Do COVID-19 Pandemic-Related Behavior Changes Affect Perioperative Respiratory Adverse Events in Children Undergoing Cardiac Interventional Catheterization? (preprint)

Background: The Novel Coronavirus Disease (COVID-19) pandemic-related behavior changes could affect the perioperative respiratory adverse events in children with congenital heart disease (CHD). This study was designed to compare the incidence of perioperative respiratory adverse events (PRAEs) in children with and without upper respiratory infection (URI) undergoing the cardiac catheterization before and during COVID-19 pandemic.Methods：COVID-19 was outbreak in January 2020 in China. 260 pediatric patients scheduled for elective therapeutic cardiac catheterization were included from January 2019 to March 2021 and 154 were completed during the pandemic. Recent URI was diagnosed by the attending anesthesiologist owing to different PRAEs incidence in non-URI and URI children. The overall incidence of PRAEs (laryngospasm, bronchospasm, coughing, airway secretion, airway obstruction, and oxygen desaturation) in non-URI and URI children undergoing the elective cardiac catheterization were compared before and during the COVID-19 pandemic. Logistic regression model was fitted to identify the potential risk factors associated with PRAEs. Results: Of 564 children enrolled, 359 completed the study and was analyzed finally. URI incidence decreased substantially during the COVID-19 pandemic (14% vs. 41%, P <0.001). Meanwhile, the overall PRAEs also significantly declined no matter whether or not the child had recent URI (22.3% vs. 42.3%, P =0.001 for non-URI and 29.2% vs. 58.7%, P =0.012 for URI respectively). Post-operative agitation in non-URI children occurred less frequently during the pandemic than before (2.3% vs. 16.2%, P =0.001). Behaviors before the COVID-19 pandemic (odd ratio=2.84, 95%CI 1.76 to 4.58) and recent URI (odd ratio =1.79, 95%CI 1.09 to 2.92) were associated with the PRAEs. Conclusions: COVID-19 pandemic-related behavior changes were associated with the reduction of PRAEs in non-URI and URI children undergoing elective therapeutic cardiac catheterization.

Genomic Variations in SARS-CoV-2 Strains at the Target Sequences of Nucleic Acid Amplification Tests (preprint)

Background: Nucleic acid amplification is the main method used to detect infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the false-negative rate of nucleic acid tests cannot be ignored. Methods: Herein, we demonstrated genomic variations at the target sequences for the tests and the geographical distribution of the variations across countries by analyzing the whole-genome sequencing data of SARS-CoV-2 strains from the 2019 Novel Coronavirus Resource (2019nCoVR) database. Results: Among the 21 pairs of primer sequences in regions ORF1ab, S, E, and N, the total length of primer and probe target sequences was 938bp, with 131(13.97%) variant loci in 2415 (38.96%) isolates. Primer targets in the N region contained the most variations that were distributed among the most isolates, and the E region contained the least. Single nucleotide polymorphisms were the most frequent variation, with C to T transitions being detected in the most variant loci. G to A transitions and G to C transversions were the most common and had the highest isolate density. Genomic variations at the three mutation sites N: 28881, N: 28882, and N: 28883 were the most commonly detected, including in 608 SARS-CoV-2 strains from 33 countries, especially in the United Kingdom, Portugal, and Belgium. Conclusions: Our work comprehensively analyzed genomic variations on the target sequences of the nucleic acid amplification tests, offering evidence to optimize primer and probe target sequence selection, thereby improving the performance of the SARS-CoV-2 diagnostic test.

Genomic Variations in SARS-CoV-2 Strains at the Target Sequences of Nucleic Acid Amplification Tests (preprint)

Background Nucleic acid amplification is the main method used to detect infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the false-negative rate of nucleic acid tests cannot be ignored.Methods Herein, we demonstrated genomic variations at the target sequences for the tests and the geographical distribution of the variations across countries by analyzing the whole-genome sequencing data of SARS-CoV-2 strains from the 2019 Novel Coronavirus Resource (2019nCoVR) database.Results Among the 21 pairs of primer sequences in regions ORF1ab, S, E, and N, the total length of primer and probe target sequences was 938 bp, with 131(13.97%) variant loci in 2415 (38.96%) isolates. Primer targets in the N region contained the most variations that were distributed among the most isolates, and the E region contained the least. Single nucleotide polymorphisms were the most frequent variation, with C to T transitions being detected in the most variant loci. G to A transitions and G to C transversions were the most common and had the highest isolate density. Genomic variations at the three mutation sites N: 28881, N: 28882, and N: 28883 were the most commonly detected, including in 608 SARS-CoV-2 strains from 33 countries, especially in the United Kingdom, Portugal, and Belgium.Conclusions Our work comprehensively analyzed genomic variations on the target sequences of the nucleic acid amplification tests, offering evidence to optimize primer and probe target sequence selection, thereby improving the performance of the SARS-CoV-2 diagnostic test.

Asymptomatic “Exposers” and “Infectors” are Sources of Infection by SARS-CoV-2: Analysis based on Family Clustering (preprint)

Background: Previous studies have documented the clinical characteristics of patients with Coronavirus disease 2019(COVID-19) and presented evidence of person-to-person transmission. Limited data are available for patients with asymptomatic infections. Some asymptomatic carriers, whom we characterize as “exposers” or “infectors”, may be responsible for family clustering of COVID-19.Methods: A questionnaire survey and follow-up survey based on media reports were used to assess familial clustering of SARS-CoV-2 infection induced by asymptomatic exposers/infectors. Individual data were collected for all members of each tracked family. A transmission map was then drawn for each family.Results: Our study of 5 families indicated that individuals with no obvious symptoms of COVID-19, regardless of the PCR results, transmitted the virus to other family members who were community contained at home and had no contact with other infected individuals. There was one death case in Family No.3. Conclusion: Asymptomatic exposers/infectors of SARS-CoV-2 were all middle-aged (average age: 44.4 ± 14.9 years) who had no symptoms but had the ability to disseminate the virus. Medical staff participating in treatment of COVID-19 cases all had a high risk of infection, they should be quarantined so as to protect their families. The morbidity and mortality of Case 3.2 remind us that although these asymptomatic infected people have no symptoms, they are also infectious. It is not ruled out that the subsequent infected people are seriously ill or even die. Therefore, we should not take it lightly.