A Case Series of Recurrent Viral RNA Positivity in Recovered COVID-19 Chinese Patients

Characteristics of patients with SARS-COV-2 PCR re-positivity after recovering from COVID-19

The purpose of this study was to analyse the clinical characteristics of patients with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) PCR re-positivity after recovering from coronavirus disease 2019 (COVID-19). Patients (n = 1391) from Guangzhou, China, who had recovered from COVID-19 were recruited between 7 September 2021 and 11 March 2022. Data on epidemiology, symptoms, laboratory test results and treatment were analysed. In this study, 42.7% of recovered patients had re-positive result. Most re-positive patients were asymptomatic, did not have severe comorbidities, and were not contagious. The re-positivity rate was 39%, 46%, 11% and 25% in patients who had received inactivated, mRNA, adenovirus vector and recombinant subunit vaccines, respectively. Seven independent risk factors for testing re-positive were identified, and a predictive model was constructed using these variables. The predictors of re-positivity were COVID-19 vaccination status, previous SARs-CoV-12 infection prior to the most recent episode, renal function, SARS-CoV-2 IgG and IgM antibody levels and white blood cell count. The predictive model could benefit the control of the spread of COVID-19.

Serum Proteomic Analysis for New Types of Long-Term Persistent COVID-19 Patients in Wuhan

The emergence of a new type of COVID-19 patients, who were retested positive after hospital discharge with long-term persistent SARS-CoV-2 infection but without COVID-19 clinical symptoms (hereinafter, LTPPs), poses novel challenges to COVID-19 treatment and prevention. Why was there such a contradictory phenomenon in LTPPs? To explore the mechanism underlying this phenomenon, we performed quantitative proteomic analyses using the sera of 12 LTPPs (Wuhan Pulmonary Hospital), with the longest carrying history of 132 days, and mainly focused on 7 LTPPs without hypertension (LTPPs-NH). The results showed differential serum protein profiles between LTPPs/LTPPs-NH and health controls. Further analysis identified 174 differentially-expressed-proteins (DEPs) for LTPPs, and 165 DEPs for LTPPs-NH, most of which were shared. GO and KEGG analyses for these DEPs revealed significant enrichment of "coagulation" and "immune response" in both LTPPs and LTPPs-NH. A unity of contradictory genotypes in the 2 aspects were then observed: some DEPs showed the same dysregulated expressed trend as that previously reported for patients in the acute phase of COVID-19, which might be caused by long-term stimulation of persistent SARS-CoV-2 infection in LTPPs, further preventing them from complete elimination; in contrast, some DEPs showed the opposite expression trend in expression, so as to retain control of COVID-19 clinical symptoms in LTPPs. Overall, the contrary effects of these DEPs worked together to maintain the balance of LTPPs, further endowing their contradictory steady-state with long-term persistent SARS-CoV-2 infection but without symptoms. Additionally, our study revealed some potential therapeutic targets of COVID-19. Further studies on these are warranted. IMPORTANCE This study reported a new type of COVID-19 patients and explored the underlying molecular mechanism by quantitative proteomic analyses. DEPs were significantly enriched in "coagulation" and "immune response". Importantly, we identified 7 "coagulation system"- and 9 "immune response"-related DEPs, the expression levels of which were consistent with those previously reported for patients in the acute phase of COVID-19, which appeared to play a role in avoiding the complete elimination of SARS-CoV-2 in LTPPs. On the contrary, 6 "coagulation system"- and 5 "immune response"-related DEPs showed the opposite trend in expression. The 11 inconsistent serum proteins seem to play a key role in the fight against long-term persistent SARS-CoV-2 infection, further retaining control of COVID-19 clinical symptom of LTPPs. The 26 proteins can serve as potential therapeutic targets and are thus valuable for the treatment of LTPPs; further studies on them are warranted.

The prevalence of adaptive immunity to COVID-19 and reinfection after recovery - a comprehensive systematic review and meta-analysis

This study aims to estimate the prevalence and longevity of detectable SARS-CoV-2 antibodies and T and B memory cells after recovery. In addition, the prevalence of COVID-19 reinfection and the preventive efficacy of previous infection with SARS-CoV-2 were investigated. A synthesis of existing research was conducted. The Cochrane Library, the China Academic Journals Full Text Database, PubMed, and Scopus, and preprint servers were searched for studies conducted between 1 January 2020 to 1 April 2021. Included studies were assessed for methodological quality and pooled estimates of relevant outcomes were obtained in a meta-analysis using a bias adjusted synthesis method. Proportions were synthesized with the Freeman-Tukey double arcsine transformation and binary outcomes using the odds ratio (OR). Heterogeneity was assessed using the I² and Cochran's Q statistics and publication bias was assessed using Doi plots. Fifty-four studies from 18 countries, with around 12,000,000 individuals, followed up to 8 months after recovery, were included. At 6-8 months after recovery, the prevalence of SARS-CoV-2 specific immunological memory remained high; IgG - 90.4% (95%CI 72.2-99.9, I² = 89.0%), CD4+ - 91.7% (95%CI 78.2-97.1y), and memory B cells 80.6% (95%CI 65.0-90.2) and the pooled prevalence of reinfection was 0.2% (95%CI 0.0-0.7, I² = 98.8). Individuals previously infected with SARS-CoV-2 had an 81% reduction in odds of a reinfection (OR 0.19, 95% CI 0.1-0.3, I² = 90.5%). Around 90% of recovered individuals had evidence of immunological memory to SARS-CoV-2, at 6-8 months after recovery and had a low risk of reinfection.RegistrationPROSPERO: CRD42020201234.

The importance of fecal nucleic acid detection in patients with coronavirus disease(COVID-19):a systematic review and meta-analysis

Pooled data from 2352 hospitalized coronavirus disease 2019 (COVID‐19) patients with viral RNA in feces across 46 studies were analyzed and the pooled prevalence of fecal RNA was 46.8% (95% confidence interval [CI]: 0.383–0.554). The pooled analysis showed that the occurrence of total gastrointestinal (GI) symptoms was 28.5% (95% CI: 0.125–0.44) in COVID‐19 patients with fecal RNA, that of both respiratory and GI symptoms was 21.9% (95% CI: 0.09–0.346), that of only GI symptoms was 19.8% (95% CI: 0.107–0.288), and that of only respiratory symptoms was 50.5%（95% CI: 0.267–0.744). The pooled data showed no significant difference in positive fecal RNA between severe and nonsevere cases (odds ratio = 2.009, p = 0.079, 95% CI: 0.922–4.378). During hospital admission, after samples from the respiratory system tested negative for viral RNA, 55.4% (95% CI: 0.418–0.669) of the patients with positive fecal RNA had persistent shedding of fecal RNA and pooled results from the other 4 studies including 848 discharged patients with nucleic acid‐negative stool samples indicated that the occurrence of repositive stool swabs was 18.1% (95% CI: 0.028–0.335), that of repositive respiratory swabs was 22.8% (95% CI: 0.003–0.452), that of both repositive stool and respiratory swabs was 19.1% (95% CI: 0.019–0.363), and that of only repositive stool swabs was 9.6% (95% CI: 0.010–0.203). The digestive tract may be an important organ involved in COVID‐19 infection and in the excretion of the virus. Because of the potential risk of fecal–oral transmission, giving emphasis on stool swab tests can help increase the detection rate of asymptomatic carriers and reduce missed diagnoses.

A systematic review on SARS-CoV-2 remission: an Emerging challenge for its management, treatment, immunization strategies and post-treatment guidelines

The COVID-19 disease caused by severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2) has posed as a major health concern for people all across the globe. Along with the increasing confirmed patients being readmitted with complaints for fever, cough, cold, the effective monitoring of 'relapse' of the SARS-CoV-2 virus in the previously discharged patients have become the next area of focus. However, availability of limited data on reactivation of SARS-CoV-2 makes the disease prognosis as well as the effective control of re-infection an immense challenge. Prompted by these challenges, we assessed the possibility of re-infection in discharged patients and the risk of the transmission, proficiency of RT-PCR results and approximate period required for the quarantine and the real challenges for the development of vaccine. In the present review, the published literature on all the possible cases of re-infection from February to July were reported, thereby selected 142 studies from a hub of overall 669 studies after full text screening. The incomplete virus clearance, poor sensitivity of the present diagnostic testing, emergence of mutant strains, insufficient mucus collection from the throat swab etc. are some of the possible causes of re-infection. The new protocols for management of COVID-19 discharged patients should be revised in the guidelines.

The mystery of COVID-19 reinfections: A global systematic review and meta-analysis

BACKGROUND

As the COVID-19 pandemic rages on, reports on disparities in vaccine roll out alongside COVID-19 reinfection have been emerging. We conducted a systematic review to assess the determinants and disease spectrum of COVID-19 reinfection.

MATERIALS AND METHODS

A comprehensive search covering relevant databases was conducted for observational studies reporting Polymerase Chain Reaction (PCR) confirmed infection and reinfection cases. A quality assessment tool developed by the National Institute of Health (NIH) for the assessment of case series was utilized. Meta-analyses were performed using RevMan 5.3 for pooled proportions of findings in first infection and reinfection with a 95% confidence interval (CI).

RESULTS

Eighty-one studies reporting 577 cases were included from 22 countries. The mean age of patients was 46.2 ± 18.9 years and 179 (31.0%) cases of comorbidities were reported. The average time duration between first infection and reinfection was 63.6 ± 48.9 days. During first infection and reinfection, fever was the most common symptom (41.4% and 36.4%, respectively) whilst anti-viral therapy was the most common treatment regimen administered (44.5% and 43.0%, respectively). Comparable odds of symptomatic presentation and management were reported for the two infections. However, a higher Intensive Care Unit (ICU) admission rate was observed in reinfection compared to first infection (10 vs 3). Ten deaths were reported with respiratory failure being the most common cause of death (7/10 deaths).

CONCLUSION

Our findings support immunization practices given increased ICU admissions and mortality in reinfections. Our cohort serves as a guide for clinicians and authorities in devising an optimal strategy for controlling the pandemic. (249 words).

Clinical features and independent predictors for recurrence of positive SARS-CoV-2 RNA: A propensity score-matched analysis

Patients with COVID‐19 may be recurrence positive for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) RNA after being cured and discharged from the hospital. The aim of this study was to explore independent influencing factors as markers for predicting positive SARS‐CoV‐2 RNA recurrence. The study included 601 COVID‐19 patients who were cured and discharged from the Public and Health Clinic Centre of Chengdu from January 2020 to March 2021, and the recurrence positive of patients within 6 weeks after SARS‐CoV‐2 RNA turned negative was followed up. We used propensity score matching to eliminate the influence of confounding factors, and multivariate Logistic regression analysis was used to determine the independent influencing factors for positive SARS‐CoV‐2 RNA recurrence. Multivariate Logistic regression showed that the elevated serum potassium (odds ratio [OR] = 6.537, 95% confidence interval [CI]: 1.864–22.931, p = 0.003), elevated blood chlorine (OR = 1.169, 95% CI: 1.032–1.324, p = 0.014) and elevated CD3⁺CD4⁺ count (OR = 1.003, 95% CI: 1.001–1.004, p < 0.001) were identified as independent risk factors for positive SARS‐CoV‐2 RNA recurrence (p < 0.05). The difference in virus shedding duration (OR = 1.049, 95% CI: 1.000–1.100, p = 0.05) was borderline statistically significant. For sensitivity analysis, we included virus shedding duration as a categorical variable in the model again and found that the OR value related to recurrence positively increased with delayed virus shedding duration, and the trend test showed a statistical difference (P trend = 0.03). Meanwhile, shortening of activated partial prothrombinase time (OR = 0.908, 95% CI: 0.824–1.000, p = 0.049) was identified as an independent protection factor for SARS‐CoV‐2 RNA recurrence positive. We have identified independent factors that affect the recurrence of SARS‐CoV‐2 RNA positive. It is recommended that doctors pay attention to these indicators when first admitted to the hospital.

How strong is the evidence that it is possible to get SARS-CoV-2 twice? A systematic review

With a large number of coronavirus disease 2019 (Covid-19) patients being discharged from hospital with negative test results for SARS-CoV-2, it has been reported that several recovered cases tested positive after discharge (re-positive, RP). This finding has raised several important questions for this novel coronavirus and Covid-19 disease. In this review, we have discussed several important questions, including: (1) Can the virus re-infect recovered individuals? (2) What are the possible causes of the re-positive reverse transcriptase-polymerase chain reaction (RT-PCR) test in recovered patients? (3) What are the implications of these re-positive cases concerning the spread of the virus? Understanding how recovery from Covid-19 confers immunity to decrease the risk of re-infection is needed to inform current efforts to safely scale back population-based interventions, such as physical distancing. We have also described what is currently known about the immune response to Covid-19, highlighted key gaps in knowledge, and identified opportunities for future research. Overall, the quality of the evidence is poor and we describe the features that should be described for future cases.

Residual Lung Injury in Patients Recovering From COVID-19 Critical Illness: A Prospective Longitudinal Point-of-Care Lung Ultrasound Study

Scarce data exist regarding the natural history of lung lesions detected on ultrasound in those who survive severe COVID-19 pneumonia.

OBJECTIVE

We performed a prospective analysis of point-of-care ultrasound (POCUS) findings in critically ill COVID-19 patients during and after hospitalization.

METHODS

We enrolled 171 COVID-19 intensive care unit patients. POCUS of the lungs was performed with phased array (2-4 MHz), convex (2-6 MHz) and linear (10-15 MHz) transducers, scanning 12 lung areas. Chest computed tomography angiography was performed to exclude suspected pulmonary embolism. Survivors were clinically and sonographically evaluated during a 4 month period for evidence of residual lung injury. Chest computed tomography angiography and echocardiography were used to exclude pulmonary hypertension (PH) and chest high-resolution-computed-tomography to exclude interstitial lung disease (ILD) in symptomatic survivors.

RESULTS

Cox regression analysis showed that lymphocytopenia (hazard ratio [HR]: 0.88, 95% confidence intervals [CI]: 0.68-0.96, p = .048), increased lactate (HR: 1.17, 95% CI: 0.94-1.46, p = 0.049), and D-dimers (HR: 1.21, 95% CI: 1.03-1.44, p = .03) were mortality predictors. Non-survivors had increased incidence of pulmonary abnormalities (B-lines, pleural line irregularities, and consolidations) compared to survivors (p < .05). During follow-up, POCUS with clinical and laboratory parameters integrated in the semi-quantitative Riyadh-Residual-Lung-Injury scale had sensitivity of 0.82 (95% CI: 0.76-0.89) and specificity of 0.91 (95% CI: 0.94-0.95) in predicting ILD. The prevalence of PH and ILD (non-specific-interstitial-pneumonia) was 7% and 11.8%, respectively.

CONCLUSION

POCUS showed ability to monitor the evolution of severe COVID-19 pneumonia after hospital discharge, supporting its integration in clinical predictive models of residual lung injury.

Recurrence, Reactivation, or Inflammatory Rebound of SARS-CoV-2 Infection With Acute Vestibular Symptoms: A Case Report and Revision of Literature

A case of recurrent coronavirus disease 2019 (COVID-19) with neurovestibular symptoms was reported. In March 2020, a physician working in an Italian pediatric hospital had flu-like symptoms with anosmia and dysgeusia, and following a reverse transcription PCR (RT/PCR) test with a nasopharyngeal swab tested positive for SARS-CoV-2. After home quarantine, 21 days from the beginning of the symptoms, the patient tested negative in two subsequent swabs and was declared healed and readmitted to work. Serological testing showed a low level of immunoglobulin G (IgG) antibody title and absence of immunoglobulin M (IgM). However, 2 weeks later, before resuming work, the patient complained of acute vestibular syndrome, and the RT/PCR test with mucosal swab turned positive. On the basis of the literature examined and reviewed for recurrence cases and vestibular symptoms during COVID-19, to our knowledge this case is the first case of recurrence with vestibular impairment as a neurological symptom, and we defined it as probably a viral reactivation. The PCR retest positivity cannot differentiate re-infectivity, relapse, and dead-viral RNA detection. Serological antibody testing and viral genome sequencing could be always performed in recurrence cases.

Continued nucleic acid tests for SARS-CoV-2 following discharge of patients with COVID-19 in Lu'an, China

BACKGROUND

Studies have shown that discharged Coronavirus disease 2019 (COVID-19) patients have retested positive for SARS-CoV-2 during a follow-up RT-PCR test. We sought to assess the results of continued nucleic acid testing for SARS-CoV-2 patients in COVID-19 patients after they were discharged in Lu'an, China.

METHODS

We conducted RT-PCR tests on sputum, throat swabs, fecal or anal swabs, and urine samples collected from 67 COVID-19 patients following discharge. Samples were collected on the 7th and 14th days following discharge. Patients testing positive on the 7th or 14th day were retested after 24 hours until they tested negative twice.

RESULTS

Seventeen (17/67, 25.4%) discharged COVID-19 patients had a positive RT-PCR retest for SARS-CoV-2. Among them, 14 (82.4%) were sputum positive, five (29.4%) were throat swab positive, seven (41.2%) were fecal or anal swab positive, one (5.9%) was urine sample positive, five (29.4%) were both sputum and throat swab positive, four (23.5%) were both sputum and fecal test positive, and one (5.9%) was positive of all four specimens. The shortest period of time between discharge and the last positive test was 7 days, the longest was 48 days, and the median was 16 days. The proportion of positive fecal or anal swab tests increased from the third week. The median Cq cut-off values after onset were 26.7 after the first week, 37.7 the second to sixth week, and 40 after the sixth week. There were no significant differences between the RT-PCR retest positive group and the unrecovered positive group.

CONCLUSIONS

There was a high proportion of patients who retested positive for COVID-19. Discharge criteria have remained fairly consistent so we encourage regions affected by COVID-19 to appropriately amend their current criteria.

Reinfection or Reactivation of Severe Acute Respiratory Syndrome Coronavirus 2: A Systematic Review

As the pandemic continues, individuals with re-detectable positive (RP) SARS-CoV-2 viral RNA among recovered COVID-19 patients have raised public health concerns. It is imperative to investigate whether the cases with re-detectable positive (RP) SARS-CoV-2 might cause severe infection to the vulnerable population. In this work, we conducted a systematic review of recent literature to investigate reactivation and reinfection among the discharged COVID-19 patients that are found positive again. Our study, consisting more than a total of 113,715 patients, indicates that the RP-SARS-CoV-2 scenario occurs plausibly due to reactivation, reinfection, viral shedding, or testing errors. Nonetheless, we observe that previously infected individuals have significantly lower risk of being infected for the second time, indicating that reactivation or reinfection of SARS-CoV-2 likely have relatively less impact in the general population than the primary infection.

A systematic review on the recurrence of SARS-CoV-2 virus: frequency, risk factors, and possible explanations

BACKGROUND

Since late 2019, SARS-CoV-2 which leads to coronavirus disease 2019 (COVID-19), has caused thousands of deaths. There are some pieces of evidence that SARS-CoV-2 genome could be re-detectable in recovered patients.

METHODS

We performed a systematic review in the PubMed/Medline database to address the risk of SARS-CoV-2 recurrence. The last update was for 20 November 2020. Among the 1178 initially found articles, 66 met the inclusion criteria and were considered.

FINDINGS

In total, 1128 patients with at least one-time recurrence of SARS-CoV-2 were included. Recurrence rate has been reported between 2.3% and 21.4% in cohort studies, within a mean of 20 (ranged 1-98) days after discharge; younger patients are being affected more. Following the second course of disease, the disease severity decreased or remained unchanged in 97.3% while it increased in 2.6%. Anti-SARS-CoV-2 IgG and IgM were positive in 11-95% and 58.8-100%, respectively. Based on the literature, three possibilities include reactivation of previous disease, reinfection with the same virus, and false negative, which have been discussed in details.

CONCLUSION

There is a relatively notable risk of disease recurrence in previously recovered patients, even those who are immunised against the virus. More studies are required to clarify the underlying cause of this phenomenon.

COVID-19 re-infection in Shahroud, Iran: a follow-up study

Although many people became infected and recovered during the COVID-19 epidemic, the immunity duration and re-infection in recovered patients have recently attracted many researchers. The aim of this study was to evaluate the recurrence of the infection in recovered individuals over a 9-month period after the onset of the COVID-19 epidemic. In this study, data related to COVID-19 patients in Shahroud city were collected using the electronic system for registering suspicious patients and also by checking patients' hospital records. In this study, from 20 March 2020 to 20 November 2020 (9 months), a total of 8734 suspected patients with respiratory symptoms were observed and followed up. RT-PCR was positive for 4039 patients. During this period, out of the total number of positive cases of COVID-19, 10 cases became re-infected after complete recovery. The risk of re-infection was 2.5 per thousand (0.95 CI 1.2–4.5). The mean time interval between the first infection and re-infection was 134.4 ± 64.5 days (range 41–234 days). The risk of re-infection between male and females was not statistically different (1.98 per 1000 women and 2.96 per 1000 men). Exposure to COVID-19 may not establish long-term protective immunity to all patients and may predispose them to re-infection. This fact can be reminded that the use of masks, social distancing and other preventive measures are very important in recovered patients and should be emphasised especially in health care personnel who are more exposed to the virus.

Prevalence and Persistent Shedding of Fecal SARS-CoV-2 RNA in Patients With COVID-19 Infection: A Systematic Review and Meta-analysis

INTRODUCTION

The prevalence and shedding of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA indicate coronavirus disease 2019 (COVID-19) infection in the gastrointestinal (GI) tract and likely infectivity. We performed a systemic review and meta-analysis to evaluate the prevalence and the duration of shedding of fecal RNA in patients with COVID-19 infection.

METHODS

PubMed, Embase, Web of Science, and Chinese databases Chinese National Knowledge Infrastructure and Wanfang Data up to June 2020 were searched for studies evaluating fecal SARS-CoV-2 RNA, including anal and rectal samples, in patients with confirmed COVID-19 infection. The pooled prevalence of fecal RNA in patients with detectable respiratory RNA was estimated. The days of shedding and days to loss of fecal and respiratory RNA from presentation were compared.

RESULTS

Thirty-five studies (N = 1,636) met criteria. The pooled prevalence of fecal RNA in COVID-19 patients was 43% (95% confidence interval [CI] 34%-52%). Higher proportion of patients with GI symptoms (52.4% vs 25.9%, odds ratio = 2.4, 95% CI 1.2-4.7) compared with no GI symptoms, specifically diarrhea (51.6% vs 24.0%, odds ratio = 3.0, 95% CI 1.9-4.8), had detectable fecal RNA. After loss of respiratory RNA, 27% (95% CI 15%-44%) of the patients had persistent shedding of fecal RNA. Days of RNA shedding in the feces were longer than respiratory samples (21.8 vs 14.7 days, mean difference = 7.1 days, 95% CI 1.2-13.0). Furthermore, days to loss of fecal RNA lagged respiratory RNA by a mean of 4.8 days (95% CI 2.2-7.5).

DISCUSSION

Fecal SARS-CoV-2 RNA is commonly detected in COVID-19 patients with a 3-fold increased risk with diarrhea. Shedding of fecal RNA lasted more than 3 weeks after presentation and a week after last detectable respiratory RNA.

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.

A Case Series Describing the Recurrence of COVID-19 in Patients Who Recovered from Initial Illness in Bangladesh

To date, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected over 80 million people globally. We report a case series of five clinically and laboratory confirmed COVID-19 patients from Bangladesh who suffered a second episode of COVID-19 illness after 70 symptom-free days. The International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), is a leading public health research institution in South Asia. icddr, b staff were actively tested, treated and followed-up for COVID-19 by an experienced team of clinicians, epidemiologists, and virologists. From 21 March to 30 September 2020, 1370 icddr,b employees working at either the Dhaka (urban) or Matlab (rural) clinical sites were tested for COVID-19. In total, 522 (38%) were positive; 38% from urban Dhaka (483/1261) and 36% from the rural clinical site Matlab (39/109). Five patients (60% male with a mean age of 41 years) had real-time reverse transcription-polymerase chain reaction (rRT-PCR) diagnosed recurrence (reinfection) of SARS-CoV-2. All had mild symptoms except for one who was hospitalized. Though all cases reported fair risk perceptions towards COVID-19, all had potential exposure sources for reinfection. After a second course of treatment and home isolation, all patients fully recovered. Our findings suggest the need for COVID-19 vaccination and continuing other preventive measures to further mitigate the pandemic. An optimal post-recovery follow-up strategy to allow the safe return of COVID-19 patients to the workforce may be considered.

Characteristics of COVID-19 Recurrence: A Systematic Review and Meta-Analysis

Background:

Previous studies reported the recurrence of coronavirus disease 2019 (COVID-19) among discharge patients. This study aimed to examine the characteristic of COVID-19 recurrence cases by performing a systematic review and meta-analysis.

Methods:

A systematic search was performed in PubMed and Embase and gray literature up to September 19, 2020. A random-effects model was applied to obtain the pooled prevalence of disease recurrence among recovered patients and the prevalence of subjects underlying comorbidity among recurrence cases. The other characteristics were calculated based on the summary data of individual studies.

Results:

A total of 41 studies were included in the final analysis, we have described the epidemiological characteristics of COVID-19 recurrence cases. Of 3,644 patients recovering from COVID-19 and being discharged, an estimate of 15% (95% CI, 12% to 19%) patients was re-positive with SARS-CoV-2 during the follow-up. This proportion was 14% (95% CI, 11% to 17%) for China and 31% (95% CI, 26% to 37%) for Korea. Among recurrence cases, it was estimated 39% (95% CI, 31% to 48%) subjects underlying at least one comorbidity. The estimates for times from disease onset to admission, from admission to discharge, and from discharge to RNA positive conversion were 4.8, 16.4, and 10.4 days, respectively.

Conclusion:

This study summarized up-to-date evidence from case reports, case series, and observational studies for the characteristic of COVID-19 recurrence cases after discharge. It is recommended to pay attention to follow-up patients after discharge, even if they have been in discharge quarantine.

Suspected Recurrence of Symptomatic COVID-19: Management During Inpatient Psychiatric Treatment

The widespread prevalence of coronavirus disease 2019 (COVID-19) means that inpatient psychiatric units will necessarily manage patients who have COVID-19 that is comorbid with acute psychiatric symptoms. We report a case of recurrence of respiratory symptoms and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription-polymerase chain reaction (RT-PCR) testing in a patient on an inpatient psychiatric unit occurring 42 days after the initial positive SARS-CoV-2 RT-PCR test, 38 days after initial symptom resolution, and 30 days after the first of 3 negative SARS-CoV-2 RT-PCR tests. Over the course of the admission, the patient was safely initiated on clozapine. Recent literature on COVID-19's potential recurrence and neuropsychiatric effects is reviewed and implications for the management of COVID-19 on inpatient psychiatric units are discussed. In the era of COVID-19 and our still-developing understanding of this illness, psychiatrists' role as advocates and collaborators in our patients' physical health care has become even more critical.

Is recurrence possible in coronavirus disease 2019 (COVID-19)? Case series and systematic review of literature

Can a patient diagnosed with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) be infected again? This question is still unsolved. We tried to analyze local and literature cases with a positive respiratory swab after recovery. We collected data from symptomatic patients diagnosed with SARS-CoV-2 infection in the Italian Umbria Region that, after recovery, were again positive for SARS-CoV-2 in respiratory tract specimens. Samples were also assessed for infectivity in vitro. A systematic review of similar cases reported in the literature was performed. The study population was composed of 9 patients during a 4-month study period. Among the new positive samples, six were inoculated in Vero-E6 cells and showed no growth and negative molecular test in culture supernatants. All patients were positive for IgG against SARS-CoV-2 nucleoprotein and/or S protein. Conducting a review of the literature, 1350 similar cases have been found. The presumptive reactivation occurred in 34.5 days on average (standard deviation, SD, 18.7 days) after COVID-19 onset, when the 5.6% of patients presented fever and the 27.6% symptoms. The outcome was favorable in 96.7% of patients, while the 1.1% of them were still hospitalized at the time of data collection and the 2.1% died. Several hypotheses have been formulated to explain new positive respiratory samples after confirmed negativity. According to this study, the phenomenon seems to be due to the prolonged detection of SARS-CoV-2 RNA traces in respiratory samples of recovered patients. The failure of the virus to replicate in vitro suggests its inability to replicate in vivo.

Tocilizumab in the treatment of rapidly evolving COVID-19 pneumonia and multifaceted critical illness: A retrospective case series

BACKGROUND

COVID-19 associated critical illness characterized by rapidly evolving acute respiratory failure (ARF) can develop, especially on the grounds of hyperinflammation.

AIM AND METHODS

A case-series of 61 patients admitted to our intensive care unit (ICU) between August 12 and September 12, 2020 with confirmed COVID-19 pneumonia and rapidly evolving ARF requiring oxygen support therapy and/or mechanical ventilation was retrospectively analyzed. We examined whether intravenous administration of tocilizumab, a monoclonal interleukin-6 receptor antibody, was associated with improved outcome. All patients received empiric antivirals, dexamethasone 6 mg/day for 7 days, antibiotics, and prophylactic anticoagulation. Tocilizumab was administered at a dosage of 8 mg/kg [two consecutive intravenous infusions 12 h apart]. Outcome measures such as mortality on day-14, ICU length of stay, and rate of nosocomial acquired bacterial infections were also analyzed. Results: Patients were males (88.2%) aged 51 [interquartile range (IQR): 42.5-58.75)], with admission Acute Physiology and Chronic Health Evaluation (APACHE) 4 score of 53 (IQR: 37.75-72.5), and had more than one comorbidity (62.3%). On admission, twenty nine patients (47.5%) were mechanically ventilated, and thirty two patients (52.5%) were receiving oxygen therapy. No serious adverse effects due to tocilizumab therapy were recorded. However, twelve patients (19.6%) developed nosocomial acquired infections. ICU length of stay was 13 (IQR: 9-17) days, and mortality on day-14 was 24.6%. Six patients were shifted to other hospitals but were followed-up. The overall mortality on day-30 was 31.1%. Non-mechanically ventilated patients had higher survival rates compared to mechanically ventilated patients although results were not significant [hazards ratio = 2.6 (95% confidence intervals: 0.9-7.7), p = 0.08]. Tocilizumab did not affect the mortality of critically ill COVID-19 patients.

CONCLUSION

Tocilizumab could be an adjunct safe therapy in rapidly evolving COVID-19 pneumonia and associated critical illness.

Recurrent SARS-CoV-2 RNA positivity after COVID-19: a systematic review and meta-analysis

Present study aimed to estimate the incidence of recurrent SARS-CoV-2 RNA positivity after recovery from COVID-19 and to determine the factors associated with recurrent positivity. We searched the PubMed, MedRxiv, BioRxiv, the Cochrane Library, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry for studies published to June 12, 2020. Studies were reviewed to determine the risk of bias. A random-effects model was used to pool results. Heterogeneity was assessed using I². Fourteen studies of 2568 individuals were included. The incidence of recurrent SARS-CoV-2 positivity was 14.8% (95% confidence interval [CI] 11.44–18.19%). The pooled estimate of the interval from disease onset to recurrence was 35.4 days (95% CI 32.65–38.24 days), and from the last negative to the recurrent positive result was 9.8 days (95% CI 7.31–12.22 days). Patients with younger age and a longer initial illness were more likely to experience recurrent SARS-CoV-2 positivity, while patients with diabetes, severe disease, and a low lymphocyte count were less likely to experience. Present study concluded that the incidence of recurrent SARS-CoV-2 positivity was 14.8% suggesting further studies must be conducted to elucidate the possibility of infectious individuals with prolonged or recurrent RNA positivity.

Rare case of COVID-19 presenting as acute abdomen and sepsis

Coronavirus disease 2019 (COVID-19) may present as acute abdomen, although the pathophysiology remains obscure. We report the case of a 45-year-old-man with severe COVID-19 pneumonia with associated pulmonary embolism who presented with acute abdomen. He underwent emergency laparotomy and resection of an ischaemic area of the jejunum. Postoperatively, he had septic shock, acute respiratory distress syndrome and acute kidney injury necessitating continuous renal replacement therapy. We administered antibiotics and therapeutic anticoagulation along with two sessions of haemoadsorption by CytoSorb filter, in conjunction with continuous renal replacement therapy. The patient survived. Bowel ischaemia due to thromboembolic disease should be promptly treated. Extracorporeal blood purification may be useful in managing sepsis in severe COVID-19.

Prolonged presence of viral nucleic acid in clinically recovered COVID-19 patients was not associated with effective infectiousness

Prolonged presence of viral nucleic acid was reported in certain patients with coronavirus disease 2019 (COVID-19), with unclear clinical and epidemiological significance. We here described the clinical and epidemiological characteristics of 37 recovered COVID-19 patients with prolonged presence of viral RNA in Wuhan, China. For those who had been discharged and re-admitted, their close contacts outside the hospital were traced and evaluated. The median age of the 37 patients was 62 years (IQR 50, 68), and 24 (64.9%) were men. They had common or severe COVID-19. With prolonged positive RT-PCR, most patients were clinically stable, 29 (78.4%) denied any symptoms. A total of 431 PCR tests were carried out, with each patient at a median of 8 time points. The median time of PCR positivity to April 18 was 78 days (IQR 67.7, 84.5), and the longest 120 days. 22 of 37 patients had been discharged at a median of 44 days (IQR 22.3, 50) from disease onset, and 9 had lived with their families without personal protections for a total of 258 person-days and no secondary infection was identified through epidemiological investigation, nucleic acid and antibody screening. Infectiousness in COVID-19 patients with prolonged presence of viral nucleic acid should not solely be evaluated by RT-PCR. Those patients who have clinically recovered and whose disease course has exceeded four weeks were associated with very limited infectiousness. Reconsideration of disease control in such patients is needed.

COVID-19: What do we know?

•Evidence regarding the provision of orthodontic care during the COVID-19 pandemic is examined.

COVID-19 reinfection: Linked Possibilities and future outlook

SARS-CoV-2 is the third major coronavirus epidemic to affect humans. There had been multiple instances of patients turning positive after recovering from SARS-2-CoV infection. Though many different theories emerge, false positive RT-PCR is logically the foremost cause and there is a general consensus that during quarantine re-infection from outside seems unlikely when strictly adhered to. As many new strains emerge worldwide during the course of on-going pandemic, the chances of re-infection cannot be ignored as it may contribute to false negative RT-PCR test results. SARS-2-CoV though a novel virus, is phylogenetically similar to SARS-like CoV with around 79% similarity. Studies on immunological response to these infections suggest that antibodies formed after infection confers immunity only for a short period of time before it starts to wane. Also studies on SARS-CoV-2 suggest that antibody formation and longevity of immunity in an individual is dependent on the strain of coronavirus, its severity and age of the person infected. All these considerations demand reviewing the treatment duration, discharge criteria, appropriate use of imaging techniques and importance of risk communication and health education to those recovered.

A systematic review of re-detectable positive virus nucleic acid among COVID-19 patients in recovery phase

A large number of coronavirus disease 2019 (COVID-19) patients have been cured and discharged due to timely and effective treatments. While some discharged patients have been found re-positive nucleic acid again in the recovery phase. Until now, there is still a great challenge to its infectivity and the specific potential mechanism which needs further discussion. However, more intensive attention should be paid to the prognosis of recovered patients. In this review, we mainly focus on the characteristics, potential reasons, infectivity, and outcomes of re-detectable positive patients, thereby providing some novel insights into the cognition of COVID-19.

Recurrence of SARS-CoV-2 viral RNA in recovered COVID-19 patients: a narrative review

Many studies have shown that re-positive tests for SARS-CoV-2 by RT-PCR in recovered COVID-19 patients are very common. We aim to conduct this review to summarize the clinical and epidemiological characteristics of these patients and discuss the potential explanations for recurrences, the contagiousness of re-detectable positive SARS-CoV-2 virus, and the management of COVID-19 patients after discharge from hospital. The proportion of re-positive tests in discharged COVID-19 patients varied from 2.4 to 69.2% and persisted from 1 to 38 days after discharge, depending on population size, age of patients, and type of specimens. Currently, several causes of re-positive tests for SARS-CoV-2 in recovered COVID-19 patients are suggested, including false-negative, false-positive RT-PCR tests; reactivation; and re-infection with SARS-CoV-2, but the mechanism leading to these re-positive cases is still unclear. The prevention of re-positive testing in discharged patients is a fundamental measure to control the spread of the pandemic. In order to reduce the percentage of false-negative tests prior to discharge, we recommend performing more than two tests, according to the standard sampling and microbiological assay protocol. In addition, specimens should be collected from multiple body parts if possible, to identify SARS-CoV-2 viral RNA before discharge. Further studies should be conducted to develop novel assays that target a crucial region of the RNA genome in order to improve its sensitivity and specificity.

The Interaction of Natural and Vaccine-Induced Immunity with Social Distancing Predicts the Evolution of the COVID-19 Pandemic

The existence and nature of immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are currently unknown; however, neutralizing antibodies are thought to play the major role and data from studying other coronaviruses suggest that partial clinical immunity lasting up to 1 year will occur postinfection. We show how immunity, depending on its durability, may work with current social practices to limit the spread of the virus. We further show that a vaccine that is 50% effective and taken by 50% of the population will prevent further loss of life, providing that social distancing is still practiced and that immunity does not wane quickly.IMPORTANCE The ability of our society to function effectively moving forward will depend on how the spread of the SARS-CoV-2 virus is contained. Immunity to the virus will be critical to this equation.

Aptamers, the bivalent agents as probes and therapies for coronavirus infections: A systematic review

The recently known coronavirus, SARS-CoV-2, has turn into the greatest global health challenge, affecting a large number of societies. The lack of specific treatment and gold-standard diagnostic system has made the situation more complicated. Efforts have led to production of several diagnostic kits that are associated with limitations such as inadequate sensitivity and accuracy. Aptamers as multipotent biological probes could be promising candidates to design sensitive and specific biosensors. Although few studies have introduced specific aptamer types of coronavirus, they may help us select the best approach to obtain specific aptamers for this virus. On the other hand, some of already-introduced aptamers have shown the inhibitory effects on coronavirus that could be applied as therapeutics. The present study has provided a systematic overview on use of aptamer-based biosensors and drugs to diagnose and treat coronavirus.

Re-positive coronavirus disease 2019 PCR test: could it be a reinfection?

The coronavirus disease 2019 (COVID-19) outbreak started in December 2019 and rapidly spread around the globe as a major health threat. Several reports on re-positive cases subsequent to discharge from hospitals caught our attention. We aimed to highlight RT-qPCR positivity re-detection after discharge from isolation, with special consideration of the possible reasons behind it. We found that re-positive RT-qPCR assays for severe acute respiratory syndrome coronavirus 2 after previous negative results might be attributed to false-negative laboratory results and prolonged viral shedding, rather than to re-infection. These findings are encouraging and should be validated in a larger cohort.

Insidious development of pulmonary embolism in asymptomatic patients with COVID-19: Two rare case-reports

Scarce data exist regarding the clinical sequelae of COVID-19 and/or the prevalence of thromboembolic disease in asymptomatic patients. Surely, there is increased prevalence of thromboembolic disease and pulmonary embolism (PE) in critically ill patients with COVID-19; hence the administration of even enhanced thromboprophylaxis was suggested. However, the administration of regular thromboprophylaxis in asymptomatic outpatients is an entirely different matter. Herein, we present the clinical story of insidious PE development in two asymptomatic COVID-19 female patients. Issues regarding the pathogenesis of thromboembolism in COVID-19 and the clinical management are equally discussed.

Extrapulmonary complications of COVID-19: A multisystem disease?

The outbreak of coronavirus disease 2019 (COVID‐19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has been recently declared a pandemic by the World Health Organization. In addition to its acute respiratory manifestations, SARS‐CoV‐2 may also adversely affect other organ systems. To date, however, there is a very limited understanding of the extent and management of COVID‐19‐related conditions outside of the pulmonary system. This narrative review provides an overview of the current literature about the extrapulmonary manifestations of COVID‐19 that may affect the urinary, cardiovascular, gastrointestinal, hematological, hematopoietic, neurological, or reproductive systems. This review also describes the current understanding of the extrapulmonary complications caused by COVID‐19 to improve the management and prognosis of patients with COVID‐19.

SARS‐CoV‐2 appears to adversely affect not only the respiratory system but also several other organ systems, including the urinary, cardiovascular, GI, and neurological systems.

To date, however, there is very limited understanding of the extent and management of COVID‐19‐related conditions outside of the pulmonary system.

Further research is needed to better understand the underlying mechanisms linking SARS‐CoV‐2 with the occurrence of multiple extra‐pulmonary complications.

Persistence of Reverse Transcription-Polymerase Chain Reaction (RT-PCR) Positivity in COVID-19 Recovered Patients: A Call for Revised Hospital Discharge Criteria

In the world scenario, the advent of COVID-19 has halted every aspect of life. It influenced every field of life, including the economy, and revealed the inadequacies in all nations' healthcare systems, from the most developed to the underdeveloped countries. There is a debate about the timing of antibodies production and detection during the disease. What is the significance of reverse transcription-polymerase chain reaction (RT-PCR) viral ribonucleic acid (RNA) in symptom resolving period? In the present manuscript, we have evaluated these points.