Update Alert 4: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings

Chou, Roger; Dana, Tracy; Jungbauer, Rebecca; Weeks, Chandler

doi:10.7326/l20-1429

Cited by 14 publications

(14 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This particularly applies to possible prevention, prophylaxis, and treatment of COVID-19. How effective cloth masks are at preventing infection, or at reducing severity of infection needs more study (268,269). The safety, efficacy (including for interrupting infectiousness, necessary to achieve herd immunity), and durability of protection from vaccines, particularly in high-risk groups, must be determined in large Phase III randomized controlled trials (246).…”

Section: Some Research Prioritiesmentioning

confidence: 99%

COVID-19: Rethinking the Lockdown Groupthink

Joffe

2021

Front. Public Health

101

View full text Add to dashboard Cite

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused the Coronavirus Disease 2019 (COVID-19) worldwide pandemic in 2020. In response, most countries in the world implemented lockdowns, restricting their population's movements, work, education, gatherings, and general activities in attempt to “flatten the curve” of COVID-19 cases. The public health goal of lockdowns was to save the population from COVID-19 cases and deaths, and to prevent overwhelming health care systems with COVID-19 patients. In this narrative review I explain why I changed my mind about supporting lockdowns. The initial modeling predictions induced fear and crowd-effects (i.e., groupthink). Over time, important information emerged relevant to the modeling, including the lower infection fatality rate (median 0.23%), clarification of high-risk groups (specifically, those 70 years of age and older), lower herd immunity thresholds (likely 20–40% population immunity), and the difficult exit strategies. In addition, information emerged on significant collateral damage due to the response to the pandemic, adversely affecting many millions of people with poverty, food insecurity, loneliness, unemployment, school closures, and interrupted healthcare. Raw numbers of COVID-19 cases and deaths were difficult to interpret, and may be tempered by information placing the number of COVID-19 deaths in proper context and perspective relative to background rates. Considering this information, a cost-benefit analysis of the response to COVID-19 finds that lockdowns are far more harmful to public health (at least 5–10 times so in terms of wellbeing years) than COVID-19 can be. Controversies and objections about the main points made are considered and addressed. Progress in the response to COVID-19 depends on considering the trade-offs discussed here that determine the wellbeing of populations. I close with some suggestions for moving forward, including focused protection of those truly at high risk, opening of schools, and building back better with a economy.

show abstract

Section: Some Research Prioritiesmentioning

confidence: 99%

COVID-19: Rethinking the Lockdown Groupthink

Joffe

2021

Front. Public Health

101

View full text Add to dashboard Cite

show abstract

“…Mask efficacy is inferior to that of other, less permeable barrier methods to prevent infections such as condoms 1 , 3 , 4 . The most commonly used cloth and hospital masks do not provide a perfect facial seal and mask fabric does not block emission or inhalation of all aerosolized viral particles 5 , 6 .…”

Section: Introductionmentioning

confidence: 96%

Slight reduction in SARS-CoV-2 exposure viral load due to masking results in a significant reduction in transmission with widespread implementation

Goyal

Reeves

Thakkar

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Masks are a vital tool for limiting SARS-CoV-2 spread in the population. Here we utilize a mathematical model to assess the impact of masking on transmission within individual transmission pairs and at the population level. Our model quantitatively links mask efficacy to reductions in viral load and subsequent transmission risk. Our results reinforce that the use of masks by both a potential transmitter and exposed person substantially reduces the probability of successful transmission, even if masks only lower exposure viral load by ~ 50%. Slight increases in mask adherence and/or efficacy above current levels would reduce the effective reproductive number (Re) substantially below 1, particularly if implemented comprehensively in potential super-spreader environments. Our model predicts that moderately efficacious masks will also lower exposure viral load tenfold among people who get infected despite masking, potentially limiting infection severity. Because peak viral load tends to occur pre-symptomatically, we also identify that antiviral therapy targeting symptomatic individuals is unlikely to impact transmission risk. Instead, antiviral therapy would only lower Re if dosed as post-exposure prophylaxis and if given to ~ 50% of newly infected people within 3 days of an exposure. These results highlight the primacy of masking relative to other biomedical interventions under consideration for limiting the extent of the COVID-19 pandemic prior to widespread implementation of a vaccine. To confirm this prediction, we used a regression model of King County, Washington data and simulated the counterfactual scenario without mask wearing to estimate that in the absence of additional interventions, mask wearing decreased Re from 1.3–1.5 to ~ 1.0 between June and September 2020.

show abstract

“…Conversely, the steep decrease of positive cases among hospital personnel observed after March probably reflects adequate preventive and tracing nosocomial measures implemented on daily bases, while new scientific evidence was cumulating [ 21 , 28 – 31 ].…”

Section: Discussionmentioning

confidence: 99%

Importance of mitigation measures for hospital transmission of SARS-CoV-2 at the onset of the epidemic: the experience of Brescia, Northern Italy

et al. 2021

View full text Add to dashboard Cite

Purpose Since the first Italian case of SARS-CoV-2 was detected in Lombardy (Northern Italy) Italy quickly became one of the worst-affected European countries, with a severe impact on health-care workers (HCWs). In the first epidemic, HCWs accounted for 12% of all national COVID-19 cases. We evaluated the burden of COVID-19 among HCWs and other non-health-care workers (nHCWs) in a large Italian hospital. Methods From March 1st to May 31st 2020, we performed a retrospective study at ASST Civil Hospital, in the Province of Brescia, Lombardy. The study population included all hospital personnel (n = 9265), categorized by professional status. Results A SARS-CoV-2 test was performed in 3572 workers (38.5%), with a positive result in 552 (5.9% of all hospital personnel). The temporal trend of SARS-CoV-2 cases in hospital staff broadly reflected that in the community, with a great majority of infections occurred during March 2020 (87.7%). From April onward, a steep decrease of positive cases was observed among hospital personnel, while in the community the decrease was much slower. Medical doctors (8.9%) and nurses (8.5%) were the most affected professional categories with a significantly higher risk of SARS-CoV-2 infection (OR 1.436 and OR 1.410, respectively p < 0.0001). HCWs in COVID-19 units presented a significantly higher risk of infection compared to HCWs in non-COVID units (p < 0.001). Conclusion HCWs were severely affected by the COVID-19 epidemic, probably associated with an overwhelming burden of work and lack of preparedness in prevention of nosocomial transmission of the infection. The rapid decrease of COVID-19 spread in the hospital, registered before the one in the community, suggests that the adopted preventive measures were effective.

show abstract

Update Alert 4: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings

Cited by 14 publications

References 8 publications

COVID-19: Rethinking the Lockdown Groupthink

COVID-19: Rethinking the Lockdown Groupthink

Slight reduction in SARS-CoV-2 exposure viral load due to masking results in a significant reduction in transmission with widespread implementation

Importance of mitigation measures for hospital transmission of SARS-CoV-2 at the onset of the epidemic: the experience of Brescia, Northern Italy

Contact Info

Product

Resources

About