SARS-CoV-2 re-positivity within the first 3 months of COVID-19 recovery; probable re-infection

Objectives Possibility of reinfection with SARS-CoV-2 changes our view on herd immunity and vaccination, and can impact worldwide quarantine policies. We performed RT-PCR follow-up studies on recovered patients to assess possible development of reinfections and re-positivity. Method During a 6-month period, 202 PCR-confirmed recovering COVID-19 patients entered this study. Follow-up RT-PCR tests and symptoms assessment were performed one month after the initial Positive results. patients who tested negative were tested again one and three months later. The Serum IgG and IgM levels were measured in the last follow-up session. Results In the first two follow-up sessions, 82 patients continued their participation, of which four patients tasted positive. In the second follow-up 44 patients participated, three of whom tested positive. None of the patients who tested positive in the first and second follow-up session were symptomatic. In the last session, 32 patients were tested and four patients were positive, three of them were mildly symptomatic and all of them were positive for IgG. Conclusion A positive RT-PCR in a recovering patient may represent reinfection. While we did not have the resources to prove reinfection by genetic sequencing of the infective viruses, we believe presence of mild symptoms in the three patients who tested positive over 100 days after becoming asymptomatic, can be diagnosed as reinfection. The IgG may have abated the symptoms of the reinfection, without providing complete protection.

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SARS-CoV-2 Reinfection within the first 3 months of COVID-19 Recovery in A Referral Hospital, Tehran, Iran

10.21203/rs.3.rs-271345/v1 ◽

2021 ◽

Author(s):

Sara Sadr ◽

Melika Arab Bafrani ◽

Alireza Abdollahi ◽

SeyedAhmad SeyedAlinaghi ◽

Esmaeil Mohammadnejad ◽

...

Keyword(s):

Herd Immunity ◽

Referral Hospital ◽

Rt Pcr ◽

Complete Protection ◽

Genetic Sequencing ◽

Serum Igg ◽

Asymptomatic Patients ◽

Follow Up Studies ◽

Positive Results

Abstract ObjectivesPossibility of reinfection with SARS-CoV-2 changes our view on herd immunity and vaccination, and can impact quarantine policies. We performed follow-up studies on recovered patients to assess possible development of reinfections.MethodDuring a 6-month period, 202 PCR-confirmed recovering COVID-19 patients entered this study. Follow-up RT-PCR tests and symptoms assessment were performed one month after the initial Positive results. patients who tested negative were tested again one and three months later. The Serum IgG and IgM levels were measured in the last follow-up session.ResultsIn the first two follow-up sessions, 82 (out of 202) and 44 patients participated with four and three asymptomatic patients testing positive. In the last session, 32 patients were tested and four were positive, three of them were mildly symptomatic and all of them were positive for IgG.ConclusionA positive RT-PCR in a recovering patient may represent reinfection. While we did not have the resources to prove reinfection by genetic sequencing of the infective viruses, we believe presence of mild symptoms in the three patients who tested positive over 100 days after becoming asymptomatic, can be diagnosed as reinfection. The IgG may have abated the symptoms of the reinfection, without providing complete protection.

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Clinical and epidemiologic characteristics of inconclusive results in SARS-CoV-2 RT-PCR assays

BMC Infectious Diseases ◽

10.1186/s12879-021-06534-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yong Kwan Lim ◽

Oh Joo Kweon ◽

Hye Ryoun Kim ◽

Tae-Hyoung Kim ◽

Mi-Kyung Lee

Keyword(s):

Infection Prevention ◽

Infection Prevention And Control ◽

Rt Pcr ◽

Subgenomic Rna ◽

Pcr Assays ◽

And Control ◽

Positive Results ◽

Epidemiologic Characteristics ◽

Respiratory Specimens

Abstract Background Inconclusive results in SARS-CoV-2 molecular assays cause confusion among clinicians and delay appropriate infection prevention and control. In this study, we aimed to characterize the respiratory specimens associated with inconclusive SARS-CoV-2 molecular assay results. Methods We re-evaluated inconclusive specimens by 3 additional RT-PCR assays and attempted to detect subgenomic RNA (sgRNA) in these specimens. Results Among follow-up tests from confirmed SARS-CoV-2 cases, 36.3% of the inconclusive results were classified as presumptive positive results (45/124). However, none of the specimens from 36 screening cases was classified as a presumptive positive result. Among 160 inconclusive specimens, sgRNAs were detected in 78 samples (48.8%): 58 were confirmed cases (58/124, 46.8%) and 20 were screening cases (20/36, 55.6%). Conclusions The results of our study suggest the recommendation of considering inconclusive results as positive results for confirmed SARS-CoV-2 cases. In screening cases, viral remnants could be partially amplified in PCR assays, and these inconclusive results could be related to previous infections. In addition, sgRNAs were detected in about half of the inconclusive specimens; however, the clinical significance of sgRNA is not yet clear.

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rt-PCR method for diagnosis and follow-up of hematological malignancies: First approach in Bangladesh

Bangladesh Medical Research Council Bulletin ◽

10.3329/bmrcb.v34i1.1162 ◽

2008 ◽

Vol 34 (1) ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Tanvira Afroze Sultana ◽

Md. Abdul Mottalib ◽

Md. Sirazul Islam ◽

Mohiuddin Ahmed Khan ◽

Subhagata Choudhury

Keyword(s):

Hematological Malignancies ◽

Residual Disease ◽

Strong Positive Correlation ◽

Rt Pcr ◽

Duration Of Treatment ◽

All Trans Retinoic Acid ◽

Pcr Method ◽

First Time ◽

Positive Results

Nested reverse-transcriptase polymerase chain reaction (rt-PCR) was performed on 58 leukemia patients at BIRDEM Laboratory, as a pioneering work in Bangladesh. Thirty of them were examined for the presence of BCR-ABL being clinically and morphologically diagnosed as chronic myeloid leukemia (CML) and 28 for PML-RARα fusion transcripts being clinically and morphologically diagnosed as acute promyelocytic leukemia (APL/ AML M3). The cases were selected for targeted therapy with imatinib mesylate and all-Trans retinoic acid (ATRA) to treat CML and APL respectively. Samples were received either before commencement or during therapy. In the positive cases, amplified DNA products were visible after gel electrophoresis and were reported accordingly. In case of BCR-ABL, positive results were found for five out of six (83.33%) untreated cases and 11 out of 24 (45.83%) treated cases. Positive results for PML-RARα were found for 12 out of 14 (85.70%) untreated cases and 11 out of 16 (68.75%) treated cases. A strong positive correlation was found between duration of treatment and negativity of PCR results in both the cases. In present times, the detection of minimal residual disease in patients undergoing treatment for hematological malignancies has become an important goal, not only to monitor the effectiveness of therapy but also to detect an impending relapse. This is the first time in Bangladesh that rt-PCR method is being employed to detect or monitor the presence of abnormal fusion genes in hematological malignancies. Keywords: Bangladesh; malignancy; rt-pcrDOI: 10.3329/bmrcb.v34i1.1162Bangladesh Med Res Counc Bull 2008; 34: 1-11

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Positive results for patients with COVID-19 discharged form hospital in Chongqing, China

10.21203/rs.3.rs-17725/v4 ◽

2020 ◽

Author(s):

Wang Deng ◽

Tian-wen Guang ◽

Mei Yang ◽

Jian-rong Li ◽

De-peng Jiang ◽

...

Keyword(s):

Clinical Evidence ◽

Medical Illness ◽

Test Results ◽

Rt Pcr ◽

Pharyngeal Swab ◽

Viral Nucleic Acid ◽

Negative Results ◽

Chronic Medical Illness ◽

Positive Results

Abstract Background: Since December 2019, over 80,000 patients with coronavirus disease 2019 (COVID-19) have been confirmed in China. With the increasing number of recovered patients, more attention should be paid to the follow-up of these patients. Methods: In the study, 576 patients with COVID-19 discharged from hospital in Chongqing, China from January 24, 2020, to March 10, 2020 were evaluated by viral nucleic acid tests for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) to determine if they could be released from quarantine. Among the 576 patients, 61 patients (10.6%) had positive RT-PCR test results of SARS-CoV-2. We aimed to analyze the demographics, clinical characteristics and treatment of 61 patients.Results: These positive patients were characterized by older age, chronic medical illness and mild conditions. 38 (62.3%) patients who were asymptomatic without abnormalities on chest radiographs were found in the positive with COVID-19. Also, they showed positive results of stool or sputum specimens with negative results of nasal and pharyngeal swab specimens. The median duration of positive result of SARS-CoV-2 was varied from 3 days to 35 days in the patients discharged from hospital with no family member infection. Conclusions: Multi-site screening of SARS-CoV-2 including nasal and pharyngeal swabs, stool and sputum specimens could be considered to improve the diagnosis, treatment and infection control in patients with COVID-19. Our findings provide the important information and clinical evidence for the improved management of patients recovered from COVID-19

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Positive results for patients with COVID-19 discharged form hospital in Chongqing, China

10.21203/rs.3.rs-17725/v3 ◽

2020 ◽

Author(s):

Wang Deng ◽

Tian-wen Guang ◽

Mei Yang ◽

Jian-rong Li ◽

De-peng Jiang ◽

...

Keyword(s):

Clinical Evidence ◽

Medical Illness ◽

Test Results ◽

Rt Pcr ◽

Pharyngeal Swab ◽

Viral Nucleic Acid ◽

Negative Results ◽

Chronic Medical Illness ◽

Positive Results

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The value of multi-marker reverse transcriptase-polymerase chain reaction (MM RT-PCR) assay in lymphatic drainage (LY) and peripheral blood (BL) for molecular staging of melanoma patients (pts) after lymph node dissection (LND)

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.8053 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 8053-8053

Author(s):

W. Ruka ◽

Z. I. Nowecki ◽

P. Rutkowski ◽

J. Kulik ◽

E. Lorenc ◽

...

Keyword(s):

Lymph Node ◽

Regional Lymph Node ◽

Disease Free Survival ◽

Melanoma Cells ◽

Rt Pcr ◽

Pcr Assay ◽

Melanoma Patients ◽

Pcr Assays ◽

Positive Results

8053 Background: We assessed the presence of melanoma cells in LY and BL in melanoma pts after LND with MM RT-PCR assay for the evaluation of disease outcomes. Methods: Between 05/2002 and 06/2005 we collected 24-hr LY in 207 stage III melanoma patients after radical LND (91 - completion LND after positive sentinel node biopsy - CLND and 116 - therapeutic LND for clinically/cytologically detected regional lymph node (LN) metastases - TLND). In 101 pts (since 02/2004) we have simultaneously collected a 5 ml sample of BL. In order to detect melanoma cells, RT-PCR assays with primers specific for tyrosinase, MART1 (MelanA) and uMAGE mRNA were applied. The drain fluid or BL sample was assumed to be positive if the presence of at least 1 marker was detected in the assay. Median follow-up time for survivors was 13 months (range: 4 - 39 months). Results: The LY MM RT-PCR assay results were positive in 57/207 pts (27.5%) - in 13 for tyrosinase only, in 17 for MART1 only, in 10 for uMAGE only, in 13 for a combination of the two markers and in 4 simultaneously for all three markers. We observed a significantly higher rate of recurrences in pts with positive LY MM RT-PCR results (44/57 cases; 77%) than in those with negative results (72/150 cases; 48%; p=0.0004). Positive results of the LY MM RT-PCR correlated with established predictive factors: the number of involved lymph nodes (p=0.03), extracapsular extension of LN metastases (p=0.004) and type of LND (CLND vs. TLND; p = 0.0004). We observed a significant relationship between positive LY MM RT-PCR results and shorter overall (OS) and disease free survival (DFS), both in univariate and multivariate analyses. In 107 pts, in whom the LY and BL MM RT-PCR assays were analyzed concurrently, we found positive results of the LY RT-PCR assay in 33 cases (32.7%) and the BL RT-PCR assay in 24 cases (23.7%) (17 of these positive results were detected in both tests), but longer follow-up time is necessary to perform a survival analysis in this group. Conclusions: We observed positive results of MM RT-PCR assay for melanoma cells in approximately 28% of LY after LND, which correlated significantly with early melanoma recurrences and shorter survival. No significant financial relationships to disclose.

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Specific allelic discrimination of N501Y and other SARS-CoV-2 mutations by ddPCR detects B.1.1.7 lineage in Washington State

10.1101/2021.03.10.21253321 ◽

2021 ◽

Author(s):

Garrett A. Perchetti ◽

Haiying Zhu ◽

Margaret G. Mills ◽

Lasata Shrestha ◽

Cassia Wagner ◽

...

Keyword(s):

Real Time ◽

Washington State ◽

Molecular Diagnostic ◽

Diagnostic Tools ◽

Rt Pcr ◽

Allelic Discrimination ◽

Genetic Sequencing ◽

S Gene ◽

Generation Sequencing

ABSTRACTReal-time epidemiological tracking of variants of interest can help limit the spread of more contagious forms of SARS-CoV-2, such as those containing the N501Y mutation. Typically, genetic sequencing is required to be able to track variants of interest in real-time. However, sequencing can take time and may not be accessible in all laboratories. Genotyping by RT-ddPCR offers an alternative to sequencing to rapidly detect variants of concern through discrimination of specific mutations such as N501Y that is associated with increased transmissibility. Here we describe the first cases of the B.1.1.7 lineage of SARS-CoV-2 detected in Washington State by using a combination of RT-PCR, RT-ddPCR, and next-generation sequencing. We screened 1,035 samples positive for SARS-CoV-2 by our CDC-based laboratory developed assay using ThermoFisher’s multiplex RT-PCR COVID-19 assay over four weeks from late December 2020 to early January 2021. S gene dropout candidates were subsequently assayed by RT-ddPCR to confirm four mutations within the S gene associated with the B.1.1.7 lineage: a deletion at amino acid (AA) 69-70 (ACATGT), deletion at AA 145, (TTA), N501Y mutation (TAT), and S982A mutation (GCA). All four targets were detected in two specimens, and follow-up sequencing revealed a total of 10 mutations in the S gene and phylogenetic clustering within the B.1.1.7 lineage. As variants of concern become increasingly prevalent, molecular diagnostic tools like RT-ddPCR can be utilized to quickly, accurately, and sensitively distinguish more contagious lineages of SARS-CoV-2.

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