Factors associated with negative conversion of viral RNA in hospitalized children infected with SARS-CoV-2 Omicron Variant in Shanghai, China:a retrospective analysis (preprint)

Objectives: This study aimed to identify the related risk factors and potential predictors of SARS-CoV-2 RNA negative conversion by describing the dynamics of viral shedding in infected children admitted to two hospitals from Shanghai during Omicron variant outbreak. Methods: This retrospective cohort included laboratory-confirmed cases of SARS-CoV-2 infection from Shanghai between March 28 and May 31, 2022. Clinical characteristics, personal vaccination, household vaccination rates were collected through electronic health records and telephone interviews. Results: The total of 603 pediatric cases confirmed with COVID-19 was included in this study. Both Univariate and multivariate analysis were performed to filter independent factors for the duration to viral RNA negative conversion. Data on cases re-detected SARS-CoV-2after showing negative results on RT-PCR test (intermittent negative status) were also analyzed. The median duration of virus shedding was 12(Interquartile Qange,IQR: 10-14) days. The severity of clinical outcome, personal vaccination-2doses, household vaccination rates, abnormal defecation were factors indecently affecting negative conversion of SARS-CoV-2 RNA, suggesting that patient who had abnormal defecation or with more severe condition would delay virological clearance, while patient accepted 2 doses vaccination or with higher household vaccination rates would accelerate virological clearance. Loss of appetite (Odds Ratio (OR) :5.343; 95%CI: 3.307-8.632) and abnormal defecation (OR:2.840; 95%CI: 1.736-4.645) were significantly associated with intermittent negative status. Conclusion: These findings could provide clues for early identification of pediatric patients with prolonged viral shedding, enriching the evidence for development of prevention and control strategies especially the vaccination policies for children and adolescents.

Factors associated with negative conversion of viral RNA in hospitalized children infected with SARS-CoV-2 Omicron Variant in Shanghai, China (preprint)

Abstract Objectives: This study aimed to identify the related risk factors and potential predictors of SARS-CoV-2 RNA negative conversion by describing the dynamics of viral shedding in infected children admitted to two hospitals from Shanghai during Omicron variant outbreak. Methods: This retrospective cohort included laboratory-confirmed cases of SARS-CoV-2 infection from Shanghai between March 28 and May 31, 2022. Clinical characteristics, personal vaccination, household vaccination rates were collected through electronic health records and telephone interviews. Results: The total of 603 pediatric cases confirmed with COVID-19 was included in this study. Both Univariate and multivariate analysis were performed to filter independent factors for the duration to viral RNA negative conversion. Data on cases re-detected SARS-CoV-2 after showing negative results on RT-PCR test (intermittent negative status) were also analyzed. The median duration of virus shedding was 12(Interquartile Qange,IQR: 10-14) days. The severity of clinical outcome, personal vaccination-2doses, household vaccination rates, abnormal defecation were factors indecently affecting negative conversion of SARS-CoV-2 RNA, suggesting that patient who had abnormal defecation or with more severe condition would delay virological clearance, while patient accepted 2 doses vaccination or with higher household vaccination rates would accelerate virological clearance. Loss of appetite (Odds Ratio (OR) :5.343; 95%CI: 3.307-8.632) and abnormal defecation (OR:2.840; 95%CI: 1.736-4.645) were significantly associated with intermittent negative status. Conclusion: These findings could provide clues for early identification of pediatric patients with prolonged viral shedding, enriching the evidence for development of prevention and control strategies especially the vaccination policies for children and adolescents.

Influence of plasma preparation process on SARS-CoV-2 IgG antibody titer of convalescent COVID-19 patients

Objective: To observe the changes of IgG antibody titers in plasma of convalescent COVID-19 patients before and after methylene blue/photochemical virus inactivation and freezing preservation.

Effect on implant drills and postoperative reactions for pre-extraction interradicular implant bed preparation during the COVID-19 pandemic and beyond.

The aim of the present study was to observe the abrasion of implant drills and postoperative reactions for the preparation of the interradicular immediate implant bed during the COVID-19 pandemic and beyond. Thirty-two implant drills were included in four groups: blank, improved surgery, traditional surgery, and control. In the improved surgery group, a dental handpiece with a surgical bur was used to decoronate the first molar and create a hole in the middle of the retained root complex, followed by the pilot drilling protocol through the hole. The remaining root complex was separated using a surgical bur and then extracted. Subsequently, the implant bed was prepared. Implant drills were used in the traditional surgery group to complete the decoronation, hole creation, and implant-drilling processes. The tooth remained intact until the implant bed was prepared. The surface roughness of the pilot drill was observed and measured. Surgery time, postoperative reactions (swelling, pain, and trismus), and fear of coronavirus disease 2019 scale (FCV-19S) were measured and recorded, respectively. Statistical analysis revealed significant difference with surface roughness among blank group (0.41 ± 0.05 µm), improved surgery group (0.37 ± 0.06 µm), traditional surgery group (0.16 ± 0.06 µm), and control group (0.26 ± 0.04 µm) (P < .001). Significant differences were revealed with surgery time between improved surgery group (5.63 ± 1.77 min) and traditional surgery group (33.63 ± 2.13 min) (P < .001). Swelling, pain, and trismus (improved group: r ≥ 0.864, P ≤ .006; traditional group: r ≥ 0.741, P ≤ .035) were positively correlated with the FCV-19S. This study proved that a new pilot drill could only be used once in traditional surgery but could be used regularly in improved surgery. Improved surgery was more effective, efficient, and economical than the traditional surgery. The higher FCV-19S, the more severe swelling, pain, and trismus.

Medical students' perceptions and performance in an online regional anatomy course during the Covid-19 pandemic.

The present study evaluated the students' psychological well-being, experiences, performance, and perception of learning regional anatomy remotely. A regional anatomy remote learning curriculum was designed and learning materials were delivered virtually to 120 undergraduate medical students at Jinan University, China. All the students consented and voluntarily participated in this study by completing self-administered online questionnaires including the Zung's Self-Rating Anxiety and Depression Scales at the beginning and end of the learning session. A subset participated in focus group discussions. Most of the students (90.0%) positively evaluated the current distance learning model. More than 80% were satisfied with the content arrangement and coverage. Many students preferred virtual lectures (68.2%) and videos showing dissections (70.6%) during the distance learning sessions. However, writing laboratory reports and case-based learning were the least preferred modes of learning as they were only preferred by 23.2% and 14.1% of the students, respectively. There was no significant lockdown-related anxiety or depression reported by students using depression and anxiety scales as well as feedback from focus group discussions. The surveyed students' confidence scores in distance learning were significantly higher after 5 weeks than at the beginning of the session (3.05 ± 0.83 vs. 3.70 ± 0.71, P < 0.05). Furthermore, the present results showed no significant differences between the current group's academic performance in the unit tests as well as the final overall evaluation for different parts of the course compared to that of the previous year's cohort. The findings above were congruent with focus group discussion data that the use of the online teaching platform for regional anatomy significantly improved the students' confidence in virtual and self-directed learning and did not negatively affect their academic performance.

Prevention and community management of COVID-19, an example of epidemic rebound in Harbin

Novel coronavirus pneumonia outbreak was still not a promising global epidemic since the outbreak of COVID-19 in the end of 2019. As the first country to outbreak and control the epidemic situation, China provides experience for the global COVID-19 public health and epidemic prevention. However, with the gradual improvement of the domestic epidemic situation, some regions in China began to relax, which led to "epidemic rebound" in some areas. This study analyzes the case of the outbreak again in Harbin City, Heilongjiang Province, China in April 2020, and traces the source of the epidemic and the formation of the local transmission chain. Then,it analyzes the lack of the control of the COVID-19 community behind the outbreak from the aspects of overseas import control, loose aggregation control, hospital management, civic awareness and responsibility. In the aspect of community management and control, it provides feasible measures for preventing the rebound of epidemic situation in China.

Elevated Procalcitonin Is Positively Associated with the Severity of COVID-19: A Meta-Analysis Based on 10 Cohort Studies.

Background and Objectives: Procalcitonin (PCT) is positively associated with the severity of COVID-19 (including severe, critical, or fatal outcomes), but some of the confounding factors are not considered. The aim of this meta-analysis was to estimate the adjusted relationship between elevated procalcitonin on admission and the severity of COVID-19. Materials and Methods: We searched 1805 articles from PubMed, Web of Science, and Embase databases up to 2 April 2021. The articles were selected which reported the adjusted relationship applying multivariate analysis between PCT and the severity of COVID-19. The pooled effect estimate was calculated by the random-effects model. Results: The meta-analysis included 10 cohort studies with a total of 7716 patients. Patients with elevated procalcitonin on admission were at a higher risk of severe and critical COVID-19 (pooled effect estimate: 1.77, 95% confidence interval (CI): 1.38-2.29; I2 = 85.6%, p < 0.001). Similar results were also observed in dead patients (pooled effect estimate: 1.77, 95% CI: 1.36-2.30). After adjusting for diabetes, the positive association between PCT and the severity of COVID-19 decreased. Subgroup analysis revealed heterogeneity between studies and sensitivity analysis showed that the results were robust. There was no evidence of publication bias by Egger's test (p = 0.106). Conclusions: Higher procalcitonin is positively associated with the severity of COVID-19, which is a potential biomarker to evaluate the severity of COVID-19 and predict the prognosis.

Trends of injury mortality during the COVID-19 period in Guangdong, China: a population-based retrospective analysis.

OBJECTIVE: We aimed to ascertain the trends of injury mortality during the COVID-19 period in southern China. METHODS: We conducted a population-based retrospective analysis to compare the mortality changes of all-cause injury and transport injuries, poisoning, falls, fire/heat/hot substances, drowning, self-harm and interpersonal violence, which were further stratified by sex and age. Comparisons were made between the COVID-19 period (between January 2020 and June 2020) and control period (between January 2019 and June 2019) in Guangdong province. We used the negative binomial models to explore the associations of deaths during the COVID-19 period, according to the different sex and age strata. RESULTS: The all-cause injury mortality in Guangdong province decreased significantly from 28.65 per 100 000 population during the control period to 23.24 per 100 000 population during COVID-19 pandemic period. Similar results were found in specific injury categories. Mortality of self-harm increased by 139.26% in the 10-14 year group during the COVID-19 period as compared with the control period. Although mortality changes in some groups were not statistically significant, some increases were noteworthy during the COVID-19 period (ie, self-harm, transport injury and falls) in the 70-79 year group. The corresponding increase in mortality rate was 16.83%, 3.32% and 4.92%, respectively. CONCLUSION: The mortality of all-cause injury, transport injury and drowning during the COVID-19 pandemic was consistently decreased. However, the increase in mortality associated with falls, fire/heat/hot substance injury and self-harm in specific age populations warrant the targeted control and prevention measures for the population at risk.

Semen parameters in men recovered from COVID-19.

The novel coronavirus disease (COVID-19) pandemic is emerging as a global health threat and shows a higher risk for men than women. Thus far, the studies on andrological consequences of COVID-19 are limited. To ascertain the consequences of COVID-19 on sperm parameters after recovery, we recruited 41 reproductive-aged male patients who had recovered from COVID-19, and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge. For longitudinal analysis, a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling. Compared with controls who had not suffered from COVID-19, the total sperm count, sperm concentration, and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling, while sperm vitality and morphology were not affected. The total sperm count, sperm concentration, and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined. Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls, no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients. Although it should be interpreted carefully, these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.