Thread by @andreaprinzi

I had a request from a friend to provide some literature on the use of #masks. I am happy to provide that here today. As always, the original manuscripts can be accessed by clicking on the link provided. Stay well!
#COVID19 #MedTwitter #IDTwitter

1.Title: COVID-19: in the absence of vaccination – ‘mask-the-nation’
Link: doi.org/10.2217/fmb-20…
Brief Study Design: Editorial

Simple Summary: Without an effective vaccine and/or antiviral agent, best way to prevent the spread of the SARS-CoV-2 is to physically block spread. At this time, droplet spread is considered to be the primary form of transmission of the virus.

Recent studies have demonstrated that homemade masks could block 95.15% of the avian influenza virus, compared with 99.98% for N95 masks and 97.14% for surgical masks (demonstrates prevention of spread of respiratory viruses spread via the droplet route).

If everyone wears a mask, spread of SARS-CoV2 can be greatly reduced, as well as other respiratory viruses that are going to make this coming respiratory season especially difficult.

2. Title: Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis
Link: reader.elsevier.com/reader/sd/pii/…

Brief Study Design: Systematic Review and Meta-analysis
Simple Summary: This study analyzed 172 observational studies across 16 countries, no RCTs and 44 relevant comparative studies in health-care and non-health-care settings. This included 25,697 patients.

Key findings: Transmission of viruses is lower with physical distancing of 1 m (3 ft) or more, compared with less than 1 m (3 ft). Protection becomes greater as the distance is increased (further is better!). Face mask use results in a large reduction in risk of infection.

N95 masks are the best (when used properly…we have to actually be FIT for these at the hospital, and it’s important to understand that they are not as useful as they could be if not fitted correctly…but still protective!), but other mask types are effective as well.

Some stats: Transmission of viruses=lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted OR [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] –10·2%, 95% CI –11·5 to –7·5; moderate certainty)

Protection was ⬆️ as distance was ⬆️ (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty).
Mask use could result in a large ⬇️ in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34

Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD –10·6%, 95% CI –12·5 to –7·7; low certainty).

3.Title: A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients
Link: reader.elsevier.com/reader/sd/pii/…

Brief Study Design: A systematic review of randomized controlled clinical trials on use of respiratory protection by healthcare workers, sick patients and community members

Simple Summary: In the community, masks appear to be effective with and without hand hygiene, and both together are more protection. Masks protect from disease transmission in high transmission areas like households and colleges, crowded public spaces and public transportation.

The study suggests that community mask use by well people could be beneficial, particularly for COVID-19, where transmission may be pre-symptomatic. The evidence supports that healthcare workers should wear staff respirators continuously throughout a shift.

4.Title: SARS Transmission, Risk Factors, and Prevention in Hong Kong

Link: ncbi.nlm.nih.gov/pmc/articles/P…

Brief Study Design: This is a case-control study that was performed in Hong Kong in 2004, during the first SARS outbreak. This study looked at 1,690 patients with probable SARS, diagnosed using accepted clinical criteria at the time.

Patients with known SARS were matched with a negative control patient. The researchers then obtained information about exposures for all patients and used statistics to determine relationships between a given exposure and the development of SARS (or not).

Simple Summary: VERY simple overview of odds ratios here...Odds ratios (OR) < 1 suggest that there is protection. Odds ratios >1 suggest increased odds of getting the outcome of interest (no protection)...

The ORs of acquiring SARS when frequently using a mask in public, handwashing and disinfecting were between 0.36 and 0.58 (PROTECTIVE). People who frequently used masks in public were less likely to get SARS than those who did not.

For ppl who want to see some statistics: multivariate stepwise conditional logistic regression analysis showed: Using a mask frequently in public places (OR = 0.27, p < 0.001), washing hands >10 times a day (OR = 0.58, p = 0.008), disinfecting house (OR = 0.41, p < 0.001).

Title: Potential utilities of mask‐wearing and instant hand hygiene for fighting SARS‐CoV‐2

Link:
doi.org/10.1002/jmv.25…

Brief Study Design: This study looked at the efficacy of three different types of masks and hand/surface decontamination. A modified Avian Influenza virus was used to mock SARS-CoV-2 in this study. A nebulizer was used to aerosolize the virus, RT-PCR was used to detect the virus.

Simple Summary: Handwashing removed 99.98% of virus from hands. N95 masks blocked 99.98% of virus, homemade cloth masks blocked 97.14% of virus, one‐layer cloth could block 95.15% of the virus. Masks should be work regularly to slow or prevent the exponential spread of SARS-CoV-2

@threadreaderapp unroll