New study in @AnnalsofIM with detailed results of SARS-CoV-2 testing across 14 homeless shelters in the Seattle area. Brief https://www.acpjournals.org/doi/10.7326/M20-3799

Overall, I have to say that this is great work but drawing strong conclusions from the study is somewhat difficult because there was a variety of different types of testing (e.g., surge and surveillance) occurring across multiple population types. So take with a grain of (2/)

One clear finding that confirms findings from multiple other studies is that the large majority of positive SARS-CoV-2 cases detected were *asymptomatic*. This highlights the limitations of symptom-based screening in shelters (& other congregate settings). (3/)

Second, positive cases were found among both homeless clients and staff -- we knew that both groups would be at risk, but here's more evidence to confirm. (4/)

Findings on density less clear (sample size issues, selection bias, etc.) but overall 86% of positive cases were among those who had slept in communal (vs. private) spaces compared to 78% of negative cases. Statistical significance not tested & no multivariable analysis. (5/)

At one shelter, 3 of 5 detected cases were among people who shared the same private room. Not surprising given what we know about shared spaces and SARS-CoV-2. (6/)

The authors note that there were more cases in communal spaces w/sleeping mats<6 feet apart w/out dividers & only 1 case in a shelter with bunk beds. I don't think we can read into this that "bunk beds are safe, hooray!" but rather again that more density = generally worse. (7/)

Other details in the study itself (which is available free!) -- we are continuing to build our knowledge from research on homelessness & testing. (8/)

We still need to build better systems for gathering rapid national information about homeless populations for the future. @NatlHCHCouncil & @CDCgov partnered to create a great dashboard but limited by not enough people reporting to it. (end) https://nhchc.org/cdc-covid-dashboard/home/

For more reflections on this study see this thread from @StefanKertesz https://twitter.com/stefankertesz/status/1306018171938394114?s=21 https://twitter.com/stefankertesz/status/1306018171938394114