Published: April 22, 2015
The aim of this study was to compare the efficacy of cloth masks to medical masks in hospital healthcare workers (HCWs). The rates of all infection outcomes were highest in the cloth mask arm. Penetration of cloth masks by particles was almost 97% and medical masks 44%.
Conclusions: This study is the first RCT of cloth masks, and the results caution against the use of cloth masks. This is an important finding to inform occupational health and safety. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.
Published: November 16, 2020
Cloth masks have been proven to effectively block at least some exhaled particles when worn over the mouth and nose, but only to a meaningful degree when the masks are multiple layers or medical grade. The CDC says that cloth masks “effectively block most large droplets” and “block the exhalation of fine droplets and particles (also often referred to as aerosols)”. According to Lindsley et. al, the efficacy of masks in blocking “cough aerosol” varied greatly between the N95 mask (99% effective), a 3-ply cloth mask (59% effective), and a single layer neck gaiter (47% effective). The variety of mask types and efficacy in usage by the general population makes the true effectiveness of mask usage impossible to predict
Published: September 2, 2020
Cloth masks can be effective at reducing the respiratory droplets expelled from the mouth in controlled environments. The CDC refers to a 2020 study by Fischer et. al. to note that “upwards of 80% blockage has been achieved in human experiments that have measured blocking of all respiratory droplets, with cloth masks in some studies performing on par with surgical masks as barriers for source control.” This study used low-cost equipment to measure the spray of droplets through cloth masks with regular speech. The light source used to reflect the droplets in this study was an unreliable cell-phone camera that is not advanced enough to catch the smaller droplet particles that may have sprayed from each mask studied. The 80% effectiveness that the study refers to is the very most effective blockage achieved in an isolated experiment. This ideal number does not reflect the actual efficacy achieved in everyday usage.
Published: November 18, 2021
A study out of Denmark demonstrated that inconsistent community usage of masks on top of other health measures did not reduce the risk of Covid-19 transmission by a considerable percentage. The study concluded that “the recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use.” The study also did not study usage of common cloth masks.
Published: February 12, 2021
This study found that mask mandates lowered the hospitalizations in the 18-39 and 40-64 age groups, however, no 0-17 age group was studied, as children and adolescents were not hospitalized often enough to provide a data set: “Hospitalizations among children and adolescents aged <18 years were not included because few hospitalizations were reported among this age group during the study period.”
Published: March 1, 2021
Conclusions and Relevance: This cohort study among infants and young children in Italy found that the use of facial masks was not associated with significant changes in Sao2 or Petco2 including children aged 24 months and younger.
Published: July 23, 2020
According to Carl Heneghan and Tom Jefferson from the Center for Evidence-Based Medicine, the more recent studies that find usage of cloth masks effective in reducing the transmission of Covid-19 contradict the findings of older, less hastily constructed studies that found cloth masks to be detrimental to the health of the wearer: “It would appear that despite two decades of pandemic preparedness, there is considerable uncertainty as to the value of wearing masks. For instance, high rates of infection with cloth masks could be due to harms caused by cloth masks, or benefits of medical masks. The numerous systematic reviews that have been recently published all include the same evidence base so unsurprisingly broadly reach the same conclusions. However, recent reviews using lower quality evidence found masks to be effective. Whilst also recommending robust randomised trials to inform the evidence for these interventions.”
Published: March 1, 2021
Communities with high reported mask-wearing and physical distancing had the highest predicted probability of transmission control. Segmented regression analysis of reported mask-wearing showed no statistically significant change in the slope after mandates were introduced; however, the upward trend in reported mask-wearing was preserved. The widespread reported use of face masks combined with physical distancing increases the odds of SARS-CoV-2 transmission control.” Studies rarely specifically focused on mask mandates in the school setting or in settings in which individuals are in close proximity for prolonged periods rather than short periods. Most studies that the CDC points to to justify mask mandates are focused on adult populations or too broad to directly relate to the school setting.
Interpretation: The widespread reported use of face masks combined with physical distancing increases the odds of SARS-CoV-2 transmission control. Self-reported mask-wearing increased separately from government mask mandates, suggesting that supplemental public health interventions are needed to maximise adoption and help to curb the ongoing epidemic.
Published: April 14, 2020
A study in the New England Journal of Medicine analyzed results from Iceland’s systematic screening process. This study concluded that if children do get the virus they are less likely to transmit the disease to adults and that there was not a single instance of a child infecting parents.
Published: April 26, 2021
A study of school re-openings in Israel compared the rate of infection and transmission of Covid-19 in children between 0-19 years of age with other age groups. The study concluded that “children aged 0 to 9 years did not have substantial rates of SARS-CoV-2 infection during school attendance periods, and it may be assumed that they did not have a substantial role in COVID-19 spread either during this period.” While the study suggested the concern for spread of the virus is higher for older children, those under nine years of age are much less susceptible to the virus and showed minimal risk of transmission in the school setting.
Published: October 29, 2021
The highest peak in the recorded time interval of COVID-19 hospitalizations was the week ending January 9, 2021. In this week, among those 65 years and older, there were roughly 3,470 hospitalizations that were COVID-19 related. For the week ending October 2, 2021, there were again more COVID-19 hospitalizations among the age group 65 years and older (1,128) compared to those 18-49 years (849). This statistic illustrates the weekly number of COVID-19 associated hospitalizations in the United States from the week ending March 7, 2020 to October 2, 2021, by age group. Note the weekly hospitalizations among the 0-4 and 5-17 is the lowest.
Published: October 29, 2021
The graph provides the number of coronavirus disease 2019 (COVID-19) deaths in the U.S. as of August 18, 2021, by age. Please note that children between the ages of 0-17 make up .00058 percent of the COVID mortality rate. Of the 614,531 COVID deaths reported by Statista, 361 of them were between the ages of 0-17: “Between the beginning of January 2020 and August 18, 2021, of 614,531 deaths caused by COVID-19 in the United States, around 180,608 had occurred among those aged 85 years and older. This statistic shows the number of coronavirus disease 2019 (COVID-19) deaths in the U.S. from January 2020 to August 2021, by age.”
Published: July 17, 2020
This study sees short term exposure of masked individuals to symptomatic carriers. In the school setting, children spend hours out of the day in close proximity. This study holds no insight for the efficacy of masks in preventing the spread of the virus among individuals in prolonged contact.
Published: July 12, 2020
The researchers identified a decrease in cases of Covid-19 in healthcare workers
after the implementation of universal masking policies in the hospitals. The researchers conclude “these results support universal masking as part of a multipronged infection reduction strategy in health care settings.” The recommendation justified here is only applicable to healthcare settings. Because all of the healthcare workers and patients in the study wore surgical masks, this study also cannot be used to justify the requirement of regular cloth masks for the reduction of Covid-19 transmission.
Published: September 15, 2020
A study in Thailand was published in November 2020 demonstrating that mask wearing, disinfectant, and social distancing are productive in reducing the risk of asymptomatic carriers of the Covid-19 virus spreading the virus to those they came in contact with. The study traced 211 people with confirmed asymptomatic cases of Covid-19 and 839 contacts that did not contract Covid-19 after interaction with the asymptomatic cases. The study authors found that wearing masks at all times during contact reduced the risk of infection, while wearing masks some of the time during interaction did not. Independently, hand washing and social distancing were found to reduce the risk of virus transmission. The study does not specify the ages of participants.
Published:October 26, 2021
Hospital admissions are declining sharply among U.S. children with Covid-19. Daily pediatric admissions with confirmed Covid have fallen 56% since the end of August to an average of about 0.2 per 100,000, according to Department of Health and Human Services data. Some schools dropped mask mandates this year under pressure from Republican governors, adding to public health experts’ concerns about returning to classrooms amid high viral transmission from the delta variant. Instead, the Delta wave has waned over the first two months of school.
Published: July 15,2021
Studies find that overall risk of death or severe disease from COVID-19 is very low in kids. A comprehensive analysis of hospital admissions and reported deaths across England suggests that COVID-19 carries a lower risk of dying or requiring intensive care among children and young people than was previously thought. In a series of preprints published on medRxiv1,2,3, a team of researchers picked through all hospital admissions and deaths reported for people younger than 18 in England. The studies found that COVID-19 caused 25 deaths in that age group between March 2020 and February 2021. About half of those deaths were in individuals with an underlying complex disability with high health-care needs, such as tube feeding or assistance with breathing.
