what has happened is that Canadians with covid can't return home to Canada and are stuck abroad.
It really gives some teeth to the "do not travel" recommendation - if you get covid abroad you can't come home until you test negative. If you get covid at home and then go abroad you can't come home until you test negative.
I think people who previously would have travelled and just risked it will be a lot more careful now since they can't get home if they are sick with covid. Instead of dozens of flights per day entering canada with covid cases we now have zero [1].
Small correction: you can't board a flight to Canada. You're always welcome at a land border without a test report in hand. In which case you'll be required to spend 14 days in government quarantine.
I recently had to get a negative COVID result to travel to Hawaii to see family. Hawaii only accepted tests from a very limited number of providers which complicated things, but after some effort I made an appointment and got a test. The rest of the process was very painless. We all had to keep masks on for the entire flight of course since there was no requirement that we all have a negative result before getting on the flight but it was comforting to know that nearly everyone else on the flight would have had a negative result so as to avoid the mandatory 14 day quarantine upon arrival.
If you enter Mauritius you have to get four tests in total over several weeks. Islands are taking advantage of their isolation to get this pandemic under control.
Madeira has been very successful during all of 2020 with not letting it escalate.
I don't at all see how this is relevant to the United States in 2021, when COVID-19 is almost completely prevalent, and we require universal vaccination to exit out of the pandemic - International travel restrictions seem meaningless to me now - though they would have been invaluable in January 2020, and maybe even February 2020 - right now the major risk of COVID-19 infection is inside the United States. A handful (or heck, even hundreds) of people coming into the country won't make any difference when we have thousands of new cases a day regardless.
There's a reason Epidemologists don't put much stock in travel restrictions once a pandemic is well underway around the world - they don't do much good.
But - generally, having widespread (ideally very sensitive) COVID testing for any type of travel outside of the home is a good thing. We should have it universally available. Ideally <$10, something that everyone could do weekly, or even daily if they travel a lot.
Just unclear what the focus on international travel is all about here.
Some rationale for blocking international travel - preventing the spread of international variants, and preventing the destination country from being overloaded by incoming infections.
Most nations aren't getting the vaccines yet. Vaccination distribution and delivery require complex logistics. Nations that don't have a good public healthcare infrastructure need time to gear up. Vaccinations have just started and are being given in a phased manner. Blocking International Travel (or at least mandating a 14 day quarantine) helps keep variants in check.
I think all domestic and international travel should have this requirement at a minimum. Nobody should be on an airplane without a recent negative test. Or working in a factory, hospital, or other indoor environment for that matter, it would be great if essential workers could all routinely get tested once or twice a week, though maybe that's not feasible.
I don't really get the international focus of this either, but it seems like a step in the right direction.
This is no surprise, although according to CDC research, this only reduces the infection rate among these passengers by 5-9%.
A lot of EU countries require their own citizens of their countries to get a COVID-19 PCR test prior to entry. A lot of times, this has to be paid out of pocket abroad.
By now people can purchase negative Covid PCR test results at many international airports, sometimes for as little as $0.50. Entrepreneurial spirit is hard to tame.
This is moronic. We have between 30M and 130M cases here. There is no mathematically possible way in hell that international passengers could bring COVID here in any noticeable way at this point.
Why would they do this? I'll tell you the one and only one reason: some people are making tons of money off it. I just flew back to Hawaii from California and had to pay $170 for a COVID test, even though I'm already immune.
I get why they’re doing this, but I fear as a society we’ve learned the wrong lessons about testing.
These tests have a pretty high failure rate. That’s probably ok for social level spread tracking (with wide error bars) or low volume contact tracing (where quarantining a few extra people is worth it). It’s far better than nothing of course, but it’s also far short of what we expect from something like a pregnancy test.
But as a means to sign people off as safe to travel? Yeah, not so much. So many people have had the “one negative test so I can go party” only to discover what a false negative is.
Most US states already require a negative test or quarantine, with some exceptions. The only issue is that almost no one is enforcing it (maybe some airports do, I'm not sure). It makes sense if it becomes like visa where airlines wouldn't let you board the plane without it (until things are under control). It can be an issue for emergency travel though. Thinking about it, this should be of interest of airlines to protect their staff.
It's not clear to me how this works. What if you've recently recovered from a confirmed case of COVID-19? People can still test positive up to 90 days after recovery, even though all guidances say they stop being contagious 10 days from the onset of symptoms (assuming symptoms have improved and no fever).
And what about people who have been vaccinated. Wouldn't proof of vaccination be sufficient and spare limited testing capacity?
Not to be inflammatory, but why? The only benefit I can see is reducing the likelihood of new strains getting into the US, but to me this is like a swimming pool requiring people to be dry before they get in.
It would make sense as part of a national strategy, no doubt. But on it's own, I don't see the value in this?
Especially since it doesn't apply to passengers transiting through the US, so technically not everybody on the flight will have to do this, meaning you're going to spend a lot of time in an enclosed place with (as a complete guess) 80% covid negative people and 20% YOLO people. That's, err, that's exactly how covid spreads...
Just so silly. More theater. We're already seeing millions of new cases per week including the strains with mutations to the target spike proteins - what problem does this solve?
[+] [-] nilkn|5 years ago|reply
As it happens, I currently have COVID. When I first noticed I was getting sick, I was scheduled to fly in the near future, so I got a rapid COVID test that delivers results in 15 minutes.
It was negative. I got another one, and it was negative too. I had thus intended to go ahead with the trip under the assumption I had a minor cold.
Later, a few days before I was to fly, I lost all smell and taste. Now I didn’t know what to think. I wasn’t particularly congested, and the loss of smell was total. I’d never experienced this before. Could both tests have been false negatives?
I delayed the flight (free of charge luckily, so no big deal) and got a test that had to be sent to a lab for analysis. A week later, the positive test result came back.
Take from this what you will. I'm not a scientist or a doctor and frankly there's nothing remotely intelligent I can say about the various tests out there for COVID. But if the rapid tests are as unreliable in general as they were for me, it’s sort of no wonder COVID is spreading like wildfire. I was very, very close to boarding a plane with an active case of COVID, and I would have if I hadn’t acted out of an abundance of caution.
[+] [-] dragonwriter|5 years ago|reply
> I would have if I hadn’t acted out of an abundance of caution.
The bare minimum of caution with a rapid test is treating a positive as a true positive and a negative as an indicator that you need a regular test. That you understood your actions to be an abundance of caution demonstrates a failure to effectively communicate on some level (I'm not saying that you are culpable; the information is out there's but delivery is...mixed, even before considering how it is muddled by misinformation from various sources.)
[+] [-] Osmium|5 years ago|reply
> the assumption I had a minor cold > the loss of smell was total
Since there does seem to be a messaging problem about the reliability of testing, I think it's worth emphasizing: if someone has symptoms of COVID, they should proceed as-if they have COVID. CDC guidance[1] is to isolate if you have a positive test OR if you have symptoms.
To do otherwise is to gamble with the health and lives of the people they meet, and the people those people meet, and so on. It may prove almost impossible to show who caught COVID from whom, but that doesn't mean that ignoring guidance won't lead to deaths. A statistical death is still the death of a real person, even if we can't put a name to them.
[1] https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/is...
[+] [-] DeRock|5 years ago|reply
I think you testing negative was a combination of the rapid test being unreliable, as well as getting tested early with respect to symptoms.
[+] [-] pvarangot|5 years ago|reply
One of the rapid tests that we considered has, as advertised by its own manufacturer, a 10% false positive rate on basically all the population, and a 50% false negative rate even on symptomatic individuals with high viral load. Do the math, but using that type of test in something like for example a 100 person event or a restaurant will result in people being turned out of the door daily even if they were not symptomatic, and at least one or two people with high viral load being admitted into your place. I can't find the link of the test now, but there's better data about how harmful rapid tests are when not used together with PCR testing, for example here: https://www.bmj.com/content/371/bmj.m4941 and here: https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Se...
That's why most countries that really thought this through require a recent PCR test result for admittance.
It's really not clear what benefits rapid tests have if you don't have a model for population behavior. I think at lest the SF government is only doing them to save face now that the cat is out of the bag.
[+] [-] devy|5 years ago|reply
Many rapid tests are indeed not accurate[1] but they still serve a purpose, depending on the sensitivity and specificity of the tests[2].
For the rapid tests with high sensitivity and you get a positive result, it's highly likely you have COVID.
For the rapid tests with high specificity and you get a negative result, it's highly likely that you don't have COVID.
And the public health measures of testing / contact tracing ONLY works if testing results come back quick. PCR tests are neither fast nor cheap, so those are not as effective in prevention of spreading because you don't do those all the time (slow + expensive).
Medcram has a good video talking about this. [3]
[1]: https://www.wsls.com/news/local/2021/01/08/cdc-study-shows-c...
[2]: https://en.wikipedia.org/wiki/Sensitivity_and_specificity
[3]: https://www.youtube.com/watch?v=h7Sv_pS8MgQ
[+] [-] jedberg|5 years ago|reply
[+] [-] Reason077|5 years ago|reply
That means they’re biased towards the negative side: they’re unlikely to return false positives, but quite likely to give false negatives.
Such tests are useful for epidemiological studies, or for answering the “do I have Covid antibodies?” question.
But they’re not a reliable way to actually test for Covid. You need a PCR test for that!
[+] [-] situationista|5 years ago|reply
[+] [-] graeme|5 years ago|reply
So the use you made of them didn’t fit their ideal use case, as you used them several days before travel.
Even then, with symptoms, I am not sure they would be enough to rule out a positive. The biggest use of rapid tests is finding additional positives that would not otherwise have been found.
[+] [-] koyote|5 years ago|reply
Which country do you live in that it takes a week for the PCR test to come back? It's around 24 hours here and I thought that was the case in all developed countries.
I hope you recover quickly!
[+] [-] lol768|5 years ago|reply
But I'm not convinced the data on their effectiveness really supported using the tests in this way: https://twitter.com/deeksj/status/1340975400726478849
But it was a political "win".
[+] [-] Tainnor|5 years ago|reply
Please don't do that.
There is enough knowledge out there about the various kinds of tests (PCR, antibody, antigene) and what they're good for and what they're not. It's perfectly understood that while rapid tests are, well, rapid, they're much less precise than PCR testing. However, they are often better than nothing (you can't give a PCR test to everyone who wants to visit relatives in a nursing home), so they serve to minimise risk, not to remove it. (They also have a tendency to be more likely to be positive while you're actually infectious, which is not the same thing as having symptoms.)
I really don't think we should be discussing personal anecdotes during a health crisis, when there's enough data around that we can actually look at.
[+] [-] luisvel88|5 years ago|reply
[+] [-] argonaut|5 years ago|reply
For the ones that are reliable (like Abbott's test), they are highly accurate at determining whether someone is currently infectious. So you could have been infected but not capable of transmitting to others yet. These tests would be highly useful for onsite testing, such as if airlines required a rapid test right at the airport.
[+] [-] raxxorrax|5 years ago|reply
[+] [-] anonytrary|5 years ago|reply
[+] [-] option|5 years ago|reply
[+] [-] glandium|5 years ago|reply
[+] [-] jonny_eh|5 years ago|reply
[+] [-] maxerickson|5 years ago|reply
[+] [-] Technically|5 years ago|reply
[deleted]
[+] [-] arcticbull|5 years ago|reply
[1] https://www.healthline.com/health/coronavirus-loss-of-taste-...
[+] [-] jedberg|5 years ago|reply
- When you arrive in the US, you either spend two weeks at a government approved hotel, at your expense, which is monitored by federal agents to make sure you don't leave your room. You pay for room service for two weeks to get food. This is what Singapore does.
- If you don't want to stay at the government hotel, you agree to let the government track your cell phone for two weeks to make sure you stay in your home, and randomly call you twice a day to make sure you didn't ditch your phone. This is what Taiwan does.
As a plus, all the hotels near airports would be so thankful for all the forced business to make up for the loss of travel business.
They should have been doing this for the last nine months.
Edit: And obviously combine these rules with a relief bill that helps the industries that are hurt by these rules, or you know, everyone.
[+] [-] rhodozelia|5 years ago|reply
[1] http://www.bccdc.ca/health-info/diseases-conditions/covid-19...
[+] [-] triceratops|5 years ago|reply
[+] [-] eloff|5 years ago|reply
But people are getting stuck because they can't get results back in the 72 hour window. That's really not cool.
[+] [-] ngngngng|5 years ago|reply
[+] [-] Tepix|5 years ago|reply
Madeira has been very successful during all of 2020 with not letting it escalate.
[+] [-] ghshephard|5 years ago|reply
There's a reason Epidemologists don't put much stock in travel restrictions once a pandemic is well underway around the world - they don't do much good.
But - generally, having widespread (ideally very sensitive) COVID testing for any type of travel outside of the home is a good thing. We should have it universally available. Ideally <$10, something that everyone could do weekly, or even daily if they travel a lot.
Just unclear what the focus on international travel is all about here.
[+] [-] solarengineer|5 years ago|reply
Most nations aren't getting the vaccines yet. Vaccination distribution and delivery require complex logistics. Nations that don't have a good public healthcare infrastructure need time to gear up. Vaccinations have just started and are being given in a phased manner. Blocking International Travel (or at least mandating a 14 day quarantine) helps keep variants in check.
[+] [-] cactus2093|5 years ago|reply
I don't really get the international focus of this either, but it seems like a step in the right direction.
[+] [-] benibela|5 years ago|reply
It would also be good to test for any disease before traveling. Flu, cold, just stay home for those, too
[+] [-] disabled|5 years ago|reply
A lot of EU countries require their own citizens of their countries to get a COVID-19 PCR test prior to entry. A lot of times, this has to be paid out of pocket abroad.
[+] [-] FreakyT|5 years ago|reply
[+] [-] opwieurposiu|5 years ago|reply
https://www.nytimes.com/2020/08/29/health/coronavirus-testin...
[+] [-] balozi|5 years ago|reply
[+] [-] breck|5 years ago|reply
Why would they do this? I'll tell you the one and only one reason: some people are making tons of money off it. I just flew back to Hawaii from California and had to pay $170 for a COVID test, even though I'm already immune.
[+] [-] ashtonkem|5 years ago|reply
These tests have a pretty high failure rate. That’s probably ok for social level spread tracking (with wide error bars) or low volume contact tracing (where quarantining a few extra people is worth it). It’s far better than nothing of course, but it’s also far short of what we expect from something like a pregnancy test.
But as a means to sign people off as safe to travel? Yeah, not so much. So many people have had the “one negative test so I can go party” only to discover what a false negative is.
[+] [-] cbg0|5 years ago|reply
The rapid ones maybe, the PCR ones are quite accurate.
[+] [-] tinyhouse|5 years ago|reply
[+] [-] standardUser|5 years ago|reply
And what about people who have been vaccinated. Wouldn't proof of vaccination be sufficient and spare limited testing capacity?
[+] [-] outside1234|5 years ago|reply
I'm always stunned when I see these questions because I am like "People are traveling internationally - test or no test????"
[+] [-] Ericson2314|5 years ago|reply
[+] [-] SpicyLemonZest|5 years ago|reply
[+] [-] Andaith|5 years ago|reply
It would make sense as part of a national strategy, no doubt. But on it's own, I don't see the value in this?
Especially since it doesn't apply to passengers transiting through the US, so technically not everybody on the flight will have to do this, meaning you're going to spend a lot of time in an enclosed place with (as a complete guess) 80% covid negative people and 20% YOLO people. That's, err, that's exactly how covid spreads...
[+] [-] addicted|5 years ago|reply
This is at least 6-9 months too late.
[+] [-] mikeyouse|5 years ago|reply
[+] [-] sneak|5 years ago|reply
They should do this for every bar, restaurant, uber, taxi, train station, and airport inside the US; that would solve the issue right quick.
This is just xenophobia, nothing more. There's more covid danger inside the US than there is from people coming from outside of it.
[+] [-] rhacker|5 years ago|reply