Non-generalizability of biomarkers for mortality in SARS-CoV-2: a meta-analyses series (preprint)

Objectives: Sophisticated scores have been proposed for prognostication of mortality due to SARS-CoV-2 but perform inconsistently. We conducted these meta-analyses to uncover why and to pragmatically seek a single dependable biomarker for mortality. Design: We searched the PubMed database for the keywords SARS-CoV-2 with biomarker name and mortality. All studies published from 01st December 2019 to 30th June 2021 were surveyed. To aggregate the data, the meta library in R was used to report overall mean values and 95% confidence intervals. We fitted a random effects model to obtain pooled AUCs and associated 95% confidence intervals for the European/North American, Asian, and overall datasets. Setting and Participants: Data was collected from 131 studies on SARS-CoV-2 PCR-positive general hospital adult admissions (n=76,169 patients in total). Main Outcome Measures: We planned a comparison of pooled area under curves (AUCs) from Receiver Operator Characteristic curves plotted for admission D-dimer, CRP, urea, troponin and interleukin-6 levels. Main Results: Biomarker effectiveness varies significantly in different regions of the world. Admission CRP levels are a good prognostic marker for mortality due to SARS-CoV-2 in Asian countries, with a pooled area under curve (AUC) of 0.83 (95% CI 0.80-0.85), but only an average predictor of mortality in Europe/North America, with a pooled AUC of 0.67 (95% CI 0.63-0.71, P<0.0001). We observed the same pattern for D-dimer and IL-6. This variability explains why the proposed prognostic scores did not perform evenly. Notably, urea and troponin had pooled AUCs [≥] 0.78 regardless of location, implying that end-organ damage at presentation is a key prognostic factor. These differences might be due to age, genetic backgrounds, or different modes of death (younger patients in Asia dying of cytokine storm while older patients die of multi-organ failure). Conclusions: Biomarker effectiveness for prognosticating SARS-CoV-2 mortality varies significantly by geographical location. We propose that biomarkers and by extension prognostic scores need to be tailored for specific populations. This also implies that validation of commonly used prognostic scores for other conditions should occur before they are used in different populations.

Persistence of SARS-CoV-2 Antibodies in Vaccinated Health Care Workers Analyzed by Coronavirus Antigen Microarray.

Recent studies provide conflicting evidence on the persistence of SARS-CoV-2 immunity induced by mRNA vaccines. Here, we aim to quantify the persistence of humoral immunity following vaccination using a coronavirus antigen microarray that includes 10 SARS-CoV-2 antigens. In a prospective longitudinal cohort of 240 healthcare workers, composite SARS-CoV-2 IgG antibody levels did not wane significantly over a 6-month study period. In the subset of the study population previously exposed to SARS-CoV-2 based on seropositivity for nucleocapsid antibodies, higher composite anti-spike IgG levels were measured before the vaccine but no significant difference from unexposed individuals was observed at 6 months. Age, vaccine type, or worker role did not significantly impact composite IgG levels, although non-significant trends towards lower antibody levels in older participants and higher antibody levels with Moderna vaccine were observed at 6 months. A small subset of our cohort were classified as having waning antibody titers at 6 months, and these individuals were less likely to work in patient care roles and more likely to have prior exposure to SARS-CoV-2.

Spatial Variability of the ‘Airbnb Effect’: A Spatially Explicit Analysis of Airbnb’s Impact on Housing Prices in Sydney

Over the last decade, the emergence and significant growth of home-sharing platforms, such as Airbnb, has coincided with rising housing unaffordability in many global cities. It is in this context that we look to empirically assess the impact of Airbnb on housing prices in Sydney—one of the least affordable cities in the world. Employing a hedonic property valuation model, our results indicate that Airbnb’s overall effect is positive. A 1% increase in Airbnb density is associated with approximately a 2% increase in property sales price. However, recognizing that Airbnb’s effect is geographically uneven and given the fragmented nature of Sydney’s housing market, we also employ a GWR to account for the spatial variation in Airbnb activity. The findings confirm that Airbnb’s influence on housing prices is varied across the city. Sydney’s northern beaches and parts of western Sydney experience a statistically significant value uplift attributable to Airbnb activity. However, traditional tourist locations focused around Sydney’s CBD and the eastern suburbs experience insignificant or negative property price impacts. The results highlight the need for policymakers to consider local Airbnb and housing market contexts when deciding the appropriate level and design of Airbnb regulation.

Roundtable: Animal History in a Time of Crisis

Before we knew it, the world was locked down and COVID-19 was our unavoidable daily reality. Because of this dynamic, the roundtable became a kind of historical chronicle of what will surely be one of the transformational moments of the twenty-first century. SUSAN NANCE is professor of history and affiliated faculty with the Campbell Centre for the Study of Animal Welfare at the University of Guelph in Ontario, Canada. GABRIEL N. ROSENBERG is associate professor of gender, sexuality, and feminist studies and history at Duke University. [...]there is a rich opportunity for scholars to give animals their due.

An Australian Response to the COVID-19 Pandemic and Its Implications on the Practice of Neurosurgery.

OBJECTIVE: This study was designed to assess the impact of public health policy in Australia in response to the coronavirus disease identified in 2019 (COVID-19) pandemic on the delivery of neurosurgical services. Being essential services, we postulated that there would not be a decrease in elective and emergency neurosurgical presentations and surgeries. METHODS: This is a prospective, observational, epidemiologic study in strict adherence to the "STROBE" (Strengthening The Reporting of OBservational studies in Epidemiology) guidelines. It is a cross-sectional, multicentric study involving 5 tertiary neurosurgical centers to capture all public neurosurgical admissions in Queensland during the past 3 months (February-April, 2020) of significant public health policy changes to combat COVID-19. RESULTS: An analysis of the 1298 admissions for the Queensland population of 5.07 million Australians demonstrated a decrease in the number of elective and emergency admissions. The decline in elective admissions, particularly degenerative spine, benign neoplasms, and vascular pathologies, was a direct response of government strategy to curb activity to urgent surgical interventions only. Moreover, a trend toward fewer emergency admissions was also noted, partly explained by less trauma and also a decline in vascular pathologies including subarachnoid hemorrhage. CONCLUSIONS: In comparison with Europe and North America, this study demonstrates the impact of proactive public health measures in Australia that successfully flattened the COVID-19 curve while facilitating ongoing care of acutely unwell neurosurgical patients.

An international comparison of the second derivative of COVID-19 deaths after implementation of social distancing measures (preprint)

This work compares deaths for confirmed COVID-19 cases in China to eight other countries, Italy, Spain, France, USA, UK, Germany, Netherlands and South Korea. After implementing varying intensities and timing of social distancing measures, several appear to be converging onto the decline in the daily growth rate of deaths, or relative second derivative of total deaths, seen in China after the implementation an aggressive social distancing policy. By calculating future trajectories in these countries based on the observed Chinese fatality statistics, an estimate of the total deaths and maximum daily death rates over a defined period of time is made. Our lower bound estimate for the United Kingdom based on the real data approximates the lower bound estimate of the recent modelling study of Ferguson et al. [1]. These results suggest there may be a threshold of effective public health intervention. Our method of viewing the data may be helpful in monitoring the course of the epidemic, judging the effectiveness of implementation, and monitoring the relaxation of social distancing.