Residential Mobility of a Cohort of Homeless People in Times of Crisis: COVID-19 Pandemic in an European Metropolis (preprint)

Most vulnerable individuals are particularly affected by the COVID-19 pandemic. This study takes place in a large city in France. The aim of this study is to describe the mobility of the homeless population at the begin-ning of the health crisis and to analyze its impact in terms of COVID-19 prevalence. From June to August 2020 and September to December 2020, 1272 homeless people were invited to be tested for SARS-CoV-2 antibodies and virus in and completed questionnaires. Our data show that homeless populations are sociologically dif-ferent depending on where they live. We show that people living on the street were most likely to be relocated to emergency shelters than other inhabitants. Some neighborhoods are points of attraction for homeless peo-ple in the city while others emptied during the health crisis, which had consequences for virus circulation. People with a greater number of different dwellings reported became more infected. This first study of the mo-bility and epidemiology of homeless people in time of pandemic provides unique information about mobility mapping, sociological factors of this mobility, mobility at different scales and epidemiological consequences. We suggest that homeless policies need to be radically transformed since actual model exposes people to infection in emergency.

Cumulative Incidence of SARS-CoV-2 Infection Within the Homeless Population: Insights From a Citywide Longitudinal Study (preprint)

Background: Studies showed high prevalence of SARs-CoV-2 among homeless people in shelters, but no longitudinal studies confirmed these findings, put them into perspective, or considered homeless populations beyond shelters. Methods: All homeless adults sleeping rough, in slums or squats, in emergency shelters or transitional accommodation in Marseille were eligible. There were two testing sessions, 3 months apart, during which each participant was tested for anti-SARS-CoV-2 antibodies and completed a face-to-face surveys. The primary outcome was the occurrence of a seroconversion event defined as a biologically confirmed SARS-CoV-2 infection. Cox proportional hazards regression models and Kaplan-Meier survival analysis with log-rank test were performed to evaluate risk factors associated with seroconversion. Local data from a national seroprevalence survey were used for comparison between homeless people and the general population.Findings: A total of 1249 people were included. SARS-CoV-2 seroprevalence increased from 6.0% [4.7-7.3] during the first session to 18.9% [16.0-21.7] during the second one, compared to 3.0% [1.9-4.2] and 6.5% [4.5-8.7] in the general population. Factors significantly associated with an increased risk of COVID-19 infection were: having stayed in emergency shelters (1.93 [1.18 – 3.15]), being an isolated parent (1.64 [1.07-2.52]) and having contact with more than 5-15 people per day (1.84 [1.27 – 2.67]). By contrast, smoking (0.46 (0.32 – 0.65)), having financial resources (0.70 (0.51 – 0.97)) and psychiatric or addictive comorbidities (0.52 (0.32 – 0.85)) were associated with a lower risk.Interpretation: We confirm that homeless people have higher infection rates than the general population, with increased risk in emergency shelters.Funding Information: French Directorate of Health care facilities (DGOS) – research grant PHRC COVID-19 (COVID-homeless 0047)Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: All participants provided a written informed consent. The COVIDHomeless study was designed and carried out in compliance with the Declaration of Helsinki and with legal and regulatory provisions. It was approved by the ethics committee on May 28, 2020 (CPP IDF VI - number 44-20; ID: 2020-AO1398-31). The database was anonymized and declared to the French data protection commission (Commission Nationale de l’Informatique et des Libertés, CNIL, n°2018172v0).

Seroprevalence of SARS-CoV-2 Antibodies Among Homeless People Living Rough, in Shelters and Squats: A Large Population-Based Study in France (preprint)

Background: Overcrowded housing, as well as inadequate sanitary conditions, contribute to making homeless people particularly vulnerable to the SARS-CoV-2 infection. We aimed to assess the seroprevalence of the SARS-CoV-2 infection among people experiencing homelessness on a large city-wide scale in France, taking into account different community settings. Methods: A consortium of outreach teams in 48 different locations including streets, slums, squats, emergency or transitional shelters and drop-in centres participated in the inclusion process. All participants consented to receive a validated rapid assay for immunoglobulins M (IgM) and G (IgG) antibodies and to answer a questionnaire on medical health conditions, comorbidities, historic of symptoms compatible with COVID-19, with a retrospective calendar of types of accommodation since COVID-19 crisis. Results: From June 01 to August 05, 2020, 1,156 homeless participants were enrolled in the study and tested. Seroprevalence of SARS-CoV-2 IgG/IgM antibodies was 5.6% (95%CI 2.3–7.0), with a range of 2.2% in people living on the streets to 8.1% in people living in emergency shelters (P=0.009). Around one third of the seropositive participants reported symptoms with COVID-19. Compared to the general population in Marseille (3.6%), the homeless population living in the same urban area experienced an significant increased risk of SARS-CoV-2 infection (|z|=3.65 > 1.96). Conclusion: These results highlight the need for organizing regular screening to prevent clusters forming in homeless accommodations and for providing basic resources for health maintenance.

On the association between SARS-COV-2 variants and COVID-19 mortality during the second wave of the pandemic in Europe (preprint)

BACKGROUND: Preliminary clinical evidence suggests an increased COVID-19 mortality associated with the variant of concern 20I/501Y.V1. The evidence outside the UK and a real-world comparison of variants spread and mortality is sparse. This study aims at investigating the association between COVID-19 mortality and SARS-COV-2 variants spread during the second wave of the COVID-19 pandemic in Europe. METHODS: For 38 European countries, publicly available data were collected on numbers of COVID-19 deaths, SARS-COV-2 variants spread through time using Nextstrain classification and countries demographic and health characteristics. The cumulative number of COVID-19 deaths and the height of COVID-19 daily deaths peak during the second wave of the pandemic were considered as outcomes. Pearson correlations and multivariate generalized linear models with selection algorithms were used. FINDINGS: The average proportion of 20I/501Y.V1 variant (B.1.1.7) was found to be a significant predictor of cumulative number of COVID-19 deaths within two months before the deaths peak and between 1 January - 25 February 2021, as well as of the deaths peak height when calculating the proportion during the second wave and the pre-peak period. The average proportion of 20A.EU2 variant (S:477N) was a significant predictor of cumulative COVID-19 deaths in the pre-peak period. INTERPRETATION: Our findings suggest that the spread of a new variant of concern 20I/501Y.V1 had a significant impact on the mortality during the second wave of COVID-19 pandemic in Europe and that proportions of 20A.EU2 and 20I/501Y.V1 variants were associated with increased mortality in the initial phase of that wave. KEYWORDS: COVID-19, mortality, SARS-COV-2 variants, variant of concern.

On the Association between SARS-CoV-2 Variants and COVID-19 Mortality During the Second Wave of the Pandemic in Europe (preprint)

BACKGROUND: Preliminary clinical evidence suggests an increased COVID-19 mortality associated with the variant of concern 20I/501Y.V1. The evidence outside the UK and a real-world comparison of variants spread and mortality is sparse. This study aims at investigating the association between COVID-19 mortality and SARS-COV-2 variants spread during the second wave of the COVID-19 pandemic in Europe.METHODS: For 38 European countries, publicly available data were collected on numbers of COVID-19 deaths, SARS-COV-2 variants spread through time using Nextstrain classification and countries’ demographic and health characteristics. The cumulative number of COVID-19 deaths and the height of COVID-19 daily deaths peak during the second wave of the pandemic were considered as outcomes. Pearson correlations and multivariate generalized linear models with selection algorithms were used.FINDINGS: The average proportion of 20I/501Y.V1 variant (B.1.1.7) was found to be a significant predictor of cumulative number of COVID-19 deaths within two months before the deaths peak and between 1 January – 25 February 2021, as well as of the deaths' peak height when calculating the proportion during the second wave and the pre-peak period. The average proportion of 20A.EU2 variant (S:477N) was a significant predictor of cumulative COVID-19 deaths in the pre-peak period.INTERPRETATION: Our findings suggest that the spread of a new variant of concern 20I/501Y.V1 had a significant impact on the mortality during the second wave of COVID-19 pandemic in Europe and that proportions of 20A.EU2 and 20I/501Y.V1 variants were associated with increased mortality in the initial phase of that wave.FUNDING: None.DECLARATION OF INTERESTS: None.ETHICS APPROVAL STATEMENT: Not required. This study does not require ethical approval as it was conducted on country-level data and involved information freely available in the public domain.

Disparities in Intensive Care Unit Admission and Mortality Among Patients with Schizophrenia and COVID-19: A National Cohort Study (preprint)

Background: Patients with schizophrenia (SCZ) represent a vulnerable population who have been understudied in COVID-19 research. We aimed to establish whether health outcomes and care differed between patients with SCZ and patients without a diagnosis of severe mental illness.Methods: We conducted a population-based cohort study of all patients with identified COVID-19 and respiratory symptoms who were hospitalized in France between February and June 2020. Cases were patients who had a diagnosis of SCZ. Controls were patients who did not have a diagnosis of severe mental illness. The outcomes were in-hospital mortality and intensive care unit (ICU) admission.Findings: A total of 50,750 patients were included, of whom 823 were SCZ patients (1.6%). The SCZ patients had an increased in-hospital mortality (25.6% vs. 21.7%; adjusted odds ratio (aOR) 1.30 [95% CI 1.08-1.56], p=0.0093) and a decreased ICU admission rate (23.7% vs. 28.4%; aOR 0.75 [95% CI 0.62-0.91], p=0.0062) compared to controls. Significant interactions between SCZ and age for mortality and ICU admission were observed (p=0.0006 and p<0.0001). SCZ patients between 65 and 80 years had a significantly higher risk of death than controls of the same age (+7.89%). SCZ patients younger than 55 years had more ICU admissions (+13.93%) and SCZ patients between 65 and 80 years and older than 80 years had less ICU admissions than controls of the same age (-15.44% and-5.93%, respectively).Interpretation: Our findings report the existence of disparities in health and health care between SCZ patients and patients without a diagnosis of severe mental illness. These disparities differed according to the age and clinical profile of SCZ patients, suggesting the importance of personalized COVID-19 clinical management and health care strategies before, during and after hospitalization for reducing health disparities in this vulnerable population.Funding Statement: This work was funded by Assistance Publique – Hôpitaux Marseille (APHM) – Aix-Marseille University (AMU) and the PHRC National, Direction générale de l’offre de soins (DGOS), France.Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: The authors state that data from the PMSI database are anonymized and can be reused for research purposes.