Asymptomatic COVID-19 Infection Research Articles

Should Covid-19 RT-PCR Test Be Performed Before Elective Cataract Surgery? A study In the Light of Prevalence and Cost Analysis

Objective: It was aimed to argue the asymptomatic Covid-19 seroprevalence in patients scheduled for elective cataract surgery, to investigate the cost effects of Covid-19 on cataract surgery, and the effects of routinely using the screening test before surgery.Materials and Methods: This is a cross-sectional and observational study. The study group included 217 patients without any symptoms of Covid-19 who underwent real-time polymerase chain reaction (RT PCR) testing for SARS CoV 2 before surgery during the pandemic period and the control group included 200 patients who underwent elective cataract surgery procedure before the Covid-19 pandemic. Their demographic characteristics and the length of hospital stay were recorded. Equipment fees, laboratory fees, drug fees, and hospital service fees were recorded, and cost analysis was made. Seroprevalence of Covid-19 was calculated.Results: The seroprevalence of the asymptomatic Covid-19 infection among all elective cataract surgery patients in our hospital was 1.8%. There was a significant difference between the average cost of the groups (p<0.001).Conclusion: Although the seroprevalence of the disease is very low among asymptomatic patients and the disease increases the cost of the surgery, we think that to identify asymptomatic patients and reduce contagiousness, screening for COVID-19 should continue.

Upregulated type I interferon responses in asymptomatic COVID-19 infection are associated with improved clinical outcome

Understanding key host protective mechanisms against SARS-CoV-2 infection can help improve treatment modalities for COVID-19. We used a blood transcriptome approach to study biomarkers associated with differing severity of COVID-19, comparing severe and mild Symptomatic disease with Asymptomatic COVID-19 and uninfected Controls. There was suppression of antigen presentation but upregulation of inflammatory and viral mRNA translation associated pathways in Symptomatic as compared with Asymptomatic cases. In severe COVID-19, CD177 a neutrophil marker, was upregulated while interferon stimulated genes (ISGs) were downregulated. Asymptomatic COVID-19 cases displayed upregulation of ISGs and humoral response genes with downregulation of ICAM3 and TLR8. Compared across the COVID-19 disease spectrum, we found type I interferon (IFN) responses to be significantly upregulated (IFNAR2, IRF2BP1, IRF4, MAVS, SAMHD1, TRIM1), or downregulated (SOCS3, IRF2BP2, IRF2BPL) in Asymptomatic as compared with mild and severe COVID-19, with the dysregulation of an increasing number of ISGs associated with progressive disease. These data suggest that initial early responses against SARS-CoV-2 may be effectively controlled by ISGs. Therefore, we hypothesize that treatment with type I interferons in the early stage of COVID-19 may limit disease progression by limiting SARS-CoV-2 in the host.

COVID-19 infection in pediatric patients treated for cancer.

BackgroundCOVID-19, the novel coronavirus, has caused a global pandemic affecting millions of people around the world. Risk factors for critical disease in adults are advanced age and underlying medical comorbidities, including cancer. Data are sparse on the effect of COVID-19 infection on pediatric patients with cancer during their active antineoplastic therapy. The optimal management of antineoplastic treatment during COVID-19 infection in this unique population is controversial.AimTo describe the severity and clinical course of COVID-19 infection in pediatric patients with cancer during active antineoplastic treatment and to study their course of treatment.MethodsClinical and laboratory data were collected from medical files of patients diagnosed with COVID-19, confirmed by polymerase chain reaction (PCR), who received active antineoplastic treatment between March 2020 and May 2021 in a large tertiary pediatric medical center.ResultsEighteen patients with diverse pediatric cancers are described. They were infected with COVID-19 at different stages of their antineoplastic treatment regimen. Eight had an asymptomatic COVID-19 infection, nine had mild symptoms, and one had severe disease. All of them recovered from COVID-19 infection. Two patients experienced delays in their antineoplastic treatment; none of the other patients had delays or interruptions, including patients who were symptomatic for COVID-19.ConclusionIn pediatric patients with cancer who test positive for COVID-19, yet are asymptomatic or have mild symptoms, the continuance of antineoplastic therapy may be considered.

Profound B-Cell Lymphopenia Is a Major Factor Predicting Poor Humoral Response after BNT162b2 mRNA Sars-Cov-2 Vaccines in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

BackgroundSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection results in poor outcome in patients with hematologic malignancies. Moreover, the efficacy of anti-SARS-CoV-2 mRNA vaccines appears lower in immunocompromised patients, including recipients of allogeneic stem cell transplantation (Allo-HSCT). In this population, data are scarce regarding factors predicting the response to mRNA vaccines.MethodsThis retrospective study aimed to decipher which factors, including immune status at time of vaccine and recipient/donor blood groups, might influence the antibody response after two injections (V1 and V2) of BNT162b2 (Pfizer-BioNTech) vaccine in a cohort of allografted patients with no previous symptomatic nor asymptomatic COVID-19 infection. Possible previous asymptomatic COVID-19 infection was investigated in pre-V1 samples by testing for anti-nucleocapsid (N) antibodies (anti-SARS-CoV-2 immunoassay, Roche Elecsys®, Rotkreuz, Switzerland). Antibody response to the SARS-CoV-2 spike protein receptor-binding domain was tested post-V2 (Roche Elecsys®). As recommended by the manufacturer, titers ≥0.8 U/mL were considered positive, the highest value being >250 U/mL.Blood samples were also collected before V1 and at distance from V2 to evaluate, by flow cytometry, total lymphocyte (Ly) counts and quantitative Ly subsets (CD3, CD4 and CD8 T cells, B and NK cells).Statistical analyses were performed on R (version 4.0.3). Patient characteristics were compared by using the Χ² test for discrete variables and the Wilcoxon test for continuous variables. Generalized linear models were used to conduct multivariate analyses.ResultsSamples were available from 117 Allo-HSCT patients who had been vaccinated between January 20 and April 17, 2021. Patient characteristics are provided in Table 1. The average interval from Allo-HSCT day 0 (D0) to V1 (D0-V1) was 654 (IQR: 372-1367) days (d). S-antibody response rate post-V2 was 82.9% for the entire cohort. Non-humoral responders (NHR) post-V2 (n = 20) had a lower D0-V1 interval (median 271 vs 914 d, p <10 -5) and a lower pre-V1 median total Ly count (0.62 vs 1.61x10 9/L, p < 10 -4). Lymphocyte subsets possibly predictive of antibody response were then investigated. NHR were associated with lower median CD3 (0.39 vs 0.97 x10 9/L, p = 0.01), CD4 (0.13 vs 0.35 x10 9/L, p=<10 -3), and B-cell (0.00 vs 0.28 G/L, p <10 -6) counts. NK and T CD8 counts were not statistically different between NHR and HR (respectively p=0.14 and p=0.06). No influence either was observed when considering the age of donors (p=0.39) or recipients (p=0.55), underlying disease (p=1), Allo-HSCT conditioning (p=0.11), blood groups (donor, p=0.55; receiver, p=0.39) or a previous history of graft versus host disease (GVHD; 83.1 vs 83.6%, p=1). Conversely, ongoing immunosuppressive (IS)/chemotherapy treatment and a haploidentical source of graft were associated with lower responses to vaccination (respectively 62.5 vs 90.5%, p<10 -3, and 69.4 vs 88.6% for patients with matched donors, p=0.02). In multivariate analysis (Fig.1) also including D0-V1 interval, donor source, current IS/chemotherapy treatment and TCD4 Ly count, only B cell aplasia remained statistically associated with lack of antibody response after two vaccine injections (OR 0.01, 95%CI [0.00 - 0.10], p <10 -3).The possible modification in terms of lymphocyte counts between pre-V1 and post-V2 times has been also investigated showing that only CD4 lymphocytes counts improved significantly (0.31 vs 0.34 x10 9/L, p=0.01) between this interval.ConclusionB cell aplasia appears as a major predictor of anti SARS-CoV-2 mRNA vaccine failure after Allo-HSCT. It may be suggested from this result that a close immune monitoring should be proposed after allotransplant to propose the vaccine at the most appropriate time, meaning after of B cell detection, regardless of the delay from Allo-SCT or the presence of an IS/chemotherapy treatment. The possibility for these patients to have mounted a cellular response should also be considered, which was not investigated here. [Display omitted] DisclosuresMoreau: Celgene BMS: Honoraria; Sanofi: Honoraria; Abbvie: Honoraria; Oncopeptides: Honoraria; Amgen: Honoraria; Janssen: Honoraria.

Interest of a Third Dose of BNT162b2 Anti- Sars-Cov-2 mRNA Vaccine in Allogeneic Hematopoietic Stem-Cells Recipients

IntroductionIn a previous observational study of 117 allogeneic hematopoietic stem cell transplant (Allo-HSCT) recipients, we found that 83 % of them achieved a specific humoral response after two doses (V1 and V2) of BNT162b2 anti-SARS-CoV-2 messenger RNA vaccine (Pfizer BioNTech). However, although 61.5% of the patients achieved the highest detectable IgG titers, this proportion remained significantly lower than what was observed in healthy controls, where 100% reached these highest antibody titers. Here, we investigated whether a third dose of vaccine would improve the anti- SARS-CoV-2 response in Allo-HSCT recipients.MethodsThis monocentric retrospective study aimed at evaluating the efficacy of a third vaccine (V3) of BNT162b2 in a cohort of Allo-HSCT adult recipients. Patients with previous clinical or asymptomatic biological COVID-19 infection at V1 were excluded from the study. A cohort of healthy volunteers (caregivers from the Clinical Hematology Department) who had also already received V1 and V2 was considered as controls. All participants were vaccinated between January 20 and June 1, 2021. Analyses were performed in July 2021.Antibody response to the SARS-CoV-2 spike protein receptor-binding domain was tested after V2 for all subjects (Serology post V2, SpV2) using the Roche Elecsys® assay. All subjects benefited later from another evaluation of specific serum antibodies as monitoring (Serology post V2+, SpV2+) or after V3 (Serology post V3, SpV3). Various serological methods were used for these later assays because performed outside of our hospital for some patients. Considering thresholds of negativity and positivity as well as highest values for each test, we were able nevertheless to distinguish 4 sub-groups: i) negativity at both SpV2 & SpV2+/SpV3, ii) increase of the IgG titer between SpV2 & SpV2+/SpV3, including patients showing seroconversion, iii) decreased or stable IgG titer between SpV2 & SpV2+/SpV3 and iv) highest IgG titers at both SpV2 and SpV2+/SpV3.ResultsA cohort of 25 controls and 114 patients, including 91 who received V3 (V3+) and 23 who did not (V3-) was considered for the purpose of this study. The characteristics of participants and delays from SpV2 to SpV2+ or SpV2 to SpV3 are reported in Tables 1 and 2. The serological methods used for the latest assays are reported in Table 2 with criteria of negativity, positivity and highest IgG titer values. V3- patients were younger, with less myeloid disease than V3+ cases and had not received myeloablative conditioning. However, both V3+ and V3- groups shared similar median intervals between Allo-HSCT and V1, incidence of previous graft versus host disease (GVHD), proportions of patients under chemotherapy or immunosuppressive drugs and median lymphocyte counts at V1, suggesting similar immune status. The reasons for not receiving V3 were forgetting, refusal or surveillance after detection of the highest IgG titer at SV2.Samples from controls, all evaluated by Roche Elecsys®, showed the highest anti-spike antibody value (>250U/mL) at both SpV2 and SpV2+, suggesting a persistent response without the need of a third vaccine in this healthy population.The proportion of patients still negative at SpV2+/SpV3 was similar between V3- and V3+ patients (17% vs 12%, p=0.74). However, the proportion of patients showing a decreased/stable IgG titer between SpV2 and SpV2+/SpV3 was significantly higher for V3- cases (35% vs 4%, p=0.0001) (Table 2). Moreover, the proportion of patients with the highest IgG titer at SpV2+/SpV3 was significantly higher in the V3+ sub-group (80% vs 43%, p=0.001), even if it remained significantly lower than in controls (p=0.03). The proportion of patients showing an IgG titer increase between SpV2 and SpV2+/SpV3 was higher in V3+ vs V3- patients (24% vs 4%, p=0.06). The difference was not significant as surprisingly one V3- case showed a seroconversion without any argument for SARS-CoV-2 infection between SpV2 and SpV2+. Three patients out of 14 (21%), with a negative SpV2, showed a seroconversion after V3.Finally, with a median follow up from V1 of 106 days in V3+ patients, 138 days in V3- patients and 154 days in controls, no COVID-19 infection was documented in any participant.ConclusionThis study shows the interest of a third dose of BNT162b2 anti-SARS-CoV-2 messenger RNA vaccine after allograft as more patients are documented with less decrease of IgG titers and the highest IgG values after V3. [Display omitted] DisclosuresMoreau: Abbvie: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Celgene BMS: Honoraria; Oncopeptides: Honoraria.

Design and implementation of a university-based COVID-19 testing programme: an observational study

BackgroundLittle is known about how asymptomatic testing as a method to control the transmission of COVID-19 can be successfully implemented, and the prevalence of asymptomatic infection within university populations. The aim of this study was to describe the methodology of implementing a novel asymptomatic mass testing programme, and to report the number of positive cases diagnosed during the study period. To our knowledge, this study is the first to report prevalence of asymptomatic COVID-19 infection within a UK university population using reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) as a molecular diagnostic tool. MethodsAn observational study was undertaken to describe the set-up and implementation of a novel COVID-19 testing programme on a UK university campus between Sept 28 and Dec 18, 2020. Students and staff members volunteered for testing throughout the term. The programme used RT-LAMP testing to identify asymptomatic cases within the population. Any positive cases received RT-PCR testing to confirm the result using the current gold-standard testing methodology. Findings1673 tests were done using RT-LAMP during the study period, of which nine were positive for COVID-19. This gave an overall positivity rate of 0·54%, equivalent to a rate in the tested population of 538 cases per 100 000 over the duration of testing. All positive tests were also found to be positive on RT-PCR testing, giving a false positive rate of 0%. Uptake was affected by changes to delivery of university teaching, leading to lower attendance on campus throughout the term. InterpretationThis study shows that it is possible to rapidly set up a universal university testing programme for COVID-19 in collaboration with local health-care providers using RT-LAMP testing, with full concordance between RT-LAMP testing and RT-PCR testing on positive RT-LAMP results. Positive results were similar to those in the local population, although with a different weekly peak of infection. FundingNone.

S3423 The Impact of the COVID-19 Pandemic on Pediatric Endoscopies in a Single Center

Introduction: Pediatric endoscopic procedures are considered at high risk for Covid-19 transmission as it can be aerosolized during the upper and lower endoscopy. In addition to that, a higher proportion of children have mild or asymptomatic Covid-19 infection. The data in pediatric endoscopy experience during Covid-19 pandemic is scarce. Our research goal is to explore the influence of the Covid-19 pandemic on our pediatric endoscopy practice and compare the differences with pre-pandemic endoscopy experience. Methods: Pediatric endoscopic procedures are considered at high risk for Covid-19 transmission as it can be aerosolized during the upper and lower endoscopy. In addition to that, a higher proportion of children have mild or asymptomatic Covid-19 infection. The data in pediatric endoscopy experience during Covid-19 pandemic is scarce. Our research goal is to explore the influence of the Covid-19 pandemic on our pediatric endoscopy practice and compare the differences with pre-pandemic endoscopy experience. Results: Pediatric endoscopic procedures are considered at high risk for Covid-19 transmission as it can be aerosolized during the upper and lower endoscopy. In addition to that, a higher proportion of children have mild or asymptomatic Covid-19 infection. The data in pediatric endoscopy experience during Covid-19 pandemic is scarce. Our research goal is to explore the influence of the Covid-19 pandemic on our pediatric endoscopy practice and compare the differences with pre-pandemic endoscopy experience. Conclusion: In conclusion, Pediatric endoscopy volumes in our center have been clearly impacted due to pandemic in the first 2 months but afterwards volumes were similar to the pre-pandemic year. Only 1% of patients tested positive for Covid-19 which is significantly lower than the average positivity rate of 4.52% for the State of Maryland since Covid-19 pandemic started. None of the endoscopist or trainees tested positive for Covid-19 infection. With the combination of pre-procedure test and infection control precautions endoscopies could be performed safely in children.Figure 1.: A. Endoscopies by Month. B. Cancelations--Pandemic Year.

S1278 Asymptomatic Pediatric COVID-19 Positive Patients Captured Through Pre-operative Screening Program for Ambulatory Surgeries at a Tertiary Care Hospital

Introduction: Our hospital implemented universal pre-operative COVID-19 screening in April 2020 to reduce risk of transmission to caregivers as well to avert a potential anesthetic risk in COVID positive patients. The aim of this project was to determine the prevalence of asymptomatic COVID-19 infection among pediatric patients undergoing ambulatory procedures and surgeries, overall and for Pediatric Gastroenterology (GI) cases specifically. Methods: A retrospective chart review identified pediatric patients (≤21 years) who underwent ambulatory pre-operative COVID-19 testing between April 1, 2020-March 31, 2021. Demographic and health-related data was collected to identify asymptomatic COVID-19 positive patients scheduled for GI procedures and other ambulatory surgeries. We compared the proportion of patients who tested positive by age group, co-morbid condition, and surgical specialty. We also compared pediatric case rates to Ohio case rates. The study was IRB approved. Results: 4,663 asymptomatic pediatric patients underwent pre-operative COVID-19 testing by PCR and 81 patients were identified as positive (1.73%). In COVID-19 positive patients, 56% were male and 44% were female. Mean age was 12 years and patients 13-18 years were the age group with the highest fraction of positive tests (35%). 11% of patients screened were undergoing a GI-related procedure with a positivity rate of 1.3%. The peak in asymptomatic positives across all procedures occurred in November 2020 (30%), which preceded the peak in COVID-19 cases in Ohio by several weeks. Most prevalent co-morbid condition was asthma (15%) and 8% had inflammatory bowel disease. 5 patients were undergoing chemotherapy and none were on biologic therapy. 94% of cases were deferred. 25% of cases that proceeded required post-operative admission. Conclusion: Asymptomatic COVID-19 positive patients were identified before 1.73% of pediatric ambulatory procedures and before 1.3% of GI procedures. These case rates were higher than the concurrent adult case rate at our institution. The higher rate of asymptomatic COVID-19 infection in pre-operative pediatric ambulatory patients may reflect the milder disease in this age group. The peak in pediatric asymptomatic case positivity seemed to predict the subsequent peak case rate in the state of Ohio by a few weeks. As the pandemic continues with a large percentage of pediatric patients unvaccinated, pre-operative COVID-19 testing has important implications for pediatric GI and other ambulatory procedures.

Case report: a 5-year-old with new onset nephrotic syndrome in the setting of COVID-19 infection

BackgroundThis is a case report of an asymptomatic SARS-CoV-2 infection associated with new-onset nephrotic syndrome in a pediatric patient. This is the third case of new-onset nephrotic syndrome in children associated with SARS-CoV-2 infection, but is the first case report describing a new-onset nephrotic syndrome presentation in a patient who had asymptomatic COVID-19 infection.Case presentationThis is a case of a previously healthy 5 year old female who presented with new-onset nephrotic syndrome in the setting of an asymptomatic COVID-19 infection. She presented with progressive edema, and laboratory findings were significant for proteinuria and hypercholesterolemia. She was treated with albumin, diuretics, and corticosteroid therapy, and achieved clinical remission of her nephrotic syndrome within 3 weeks of treatment. Though she was at risk of hypercoagulability due to her COVID-19 infection and nephrotic syndrome, she was not treated with anticoagulation, and did not develop any thrombotic events.ConclusionsOur case report indicates that SARS-CoV-2 infection could be a trigger for nephrotic syndrome, even in the absence of overt COVID-19 symptoms.

The utilization of hydroxychloroquine to reduce the main signs and symptoms of COVID-19 patients, a cross-sectional study

Hydroxychloroquine (HCQ) and chloroquine were found to have positive results in some non-randomized clinical trials with more benefit in decreasing the viral load of COVID-19. HCQ is a lysosomotropic and lipophilic drug that can penetrate cell membranes, and accumulates in the acidic lysosomes. The high concentration of alkaline HCQ increases the pH in lysosomes from the normal levels of 4.7–4.8 to 6 which leads to inhibition of lysosomes functions and thus, prevents the entry of coronavirus into cells. ObjectivesThe main aim of this study is to find out the appropriateness of using HCQ in asymptomatic/mildly symptomatic COVID-19 positive patients in an attempt to reduce the development of signs and symptoms of COVID-19 and severe disease. MethodologyRandomized selection, open-label trial to evaluate the efficacy of HCQ for patients presenting with asymptomatic COVID-19 upon diagnosis. Cases that met the inclusion criteria were divided into two arms [102 subjects to take HCQ (a loading dose of 400 mg twice daily given orally, followed by a maintenance dose of 200 mg twice daily for 4 days), and 100 subjects were used as a control group]. A follow-up for all the participants on daily basis for 14 days for any signs and symptoms (fever, cough, and shortness of breath). The main variables are action profile (represented by Area under the curve (AUC) for fever, cough, and shortness of breath statistically analyzed to differentiate between the two groups. ResultsData in this study showed that HCQ was effective in reducing body temperature from the first day to the fifth day; this positive effect was significant with (p < 0.001) compared with subjects who didn't receive HCQ. While there was no significant effect on cough or Shortness of breath. ConclusionThe recommendation of this study is to utilize HCQ to all subjects with asymptomatic COVID-19 infection providing that these subjects are within the inclusion criteria of this study. There was no adverse drug reaction observed for HCQ on daily follow-up.

Fatal pulmonary thromboembolism in asymptomatic COVID-19

BackgroundCoronavirus disease 2019 (COVID-19) has claimed the lives of millions of people globally.AimsThis study aims to identify the pathological findings at autopsy of asymptomatic COVID-19 death, to compare the incidence of acute bilateral pulmonary thromboembolism (ABPTE) in asymptomatic COVID-19 deaths versus non-COVID-19 deaths and to explore the possible pathogenesis of thrombosis in COVID-19. We also consider the place of COVID-19 in the death certification of 4 cases who died from ABPTE.MethodsThis study primarily reviewed post-mortem reports of 6 asymptomatic COVID-19 deaths. Post-mortem reports for the years 2019 and 2020 were also reviewed to establish the incidence of ABPTE. Each post-mortem report was reviewed for gross examination, histology and toxicology findings. A literature review on COVID-19 autopsy findings, COVID-19 pathogenesis, thrombosis in COVID-19 and asymptomatic SARS-CoV-2 infection was also conducted using PubMed.ResultsOf the 6 asymptomatic COVID-19 deaths, 4 died as a result of ABPTE, 1 died of ischaemic and hypertensive cardiac disease caused by coronary artery disease and ventricular hypertrophy and the remaining case died of heart failure due to dilated cardiomyopathy caused by subendocardial fibrosis. There were 2 cases of bilateral pulmonary thromboembolism (BPTE) in 2019 out of 140 post-mortems. Excluding the 4 cases of ABPTE described already, there was 1 case of ABPTE in 2020 out of 156 post-mortems. A literature review on the pathogenesis of thrombosis in COVID-19 highlighted the significant role that the endothelium plays.ConclusionsMassive pulmonary thromboembolism may be a significant cause of death in asymptomatic COVID-19 infection.

A Hazy Picture of Long-Haul COVID Begins to Emerge

A Hazy Picture of Long-Haul COVID Begins to Emerge

New problems and countermeasures in the prevention and control of COVID-19

New problems and countermeasures in the prevention and control of COVID-19

SARS-CoV-2 Seroprevalence in Aden, Yemen a Population-Based Study

Background: In Yemen; initial surveillance of COVID-19 focused primarily on patients with symptoms or severe disease, and, as such, the full spectrum of the disease, are not clear that make the epidemiology of COVID-19 is uncertain. To the best of our knowledge, this is the first seroprevalence study done in Yemen to measure the seroprevalence of anti-SARS-CoV-2 antibodies in the general population by sex and age group in Aden, Yemen.Methods: It is a one-time cross-sectional investigation among 2000 participants from all age groups from four districts in Aden at southern Yemen. A multi-stage sampling method used. Data collected by using a well-structured questionnaire and blood sample were collected. Healgen COVID-19 IgG/IgM Rapid Test Cassette was used in all participants. All positive RDT and 14% of the negative RDTs underwent ELISA test (WANTAI SARS-CoV-2 Ab Elisa Kit). Results: A 549 out of 2001 participants were RDT positive and proved by ELISA giving the prevalence of COVID-19 infection to 27·4% and specifically the prevalence of IgG was 25%. The prevalence of asymptomatic COVID-19 infection in all the study group was 7·9%. The highest prevalence was observed in Al-Mansurah district (33·4%). Regarding socio-demographic factors females, housewives and history of contact with COVID-19 patients have significant higher prevalence rates (32%, 31% and 39% respectively).Interpretation: high prevalence of SARS-CoV-2 antibodies was reported. Household contacts are the main factors for transmission. Enhancing population immunity is recommended by introducing COVID-19 vaccine.Funding: The study was funded from WHO/ EMRO. Aden OfficeDeclaration of Interest: None to declare. Ethical Approval: This study was approved by the University of Yemen.

Focal Myocarditis after Mild COVID-19 Infection in Athletes

COVID-19 infection in athletes usually has a milder course, but in the case of complications, myocarditis and even sudden cardiac death may occur. We examined an athlete who felt symptoms upon returning to training after asymptomatic COVID-19 infection. Physical, laboratory, and echocardiography findings were normal. The cardiopulmonary exercise test was interrupted at submaximal effort due to severe dyspnea in the presence of reduced functional capacity in comparison to previous tests. Cardiac magnetic resonance (CMR) detected the focal myocarditis. After three months of recovery, CMR still revealed the presence of focal myocarditis and the persistence of decreased functional capacity. This case raises the question of screening athletes even after asymptomatic forms of COVID-19 infection.

Dynamic Changes of Antibodies to SARS-CoV-2 in Close Contacts.

IntroductionClose contacts of individuals with COVID-19 may directly gain immunity against SARS-CoV-2 despite lacking a detectable infection. This study examined SARS-CoV-2-specific antibodies levels based on gender, age, and exposure source in close contacts of individuals with COVID-19 and compared antibody levels to patients with an asymptomatic or symptomatic COVID-19 infection.MethodsTwo patients had confirmed COVID-19 infections at a community hospital in Qiongzhong, Hainan province. Contact tracing identified all individuals in the community who had been exposed to the two patients during the 14 days before their diagnoses. Close contacts quarantined for 14 days, underwent two SARS-CoV-2 tests, and were screened for SARS-CoV-2-specific antibodies at 7 and 12 weeks after the end of quarantine. SARS-CoV-2-specific antibody levels for the close contacts were compared to those for patients with an asymptomatic or symptomatic COVID-19 infection at 7 and 12 weeks after their diagnoses.ResultsContact tracing identified 10,573 individuals in the community, including 360 (3.4%) close contacts. At 7 weeks, 30 (8.33%) close contacts were positive for SARS-CoV-2-specific antibodies (IgG, n = 26 [7.22%]; IgM, n = 4 [1.11%]), which were lower than the proportion of patients with an asymptomatic (IgG, 100% [12/12]) or symptomatic (IgG, 93.6% [44/47]) COVID-19 infection. SARS-CoV-2-specific IgM antibody levels were significantly higher in close contacts who were exposed through a relative compared to a doctor–patient relationship (P = 0.032). SARS-CoV-2-specific IgG antibody levels were significantly higher in close contacts aged <18 years vs 18–64 years (P = 0.014). At 12 weeks, SARS-CoV-2-specific IgG antibody levels among close contacts were significantly lower than among patients with an asymptomatic (P = 0.004) or symptomatic COVID-19 infection (P < 0.001).ConclusionImmune protection conferred by close contact is short term and unlikely to contribute to herd immunity. There remains an unmet public health need for mass vaccination of populations to increase levels of protective antibodies and achieve and maintain herd immunity.

Pulmonary Parenchymal Changes in COVID-19 Survivors

BackgroundAs the COVID-19 pandemic moves into the survivorship phase, questions regarding long-term lung damage remain unanswered. Previous histopathologic studies are limited to autopsy reports. We studied lung specimens from COVID-19 survivors who underwent elective lung resections to determine whether postacute histopathologic changes are present. MethodsThis multicenter observational study included 11 adult COVID-19 survivors who had recovered but subsequently underwent unrelated elective lung resection for indeterminate lung nodules or lung cancer. We compared these against an age- and procedure-matched control group who never contracted COVID-19 (n = 5) and an end-stage COVID-19 group (n = 3). A blinded pulmonary pathologist examined the lung parenchyma focusing on 4 compartments: airways, alveoli, interstitium, and vasculature. ResultsElective lung resection was performed in 11 COVID-19 survivors with asymptomatic (n = 4), moderate (n = 4), and severe (n = 3) COVID-19 infections at a median 68.5 days (range 24-142 days) after the COVID-19 diagnosis. The most common operation was lobectomy (75%). Histopathologic examination identified no differences between the lung parenchyma of COVID-19 survivors and controls across all compartments examined. Conversely, patients in the end-stage COVID-19 group showed fibrotic diffuse alveolar damage with intra-alveolar macrophages, organizing pneumonia, and focal interstitial emphysema. ConclusionsIn this study to examine the lung parenchyma of COVID-19 survivors, we did not find distinct postacute histopathologic changes to suggest permanent pulmonary damage. These results are reassuring for COVID-19 survivors who recover and become asymptomatic.

Elucidating causes of COVID-19 infection and related deaths after vaccination

Background and aimsSymptomatic or asymptomatic COVID-19 infection has been reported in vaccination. In the current article, we try to elucidate various causes behind COVID-19 infection and mortality following COVID-19 vaccination and suggest possible strategies to counteract this threat. MethodsWe carried out a comprehensive review of the literature using suitable keywords such as ‘COVID-19’, ‘Pandemics’, ‘Vaccines’, ‘Mortality’, ‘deaths’, ‘infections’, and ‘India’ on the search engines of PubMed, SCOPUS, Google Scholar, and ResearchGate in from January to May 2021. Epidemiology, risk factors, Adverse Events Following Immunization (AEFI) and mortality after COVID-19 vaccination were assessed. ResultsA number of factors have been associated with symptomatic or asymptomatic COVID-19 infection reported after vaccination. A high viral load, comorbidities, mutant strains, Variants of Concern (VOC) leading to Vaccine escape and casual attitude towards COVID Appropriate Behaviors appear to be the most important factors for infection and deaths after COVID-19 vaccination. ConclusionsCOVID-19 Infection and mortality after COVID-19 vaccination are of great concern. Application of COVID Appropriate Behaviour (CAB) before and after vaccination is essential for the population. Effective Vaccines against mutant strains and enhanced vaccination drive are key strategies to avoid this quintessential threat. Early medical intervention in high-risk groups can prevent overall mortality.

Asymptomatic and Symptomatic COVID-19 Infections Among Health Care Personnel Before and After Vaccination

This cohort study investigates asymptomatic and symptomatic COVID-19 case rates before and after the initial vaccine rollout among health care personnel in Orange County, California.

The Role of Preprocedure Screening of SARS-CoV-2 Infection: A Tertiary Care Medical Center Analysis

Purpose: This study aimed to understand the prevalence of asymptomatic COVID-19 infection among patients undergoing endoscopic procedures at a tertiary care hospital. The results allow prediction of the magnitude of cases which this endoscopic service might witness in the next months and planning of future actions accordingly. Methods: This retrospective study was conducted in the gastroenterology department of a large urban tertiary care medical center from October 15, 2020, to November 15, 2020. In this institution, all patients proposed for endoscopic procedures under deep sedation must be submitted to reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) detection. These results were thoroughly reviewed. Results: In the 1-month period, a total of 833 different procedures were done in 833 patients admitted to the endoscopy unit. Of these, 167 (20%) were submitted to nasal swab for SARS-CoV-2. Only 1 (0.6%) was positive for this infection, and her procedure was postponed. This RT-PCR-positive patient was not symptomatic for CO­VID-19 infection at the time of preprocedure screening. She had no positive contacts for COVID-19 and had not traveled outside the country. Conclusion: We found that the proportion of patients proposed for an endoscopic intervention who were asymptomatic carriers of SARS-CoV-2 was low. However, only one fifth of patients were tested and, considering the proportion of 0.6%, it is reasonable to consider that exposure of healthcare workers and other patients can occur. So, all prevention measures must be strictly followed. However, the cost-benefit of an universal testing policy must be proven.