One family's diagnostic testing experiences

[LOL!]

I thought folks would like to see the ambiguity of covid-19 diagnostic testing in a family of 4.

This article describes the testing for covid-19 of a family of 4 in New York City:

https://www.reuters.com/article/us-...the-limits-of-coronavirus-tests-idUSKBN22J1NK

It describes both the swab-up-the-nose for virus genetic material and antibody-in-the-blood testing.

Of course, the testing was done weeks ago before better tests have been invented.

Dr. Danielle Ompad, an epidemiologist at New York University’s School of Global Public Health, said it was challenging to get the general public to accept the limitations of tests.

 

[audreyh1]

Thanks. I thought this part was interesting:

About six weeks after calling the state health department, Johnson-Baruch heard back from an official saying the family could finally get a test for the actual virus that works by looking for distinctive parts of the pathogen’s genetic material, RNA, in a patient’s sample.

“We were well over a month out of our symptoms by that point, so we were surprised to get the call from them sort of out of the blue,” Johnson-Baruch said.

Johnson-Baruch noticed her eldest daughter particularly squirmed when healthcare workers stuck swabs, one by one, deep into the back of their noses.

Once again, the results surprised them. Johnson-Baruch, her husband and their youngest daughter all tested positive. Their eldest daughter tested negative.

What did it mean, the family wondered. Were they still in some sense sick? Could they still infect others?

A health department official who called to relay the results was not much help. “She was quite surprised to hear we were sick six weeks ago,” Johnson-Baruch said.

The tests used by the health department “cannot distinguish between RNA from live or dead virus,” Jonah Bruno, a department spokesman, wrote in an email. “This persistent positive test result can continue long after a person has recovered and does not necessarily indicate that a person continues to be infectious.”

So how do they determine that someone is no longer infectious?

 

[LOL!]

I think the jury is still out on how to determine that someone is no longer infectious.

It has been well-known that finding the RNA or DNA of the covid-19 virus does not mean that viable viroid particles that can cause infection are present. Indeed, those tests that found stuff on the cruise ship, on various surfaces, in sewage water are finding the RNA/DNA because a PCR test is so easy to do and extremely sensitive. But a PCR test can also suffer from contamination of different kinds.

For instance, your body creates enzymes to degrade DNA and RNA and you are a walking/talking/breathing anti-infection machine. In a molecular biology lab, most of the PPE is to prevent the technicians, scientists, and staff from contaminating their experiments and not for the safety of the scientists.

 

[audreyh1]

Well, they let recovered people go home after they’ve tested negative a couple of times. But these people tested positive 5 weeks later. Something is not adding up. Recovered folks generally aren’t having to wait 5 weeks or longer.

 

[6miths]

They let recovered people go home when they don't need the services offered in hospitals. Generally with advice to self-quarantine for some period of time. The answers are just not known yet and even when they are the answer is going to be 'it depends' given that this is biology. It is the nature of tests that they have 'false positive' and 'false negative' results for many different reasons. A significant amount of time in the medical school curriculum is spent educating students about the implications of this and the performance of different tests. There are few 'perfect' tests in medicine that have 100% sensitivity and 100% specificity.

 

[audreyh1]

In other countries they tested until negative before letting out of hospital or quarantine or wherever they were confined.

 

[6miths]

One doesn't have to be in hospital to be quarantined and in places that they were very tight on beds they definitely tried to not admit at all or discharge when not needing services that could only be provided in hospital. Ideally, patients were meant to have two negative swabs but due to the limitations of the testing and the pressure on hospitals the clinical decision-making was allowed to be on a case-by-case basis so all the suggested criteria were not always fulfilled. This especially if the individual was well recovered and could be discharge into a low risk situation. And the initial swabs were only about 60% sensitive so they would be negative almost half the time in people who had the virus, as the story is trying to get across. Testing is far from a panacea - either viral or antibody. And even if a true positive on the antibody test, it is not clear what the implications are yet for risk of future infection.

 

[audreyh1]

I understand that. I’m just pointing out that swabbing negative for “release” from whatever is not jiving with this family still testing positive 5 weeks later.

 

[LOL!]

I understand that. I’m just pointing out that swabbing negative for “release” from whatever is not jiving with this family still testing positive 5 weeks later.

No member of this family was ever hospitalized ... or did I get that wrong? Thus, none of them could be released.

In other news, it looked like there was significant dip in new confirmed cases in our area yesterday. But it turned out the medical device/instrument used to test samples collected from people broke.

 

[6miths]

In other news, it looked like there was significant dip in new confirmed cases in our area yesterday. But it turned out the medical device/instrument used to test samples collected from people broke.

Yes the virus takes a break on weekends as well!! There is a pretty apparent 5:2 pattern in most of the graphs.

 

[audreyh1]

No member of this family was ever hospitalized ... or did I get that wrong? Thus, none of them could be released.

In other news, it looked like there was significant dip in new confirmed cases in our area yesterday. But it turned out the medical device/instrument used to test samples collected from people broke.

No, they weren't hospitalized. I'm just trying to jive their experience with people from other countries or wherever that were finally given a green light after having been sick, and it usually involved testing negative at least twice before being "let go". If this family recovered, but still testing positive 5 weeks later, how can the other recovered patients have tested negative?

 

[LOL!]

No, they weren't hospitalized. I'm just trying to jive their experience with people from other countries or wherever that were finally given a green light after having been sick, and it usually involved testing negative at least twice before being "let go". If this family recovered, but still testing positive 5 weeks later, how can the other recovered patients have tested negative?

There can be numerous reasons. Some are discussed in the article.
1. Improper sample collection.
2. Different test from those in other country or countries.
3. False negative.
4. False positive originally.
5. Contamination after sample collection.
6. Operator error when doing the testing.
7. Still infected, but asymptomatic.
8. Breathed in air containing virus genetic material just before being tested.
9. Cross-contamination anywhere along the way.

10. You should get the idea by now that so many things can go wrong that no testing can be foolproof.

 

[LOL!]

Yes the virus takes a break on weekends as well!! There is a pretty apparent 5:2 pattern in most of the graphs.

But of course!

Our local authorities have explicitly stated that they don't report any results on Sunday.

 

[gamboolman]

Regarding available Tests:
Here in The Woodlands, Texas, yesterday we went to a Drive Thru testing station set up at one of the larger Churches. They were doing the Drive Thru testing for 2 X Tests.

Cost was $75 and $150 for the 2 X tests. So $225 per person if you got both tests.

We used our insurance and will see how much insurance pays.

ms gamboolgal and I had both Tests done.

1) PCR Swab Test - which takes ~3 to 5 days to get results back and will determine if you have the Covid-19 virus.

2) Blood tests for Antibody test to determine if we have had the virus already. You get these results on location within about 20 to 30 minutes

We have not had the virus per the Antibodies test.

Should get results back next week on the PCR Swab Tests - on if we have the virus now - but doubtful as we have not had any symptoms

 

[LOL!]

Regarding available Tests:
Here in The Woodlands, Texas, yesterday we went to a Drive Thru testing station set up at one of the larger Churches. They were doing the Drive Thru testing for 2 X Tests....

Should get results back next week on the PCR Swab Tests - on if we have the virus now - but doubtful as we have not had any symptoms

What was your motivation for getting tested at all? You will probably have to be re-tested in the future anyways.

I would get myself tested if

(a) I had symptoms now or in the recent past, or
(b) one of the people living with me had symptoms now or in the recent past, or
(c) testing was easy AND free.

A private company, America's ER, is using the Stonebridge Church site until 6 pm today, but wasn't free for people like me. They intend to switch to another site on May 13th, so no testing at these places May 9-12th.

Many of the confirmed infections in Montgomery County, TX are from senior living centers, nursing homes, or detention centers. Others are travel-related, but people have stopped traveling to hot spots.

 

[folivier]

My DW and I meet all 3 of your requirements LOL!
So yesterday we had the antibody test done. I asked the nurse which test this was and she said "Covid 19". Asked again if it was the Abbott test or other and she said she didn't know. Hope to get results back Monday.

 

[EastWest Gal]

Try to find out which test it is. They vary in sensitivity and specificity. The nurse collectors generally don’t know. But the site coordinators must know.