The Possibility and Cause of Relapse After Previously Recovering From COVID-19: A Systematic Review

Association of Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease with Coronavirus Disease 2019 Vaccination and Infection: A Case Report of Cortical Encephalitis and Transverse Myelitis Relapse

We herein report a case of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) that occurred following coronavirus disease 2019 (COVID-19) vaccination and its subsequent relapse after COVID-19 infection. A 34-year-old woman developed cortical encephalitis in the right temporoparietal lobe one week after receiving the mRNA-1273 vaccine. The cerebrospinal fluid was positive for anti-MOG antibody. Her symptoms gradually improved after three courses of intravenous methylprednisolone therapy. Six months later, she experienced a relapse of transverse myelitis following COVID-19 infection. Despite treatment with plasma exchange, the patient remained paralyzed in both lower limbs. We herein review the relationship between MOGAD and COVID-19 vaccination/infection.

Recurrent SARS-CoV-2 infections and their potential risk to public health - a systematic review

OBJECTIVE

To inform quarantine and contact-tracing policies concerning re-positive cases-cases testing positive among those recovered.

MATERIALS AND METHODS

We systematically reviewed and appraised relevant literature from PubMed and Embase for the extent of re-positive cases and their epidemiological characteristics.

RESULTS

In 90 case reports/series, a total of 276 re-positive cases were found. Among confirmed reinfections, 50% occurred within 90 days from recovery. Four reports related onward transmission. In thirty-five observational studies, rate of re-positives ranged from zero to 50% with no onward transmissions reported. In eight reviews, pooled recurrence rate ranged from 12% to 17.7%. Probability of re-positive increased with several factors.

CONCLUSION

Recurrence of a positive SARS-CoV-2 test is commonly reported within the first weeks following recovery from a first infection.

Overview of the pathogenesis of COVID-19 (Review)

At present, the pathogenesis of the novel coronavirus disease 2019 (COVID-19) has not been fully elucidated. Clinical and experimental findings from studies investigating COVID-19 have suggested that the immune-inflammatory response has a crucial role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The present article aimed to systematically review the available literature on the pathogenesis of COVID-19. Severe COVID-19 is characterized by organ dysfunction, hypercytokinemia and lymphopenia. It is assumed that the direct cytopathological damage of host cells and the dysregulated immune response caused by SARS-CoV-2 may be the primary underlying mechanisms of COVID-19. Based on the published literature, this review attempts to provide an integrated view of the immunological mechanisms and the potential pathogenesis of COVID-19, providing an in-depth summary of the host-pathogen interaction and host immune responses. It is of great importance to elucidate the possible pathogenesis of COVID-19 to determine the direction of future research.

A systematic review and meta-analysis of discharged COVID-19 patients retesting positive for RT-PCR

BACKGROUND

With the increased number of patients discharged after having COVID-19, more and more studies have reported cases whose retesting was positive (RP) during the convalescent period, which brings a new public health challenge to the world.

METHODS

We searched PubMed, Web of Science, The Cochrane Library, CNKI, WanFang and VIP from December 1, 2019 to December 31, 2020. The included studies were assessed using JBI critical appraisal tools and Newcastle-Ottawa Scale. The RP rate of discharge patients was analyzed by a meta-analysis. We adhered to PRISMA reporting guideline.

FINDINGS

We have included 117 studies with 2669 RP participants after discharge. The methodological quality of 66 case reports were low to high, 42 case series and 3 cohort study were moderate to high, 3 case-control studies were moderate and 3 cross-sectional studies were low to moderate. The clinical manifestations of most RP patients were mild or asymptomatic, and CT imaging and laboratory examinations were usually normal. The existing risk factors suggest that more attention should be paid to sever patients, elderly patients, and patients with co-morbidities. The summary RP rate was 12·2% (95% CI 10·6-13·7) with high heterogeneity (I²  = 85%).

INTERPRETATION

To date, the causes and risk factors of RP result in discharged patients are not fully understood. High-quality etiological and clinical studies are needed to investigate these issues to further help us to make strategies to control and prevent its occurrence.

Repeated SARS-CoV-2 Positivity: Analysis of 123 Cases

Repeated positivity and reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is a significant concern. Our study aimed to evaluate the clinical significance of repeatedly positive testing after coronavirus disease 2019 (COVID-19) recovery. We performed a systematic literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. With available individual patient data reporting on repeatedly SARS-CoV-2 positive (RSP) patients, case reports, and case series were included in this analysis. We performed a descriptive analysis of baseline characteristics of repeatedly positive cases. We assessed the cases according to the length of their polymerase chain reaction (PCR) negative interval between the two episodes. Risk factors for the severity of second episodes were evaluated. Overall, we included 123 patients with repeated positivity from 56 publications, with a mean repeated positivity length of 47.8 ± 29.9 days. Younger patients were predominant in the delayed (>90 days) recurrent positive group. Furthermore, comparing patients with RSP intervals of below 60 and above 60 days, we found that a more severe disease course can be expected if the repeated positivity interval is shorter. Severe and critical disease courses might predict future repeatedly positive severe and critical COVID-19 episodes. In conclusion, our results show that the second episode of SARS-CoV-2 positivity is more severe if it happens within 60 days after the first positive PCR. On the other hand, the second episode's severity correlates with the first.