Central Virology Laboratory, Ministry of Health, Tel-Hashomer, Israel.
Sackler Faculty of Medicine, Tel-Aviv University, Israel.
Euro Surveill. 2021 Dec;26(48). doi: 10.2807/1560-7917.ES.2021.26.48.2001690.
IntroductionThe COVID-19 pandemic has put healthcare workers (HCW) at significant risk. Presence of antibodies can confirm prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.AimThis study investigates the prevalence of IgA and IgG antibodies against SARS-CoV-2 in HCW.MethodsPerformance of IgA and IgG antibody ELISA assays were initially evaluated in positive and negative SARS-CoV-2 serum samples. IgA and IgG antibodies against SARS-CoV-2 were measured in 428 asymptomatic HCW. We assessed the risk of two groups: HCW with high exposure risk outside work (HROW) residing in areas where COVID-19 was endemic (n = 162) and HCW with high exposure risk at work (HRAW) in a COVID-19 intensive care unit (ICU) (n = 97).ResultsSensitivities of 80% and 81.2% and specificities of 97.2% and 98% were observed for IgA and IgG antibodies, respectively. Of the 428 HCW, three were positive for IgG and 27 for IgA. Only 3/27 (11%) IgA-positive HCW had IgG antibodies compared with 50/62 (81%) in a group of previous SARS-CoV-2-PCR-positive individuals. Consecutive samples from IgA-positive HCW demonstrated IgA persistence 18-83 days in 12/20 samples and IgG seroconversion in 1/20 samples. IgA antibodies were present in 8.6% of HROW and 2% of HRAW.ConclusionsSARS-CoV-2 exposure may lead to asymptomatic transient IgA response without IgG seroconversion. The significance of these findings needs further study. Out of work exposure is a possible risk of SARS-CoV-2 infection in HCW and infection in HCW can be controlled if adequate protective equipment is implemented.
简介
COVID-19 大流行使医护人员（HCW）面临重大风险。抗体的存在可以确认先前严重急性呼吸系统综合症冠状病毒 2（SARS-CoV-2）感染。
目的
本研究调查了 SARS-CoV-2 抗体 IgA 和 IgG 在 HCW 中的流行情况。
方法
最初在 SARS-CoV-2 阳性和阴性血清样本中评估了 IgA 和 IgG 抗体 ELISA 检测的性能。在 428 名无症状 HCW 中测量了针对 SARS-CoV-2 的 IgA 和 IgG 抗体。我们评估了两组的风险：工作地点以外高暴露风险（HROW）的 HCW 居住在 COVID-19 流行地区（n = 162）和 COVID-19 重症监护病房（ICU）工作地点高暴露风险（HRAW）的 HCW（n = 97）。
结果
观察到 IgA 和 IgG 抗体的灵敏度分别为 80%和 81.2%，特异性分别为 97.2%和 98%。在 428 名 HCW 中，3 名 IgG 阳性，27 名 IgA 阳性。与先前 SARS-CoV-2-PCR 阳性个体组中的 50/62（81%）相比，仅 3/27（11%）IgA 阳性 HCW 有 IgG 抗体。12/20 份 IgA 阳性 HCW 的连续样本在 18-83 天内显示 IgA 持续存在，20 份样本中的 1 份 IgG 血清转换。HROW 中有 8.6%的人有 IgA，HRAW 中有 2%的人有 IgA。
结论
SARS-CoV-2 暴露可能导致无症状短暂 IgA 反应而无 IgG 血清转换。这些发现的意义需要进一步研究。工作地点以外的暴露可能是 HCW 感染 SARS-CoV-2 的风险因素，如果实施了足够的防护设备，可以控制 HCW 的感染。
