Seroprevalence of anti-SARS-CoV-2 antibodies after the first wave of the COVID-19 pandemic in a vulnerable population in France: a cross-sectional study

Abstract

ObjectivesWe aimed to assess the level of prior SARS-CoV-2 infection in socially deprived neighbourhoods after the first wave of the pandemic, and to identify factors associated with seropositivity.DesignA cross-sectional study.SettingThree socially deprived neighbourhoods of the city of Perpignan, in the south of France, where large settled Roma communities live.ParticipantsPeople aged 6 years old or over, living in the study area. 700 people were included in the study using two-stage stratified sampling design.InterventionsThe study included a questionnaire and SARS-CoV-2 antibody testing by the Roche Elecsys immunoassay between 29 June and 17 July 2020.Primary and secondary outcome measuresSARS-CoV-2 antibody seroprevalence was estimated from weighted data. Associated factors and reported symptoms were investigated using univariable and multivariable logistic regressions.ResultsThe seroprevalence of anti-SARS-CoV-2 antibodies was 35.4% (95% CI 30.2% to 41.0%). People aged 15–64 years old had increased odds of being seropositive than those aged 65 years or over. Obese people had higher odds of being seropositive (adjusted OR (aOR)=2.0, 95% CI 1.1 to 3.8). The odds of being seropositive were higher in households with clinical COVID-19 cases (one case: aOR=2.5, 95% CI 1.3 to 5.0; several cases: aOR=6.9, 95% CI 3.1 to 15.2). In the neighbourhood with the highest measured seroprevalence, people living in a dwelling with one to two rooms had higher odds of being seropositive than those living in a four-room house (aOR=2.8, 95% CI 1.2 to 6.3). Working during the lockdown was associated with lower odds of being seropositive (aOR=0.2, 95% CI 0.03 to 1.0).ConclusionTransmission of SARS-COV-2 in this vulnerable population was very high during the COVID-19 pandemic’s first wave. Our results highlight the need to strengthen and adapt preventive measures taking into account all social determinants of health, especially housing conditions.

Prevalence of Anti-SARS-CoV-2 Antibodies and Potential Determinants among the Belgian Adult Population: Baseline Results of a Prospective Cohort Study

“…The strong association between a prior infection with SARS-CoV-2 and a higher presence of anti-SARS-CoV-2 antibodies is in line with what can be expected and consistent with the literature [ 10 , 24 ]. In contrast to findings from other studies, the results of our study, after adjustment for cofounding factors, did not highlight a significant association between the presence of anti-SARS-CoV-2 and different risk factors such as age [ 8 , 10 , 35 ], sex [ 35 , 36 ], overweight [ 10 , 35 ], or smoking status [ 10 ].…”

Is SARS‐CoV‐2 seroconversion a risk factor for severe and acute psychiatric symptoms in children?

“…This result may be driven by a sampling bias of the control group, but studies conducted in a comparable vulnerable population in France and sampled at the same period reported similar high SARS-CoV-2 seroconversion. 3 Our results indicate a low impact of SARS-CoV-2 in the rise of psychiatric symptoms during the earlier months of the pandemic.…”

“…Contrary to our hypothesis, we observed less seroconverted children with psychiatric conditions than in the age and sex controls sampled during the same period and living in the same low‐income region. This result may be driven by a sampling bias of the control group, but studies conducted in a comparable vulnerable population in France and sampled at the same period reported similar high SARS‐CoV‐2 seroconversion 3 …”

“…This result may be driven by a sampling bias of the control group, but studies conducted in a comparable vulnerable population in France and sampled at the same period reported similar high SARS‐CoV‐2 seroconversion. 3 …”

Coronavirus Disease 2019 (COVID-19) Lockdown: Morbidity, Perception, Behaviors, and Attitudes in French Families From the PARIS Birth Cohort

“…One solution was to rely on symptoms of COVID-19 ( 2 , 3 ), or use SARS-CoV-2 serological tests ( 4 ). In France, there were studies in specific populations: in socially deprived neighborhoods ( 5 , 6 ), suburban households ( 7 ) or in day-care centers ( 8 ); but few focused on adolescents and their families. Furthermore, the susceptibility of adolescents to SARS-CoV-2 infection seems to be similar to adults to date ( 9 – 11 ) but the role of adolescents in the household transmission of the SARS-CoV-2 during lockdown remains unclear.…”