Cumulative incidence of SARS-CoV-2 infection within the homeless population: insights from a city-wide longitudinal study.

OBJECTIVES: The aim of this study was to determine the risk factors associated with SARS-CoV-2 infection in a cohort of homeless people using survival analysis. Seroprevalence in the homeless community was also compared with that of the general population. DESIGN: Cohort study. SETTING: Data were collected across two testing sessions, 3 months apart, during which each participant was tested for anti-SARS-CoV-2 antibodies and completed a face-to-face survey. PARTICIPANTS: All homeless adults sleeping rough, in slums or squats, in emergency shelters or transitional accommodation in Marseille were eligible. PRIMARY OUTCOME MEASURES: Occurrence of a seroconversion event defined as a biologically confirmed SARS-CoV-2 infection. Local data from a national seroprevalence survey were used for comparison between homeless people and the general population. RESULTS: 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 with 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. CONCLUSION: We confirm that homeless people have higher infection rates than the general population, with increased risk in emergency shelters. There is growing evidence that, in addition to usual preventive measures, public policies should pay attention to adapt the type of accommodation and overall approach of precariousness. TRIAL REGISTRATION NUMBER: NCT04408131.

Mayaro virus infection in French Guiana, a cross sectional study 2003-2019.

Mayaro Virus is an emerging arbovirus which can be responsible of important outbreaks in tropical regions. A retrospective study was performed in French Guiana, an ultraperipheral region of Europe in Amazonia. We identified 17 human cases between 2003 and 2019. The clinical and biological picture was close to Chikungunya with fever and arthralgia. One patient had acute meningo-encephalitis, and 4 had persistent arthralgia. Physicians should be aware of this virus, as imported cases in Europe have already occurred. AUTHOR SUMMARY: Latin America has experienced several epidemics of arboviruses in recent years, some known for a long time, such as the dengue virus, and others of more recent introduction such as the chikungunya or Zika viruses. There are other arboviruses for the moment more discreet which are rife with low noise in several countries of the continent, such as the Mayaro virus. This alphavirus, with a presentation similar to that of the chikungunya virus, is currently confined to transmission by forest mosquitoes, but its potential to be transmitted by coastal mosquitoes such as Aedes aegypti, make it a potential candidate for a continent-wide epidemic. It therefore seems necessary to know this virus as well as possible in order to anticipate the occurrence of a possible new epidemic. We present here a both demographic and clinical study of this endemic arbovirus disease in French Guiana.

Residential Mobility of a Cohort of Homeless People in Times of Crisis: COVID-19 Pandemic in a European Metropolis.

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 beginning 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 and complete questionnaires. Our data show that homeless populations are sociologically different depending on where they live. We show that people that were living on the street were most likely to be relocated to emergency shelters than other inhabitants. Some neighborhoods are points of attraction for homeless people 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 mobility and epidemiology of homeless people in the time of the 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 the actual model exposes people to infection in emergency.

Factors associated with SARS-CoV2 infection and care pathways among the most vulnerable populations living in Marseille: a case control study.

BACKGROUND: The Covid-19 pandemic has led to substantial and unexpected increases in morbidity and mortality in France. Vulnerable populations housed in accommodation centres have a greater risk of infection because collective housing and their dependence on social support services mean it is more difficult to apply preventive measures. They are also at greater risk of developing severe forms of Covid-19 and waiting longer before seeking healthcare (for Covid-19 or other) treatment. We aimed to identify the factors associated with SARS-CoV2 infection in the most vulnerable populations in the city of Marseille. METHODS: The study sample comprised users of various services provided by the association AAJT in Marseille, France, some presenting symptoms suggestive of Covid-19 and others not. All had routine health surveillance provided by AAJT's dedicated healthcare team between March 2020 and May 2020. Using univariate and multivariate analyses, we studied the influence of several variables on morbidity associated with Covid-19. RESULTS: The study included 64 participants, 29 of whom tested positive for Covid-19 and 35 control subjects. Median age was 21.16 years old. Individuals in the 'Covid-19 case' group (p < 0.005) - which included persons testing positive and those suspected of being infected - were younger. The study sample's male/female ratio was seven. In our multivariate analyses, living in a shared apartment and poor adherence to social distancing measures were factors associated with Covid-19 infection. Furthermore, mental health problems - such as anxiety disorder - were very frequent in the study sample. CONCLUSIONS: Allocating more and specific housing units to structures providing accommodation services to the most vulnerable people would seem to be a decisive factor in controlling the spread of SARS-CoV2, and deserves more attention from public authorities.

Seroprevalence of SARS-CoV-2 antibodies among homeless people living rough, in shelters and squats: A large population-based study in France.

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 Marseille, France, taking into account different types of accommodation. 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 have a validated rapid antibody assay for immunoglobulins M (IgM) and G (IgG) and to answer a questionnaire on medical health conditions, comorbidities, and previous COVID-19 symptoms. Information on their housing conditions since the COVID-19 crisis was also collected from the participants. RESULTS: From June 01 to August 05, 2020, 1,156 homeless participants were enrolled in the study and tested. The overall seroprevalence of SARS-CoV-2 IgG/IgM antibodies was 5.6% (95%CI 2.3-7.0), ranging from 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 COVID-19 symptoms. Compared to the general population in Marseille (3.6%), the homeless population living in the same urban area experienced a significantly increased risk of SARS-CoV-2 infection (|z| = 3.65 > 1.96). CONCLUSION: These findings highlight the need for regular screening among the homeless to prevent clustering in overcrowded or inadequate accommodations. It is also necessary to provide essential resources to keep homeless people healthy, the vast majority of whom have cumulative risk factors for SARS-CoV-2 infection.

SARS-CoV-2 rapid serological tests for field-based healthcare workers in homeless communities: A mixed-methods exploratory analysis.

OBJECTIVES: The high risk of SARS-CoV-2 transmission in homeless communities requires adapted prevention strategies for field-based healthcare workers (HCWs). Rapid serological tests (RSTs) could be an invaluable tool for HCWs to control COVID-19 transmission. This study assesses the benefits of RSTs for HCWs in Marseille, France. STUDY DESIGN: Mixed-methods exploratory analysis. METHODS: A mixed-methods approach was used, combining quantitative and qualitative data, to prospectively analyse acceptability of RSTs, prevalence of SARS-CoV-2 antibodies and prevention behaviours in 106 HCWs from 18 non-governmental organisations (NGOs) and health or social institutions in Marseille from June 1 to July 31, 2020. For the qualitative dimension, semi-structured individual interviews were conducted with 21 HCWs from 7 of 18 NGOs and institutions. RESULTS: Most of the 106 HCWs in the quantitative study reported better prevention measures at work than in their homes. Despite this, the majority reported that they felt unsafe at work in terms of COVID-19 infection risk. SARS-CoV-2 antibody seroprevalence among the study population was 6.1%. Only four HCWs refused to have an RST.The 21 qualitative interviews highlighted that HCWs were not afraid of RSTs or of any possible stigma associated with a positive serological status, although they were sometimes suspicious about RST validity. Downplaying their risk of infection was a coping strategy to keep both a sense of control and remain motivated at work. CONCLUSIONS: RSTs should be adopted as an additional tool in the strategy to protect both HCWs and healthcare service users. Additional follow-up of these observational findings is needed, especially with the increasing prevalence of vaccination in HCWs.

"Locked down outside": Perception of hazard and health resources in COVID-19 epidemic context among homeless people.

While social inequality is widely recognised as being a risk factor for COVID-19 infection or serious forms of the disease, many questions still remain concerning the perception of hazard and protective measures by the most vulnerable populations. This mixed-methods study aimed (1) to describe the self-perceived health and protective measures linked to COVID-19 of homeless people in one of the largest and poorest cities in France, and (2) to assess which skills and resources they used to address the COVID-19 pandemic. The quantitative survey addressed these questions among a sample of 995 homeless people living either on the streets, in homeless shelters or in squats/slums, whereas the qualitative survey was constructed from 14 homeless interviewees. Both data collections were carried out between June and July 2020. Results showed that COVID-19 infection was clearly perceived by homeless people as a risk, but the experience of being homeless placed this risk among several others. Different practices of protection were observed according to the type of living place. Lockdown of the general population severely impacted the survival systems of the populations furthest from housing, with alarming rates of people without access to water or food. 77% of homeless participants reported that they encountered significant financial difficulties. All interviewees were particularly attentive to their health, with awareness and even a familiarity with the risks of infectious diseases long before the pandemic. Using a capability framework, our study showed a predominant lack of external health-related resources for homeless people, while internal health-related resources were more developed than expected. None of the places and lifestyles studied was favourable to health: collective shelters due to a greater restriction of people's choices, slums and street life due to a greater lack of basic resources.

Factors associated with the spatial heterogeneity of the first wave of COVID-19 in France: a nationwide geo-epidemiological study.

BACKGROUND: The objective of this study was to better understand the factors associated with the heterogeneity of in-hospital COVID-19 morbidity and mortality across France, one of the countries most affected by COVID-19 in the early months of the pandemic. METHODS: This geo-epidemiological analysis was based on data publicly available on government and administration websites for the 96 administrative departments of metropolitan France between March 19 and May 11, 2020, including Public Health France, the Regional Health Agencies, the French national statistics institute, and the Ministry of Health. Using hierarchical ascendant classification on principal component analysis of multidimensional variables, and multivariate analyses with generalised additive models, we assessed the associations between several factors (spatiotemporal spread of the epidemic between Feb 7 and March 17, 2020, the national lockdown, demographic population structure, baseline intensive care capacities, baseline population health and health-care services, new chloroquine and hydroxychloroquine dispensations, economic indicators, degree of urbanisation, and climate profile) and in-hospital COVID-19 incidence, mortality, and case fatality rates. Incidence rate was defined as the cumulative number of in-hospital COVID-19 cases per 100 000 inhabitants, mortality rate as the cumulative number of in-hospital COVID-19 deaths per 100 000, and case fatality rate as the cumulative number of in-hospital COVID-19 deaths per cumulative number of in-hospital COVID-19 cases. FINDINGS: From March 19 to May 11, 2020, hospitals in metropolitan France notified a total of 100 988 COVID-19 cases, including 16 597 people who were admitted to intensive care and 17 062 deaths. There was an overall cumulative in-hospital incidence rate of 155·6 cases per 100 000 inhabitants (range 19·4-489·5), in-hospital mortality rate of 26·3 deaths per 100 000 (1·1-119·2), and in-hospital case fatality rate of 16·9% (4·8-26·2). We found clear spatial heterogeneity of in-hospital COVID-19 incidence and mortality rates, following the spread of the epidemic. After multivariate adjustment, the delay between the first COVID-19-associated death and the onset of the national lockdown was positively associated with in-hospital incidence (adjusted standardised incidence ratio 1·02, 95% CI 1·01-1·04), mortality (adjusted standardised mortality ratio 1·04, 1·02-1·06), and case fatality rates (adjusted standardised fatality ratio 1·01, 1·01-1·02). Mortality and case fatality rates were higher in departments with older populations (adjusted standardised ratio for populations with a high proportion older than aged >85 years 2·17 [95% CI 1·20-3·90] for mortality and 1·43 [1·08-1·88] for case fatality rate). Mortality rate was also associated with incidence rate (1·0004, 1·0002-1·001), but mortality and case fatality rates did not appear to be associated with baseline intensive care capacities. We found no association between climate and in-hospital COVID-19 incidence, or between economic indicators and in-hospital COVID-19 incidence or mortality rates. INTERPRETATION: This ecological study highlights the impact of the epidemic spread, national lockdown, and reactive adaptation of intensive care capacities on the spatial distribution of COVID-19 morbidity and mortality. It provides information for future geo-epidemiological analyses and has implications for preparedness and response policies to current and future epidemic waves in France and elsewhere. FUNDING: None.