Microbial Dynamics and Pulmonary Immune Responses in COVID-19 Secondary Bacterial Pneumonia (preprint)

Secondary bacterial pneumonia (2°BP) is associated with significant morbidity following respiratory viral infection, yet mechanistically remains incompletely understood. In a prospective cohort of 112 critically ill adults intubated for COVID-19, we comparatively assessed longitudinal airway microbiome dynamics and studied the pulmonary transcriptome of patients who developed 2°BP versus controls who did not. We found that 2°BP was significantly associated with both mortality and corticosteroid treatment. The pulmonary microbiome in 2°BP was characterized by increased bacterial RNA load, dominance of culture-confirmed pathogens, and lower alpha diversity. Bacterial pathogens were detectable days prior to 2°BP clinical diagnosis, and in most cases were also present in nasal swabs. Pathogen antimicrobial resistance genes were also detectable in both the lower airway and nasal samples, and in some cases were identified prior to 2°BP clinical diagnosis. Assessment of the pulmonary transcriptome revealed suppressed TNFa signaling via NF-kB in patients who developed 2°BP, and a sub-analysis suggested that this finding was mediated by corticosteroid treatment. Within the 2°BP group, we observed a striking inverse correlation between innate and adaptive immune gene expression and bacterial RNA load. Together, our findings provide fresh insights into the microbial dynamics and host immune features of COVID-19-associated 2°BP.

The prevalence of self-reported anxiety, depression, and associated factors among Hanoi Medical University's students during the first wave of COVID-19 pandemic.

BACKGROUND: Medical students are known to have higher levels of these issues than the general population but in Vietnam the effects of the pandemic on medical student mental health was not documented. OBJECTIVES: To estimate the prevalence and identify factors associated with self-reported anxiety disorder, depression, and perception of worsening mental health among Vietnamese medical students during the COVID-19 pandemic. METHOD: A cross-sectional study was conducted from April 7th to 29th, 2020. All students in Doctor of General Medicine, Doctor of Preventive Medicine, and Bachelor of Nursing tracks at Hanoi Medical University (3672 students) were invited to participate. Data were collected using an online questionnaire including demographic characteristics, Generalized Anxiety Disorder 7 items, Patient Health Questionnaire 9 items, Fear of COVID-19 scale, and question about worsening mental health status. Robust Poisson regression was used to assess the association between mental health status and associated factors. RESULTS: Among 1583 students (43.1% response rate), the prevalence of students screened positive for anxiety disorder was 7.3%(95%C.I.:6.0-8.7), depression was 14.5%(95%C.I.:12.8-16.3), and perceiving worsening mental health was 6.9%(95%C.I.:5.7-8.3). In multivariable regression models, significant factors associated with self-reported anxiety disorder included being male (PR = 1.99,95%C.I.:1.35-2.92), difficulty in paying for healthcare services (PR = 2.05,95%C.I.:1.39-3.01), and high level of fear of COVID-19 (Q3:PR = 2.36,95%C.I.:1.38-4.02 and Q4:PR = 4.75,95%C.I.:2.65-8.49). Significant factors associated with self-reported depression were difficulty in paying for healthcare services (PR = 1.78,95%C.I.:1.37-2.30), and high level of fear of COVID-19 (Q3:PR = 1.41,95%C.I.:1.02-1.95 and Q4:PR = 2.23,95%C.I.:1.51-3.29). Significant factors associated with perceived worsening mental health status included having clinical experience (PR = 1.83,95%C.I.:1.17-2.88) and having atypical symptoms of COVID-19 (PR = 1.96,95%C.I.:1.31-2.94). CONCLUSION: The prevalence of self-reported depression, anxiety disorder, and worsening mental health among Vietnamese students during the first wave of COVID-19 was lower than in medical students in other countries. Further investigation is needed to confirm this finding.

Investor Sentiment Index during the COVID-19 crisis: Evidence from G20 Stock Markets (preprint)

The present study investigates the degree of market responses through the scope of investors’ sentiment during the COVID-19 pandemic across G20 markets, by constructing a novel positive search volume index for COVID-19. Our key findings, obtained using a Panel-GARCH model, indicate that an increased COVID19 index suggests that investors decrease their COVID-19 related crisis sentiment by escalating their Google searches for positively associated COVID-19 related keywords. Specifically, we explore the predictive power of the newly constructed index on stock returns and volatility. According to our findings, investor sentiment positively (negatively) predicts the stock return (volatility) during the COVID-19. This is the first study of its kind assessing global sentiment by proposing a novel proxy and its impacts on the G20 equity market.