Many fully recovered COVID-19 patients still test positive for virus

The general advice regarding suspected SARS-CoV-2 exposure is self-quarantining for two weeks, during which time it is expected that symptoms will appear. What about when a person tests positive? The World Health Organization (WHO) offers criteria on when a patient can be considered recovered and safe to exit quarantine, but a new study raises questions about whether some of those people may still be spreading the virus.

The new study was published by Elsevier, which found that certain continuing symptoms may indicate that a fully recovered patient will still test positive for the novel coronavirus. The research itself originates from Italy, where researchers with Fondazione Policlinico Universitario found that a notable number of fully recovered COVID-19 patients were likely to test positive for the virus a second time.

The second positive test was particularly linked to recovered patients who continued to have some respiratory symptoms, most notably a sore throat and runny nose. The findings were based on data from 131 COVID-19 patients who had met WHO's criteria for ending their quarantine, including being fever-free for at least three days, having gone at least a week without symptoms, and more.

Of those 131 patients, 16.7-percent tested positive for the coronavirus despite meeting the criteria to end their quarantine. All of these positive patients were fever-free and had experienced improvements in their condition. Many of the recovered patients, including ones who didn't test positive a second time, had persistent health issues like fatigue, coughing, and trouble breathing, however.

The big mystery here involves the fact that some of the symptom-free and fully recovered COVID-19 patients who are no longer in quarantine may still be carrying the virus. The study's lead investigator Francesco Landi, MD, Ph.D., explained:

The main question for the containment of SARS-CoV-2 pandemic infection that still needs to be answered is whether persistent presence of virus fragments means the patients is still contagious. The RT-PCR test looks for small fragments of viral RNA. A positive swab test can reveal if patients are still shedding viral fragments, but it is not able to discern whether they are or aren't infectious.