Coronavirus News: Study Alarmingly Shows That 3 Percent Of Recovered COVID-19 Patients Test Positive For Live and Infectious SARS-CoV-2 Virus!
: A study by Italian doctors and researchers published in the JAMA Internal Medicine medical journal alarmingly reveals that that 18% of recovered COVID-19 patients test positive for SARS-CoV-2, the virus that causes COVID-19, and that 3% ie 1 of 32, carry replicating virus in their respiratory tract. https://jamanetwork.com/journals/jama/fullarticle/10.1001/jamainternmed.2020.7570
Many patients who have recovered from COVID-19 with documented negative real-time polymerase chain reaction (RT-PCR) results at the time of recovery have had subsequent positive RT-PCR test results for SARS-CoV-2 in the absence of any symptoms suggestive of new infection. https://pubmed.ncbi.nlm.nih.gov/32105304/
Most of the time it is unknown whether such patients are infectious and whether they should be quarantined. Real-time PCR is not a viral culture and does not allow determination of whether the virus is viable and transmissible. We investigated RT-PCR retested positive nasal/oropharyngeal swab (NOS) samples from recovered patients with COVID-19 with prior negative results for the presence of replicative SARS-CoV-2 RNA. https://pubmed.ncbi.nlm.nih.gov/32235945/
The team studied 176 recovered patients with COVID-19 who were admitted to the postacute outpatient service of the researcher’s institution in Rome-Italy from April 21 to June 18, 2020, for COVID-19 follow-up. Before that, patients had discontinued isolation according to current criteria, which require no fever for 3 consecutive days, improvement in other symptoms, and 2 negative RT-PCR results for SARS-CoV-2 RNA 24 hours apart. https://pubmed.ncbi.nlm.nih.gov/32644129/
Nasal/oropharyngeal swab samples from patients at follow-up were analyzed for total (genomic) and replicative (subgenomic) SARS-CoV-2 RNA using RT-PCR assays. For patients with positive results for total RNA, samples previously obtained at the time of COVID-19 diagnosis and kept at −112 °F until testing were also tested for replicative RNA. Serological testing was performed for SARS-CoV-2 IgG/IgA detection. The ethics committee of the Fondazione Policlinico Universitario A. Gemelli IRCCS (Rome, Italy) approved the study, and written informed consent was obtained from each patient.
Alarmingly among the 176 patient NOS samples, 32 (18.2%) tested positive for genomic SARS-CoV-2 RNA, with viral loads ranging from 1.6 × 101 to 1.3 × 104 SARS-CoV2 RNA copies per milliliter.
The average time from diagnosis to follow-u
p in the SARS-CoV-2–positive patients was 48.6 days. One of the 32 positive samples (3.1%) had replicative, subgenomic SARS-CoV-2 RNA.
All but one of the 32 SARS-CoV-2–positive patients had a positive serology test at follow-up, as well as 139 of the remaining 144 patients. The patient who tested negative for SARS-CoV-2 antibodies was not the one with a positive test result for replicative SARS-CoV-2 RNA.
Lead researcher Dr Flora Marzia Liotti, PhD from the Università Cattolica del Sacro Cuore-Rome, told Thailand Medical News, "This study highlights that many patients who recovered from COVID-19 may be still positive (albeit at lower levels) for SARS-CoV-2 RNA, but only a minority of the patients may carry a replicating SARS-CoV-2 in the respiratory tract.”
At present no widely available test currently exists for determining viral reproduction and infectiousness, highlighting the need for further studies to verify whether recovered patients who test positive for SARS-CoV-2 are able to transmit the virus, the researchers note.
Also repeated testing for SARS-CoV-2 in recovered patients is complicated by highly sensitive RT-PCR testing that can detect nonviable remnants of the virus, leading to unnecessary quarantine and concerns about reinfection.
The study team concluded,” Similar to that reported elsewhere, 18% of patients with COVID-19 in our institution became RT-PCR positive for SARS-CoV-2 RNA after clinical recovery and previous negative results. As positivity in the patients was suggestive, but not necessarily a reflection, of viral carriage, we used replicative SARS-CoV-2 RNA detection as a proxy for virus replication in culture. This study highlights that many patients who recovered from COVID-19 may be still positive (albeit at lower levels) for SARS-CoV-2 RNA, but only a minority of the patients may carry a replicating SARS-CoV-2 in the respiratory tract. Further studies are needed to verify whether such patients can transmit the virus.” https://pubmed.ncbi.nlm.nih.gov/32492212/
This study highlights viral persistence in many recovered patients.
Considering that there are about 46.3 million recovered COVID-19 patients globally out of the infected 66.7 million cases so far, this is an area that needs further attention urgently.
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