CDC Urges COVID-19 Testing at Homeless Shelters after Finding Swift Spread of Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads rapidly within homeless shelters, and clusters of infection have been identified at homeless shelters. Therefore, testing residents and staff should be considered regardless of symptoms, according to a report on homeless shelters in 4 US cities by the US Centers for Disease Control and Prevention (CDC). The report, published in the Morbidity and Mortality Weekly Report on April 22, was based on the findings of an investigation launched in late March by CDC researchers collaborating with academic partners, clinicians, and homeless service providers. In this investigation, public health teams responded to clusters of 2 or more cases of coronavirus disease 2019 (COVID-19) at 5 homeless shelters—1 in Boston, 1 in San Francisco, and 3 in Seattle. When investigators tested a total of 730 residents and 148 staff members at the 5 shelters with COVID-19 clusters, they found overall infection rates of 37% among residents and 21% among staff members. Infection rates were as high as 95 of 143 residents (66%) tested at the San Francisco shelter and 15 of 50 staff members (30%) tested at the Boston shelter. “Given the high proportion of positive tests in the shelters with identified clusters and evidence for presymptomatic and asymptomatic transmission of SARS-CoV-2, testing of all residents and staff members regardless of symptoms at shelters where clusters have been detected should be considered,” the report said. To facilitate the isolation of individuals with SAR-CoV-2 infection to minimize ongoing spread, the agency also advised regular testing in shelters before clusters are identified, “if testing is easily accessible.” In addition, the investigators tested 213 residents and 106 staff members at 12 shelters in Seattle where only a single case had been previously identified. They found a much lower prevalence of infection, with 5% of residents and 1% of staff members testing positive for SARS-CoV-2. The researchers also found low rates of infection at 2 homeless shelters in Atlanta with no known COVID-19 cases in the preceding 2 weeks, finding that 10 of 249 residents (4%) and 1 of 59 staff members (2%) had the infection. The authors noted that the tests represent only a single point. Additional limitations to the study’s findings included having some residents or staff members unavailable or unwilling to undergo testing and lacking symptom information for some individuals who were tested. Homeless shelters pose considerable challenges that allow COVID-19 to spread rapidly. They are often crowded, making social distancing difficult. Furthermore, many residents are at higher risk for severe COVID-19–related illness because they are older or have underlying medical conditions. In a related article in the Morbidity and Mortality Weekly Report, CDC investigators and other public health researchers described a COVID-19 outbreak at 3 affiliated homeless shelters in King County, Washington. After 1 person was found to be infected on March 30, SARS-CoV-2 testing was immediately offered to all residents and staff members of that shelter and 2 other shelters that used the first location’s day services. A second round of testing was offered approximately a week later to those not tested initially or those who had negative test results. In all, 35 of 195 residents (18%) and 8 of 38 staff members (21%) who were tested had COVID-19. “Interrupting COVID-19 transmission in homeless shelters is challenging,” the report noted. “In settings with known COVID-19 outbreaks, assistance with enforcement of shelter-in-place orders, Author affiliations and article information are listed at the end of this article.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads rapidly within homeless shelters, and clusters of infection have been identified at homeless shelters. Therefore, testing residents and staff should be considered regardless of symptoms, according to a report on homeless shelters in 4 US cities by the US Centers for Disease Control and Prevention (CDC).
The report, published in the Morbidity and Mortality Weekly Report on April 22, was based on the findings of an investigation launched in late March by CDC researchers collaborating with academic partners, clinicians, and homeless service providers. In this investigation, public health teams responded to clusters of 2 or more cases of coronavirus disease 2019 (COVID-19) at 5 homeless shelters-1 in Boston, 1 in San Francisco, and 3 in Seattle.
When investigators tested a total of 730 residents and 148 staff members at the 5 shelters with COVID-19 clusters, they found overall infection rates of 37% among residents and 21% among staff members. Infection rates were as high as 95 of 143 residents (66%) tested at the San Francisco shelter and 15 of 50 staff members (30%) tested at the Boston shelter.
"Given the high proportion of positive tests in the shelters with identified clusters and evidence for presymptomatic and asymptomatic transmission of SARS-CoV-2, testing of all residents and staff members regardless of symptoms at shelters where clusters have been detected should be considered," the report said. To facilitate the isolation of individuals with SAR-CoV-2 infection to minimize ongoing spread, the agency also advised regular testing in shelters before clusters are identified, "if testing is easily accessible." In addition, the investigators tested 213 residents and 106 staff members at 12 shelters in Seattle where only a single case had been previously identified. They found a much lower prevalence of infection, with 5% of residents and 1% of staff members testing positive for SARS-CoV-2. The researchers also found low rates of infection at 2 homeless shelters in Atlanta with no known COVID-19 cases in the preceding 2 weeks, finding that 10 of 249 residents (4%) and 1 of 59 staff members (2%) had the infection.
The authors noted that the tests represent only a single point. Additional limitations to the study's findings included having some residents or staff members unavailable or unwilling to undergo testing and lacking symptom information for some individuals who were tested.
Homeless shelters pose considerable challenges that allow COVID-19 to spread rapidly. They are often crowded, making social distancing difficult. Furthermore, many residents are at higher risk for severe COVID-19-related illness because they are older or have underlying medical conditions.

In a related article in the Morbidity and Mortality Weekly Report, CDC investigators and other public health researchers described a COVID-19 outbreak at 3 affiliated homeless shelters in King
County, Washington. After 1 person was found to be infected on March 30, SARS-CoV-2 testing was immediately offered to all residents and staff members of that shelter and 2 other shelters that used the first location's day services. A second round of testing was offered approximately a week later to those not tested initially or those who had negative test results. In all, 35 of 195 residents (18%) and 8 of 38 staff members (21%) who were tested had COVID-19.
"Interrupting COVID-19 transmission in homeless shelters is challenging," the report noted. "In settings with known COVID-19 outbreaks, assistance with enforcement of shelter-in-place orders,