A Look at DESE's Cited Sources: Footnote #20 and #24 - Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US

DESE Claim 1: "masks or face coverings are among the most critical components of risk reduction"

DESE Claim 2: "In the United States, states advising face masks/face coverings be worn in public saw a decline in their COVID-19 growth rates"

Cited Source: Lyu, W. and Wehby, G. L. (2020). Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US. Health Affairs. Available at https://doi.org/10.1377/hlthaff.2020.00818

Peer Reviewed?:Yes. "Editor’s Note: This Fast Track Ahead Of Print article is the accepted version of the peer-reviewed manuscript. The final edited version will appear in an upcoming issue of Health Affairs"

Study Methodology: "event study examining changes in the daily county-level COVID-19 growth rates"

Notes: Face masks have reduced the growth rate of COVID-19. "Mandating face mask use in public is associated with a decline in the daily COVID-19 growth rate by 0.9, 1.1, 1.4, 1.7, and 2.0 percentage-points in 1–5, 6–10, 11–15, 16–20, and 21+ days after signing, respectively." The study does not that it does not attempt to measure compliance with face masks orders. 

Supports DESE Claim 1?: Yes.

Supports DESE Claim 2?: Yes.

A Look at DESE's Cited Sources: Footnote #19, #23, and #32 - Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China

DESE Claim 1 (footnote #19): "[...]masks or face coverings are among the most critical components of risk reduction."

DESE Claim 2 (footnote #23): "Masks/face coverings protect the general public against COVID-19 infection, with a recent retrospective study estimating near 80% effectiveness in reducing COVID-19 transmission, especially when worn prior to symptom onset."

DESE Claim 3 (footnote #32): "For instance, in a study of household transmission in China, keeping at least three feet of distance was associated with one-fourth the number of transmissions."

Cited Source: Wang, Y., Tian, H., Zhang, L., Zhang, M., Guo, D., Wu, W., ... & Liu, B. (2020). Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China. BMJ Global Health, 5(5), e002794. Available at https://gh.bmj.com/content/bmjgh/5/5/e002794.full.pdf

Peer Reviewed?: Yes

Study Methodology: "A retrospective cohort study of 335 people in 124 families"

Notes: This study looks at household face mask use as a risk reduction measure in families who have a member that is COVID-19 positive. "The study confirms the highest risk of transmission prior to symptom onset, and provides the first evidence of the effectiveness of mask use, disinfection and social distancing in preventing COVID-19." Masks were effective in reducing transmission. While household settings are different than schools, other evidence from outside of household settings also supports mask use.

Supports DESE Claim 1?: Yes.

Supports DESE Claim 2?: Yes.

Supports DESE Claim 3?: Yes.

A Look at DESE's Cited Sources: Footnote #18 - Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations: scientific brief

DESE Claim: "As the primary route of transmission for COVID-19 is respiratory"

Cited Source: World Health Organization. Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations: scientific brief, 27 March 2020. No. WHO/2019-nCoV/Sci_Brief/Transmission_modes/2020.1. World Health Organization, 2020. Available at: https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations

Peer Reviewed?: No (public health organization information)

Study Methodology: N/A (public health information)

Notes: This is a summary of WHO's understanding of how COVID-19 is transmitted. 

Supports DESE Claim?: Yes

A Look at DESE's Cited Sources: Footnote #16 - Identifying airborne transmission as the dominant route for the spread of COVID-19

DESE Claim: "As the primary route of transmission for COVID-19 is respiratory"

Cited Source: Zhang, Renyi, et al. "Identifying airborne transmission as the dominant route for the spread of COVID-19." Proceedings of the National Academy of Sciences (2020).

Note: the DESE report citation does not include a link or DOI to find the article I was able to Google my way to the digital version of the source here.

Peer Reviewed?: Yes (2 reviewers listed in article)

Study Methodology: Data analysis of public health data 

Notes: This study looks at trends in public health data in different disease epicenters over time. The data shows that certain public health measures, such as face coverings, altered the course of outbreaks. "Our work also highlights the necessity that sound science is essential in decision-making for the current and future public health pandemics." Based on the impact different mitigation measures had on the outbreak, the researchers were able to determine that airborne transmission is dominant, and face coverings work to reduce the spread.

Supports DESE Claim?: Yes.

A Look at DESE's Cited Sources: #15 - How COVID-19 spreads

DESE Claim: "As general background, COVID-19 spreads when people are in relatively close proximity, through respiratory droplets generated through coughing, sneezing, or talking to an infected person. Among the most effective preventive measures – when used consistently and in combination – are masks/face coverings, physical distancing, handwashing, and cleaning frequently touched surfaces."

Cited Source: CDC, How COVID-19 spreads. (2020, June 16). Available at https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html

Peer Reviewed?: no -government document

Study Methodology: N/A - government information without a study attached.

Notes: This is a general information page about how COVID-19 spreads. The information listed in the DESE claim is all included on the page. DESE did not cite the bolded sentence "The virus that causes COVID-19 is spreading very easily and sustainably between people" which seems an important point. General background information given by DESE is aligned with this source. 

Supports DESE Claim?: Yes.

A Look at DESE's Cited Sources: Footnote #14, #65, and #76 - Characteristics of Hospitalized Pediatric COVID-19 Cases—Chicago, Illinois, March–April 2020

DESE Claim 1 (footnote #14): "If infected, it appears children may be less likely to infect others with COVID-19. [...] In a U.S. study of 15 households, 73% of transmissions were from adult to child (the remaining were child-to-child or child-to adult)."

DESE Claim 2 (footnote #65): "In a Chicago study, only 1% of COVID-19 cases in Chicago were in children 0-17."

DESE Claim 3 (footnote #76): "In a Chicago study, for 15 households where data was available, 73% of transmissions were from adult to child (the remaining 27% was due to two child-to-child and two child-to adult transmissions)."

Cited Source: Mannheim, J., Gretsch, S., Layden, J. E., & Fricchione, M. J. (2020). Characteristics of Hospitalized Pediatric COVID-19 Cases—Chicago, Illinois, March–April 2020. Journal of the Pediatric Infectious Diseases Society. Available at https://academic.oup.com/jpids/advance-article/doi/10.1093/jpids/piaa070/5849922

Peer Reviewed?:  Yes

Study Methodology: "This was a case series of Chicago COVID-19 patients aged 0–17 years reported to the Chicago Department of Public Health (CDPH) from March 5 to April 8, 2020. Enhanced case investigation was performed"

Notes: This study is not primarily focused on investigation related to the DESE claim about household infection rates. The study examined hospitalization of pediatric patients. It also notes a limitation due to school closure (thus most children being home and only in contact with household members). "[...]school closures and shelter-in-place directives were instituted during this time period." Additionally, a look at hospitalized cases may not be representative of all COVID-19 cases.

Supports DESE Claim 1?: Extremely limited support in a non-school environment. Again, no conclusion about adult transmission can be drawn from pediatric studies. The fact that the study is not actually attempting to prove or support the DESE claim means it may not have been scrutinized in the same way as the main part of the study around hospitalization.

Supports DESE Claim 2?: Yes. 

Supports DESE Claim 3?: Yes, though school closures are a limiting factor.

A Look at DESE's Cited Sources: Footnote #13 and #73 - Children are unlikely to have been the primary source of household SARS-CoV-2 infections

DESE Claim 1 (footnote #13): "If infected, it appears children may be less likely to infect others with COVID-19. Most transmissions are from adults to children, rather than vice versa; this is different from some other respiratory viruses (note: pre-print study)."

DESE Claim 2 (footnote #73): "Analysis of clusters of patients with COVID-19 indicates that most transmissions are from adults to children, rather than vice versa. This is different from some other respiratory viruses."

Cited Source: Zhu, Y., Bloxham, C. J., Hulme, K. D., Sinclair, J. E., Tong, Z. W. M., Steele, L. E., ... & Gilks, C. (2020). Children are unlikely to have been the primary source of household SARS-CoV-2 infections. Available at https://www.medrxiv.org/content/10.1101/2020.03.26.20044826v1

Peer Reviewed?: No. Preprint study.

Study Methodology: Meta-analysis "observational study analysing literature published between December 2019 and March 2020"

Notes: The analysis only includes data from 40 of the 166 studies found in their data search. Most household transmission clusters had an adult index case. The study mentions that fewer contacts outside the home may be a factor in less children as index cases within households. "It is also possible that children simply have fewer interactions outside of the home than adults and are therefore less likely to be index cases. This may be magnified in countries which have implemented school closures in an attempt to control the outbreak." Testing limitations may influence the data contained in the studies analyzed.

Supports DESE Claim 1?: Limited support. This study looks only at household transmission; with no attempts to generalize to other community spread. Additionally, children's transmission rates do not predict the safety of opening schools for adult staff.

Supports DESE Claim 2?: Limited support. This study looks only at household transmission; with no attempts to generalize to other community spread.