Pattern of SARS-CoV-2 infection among dependant elderly residents living in long-term care facilities in Marseille, France, March–June 2020

Objectives: This study aimed to report the results of SARS-CoV-2 PCR-based screening campaigns conducted on dependent elderly residents (compared with staff members) in long-term care facilities (LTCFs) in Marseille, France, and the follow-up of positive cases. Methods: Data from 1691 elderly residents and 1000 members of staff were retrospectively collected through interviewing the medical teams in 24 LTCFs and using the hospitals’ electronic health recording systems. Results: Elderly residents were predominantly female (64.8%) with a mean age of 83.0 years. SARS-CoV-2 detection among residents (226, 13.4%) was significantly higher than among staff members (87, 8.7%) (P < 0.001). Of the 226 infected residents, 37 (16.4%) were detected on a case-by-case basis due to their COVID-19 symptoms and 189 (83.6%) were detected through mass screening. Most (77.0%) had possible COVID-19 symptoms, including respiratory symptoms and signs (44.5%) and fever (46.5%); 23.0% were asymptomatic. A total of 116 (51.4%) patients received a course of oral hydroxychloroquine and azithromycin (HCQ-AZM) for ≥ 3 days; 47 (20.8%) died. Through multivariate analysis, the death rate was positively associated with being male (30.7% vs. 14.0%, OR = 3.95, P = 0.002), aged > 85 years (26.1% vs. 15.6%, OR = 2.43, P = 0.041) and receiving oxygen therapy (39.0% vs. 12.9%, OR = 5.16, P < 0.001) and negatively associated with being diagnosed through mass screening (16.9% vs. 40.5%, OR = 0.20, P= 0.001) and receiving HCQ-AZM treatment ≥ 3 days (15.5% vs. 26.4%, OR = 0.37, P = 0.02). Conclusion: The high proportion of asymptomatic COVID-19 patients and independent factors for mortality suggest that early diagnosis and treatment of COVID-19 patients in LTCFs may be effective in saving lives.