Characteristics of COVID-19 in Homeless Shelters : A Community-Based Surveillance Study

Abstract

Background: Homeless shelters are a high-risk setting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission because of crowding and shared hygiene facilities.

Objective: To investigate SARS-CoV-2 case counts across several adult and family homeless shelters in a major metropolitan area.

Design: Cross-sectional, community-based surveillance study. (ClinicalTrials.gov: NCT04141917).

Setting: 14 homeless shelters in King County, Washington.

Participants: A total of 1434 study encounters were done in shelter residents and staff, regardless of symptoms.

Intervention: 2 strategies were used for SARS-CoV-2 testing: routine surveillance and contact tracing ("surge testing") events.

Measurements: The primary outcome measure was test positivity rate of SARS-CoV-2 infection at shelters, determined by dividing the number of positive cases by the total number of participant encounters, regardless of symptoms. Sociodemographic, clinical, and virologic variables were assessed as correlates of viral positivity.

Results: Among 1434 encounters, 29 (2% [95% CI, 1.4% to 2.9%]) cases of SARS-CoV-2 infection were detected across 5 shelters. Most (n = 21 [72.4%]) were detected during surge testing events rather than routine surveillance, and most (n = 21 [72.4% {CI, 52.8% to 87.3%}]) were asymptomatic at the time of sample collection. Persons who were positive for SARS-CoV-2 were more frequently aged 60 years or older than those without SARS-CoV-2 (44.8% vs. 15.9%). Eighty-six percent of persons with positive test results slept in a communal space rather than in a private or shared room.

Limitation: Selection bias due to voluntary participation and a relatively small case count.

Conclusion: Active surveillance and surge testing were used to detect multiple cases of asymptomatic and symptomatic SARS-CoV-2 infection in homeless shelters. The findings suggest an unmet need for routine viral testing outside of clinical settings for homeless populations.

Primary funding source: Gates Ventures.

Visual Abstract.. Characteristics of COVID-19 in Homeless Shelters

Congregate living situations, such as homeless shelters, are high-risk settings for transmission of SARS-CoV-2 among residents and staff. This article describes findings from a study using active surveillance for SARS-CoV-2 that took place in 14 homeless shelters in King County, Washington, between 1 January and 24 April 2020.

Figure 1.. Study flow diagram.

Symptomatic encounters include those with ≥1 self-reported symptom.

Figure 2.. Count of severe acute respiratory syndrome coronavirus 2 cases and total participant encounters by week, disaggregated by symptom status and sampling strategy, from 1 January to 24 April 2020.

Symptomatic encounters include those with ≥1 self-reported symptom.

Figure 3.. Bed map of 16 severe acute respiratory syndrome coronavirus 2 cases detected at shelter L during 2 separate surge testing events on 1 April and 23 April 2020.

Shelter L was a temporary homeless service site opened on 14 March when half of the residents at shelter H were moved to reduce crowding. Residents at shelter H shared day center services, showering facilities, and a rotating staff with shelters G and M during this period. Residents were men aged ≥50 y that slept on communal floor mats in 2 separate rooms. Participant recruitment was done through surge testing only at shelter L; routine surveillance was never available as a sampling mechanism.