Harboun M, Verdun S, Brénière V, Luquel L, Jourdan M, De Malherbe A
UNIVI santé, hôpital « La Porte Verte », 6, avenue du Maréchal Franchet-d'Esperey, 78000 Versailles, France.
Biostatistics Department-Delegations for Clinical Research and Innovation, Lille Catholic hospitals, Lille Catholic University, Lille, France.
Rev Med Interne. 2022 Feb;43(2):75-81. doi: 10.1016/j.revmed.2021.10.330. Epub 2021 Oct 21.
The pandemic caused by SARS-COV-2 infection spread rapidly during the "first wave" through France between March and May 2020. It was responsible for high mortality in subjects with comorbidities and the elderly who lived in nursing homes. In May 2020, 75% of the deaths occurred in people over 75 years old in nursing homes. It is difficult to estimate accurately the prevalence of COVID-19 infection during this period because only 50% of the diagnoses in nursing homes were made by RT-PCR. During this period, the diagnosis was mainly based on the clinical symptoms.
We carried out a prospective study among residents of the 27 EHPADs in the UNIVI group (SEROCOVID study) between August 31 and October 16, 2020 using rapid ELISA serotests carried out by pricking the fingertip. We looked for the seroprevalence by the use of rapid serotests as well as the overall prevalence by cumulating the positive results of the RT-PCR when done and of the rapid serotest. The secondary objectives were the study of risk factors for infection by multivariate analysis as well as the description of the symptoms that led to the diagnosis.
In total, 1145 residents were included aged on average 89±7.5 years old (female 78.7%). The time between the COVID-19 disease and the rapid inclusion serotest was on average 5±1.7 months. The prevalence estimated by the three diagnostic evaluation methods (medical diagnosis, RT-PCR or by rapid serotest ELISA) is about 14%, underestimated compared to the overall prevalence at 22.7%. The study of risk factors in multivariate analysis shows that the most dependent residents, living in a protected unit due to behavioral disorders or whose close contact with a person with COVID-19 had significantly higher rates of infection. Finally, the symptoms most frequently observed in residents differed from those in younger subjects with geriatric characteristics, such as the higher frequency of digestive symptoms and geriatric syndromes. Fever has only been observed in one third of cases in the elderly. Smell and taste disorders were seldom described.
Our study provides an estimate of the overall prevalence as well as the mean seroprevalence of COVID-19 in EHPAD residents five months after the diagnosis of COVID-19 disease. The difference between the two estimates is probably explained by the frailty and decreased immunity of the nursing home residents. Therefore, it would need to be reactivated by vaccination of all residents, even those already infected with SARS-COV-2. These elements corroborate the governmental strategy of vaccination deployed in all residents of EHPAD regardless of their previous contact with the virus.
2020年3月至5月期间，由SARS-CoV-2感染引发的疫情在法国“第一波”期间迅速蔓延。它导致患有合并症的人群以及居住在养老院的老年人死亡率很高。2020年5月，养老院中75%的死亡发生在75岁以上的人群中。由于养老院中只有50%的诊断是通过逆转录聚合酶链反应（RT-PCR）做出的，因此很难准确估计这一时期新冠病毒感染的患病率。在此期间，诊断主要基于临床症状。
2020年8月31日至10月16日，我们在UNIVI组的27家养老院（SEROCOVID研究）的居民中进行了一项前瞻性研究，采用指尖采血的快速酶联免疫吸附血清检测。我们通过使用快速血清检测来寻找血清阳性率，并通过累积RT-PCR检测结果（如果进行了该检测）和快速血清检测的阳性结果来计算总体患病率。次要目标是通过多变量分析研究感染的危险因素以及描述导致诊断的症状。
总共纳入了1145名居民，平均年龄为89±7.5岁（女性占78.7%）。从感染新冠病毒疾病到快速纳入血清检测的时间平均为5±1.7个月。通过三种诊断评估方法（医学诊断、RT-PCR或快速酶联免疫吸附血清检测）估计的患病率约为14%，与总体患病率22.7%相比被低估。多变量分析中的危险因素研究表明，最依赖他人的居民、因行为障碍住在受保护单元的居民或与新冠病毒感染者密切接触的居民感染率显著更高。最后，在居民中最常观察到的症状与具有老年特征的年轻受试者不同，例如消化症状和老年综合征的发生率更高。老年人中只有三分之一的病例出现发热。嗅觉和味觉障碍很少被描述。
我们的研究提供了新冠病毒疾病诊断五个月后养老院居民中新冠病毒总体患病率以及平均血清阳性率的估计。这两种估计之间的差异可能是由于养老院居民身体虚弱和免疫力下降所致。因此，即使是那些已经感染了SARS-CoV-2的居民，也需要通过接种疫苗来重新激活免疫力。这些因素证实了政府针对所有养老院居民实施的疫苗接种策略，无论他们之前是否接触过病毒。
