Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia.
Australian Red Cross Lifeblood, Melbourne, Victoria, Australia.
Vox Sang. 2022 Aug;117(8):1016-1026. doi: 10.1111/vox.13290. Epub 2022 May 24.
Most of the 233 worldwide cases of variant Creutzfeldt-Jakob disease (vCJD) have been reported in the United Kingdom and 3 have been associated with transfusion-transmission. To mitigate the potential vCJD risk to blood safety, Australian Red Cross Lifeblood imposes restrictions on blood donation from people with prior residency in, or extended travel to, the United Kingdom during the risk period 1980-1996. We have modified a previously published methodology to estimate the transfusion-transmission risk of vCJD associated with fresh component transfusion in Australia if the UK residence deferral was removed.
The prevalence of current pre-symptomatic vCJD infection in the United Kingdom by age at infection and genotype was estimated based on risk of exposure to the bovine spongiform encephalopathy agent for the period 1980-1996. These results were used to estimate the age-specific prevalence of undiagnosed, pre-symptomatic vCJD in the Australian population in the current year due to prior UK residency or travel. The primary model outputs were the 2020 vCJD risks/unit of vCJD contamination, transfusion-transmission (infections) and clinical cases.
The overall (prior UK residency in and travel to United Kingdom, 1980-1996) mean risk of contamination per unit was 1 in 29,900,000. The risks of resulting vCJD transmission (infection) and clinical case were 1 in 389,000,000 and 1 in 1,450,000,000, respectively.
Our modelling suggests that removing the Lifeblood donation deferral for travel to, or UK residence, would result in virtually no increased risk of vCJD transfusion-transmission and would be a safe and effective strategy for increasing the donor base.
全球 233 例变异型克雅氏病（vCJD）病例大多发生在英国，其中 3 例与输血传播有关。为降低血液安全的潜在 vCJD 风险，澳大利亚红十字会生命血库对在风险期 1980-1996 年期间曾在英国居住或前往英国旅行的人员，限制其献血。我们对以前发表的方法进行了修改，以估算如果取消英国居住延期，澳大利亚与新鲜成分输血相关的 vCJD 输血传播风险。
根据 1980-1996 年期间接触牛海绵状脑病因子的风险，按感染年龄和基因型估计当前英国感染前期 vCJD 的流行率。利用这些结果，估算了由于先前在英国居住或旅行，当前澳大利亚人群中因前期无症状 vCJD 的年龄特异性患病率。主要模型输出为 2020 年 vCJD 风险/单位 vCJD 污染、输血传播（感染）和临床病例。
总体（1980-1996 年期间曾在英国居住和前往英国旅行）每单位污染的平均污染风险为 1/2990 万。由此导致的 vCJD 传播（感染）和临床病例的风险分别为 1/3.89 亿和 1/14.5 亿。
我们的模型表明，取消生命血库对前往英国或在英国居住的献血者的延期规定，将几乎不会增加 vCJD 输血传播的风险，并且是增加献血者基础的安全有效的策略。
