Recovered coronavirus patients are testing positive again. Can you get reinfected?

[brooklynite]

Source: CNN

In South Korea, health officials are trying to solve a mystery: why 163 people who recovered from coronavirus have retested positive, according to the Korea Centers for Disease Control and Prevention (KCDC).

The same has been recorded in China, where some coronavirus patients tested positive after seeming to recover, although there are no official figures.

That raises the question: can you get reinfected with coronavirus?

In South Korea, the proportion of cases that retest positive is low -- of the 7,829 people who have recovered from coronavirus there, 2.1% retested positive, the KCDC said Friday. It is not clear how many of the people who have recovered have been tested again.

Read more: https://www.cnn.com/2020/04/17/health/south-korea-coronavirus-retesting-positive-intl-hnk/index.html

[Squinch]

1. This keeps coming up and there doesn't seem to be a good answer.

At first the explanation was human error, but now presumably those tests are rechecked a few times.

It could still be human error, but that seems somewhat less likely as the numbers rise.

[llashram]

3. could it be

like the herpes virus and goes into hiding after the infection subsides? Just a question for someone with a medical background here.

[Squinch]

5. That would be pretty horrifying.

[Auggie]

26. Mutations?

[The Magistrate]

4. Perhaps The Real Question, Sir

Is whether these people display symptoms or not.

There are some viral afflictions which seem to lodge permanently, but only episodically produce symptomatic evidence of their presence. Herpes and shingles come to mind. I am, of course, far too ignorant of virology to know if there are any similarities in the structure or internals of this new contagion with these established afflictions.

[moriah]

13. ... and whether they are shedding infectious viruses whilst testing positive.

Did South Korea test them because they became ill again? It's a very good question you pose, and one that seems unanswered in the article.

A question for public health becomes how long people who have had COVID-19 remain infectious -- they may be testing positive without symptoms, but are they shedding enough unattenuated virus to infect others?

I wasn't allowed to get the chickenpox vaccine when it first came out because I lived in a household with an immunosuppressed member (live attenuated viruses do cause shedding, and as he'd never had it even as a child it was a risk) -- got the shot series in college instead, when I was going to be away from my father for several months.

[Igel]

20. I'd bet they're infectious

if they're symptomatic.

There's enough virus to trigger symptoms and an immune response, so it's replicating.

Even many of the asymptomatic first-timers are shedding virions right and left, and I don't see why the repeaters wouldn't. If they're testing positive it means there virus (viable or degraded) in their nasopharyngeal cavity to be swabbed. If it wasn't there two weeks ago, where did it come from? (Granted, they could have snorted something that was infected, but let's discount that as either unlikely or just sick.)

[Igel]

18. I read it as 44% show symptoms,

and they're mild.

Anything more severe isn't worth mentioning.

KCDC deputy director Kwon Joon-wook said that so far, there's no indication that patients who retest positive are contagious, even though about 44% of them showed mild symptoms.

Rephrase it to see if it violates what you'd expect in conversation. You'd expect them to say what the strongest evidence was against the conclusion ("they're not contagious" ), not evidence immaterial because it's weak.

Infelicitous: There's no indication that patients who retest positive are contagious, even though about 44% of them showed mild symptoms, while 40% showed severe symptoms.

Acceptable: There's no indication that patients who retest positive are contagious, even though about 44% of them showed mild symptoms, while the rest showed no symptoms.


The other concern evinced by some virologists considered the connection between the immune response and antibody production: Typically a vaccine (or virus) that produces a mild immune response results in weak antibody production. Some vaccines need two doses to become really effective, others require periodic boosters. That's bad--but on the other hand, if you had a cold-like set of symptoms the first time, perhaps the second time around it'll be mostly the same. Herd immunity will be rare, but those most at risk would become immune.

But it's all speculation. Coronaviruses aren't much like herpes. There are two broad classes of virus, DNA-based and RNA-based. Herpes is a bit of DNA, coronavirus is a small package of RNA.

[unblock]

6. i've seen some articles saying there are 3 different strains

i wonder how specific the tests are. is it possible the second infection is a different strain?

[Igel]

21. There are three different strains,

but depending on the writer they're not the same three.

And there's no word on if they differ in any meaningful way. There is active discussion as to whether the mutations affect any of the binding sites that the body chooses to prepare antibodies for.

Whether the second infection is a different strain depends on what the antibodies are targeting. I've always wondered if every body's immune response picks up on the same binding targets (antibodies disable a virus by sticking to important sites, sort of like keeping somebody from opening a door by supergluing something to their key or attaching something to the person so they can't fit through the door).

It's the kind of thing that requires a bit of time to sort out.

[Maeve]

7. False positives, perhaps?

And can they infect others? And/or get sick again? If not, it may be interesting, but unimportant.

[Botany]

8. I have seen things that people who survive C-19 in some cases get temporary or transitory immunity

This needs to be left up to Fauci and the scientists and Trump can go out without
his mask and march with his brownshirts as they protest the shut down.

[spinbaby]

9. Might be like strep

Where a lot of people have it living in their airways without any signs of infection.

[Botany]

10. One way to test that theory is just to open everything back up and see who gets sick.

One of the greatest threats to humans in the history of the world and we have the dumbest
asshole of all times as POTUS.

[greatauntoftriplets]

11. My nephew is one of them.

He's a firefighter/paramedic and so qualified for testing. Early in the week he had tested negative after recovering from a mild case, so he went back to work, but had a coughing fit on the job. So the chief sent him back to be re-tested, and the results were positive. I don't know (and he wasn't told) if that was re-infection or just a slight relapse.

[mucifer]

12. The article says 44% have mild symptoms. So it seems at least they don't have severe symptoms

[WinstonSmith4740]

14. Anything's possible when it comes to the human body.

I had chicken pox twice as a kid...that wasn't supposed to happen, either.

[mr_lebowski]

19. Me too, the first one was a really mild case, only a couple sores ... nt

[yaesu]

15. A week ago it was 55, the numbers keep growing. No one knows how long immunity lasts

it there is such a thing when dealing with this virus.

[They_Live]

16. mutation tracking

https://nextstrain.org/ncov?animate=2019-12-07,2020-03-25,1,0,30000

[turbinetree]

17. Not a doctor, but it sounds like they need to develop a vaccine

it sounds like a cold sore on the lips, but this thing is more deadly, cold sores come back when under stress and there is no cure for cold sores from what I have read, and there may be no cure COVID19.................

https://www.medicalnewstoday.com/articles/324707

[Bayard]

22. I'm thinking it hides in the body after a recovery

And just waits for a chance to pop back up. Like a staph infection.

[Docreed2003]

23. How soon after "clearing symptoms" are the tests being performed?

We are seeing patients who are 2-3 weeks out from presentation who are still positive when retested.

[jberryhill]

24. 163 is an insignificant number compared to the total number of cases

There are always going to be statistical outliers, but the constant re-posting of several dozen cases of what appear to be re-infection, given the unknown false negative / false positive figures on the particular tests used on these individuals is entirely pointless and repetitive.

[DURHAM D]

25. So, chickenpox is a virus.

If you had chicken pox as a child you can get shingles later from the the same virus.

Therefore...

[Polybius]

29. Yeah, but that's usually many decades later

This is within a month or two.

[Old Crow]

27. Short on time, but one explanation:

There's a real likelihood that with these cases, what we're seeing is a RELAPSE, and not a REINFECTION. A relapse occurs when the presence of the virus in the body falls so low that the person tests negative but, for some reason, that person's immunity subsequently drops (due to stress, contracting some other illness, lack of sleep, etc.) and the virus rebounds sufficiently that they test positive again.

[not_the_one]

28. I would think that, once positive, always positive.

You may not express symptoms, but it would make sense to be positive.

I have had Lyme. It is my understanding I will ALWAYS have it. A $5 copay fixed it, AFTER a year of failure to diagnose it.

That would mean the only sure fire answer is a vaccine.

[Bengus81]

30. I thought there was a woman in China who proved you can get CV again,maybe a nurse?

Anyone remember a story like that from at least a month ago or more?

[ancianita]

31. New mutations go on all the time, so if one's immunity system is for another virus, one gets

reinfected with a new mutation until the immunity develops antibodies for THAT new one.

The immunity system learns, but it has to learn by exposure.

Which is why cv will last until broad spectrum vaccines are made. At least a year away.

[pansypoo53219]

32. are they CONTAGIOUS?

[oldsoftie]

33. I would like to know: Do we KNOW they were recovered? Are they as contagious?

How long has it been since they first tested positive?

[Warpy]

34. Piss Poor Reporting!

My main complaint is that nowhere did it give a reason why those people were retested. If they were feeling ill again, that is extremely bad news because it means the disease follows a recovery/relapse pattern in some people.

Another is that it didn't address whether or not the virus persists in feces, the way SARS did. If that is the case, people are likely transferring the virus back to mucus membranes vie poor hygiene, which happens more often than anyone would like to think. Again, if they have tested positive by this route, are they getting ill again?

Immunity to a cousin, MERS, was found to decline in about 2 years after recovery, but I can't find anything about a documented second case.

The explanation that this might represent nonviable virus particles that haven't been completely cleaned up by by phagocytes is a logical one. We just don't know if it's the right one.

[Igel]

35. Follow up.

I have no idea how this'll show up, if it's gonna be kicked.

https://en.yna.co.kr/view/AEN20200429007051320

The claim is that the SK positives aren't reinfections at all. Nor actual infections.