It is not yet established that patients who are declared recovered from COVID-19 on the basis of two NEGATIVE RT-PCR tests for SARS-CoV-19 had actually recovered due to laboratory error of testing kits or the the positivity indicates a carrier state, as none of these reports indicated any worsening of clinical condition of the patient based on symptoms, CT-scan or other parameters (1).

We have seen many patients with COVID-19 who despite making a clinical recovery are often having positive reports based on the RT-PCR results up to 35 days after initial diagnosis (2). There has been talk of viral RNA belong to dead virus (viral litter, debris) as the explanation for positive RNA-based PCR tests, as this test does not establish the presence of live virus.

Important point is that there is a disconnect between positive tests and the clinical condition of the such COVID-19 patients. If you follow up such patients, none of the patients had adverse outcome.

1. Preprint Clinical characteristics of the recovered COVID-19 patients ...

2. https://www.researchgate.net/post/What_are_the_interpretations_and_implications_of_having_negative_followed_by_positive_RT-PCR_tests_in_COVID-19_patients

Recurrence of Covid-19 is minimum as the body develops IgG against that perticular virus. It might be possible only in immunocopromised patients but no concrete data available in this regards. However, corona virus or its debris remains in the body for several days after recovary from symptom. Hence possibility of false positive report could be another possibility.

I think it depends on the

1. Strain of the virus causing initial infection

2. False positive rate of initial test

However, definitive answer is still awaited.

It will take some time before the research findings come out in this regard. I could find one research letter that talks about the possibility of reinfection. It is based on a smaller number of cases that existed at that time, hence no statistical analysis was provided.

Article Risk of reactivation or reinfection of novel coronavirus (COVID-19)

Please read the following articles.

It should be close to zero, however, there are reports of people becoming re-infected. I think that is due to them not actually having it in the first place since the false positive rate for the RT-PCR test is about 4%.

REPORTS OF REINFECTION MIGHT HAVE TO DO WITH INFECTION BY DIFFERENT STRAINS OR MULTIPLE MUTANT SARS-CoV-2 VIRUSES, as the new study shows:

The Conclusion of the study reads:

“The mutation Spike D614G is of urgent concern; it began spreading in Europe in early February, and when introduced to new regions it rapidly becomes the dominant form. Also, we present evidence of recombination between locally circulating strains, indicative of multiple strain infections. These finding have important implications for SARS-CoV-2 transmission, pathogenesis and immune interventions.”

https://www.biorxiv.org/content/10.1101/2020.04.29.069054v1

As hypothesized by me previously, RNA RT-PCR based tests may be intermittently positive even after clinical recovery.

Now Singapore has done away doing RT- PCR tests for discharging patients from COVID-19 isolation, because after clinical recovery PCR tests are misleading and did not cause transmission of infection in contacts.

Singapore abandons PCR as criteria for releasing COVID-19 patients https://english.kyodonews.net/news/2020/05/956e5ca1e3f3-singapore-abandons-pcr-as-criteria-for-releasing-covid-19-patients.html

Thank you Muhammad Yousuf

Reinfections after recovery from COVID-19 are possible because immunity induced by COVID-19 is short-liked like in common cold caused by Coronaviruses.

Further reading in this latest article:

https://www.medrxiv.org/content/10.1101/2020.06.13.20130252v1.full.pdf

One way to tell if the reinfections are really due to initial false positives is to correlate re-infections with whether they were asymptomatic the first time. I would expect false positives to be asymptomatic.

Further thought that if re-infections are due to short-lived immunity, is this endemic to all people or does it vary widely person to person. Using truly re-infected patients it would be interesting to make sure they get antibody tests spaced out in time to see if their immunity falls off rapidly again.

I think its very small

Recurrence of Covid-19 is minimum as the body develops IgG against that particular virus. It might be possible only in immunocompromised patients but no clearcut data available in this case. However, corona virus or its particulates matters remains in the body for several days after recovery from infections. Hence the possibility of a false positive report could be another possibility.