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Clin Microbiol Infect ; 27(10): 1520.e1-1520.e5, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1260695


OBJECTIVES: To evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization and fatality rates in residents of homeless shelters run by Samusocial of Paris. METHODS: We conducted a retrospective serological study between July and August 2020 on all residents and staff members of three homeless shelters run by Samusocial of Paris: two centres providing healthcare accommodation (HCA) and one a women's dormitory. We included all adults present in the shelters or who died of a proven SARS-CoV-2 infection during the first wave (March-May). SARS-CoV-2 antibodies were detected in serum samples using the SARS-CoV-2 IgG Architect (Abbott) test. Any participant with a positive PCR or serology was defined as a confirmed SARS-CoV-2 case. RESULTS: We included 100 residents and 83 staff members. The confirmed SARS-CoV-2 rate by PCR or serology was 72/100 (72.0%) for residents and 17/83 (20.5%) for staff members. Women accommodated in the dormitory had the highest infection rate (90.6%). The hospitalization rate in residents was 17/72 (23.6%) and the death rate 4/72 (5.6%). All hospitalizations and deaths occurred among HCA residents. Among the residents of HCA shelters, 34/68 (50%) presented at least two comorbidity factors associated with being at high risk for severe SARS-CoV-2 infection. CONCLUSION: The SARS-CoV-2 infection rate was high in residents of these homeless shelters (10.6% seroprevalence in the Île-de-France region during the first wave). Severe SARS-CoV-2 infection was highly associated with the prevalence of comorbidities. This population should be considered as a priority in vaccination campaigns and in access to individual housing units when at risk.

COVID-19/epidemiology , Homeless Persons/statistics & numerical data , Adult , COVID-19/blood , COVID-19/mortality , Female , France/epidemiology , Hospitalization , Humans , Incidence , Male , Middle Aged , Prevalence , Retrospective Studies , Risk Factors , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies
Sci Transl Med ; 12(559)2020 09 02.
Article in English | MEDLINE | ID: covidwho-724557


It is of paramount importance to evaluate the prevalence of both asymptomatic and symptomatic cases of SARS-CoV-2 infection and their differing antibody response profiles. Here, we performed a pilot study of four serological assays to assess the amounts of anti-SARS-CoV-2 antibodies in serum samples obtained from 491 healthy individuals before the SARS-CoV-2 pandemic, 51 individuals hospitalized with COVID-19, 209 suspected cases of COVID-19 with mild symptoms, and 200 healthy blood donors. We used two ELISA assays that recognized the full-length nucleoprotein (N) or trimeric spike (S) protein ectodomain of SARS-CoV-2. In addition, we developed the S-Flow assay that recognized the S protein expressed at the cell surface using flow cytometry, and the luciferase immunoprecipitation system (LIPS) assay that recognized diverse SARS-CoV-2 antigens including the S1 domain and the carboxyl-terminal domain of N by immunoprecipitation. We obtained similar results with the four serological assays. Differences in sensitivity were attributed to the technique and the antigen used. High anti-SARS-CoV-2 antibody titers were associated with neutralization activity, which was assessed using infectious SARS-CoV-2 or lentiviral-S pseudotype virus. In hospitalized patients with COVID-19, seroconversion and virus neutralization occurred between 5 and 14 days after symptom onset, confirming previous studies. Seropositivity was detected in 32% of mildly symptomatic individuals within 15 days of symptom onset and in 3% of healthy blood donors. The four antibody assays that we used enabled a broad evaluation of SARS-CoV-2 seroprevalence and antibody profiling in different subpopulations within one region.

Antibodies, Viral/blood , Betacoronavirus/immunology , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Serologic Tests/methods , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19 , COVID-19 Testing , Cohort Studies , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Enzyme-Linked Immunosorbent Assay/methods , Female , Flow Cytometry/methods , France/epidemiology , Healthy Volunteers , Humans , Immunoprecipitation/methods , Luciferases , Male , Middle Aged , Neutralization Tests , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , SARS-CoV-2 , Seroepidemiologic Studies , Spike Glycoprotein, Coronavirus/immunology , Young Adult