The Impact of Universal Mask Use on SARS-COV-2 in Victoria, Australia on the Epidemic Trajectory of COVID-19

The role of masks and respirators in preventing respiratory infections in healthcare and community settings

The covid-19 pandemic saw frequent changes and conflicts in mask policies and politicization of masks. On reviewing the evidence, including studies published after the pandemic, the data suggest respirators are more effective than masks in healthcare, but must be continuously worn to be protective. Healthcare and aged care settings amplify outbreaks, so protection of patients and staff is paramount. Most guidelines assume risk is only present during close contact or aerosol generating procedures, but studies show intermittent use of respirators is not protective. New research in aerosol science confirms the risk of infection is widespread in health facilities. In community settings, any mask use is protective during epidemics, especially if used early, when combined with hand hygiene, and if wearers are compliant. Community use of N95 respirators is more protective than surgical masks, which are more protective than cloth masks, but even cloth masks provide some protection. Mask guidelines should be adaptable to the specific context and should account for rising epidemic activity, and whether a pathogen has asymptomatic transmission. The main rationale for universal masking during pandemics is asymptomatic transmission, which means risk of transmission cannot be self-identified. The precautionary principle should be applied during serious emerging infections or pandemics when transmission mode is not fully understood, or vaccines and drugs are not available. If respirators are not available, medical or cloth masks could be used as a last resort. Data exist to support extended use and reuse of masks and respirators during short supply. In summary, extensive evidence generated during the covid-19 pandemic confirms the superiority of respirators and supports the use of masks and respirators in the community during periods of high epidemic activity. Some gaps in research remain, including economic analyses, research in special population groups for whom masking is challenging, and research on countering disinformation.

Masks and respirators for prevention of respiratory infections: a state of the science review

SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.

Role of masks in mitigating viral spread on networks

Masks have remained an important mitigation strategy in the fight against COVID-19 due to their ability to prevent the transmission of respiratory droplets between individuals. In this work, we provide a comprehensive quantitative analysis of the impact of mask-wearing. To this end, we propose a novel agent-based model of viral spread on networks where agents may either wear no mask or wear one of several types of masks with different properties (e.g., cloth or surgical). We derive analytical expressions for three key epidemiological quantities: The probability of emergence, the epidemic threshold, and the expected epidemic size. In particular, we show how the aforementioned quantities depend on the structure of the contact network, viral transmission dynamics, and the distribution of the different types of masks within the population. Through extensive simulations, we then investigate the impact of different allocations of masks within the population and tradeoffs between the outward efficiency and inward efficiency of the masks. Interestingly, we find that masks with high outward efficiency and low inward efficiency are most useful for controlling the spread in the early stages of an epidemic, while masks with high inward efficiency but low outward efficiency are most useful in reducing the size of an already large spread. Last, we study whether degree-based mask allocation is more effective in reducing the probability of epidemic as well as epidemic size compared to random allocation. The result echoes the previous findings that mitigation strategies should differ based on the stage of the spreading process, focusing on source control before the epidemic emerges and on self-protection after the emergence.

Anxiety, stress, and depression in Australian pregnant women during the COVID-19 pandemic: A cross sectional study

BACKGROUND

The COVID-19 pandemic necessitated rapid responses by health services to suppress transmission of the virus.

AIM

This study aimed to investigate predictors of anxiety, stress and depression in Australian pregnant women during the COVID-19 pandemic including continuity of carer and the role of social support.

METHODS

Women aged 18 years and over in their third trimester of pregnancy were invited to complete an online survey between July 2020 and January 2021. The survey included validated tools for anxiety, stress, and depression. Regression modelling was used to identify associations between a range of factors including continuity of carer, and mental health measures.

FINDINGS

1668 women completed the survey. One quarter screened positive for depression, 19% for moderate or higher range anxiety, and 15.5% for stress. The most significant contribution to higher anxiety, stress, and depression scores was a pre-existing mental health condition, followed by financial strain and a current complex pregnancy. Protective factors included age, social support, and parity.

DISCUSSION

Maternity care strategies to reduce COVID-19 transmission restricted women's access to their customary pregnancy supports and increased their psychological morbidity.

CONCLUSION

Factors associated with anxiety, stress and depression scores during the COVID-19 pandemic were identified. Maternity care during the pandemic compromised pregnant women's support systems.

Mask images on Twitter increase during COVID-19 mandates, especially in Republican counties

Wearing masks reduces the spread of COVID-19, but compliance with mask mandates varies across individuals, time, and space. Accurate and continuous measures of mask wearing, as well as other health-related behaviors, are important for public health policies. This article presents a novel approach to estimate mask wearing using geotagged Twitter image data from March through September, 2020 in the United States. We validate our measure using public opinion survey data and extend the analysis to investigate county-level differences in mask wearing. We find a strong association between mask mandates and mask wearing-an average increase of 20%. Moreover, this association is greatest in Republican-leaning counties. The findings have important implications for understanding how governmental policies shape and monitor citizen responses to public health crises.

Impact of COVID-19 pandemic on catheter ablation in China: A spatiotemporal analysis

Background

The COVID-19 pandemic has significantly impacted routine cardiovascular health assessments and services. We aim to depict the temporal trend of catheter ablation (CA) and provide experience in dealing with the negative impact of the COVID-19 pandemic.

Methods

Data on CA between January 2019, and December 2021, were extracted from the National Center for Cardiovascular Quality Improvement platform. CA alterations from 2019 to 2021 were assessed with a generalized estimation equation.

Results

A total of 347,924 patients undergoing CA were included in the final analysis. The CA decreased remarkably from 122,839 in 2019 to 100,019 (-18.58%, 95% CI: -33.40% to -3.75%, p = 0.02) in 2020, and increased slightly to 125,006 (1.81%, 95% CI: -7.01% to 3.38%, p = 0.49) in 2021. The CA experienced the maximal reduction in February 2020 (-88.78%) corresponding with the peak of monthly new COVID-19 cases and decreased by 54.32% (95%CI: -71.27% to -37.37%, p < 0.001) during the 3-month lockdown and increased firstly in June 2020 relative to 2019. Since then, the CA in 2020 remained unchanged relative to 2019 (-0.06%, 95% CI: -7.01% to 3.38%, p = 0.98). Notably, the recovery of CA in 2021 to pre-COVID-19 levels was mainly driven by the growth of CA in secondary hospitals. Although there is a slight increase (2167) in CA in 2021 relative to 2019, both the absolute number and proportion of CA in the top 50 hospitals nationwide [53,887 (43.09%) vs. 63,811 (51.95%), p < 0.001] and top three hospitals in each province [66,152 (52.73%) vs. 72,392 (59.28%), p < 0.001] still declined significantly.

Conclusions

The CA experienced a substantial decline during the early phase of the COVID-19 pandemic, and then gradually returned to pre-COVID-19 levels. Notably, the growth of CA in secondary hospitals plays an important role in the overall resumption, which implies that systematic guidance of secondary hospitals with CA experience may aid in mitigating the negative impact of the COVID-19 pandemic.

Global Excess Mortality during COVID-19 Pandemic: A Systematic Review and Meta-Analysis

BACKGROUND

Currently, reported COVID-19 deaths are inadequate to assess the impact of the pandemic on global excess mortality. All-cause excess mortality is a WHO-recommended index for assessing the death burden of COVID-19. However, the global excess mortality assessed by this index remains unclear. We aimed to assess the global excess mortality during the COVID-19 pandemic.

METHODS

We searched PubMed, EMBASE, and Web of Science for studies published in English between 1 January 2020, and 21 May 2022. Cross-sectional and cohort studies that reported data about excess mortality during the pandemic were included. Two researchers independently searched the published studies, extracted data, and assessed quality. The Mantel-Haenszel random-effects method was adopted to estimate pooled risk difference (RD) and their 95% confidence intervals (CIs).

RESULTS

A total of 79 countries from twenty studies were included. During the COVID-19 pandemic, of 2,228,109,318 individuals, 17,974,051 all-cause deaths were reported, and 15,498,145 deaths were expected. The pooled global excess mortality was 104.84 (95% CI 85.56-124.13) per 100,000. South America had the highest pooled excess mortality [134.02 (95% CI: 68.24-199.80) per 100,000], while Oceania had the lowest [-32.15 (95% CI: -60.53--3.77) per 100,000]. Developing countries had higher excess mortality [135.80 (95% CI: 107.83-163.76) per 100,000] than developed countries [68.08 (95% CI: 42.61-93.55) per 100,000]. Lower middle-income countries [133.45 (95% CI: 75.10-191.81) per 100,000] and upper-middle-income countries [149.88 (110.35-189.38) per 100,000] had higher excess mortality than high-income countries [75.54 (95% CI: 53.44-97.64) per 100,000]. Males had higher excess mortality [130.10 (95% CI: 94.15-166.05) per 100,000] than females [102.16 (95% CI: 85.76-118.56) per 100,000]. The population aged ≥ 60 years had the highest excess mortality [781.74 (95% CI: 626.24-937.24) per 100,000].

CONCLUSIONS

The pooled global excess mortality was 104.84 deaths per 100,000, and the number of reported all-cause deaths was higher than expected deaths during the global COVID-19 pandemic. In South America, developing and middle-income countries, male populations, and individuals aged ≥ 60 years had a heavier excess mortality burden.

The introduction of a mandatory mask policy was associated with significantly reduced COVID-19 cases in a major metropolitan city

BACKGROUND

Whilst evidence of use of face masks in reducing COVID-19 cases is increasing, the impact of mandatory use across a large population has been difficult to assess. Introduction of mandatory mask use on July 22, 2020 during a resurgence of COVID-19 in Melbourne, Australia created a situation that facilitated an assessment of the impact of the policy on the epidemic growth rate as its introduction occurred in the absence of other changes to restrictions.

METHODS AND FINDINGS

Exponential epidemic growth or decay rates in daily COVID-19 diagnoses were estimated using a non-weighted linear regression of the natural logarithm of the daily cases against time, using a linear spline model with one knot (lspline package in R v 3.6.3). The model's two linear segments pivot around the hinge day, on which the mask policy began to take effect, 8 days following the introduction of the policy. We used two forms of data to assess change in mask usage: images of people wearing masks in public places obtained from a major media outlet and population-based survey data. Potential confounding factors (including daily COVID-19 tests, number of COVID-19 cases among population subsets affected differentially by the mask policy-e.g., healthcare workers) were examined for their impact on the results. Daily cases fitted an exponential growth in the first log-linear segment (k = +0.042, s.e. = 0.007), and fitted an exponential decay in the second (k = -0.023, s.e. = 0.017) log-linear segment. Over a range of reported serial intervals for SARS-CoV-2 infection, these growth rates correspond to a 22-33% reduction in an effective reproduction ratio before and after mandatory mask use. Analysis of images of people in public spaces showed mask usage rose from approximately 43% to 97%. Analysis of survey data found that on the third day before policy introduction, 44% of participants reported "often" or "always" wearing a mask; on the fourth day after, 100% reported "always" doing so. No potentially confounding factors were associated with the observed change in growth rates.

CONCLUSIONS

The mandatory mask use policy substantially increased public use of masks and was associated with a significant decline in new COVID-19 cases after introduction of the policy. This study strongly supports the use of masks for controlling epidemics in the broader community.