RESUMO
In recent years, and more specifically at the beginning of the COVID-19 crisis, wastewater surveillance has been proposed as a tool to monitor the epidemiology of human viral infections. In the present work, from July to December 2020, the number of copies of SARS-CoV-2 RNA in Marseille's wastewater was correlated with the number of new positive cases diagnosed in our Institute of Infectious Disease, which tested about 20% of the city's population. Number of positive cases and number of copies of SARS-CoV-2 RNA in wastewater were significantly correlated (p = 0.013). During the great epidemic peak, from October to December 2020, the curves of virus in the sewers and the curves of positive diagnoses were perfectly superposed. During the summer period, the superposition of curves was less evident as subject to many confounding factors that were discussed. We also tried to correlate the effect of viral circulation in wastewater with containment measures, probably the most unbiased correlation on their potential inflection effect of epidemic curves. Not only is this correlation not obvious, but it also clearly appears that the drop in cases as well as the drop in the viral load in the sewers occur before the containment measures. In fact, this suggests that there are factors that initiate the end of the epidemic peak independently of the containment measure. These factors will therefore need to be explored more deeply in the future.
RESUMO
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.
