Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan.
Japanese Red Cross Hokkaido Block Blood Center, Sapporo, Japan.
Transfusion. 2024 Feb;64(2):335-347. doi: 10.1111/trf.17696. Epub 2023 Dec 28.
More than 45 cases of transfusion-transmitted hepatitis E virus infection (TT-HEV) have been reported in Japan. Therefore, in 2020, universal individual donation nucleic acid amplification testing (ID-NAT) was implemented for HEV.
We characterized HEV NAT-positive blood donors. The number of new HEV infections and the asymptomatic infection rate were estimated using the HEV NAT-positive rate. HEV RNA quantitation, phylogenetic analysis, and antibody tests were performed, and the residual risk of TT-HEV was assessed based on the lookback study results.
A total of 5,075,100 blood donations were screened with ID-NAT during the first year of implementation, among which 2804 (0.055%; males: 0.060%, females: 0.043%) were NAT-positive with regional differences. Approximately 270,000 new HEV infection cases were estimated to occur annually in Japan, with an asymptomatic infection rate of 99.9%. The median HEV RNA concentration, excluding cases below the limit of quantification, was 205 IU/mL. Among the 1113 cases where the genotype could be determined, HEV-3 and HEV-4 accounted for 98.8% (1100) and 1.2% (13), respectively. The maximum duration of HEV viremia, including the pre- and post-ID-NAT window periods, was estimated to be 88.2 days. Within the 3 years since ID-NAT implementation, no confirmed cases of breakthrough TT-HEV were observed.
Multiple indigenous HEV strains are prevalent in Japan, infecting a significant number of individuals. However, since the implementation of ID-NAT, TT-HEV has been prevented due to the test's high sensitivity.
在日本已报告超过 45 例输血传播的戊型肝炎病毒感染（TT-HEV）病例。因此，2020 年，日本对戊型肝炎病毒实施了通用个体捐献核酸扩增检测（ID-NAT）。
我们对 HEV NAT 阳性献血者进行了特征描述。通过 HEV NAT 阳性率来估计新的 HEV 感染数量和无症状感染率。进行了 HEV RNA 定量、系统进化分析和抗体检测，并根据回溯研究结果评估 TT-HEV 的残余风险。
在实施 ID-NAT 的第一年，共筛查了 5075100 份血样，其中 2804 份（0.055%；男性：0.060%，女性：0.043%）NAT 阳性，存在地域差异。日本每年估计约有 27 万例新的 HEV 感染病例，无症状感染率为 99.9%。排除定量下限以下的病例后，HEV RNA 浓度中位数为 205 IU/mL。在可确定基因型的 1113 例中，HEV-3 和 HEV-4 分别占 98.8%（1100 例）和 1.2%（13 例）。包括 ID-NAT 前和后窗口期在内，HEV 病毒血症的最长持续时间估计为 88.2 天。在实施 ID-NAT 后的 3 年内，未观察到确诊的突破性 TT-HEV 病例。
日本存在多种本土 HEV 株，感染了大量人群。然而，自实施 ID-NAT 以来，由于该检测具有很高的灵敏度，TT-HEV 已得到预防。
