背景:戊型肝炎病毒(HEV)基因型3是几个欧洲国家急性病毒性肝炎的主要原因。它主要是通过摄取受污染的猪肉来获得的,但也有报道通过输血传播。虽然大多数HEV感染,包括那些通过血液制品,通常是自我限制的,在免疫功能低下的人中,它们可能成为慢性的。因此,必须识别HEV感染的献血,以防止传播给脆弱的接受者。
目的:在决定是否对所有瑞士献血进行HEVRNA筛查之前,我们进行了一项为期2年的全国患病率研究.
方法:在5个地区献血机构的12-24个样本中对所有献血进行了筛选,和HEVRNA阳性池随后解析为个人捐赠指数捐赠(X).病毒载量,HEVIgG和IgM血清学,并确定HEV基因型。对未来的对照捐赠(X+1)和捐赠者以前的存档捐赠(X-1)进行了后续调查。
结果:在2018年10月至2020年9月之间,筛查了541,349次献血,确定了125次确认的阳性献血(患病率1:4331献血)。在献血的时候,HEVRNA阳性个体无症状.中位病毒载量为554IU/mL(范围:2.01-2,500,000IU/mL)。男性(88;70%)的感染频率高于女性(37;30%),与瑞士捐赠者的性别分布相比(57%男性/43%女性,p<0.01)。在106例基因分型病例中(85%),均属于基因型3。两种HEV亚基因型占主导地位;3h3(以前为3s)和3c。其余的亚基因型都已知在欧洲传播。确定了五个3ra基因型,这是与兔子有关的变体。总的来说,85(68%)X捐赠对HEVIgM和IgG呈阴性。其余40例(32%)为HEVIgG和/或IgM阳性,与活动性感染一致。我们在89个可用和分析的档案样品中的87个中没有发现先前HEV的标记物(X-1)。在X-1捐赠中,两名捐赠者为HEVIgG阳性,表明免疫力不足以防止HEV再感染。收集90例(72%)分析的X+1捐赠的时间在X捐赠后2.9至101.9周(中位数为35周)之间变化。不出所料,没有一个测试的HEVRNA阳性。大多数供体(89;99%)抗HEVlgG/lgM呈阳性(即,血清转换)。HEVlgM阳性(23;26%)表明在HEV感染后lgM抗体的常长持续。
结论:在研究的第一年收集的数据为决定建立强制性HEVRNA通用筛查所有瑞士在小池中献血的决定提供了依据。为所有接受者提供更安全血液的重要一步,尤其是那些免疫抑制的人。
Hepatitis E virus (HEV) genotype 3 is the major cause of acute viral hepatitis in several European countries. It is acquired mainly by ingesting contaminated pork, but has also been reported to be transmitted through blood transfusion. Although most HEV infections, including those via blood products, are usually self-limiting, they may become chronic in immunocompromised persons. It is thus essential to identify HEV-infected blood donations to prevent transmission to vulnerable recipients.
Prior to the decision whether to introduce HEV RNA screening for all Swiss blood donations, a 2-year nationwide prevalence study was conducted.
All blood donations were screened in pools of 12-24 samples at five regional blood donation services, and HEV RNA-positive pools were subsequently resolved to the individual donation index donation (X). The viral load, HEV IgG and IgM serology, and HEV genotype were determined. Follow-up investigations were conducted on future control donations (X + 1) and previous archived donations of the donor (X - 1) where available.
Between October 2018 and September 2020, 541,349 blood donations were screened and 125 confirmed positive donations were identified (prevalence 1:4331 donations). At the time of blood donation, the HEV RNA-positive individuals were symptom-free. The median viral load was 554 IU/mL (range: 2.01-2,500,000 IU/mL). Men (88; 70%) were more frequently infected than women (37; 30%), as compared with the sex distribution in the Swiss donor population (57% male/43% female, p < 0.01). Of the 106 genotyped cases (85%), all belonged to genotype 3. Two HEV sub-genotypes predominated; 3h3 (formerly 3s) and 3c. The remaining sub-genotypes are all known to circulate in Europe. Five 3ra genotypes were identified, this being a variant associated with rabbits. In total, 85 (68%) X donations were negative for HEV IgM and IgG. The remaining 40 (32%) were positive for HEV IgG and/or IgM, and consistent with an active infection. We found no markers of previous HEV in 87 of the 89 available and analyzed archive samples (X - 1). Two donors were HEV IgG-positive in the X - 1 donation suggesting insufficient immunity to prevent HEV reinfection. Time of collection of the 90 (72%) analyzed X + 1 donations varied between 2.9 and 101.9 weeks (median of 35 weeks) after X donation. As expected, none of those tested were positive for HEV RNA. Most donors (89; 99%) were positive for anti-HEV lgG/lgM (i.e., seroconversion). HEV lgM-positivity (23; 26%) indicates an often-long persistence of lgM antibodies post-HEV infection.
The data collected during the first year of the study provided the basis for the decision to establish mandatory HEV RNA universal screening of all Swiss blood donations in minipools, a vital step in providing safer blood for all recipients, especially those who are immunosuppressed.