Impact of Lifting Mask Mandates on COVID-19 Incidence and Mortality in Portugal: An Ecological Study

INTRODUCTION

The use of face masks in public was one of several COVID-19 non-pharmaceutical interventions adopted to mitigate the pandemic in Portugal. The aim of this study was to evaluate the impact of lifting the mask mandate on the April 22, 2022 on COVID-19 incidence and mortality in mainland Portugal and in the Azores. As a secondary objective, we aimed to evaluate the evolution of COVID-19 cases in a setting without a mask mandate (Azores islands) and in a setting with a mask mandate (Madeira islands).

MATERIAL AND METHODS

Surveillance data on laboratory-confirmed COVID-19 cases and COVID-19 deaths were used to conduct an interrupted time series analysis to estimate changes in daily incidence and deaths during a mask mandate period (28th March - 21st April 2022) and during a post-mask mandate period (22nd April - 15th May 2022), in mainland Portugal and the Azores. In a second phase, for each group of islands, we fitted a negative binomial regression model, with daily COVID-19 incident cases as the primary outcome of interest, and relative frequency of Omicron BA.5 lineage as explanatory variable.

RESULTS

Significant changes in trends were observed for the overall incidence rate and COVID-19 deaths; increasing trends were observed for COVID-19 incidence and deaths in the post mandate period [5.3% per day; incidence rate ratio (IRR): 1.053; 95% confidence interval (CI): 1.029 - 1.078] and [3.2% per day; mortality rate ratio (MRR): 1.032; 95% CI: 1.003 - 1.062], respectively. For every unit increase in the percentage of Omicron BA.5 lineage there was a 1.5% increase per day (IRR: 1.015; 95% CI: 1.006 - 1.024) in COVID-19 incidence rate in the Azores islands, while for Madeira islands an increase of 0.05% COVID-19 cases per day was observed (IRR: 1.005; 95% CI: 1.000 - 1.010).

CONCLUSION

Lifting the mask mandate in Portugal was associated with an increase in COVID-19 incidence and deaths, thus highlighting the positive effect of face mask policies in preventing respiratory virus transmission and saving lives.

Microbiota profile in mesophilic biodigestion of sugarcane vinasse in batch reactors

The vinasse is a residue of ethanol production with the potential for methane production, requiring an allochthonous inoculum. Several microorganisms act in the different phases of anaerobic digestion, and the identification of these microbial communities is essential to optimize the process. The characterization of the microbiota involved in the biodigestion of vinasse was observed in the initial stage (IS), at the peak of methane production (MS) and the end of the process (FS) of the best performance assay by high-throughput sequencing. The highest methane production was 0.78 mmolCH₄.gVS.h^-1 at 243.7 h in the substrate/inoculum ratio of 1.7, with consumption partial of acetic, propionic and isobutyric acids and an 82% reduction of chemical oxygen demand. High microbial diversity was found. The genera Clostridium, Acinetobacter, Candidatus Cloacamonas, Bacteroides, Syntrophomonas, Kosmotoga, the family Porphyromonadaceae and the class Bacteroidia were the most abundant in the maximum methane production. Methane production was driven by Methanobacterium and Methanosaeta, suggesting the metabolic pathways used were hydrogenotrophic and acetoclastic.

Hidden persistence of salinity and productivity gradients shaping pelagic diversity in highly dynamic marine ecosystems

While large-scale patterns of pelagic marine diversity are generally well described, they remain elusive at regional-scale given the high temporal and spatial dynamics of biological and local oceanographic processes. We here evaluated whether the main drivers of pelagic diversity can be more pervasive than expected at regional scale, using a meroplankton community of a frontal system in the Western Mediterranean. We evidence that regional biodiversity in a highly dynamic ecosystem can be summarized attending to both static (bathymetric) and ephemeral (biological and hydrographical) environmental axes of seascape. This pattern can be observed irrespectively of the regional hydroclimatic scenario with distance to coast, salinity gradient and chlorophyll a concentration being the main and recurrent drivers. By contrast, their effect is overridden in common analyses given that different non-linear effects are buffered between years of contrasting scenarios, emerging the influence of secondary effects on diversity. We conclude that community studies may reveal hidden persistent processes when they take into account different functional effects related to hydroclimatic variability. A better understanding of regional dynamics of the pelagic realm will improve our capability to forecast future responses of plankton communities as well as impacts of climate change on marine biodiversity.