Furukawa Koichi, Arii Jun, Nishimura Mitsuhiro, Tjan Lidya Handayani, Lystia Poetranto Anna, Ren Zhenxiao, Aktar Salma, Huang Jing Rin, Sutandhio Silvia, Kurahashi Yukiya, Nishino Arisa, Shigekuni Shiho, Takeda Yuichiro, Uto Kenichi, Matsui Keiji, Sato Itsuko, Inui Yoshiaki, Endo Kazuo, Kosaka Yoshiyuki, Oota Toshiaki, Saegusa Jun, Mori Yasuko
Division of Clinical Virology, Center for Infectious Disease, Kobe University Graduate School of Medicine, Kobe, Japan.
Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan.
JMA J. 2021 Jan 29;4(1):41-49. doi: 10.31662/jmaj.2020-0094. Epub 2021 Jan 14.
The coronavirus disease 2019 (COVID-19) pandemic is spreading rapidly all over the world. The Japanese government lifted the state of emergency, announced in April 2020, on May 25, but there are still sporadic clusters. Asymptomatic patients who can transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause some of these clusters. It is thus urgent to investigate the seroprevalence of antibodies against SARS-CoV-2 and their neutralizing activity. We conducted a cross-sectional study of >10,000 samples at hospitals in Hyogo Prefecture, Japan.
Between August 6 and October 1, 2020, we collected samples of residual blood from the patients who visited or were admitted to five hospitals and a foundation in Hyogo. We tested the samples for antibodies against SARS-CoV-2 by electrochemiluminescence immunoassay (ECLIA) and chemiluminescent enzyme immunoassay (CLEIA). Sera that were positive by ECLIA or CLEIA were analyzed by an immunochromatographic (IC) test and neutralizing activity assay.
We tested 10,377 samples from patients aged between 0 and 99 years old; 27 cases (0.26%) were positive on the ECLIA, and 51 cases (0.49%) were positive on CLEIA. In the 14 cases that tested positive on both ECLIA and CLEIA, the positive rates on the IC test and for neutralizing activity were high (85% and 92%, respectively). In 50 cases (0.48%) that were positive by either ECLIA or CLEIA, the corresponding rates were low (20% and 6%, respectively). The positive rate of neutralizing antibody was 0.15%.
These results indicate that most Hyogo Prefecture residents still do not have antibodies and should avoid the risk of incurring a SARS-CoV-2 infection. Two or more antibody tests should be required for seroepidemiological studies of the antibody for SARS-CoV-2, and a neutralizing activity assay is also essential.
2019冠状病毒病（COVID-19）大流行正在全球迅速蔓延。日本政府于5月25日解除了2020年4月宣布的紧急状态，但仍有散发病例群。能够传播严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的无症状患者导致了其中一些病例群。因此，迫切需要调查抗SARS-CoV-2抗体的血清流行率及其中和活性。我们在日本兵库县的医院对10000多个样本进行了一项横断面研究。
2020年8月6日至10月1日期间，我们从访问或入住兵库县五家医院和一个基金会的患者中收集了剩余血液样本。我们通过电化学发光免疫分析（ECLIA）和化学发光酶免疫分析（CLEIA）检测样本中的抗SARS-CoV-2抗体。通过ECLIA或CLEIA检测呈阳性的血清通过免疫层析（IC）试验和中和活性测定进行分析。
我们检测了10377份年龄在0至99岁之间患者的样本；27例（0.26%）在ECLIA检测中呈阳性，51例（0.49%）在CLEIA检测中呈阳性。在ECLIA和CLEIA检测均呈阳性的14例中，IC试验和中和活性的阳性率较高（分别为85%和92%）。在通过ECLIA或CLEIA检测呈阳性的50例（0.48%）中，相应的阳性率较低（分别为20%和6%）。中和抗体的阳性率为0.15%。
这些结果表明，大多数兵库县居民仍然没有抗体，应避免感染SARS-CoV-2的风险。对于SARS-CoV-2抗体的血清流行病学研究，应进行两种或更多种抗体检测，中和活性测定也必不可少。
