Blood and Tissue Bank, Transfusion Safety Laboratory, Barcelona, Spain.
CIBER Liver and Digestive Diseases (CIBERHED), Institute of Health Carlos III, Madrid, Spain.
Blood Transfus. 2022 Sep;20(5):353-361. doi: 10.2450/2022.0232-21. Epub 2022 Feb 4.
Due to the COVID-19 pandemic, a national lockdown was applied in Spain from March to May 2020. It is uncertain when SARS-CoV-2 started to circulate in Catalonia, and only a few cases were diagnosed in this period. We assessed the SARS-CoV-2 seroprevalence in blood donors before and after the first wave and compared it with public health service (PHS) data.
Retrospective archive or prospective fresh blood samples were obtained from blood donors aged 18 to 70 and anonymized after demographic data had been recorded (gender, age, place of residence, blood collection date). Two CE-marked enzyme-linked immunosorbent assays were used to test for anti-SARS-CoV-2. A SARS-CoV-2 IgM test was additionally performed in positive samples. Individuals aged 18 to 70 from among the general population diagnosed as having SARS-CoV-2 by the PHS were included for comparison with blood donor results.
A total of 10,170 blood donations were included in the first period, between 24 February and 9 March 2020, and 6,829 in the second period, between 16 May and 17 June 2020. The observed SARS-CoV-2 seroprevalence among blood donors rose from 0.27% (95% CI: 0.18-0.39) before the first wave to 5.55% (95% CI: 5.03-6.12) after it, and was even higher (6.90% [95% CI: 5.64-8.41]) among blood donors aged 18 to 29. The seroprevalence among blood donors was higher in more populated areas (Barcelona: 7.69%). A comparison of blood donor data with officially diagnosed cases showed a global 87.44% underestimation of SARS-CoV-2 in June 2020.
We analyzed the explosive 3-month increase in blood donor SARS-CoV-2 seroprevalence (from 0.27% to 5.55%) and show that more than 87% of cases went undiagnosed, despite the unprecedented deployment of testing measures. SARS-CoV-2 IgM results suggest that the virus was circulating among blood donors in February 2020. Blood donors are definitively proven to be a valuable resource for emerging disease surveillance studies.
由于 COVID-19 大流行，西班牙于 2020 年 3 月至 5 月实施了全国封锁。目前尚不确定 SARS-CoV-2 何时在加泰罗尼亚开始传播，并且在此期间仅诊断出少数病例。我们评估了第一波疫情前后献血者的 SARS-CoV-2 血清流行率，并将其与公共卫生服务（PHS）数据进行了比较。
从年龄在 18 至 70 岁之间的献血者中采集回顾性档案或前瞻性新鲜血液样本，并在记录人口统计学数据（性别，年龄，居住地，采血日期）后对其进行匿名处理。使用两种经 CE 标记的酶联免疫吸附试验来检测抗 SARS-CoV-2。对阳性样本还进行了 SARS-CoV-2 IgM 检测。从 PHS 诊断为 SARS-CoV-2 的普通人群中选择年龄在 18 至 70 岁之间的个体与献血者结果进行比较。
在第一阶段（2020 年 2 月 24 日至 3 月 9 日）共纳入了 10,170 份献血，在第二阶段（2020 年 5 月 16 日至 6 月 17 日）共纳入了 6,829 份。第一波疫情之前，献血者中观察到的 SARS-CoV-2 血清流行率从 0.27%（95%CI：0.18-0.39）上升至 5.55%（95%CI：5.03-6.12），而在 18 至 29 岁的献血者中甚至更高（6.90%[95%CI：5.64-8.41]）。在人口较多的地区（巴塞罗那：7.69%），献血者的血清流行率更高。将献血者的数据与官方确诊病例进行比较显示，2020 年 6 月 SARS-CoV-2 的总体漏诊率为 87.44%。
我们分析了献血者 SARS-CoV-2 血清流行率（从 0.27%到 5.55%）的 3 个月急剧上升，并表明尽管进行了前所未有的测试措施，但仍有超过 87%的病例未被诊断。SARS-CoV-2 IgM 结果表明，该病毒在 2020 年 2 月就在献血者中传播。献血者被明确证明是新兴疾病监测研究的有价值资源。
