In studies of the coronavirus disease 2019 (COVID-19) in homeless communities in Seattle, Boston, San Francisco and Atlanta, University of Washington researchers that the prevalence of positive COVID-19 tests was higher in shelters with clusters of confirmed positive cases than in shelters with fewer previously reported cases.
Clinical Instructor Karen Huster and Adjunct Assistant Professor Helen Chu were authors of the studies. Both are faculty members in the Department of Global Health, housed jointly in the UW Schools of Public Health and Medicine. The studies, both published in the Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report, also showed that the challenges inherent in homeless shelters fostered situations that can spread COVID-19.
“One of the key takeaways for us has been that implementation of proactive prevention measures in those congregate settings is key to prevent clusters from happening,” Huster said. “That means universal mask usage for residents and staff and adequate spacing of mats. Another key takeaway for us has been the importance of proactive testing of everyone in those congregate settings, regardless of symptoms, especially considering the significance of presymptomatic and asymptomatic transmission.”
In one study, researchers focused on clusters present in Seattle, Boston, and San Francisco shelters. They also tested a shelter in Atlanta with no previous cases. In the Seattle cluster, 17% of residents and 17% of staff members tested positive. Boston had 36% of residents and 30% of staff members test positive, and San Francisco found that 66% of residents and 16% of staff members tested positive.
However, in Seattle shelters where only one case had previously been identified, only 5% of residents and 1% of staff were infected. Numbers were also relatively low in the Atlanta shelter with zero previously identified cases, where 4% of residents and 2% of staff members tested positive. In total, 1,192 residents and 313 staff members were tested in 19 shelters across the four cities.
In a second study, researchers honed in on three shelters in King County, Washington. The study offered immediate testing for all residents and staff at each shelter after Public Health – Seattle & King County discovered an infected person at one shelter (Site A), and then learned that residents from two other shelters (Sites B and C) had also used services at Site A. Upon testing people at all three sites, the study found that 19 of the 181 participants (10.5%) had COVID-19.
All residents and staff members who were not initially tested or those who tested negative during the first round were offered testing again. The second round revealed 18 positive tests among the 188 participants (15.3%), which prompted the researchers to provide recommendations such as limiting staff member rotations, encouraging physical distancing, limiting movement in and out of the shelter, training staff members on cleaning and disinfection, and arranging sleeping mats so that residents’ heads are more than six feet apart.
Researchers noted that both studies had limitations. For example, repeat testing wasn’t conducted in the study with multiple city sites, so it could not account for future infections, and they did not screen for symptoms before testing staff and residents. Also, several residents and staff members from both studies declined to participate, or were not present at the time of testing.
However, both studies found that the challenges inherent in homeless shelters fostered situations that can spread COVID-19. Shelters are often crowded, making it difficult to social distance from others. In addition, many people experiencing homelessness are older or have pre-existing medical conditions, which makes them more susceptible to contracting the virus.
“Homeless shelters, by virtue of their configuration and the realities of the population that live in them, are challenging environments to stop disease transmission,” Huster said. “Therefore, early, pro-active implementation of infection prevention control measures, and pro-active testing regardless of symptoms to quickly identify and isolate those who have been infected, is key.”