ABSTRACT
Mathematical modelling plays a key role in understanding and predicting the epidemiological dynamics of infectious diseases. We construct a flexible discrete-time model that incorporates multiple viral strains with different transmissibilities to estimate the changing patterns of human contact that generates new infections. Using a Bayesian approach, we fit the model to longitudinal data on hospitalisation with COVID-19 from the Republic of Ireland and Northern Ireland during the first year of the pandemic. We describe the estimated change in human contact in the context of government-mandated non-pharmaceutical interventions in the two jurisdictions on the island of Ireland. We take advantage of the fitted model to conduct counterfactual analyses exploring the impact of lockdown timing and introducing a novel, more transmissible variant. We found substantial differences in human contact between the two jurisdictions during periods of varied restriction easing and December holidays. Our counterfactual analyses reveal that implementing lockdowns earlier would have decreased subsequent hospitalisation substantially in most, but not all cases, and that an introduction of a more transmissible variant - without necessarily being more severe - can cause a large impact on the health care burden.
ABSTRACT
BACKGROUND: Millions of people have acquired and died from SARS-CoV-2 infection during the COVID-19 pandemic. Healthcare workers (HCWs) are required to wear personal protective equipment (PPE), including surgical masks and P2/N95 respirators, to prevent infection while treating patients. However, the comparative effectiveness of respirators and masks in preventing SARS-CoV-2 infection and the likelihood of experiencing adverse events (AEs) with wear are unclear. METHODS: Searches were carried out in PubMed, Europe PMC and the Cochrane COVID-19 Study Register to 14 June 2021. A systematic review of comparative epidemiological studies examining SARS-CoV-2 infection or AE incidence in HCWs wearing P2/N95 (or equivalent) respirators and surgical masks was performed. Article screening, risk of bias assessment and data extraction were duplicated. Meta-analysis of extracted data was carried out in RevMan. RESULTS: Twenty-one studies were included, with most having high risk of bias. There was no statistically significant difference in respirator or surgical mask effectiveness in preventing SARS-CoV-2 infection (OR 0.85, [95%CI 0.72, 1.01]). Healthcare workers experienced significantly more headaches (OR 2.62, [95%CI 1.18, 5.81]), respiratory distress (OR 4.21, [95%CI 1.46, 12.13]), facial irritation (OR 1.80, [95%CI 1.03, 3.14]) and pressure-related injuries (OR 4.39, [95%CI 2.37, 8.15]) when wearing respirators compared to surgical masks. CONCLUSION: The existing epidemiological evidence does not enable definitive assessment of the effectiveness of respirators compared to surgical masks in preventing infection. Healthcare workers wearing respirators may be more likely to experience AEs. Effective mitigation strategies are important to ensure the uptake and correct use of respirators by HCWs.
Subject(s)
COVID-19 , COVID-19/prevention & control , Humans , N95 Respirators/adverse effects , Pandemics/prevention & control , Personal Protective Equipment , SARS-CoV-2ABSTRACT
The pathophysiology of respiratory failure associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains under investigation. One hypothesis is that progressive endothelial damage from the virus leads to microvascular thrombosis. It is uncertain if empiric therapeutic anticoagulation provides benefit over standard deep vein thrombosis (DVT) prophylaxis in critically ill patients with SARS-CoV-2. A retrospective cohort study was performed to evaluate adult patients admitted to the intensive care unit at 3 hospitals with polymerase chain reaction-confirmed SARS-CoV-2-associated respiratory failure requiring invasive mechanical ventilation. A Kaplan-Meier survival analysis was used to compare patients who were initiated on therapeutic anticoagulation prior to the time of intubation and those receiving standard DVT prophylaxis doses. The primary outcome was the difference in the 28-day mortality of patients between the 2 groups. Twenty-eight-day mortality did not differ between groups, occurring in 26.1% of patients who received therapeutic anticoagulation and 29.5% of those who received a prophylactic dose only (hazard ratio, 0.52; P = .055). There was no difference in 28-day mortality between groups in patients who were admitted with a serum D-dimer ≥ 2 µg/mL (hazard ratio, 0.67; P = .41). Empiric therapeutic anticoagulation in patients who require invasive mechanical ventilation for confirmed SARS-CoV-2 infection does not improve 28-day mortality compared with standard DVT prophylaxis, even among those with elevated D-dimer levels.
