Steele Whitney R, Hewitt Elizabeth H, Kaldun Anne M, Krysztof David E, Dodd Roger Y, Stramer Susan L
Transmissible Disease Department, American Red Cross, Rockville, Maryland.
Transfusion. 2014 Aug;54(8):2092-7. doi: 10.1111/trf.12590. Epub 2014 Mar 6.
Current Food and Drug Administration guidance specifies that all blood donors must be asked about a history of Chagas disease.
We identified all American Red Cross donors deferred for Chagas disease history from January 2000 to August 2011. Attempts were made to contact all deferred donors and invite them back for anti-Trypanosoma cruzi testing. After January 2007, all accepted donors (no Chagas history) were anti-T. cruzi tested.
Over the 12-year period (approx. 88 million donor presentations), 34 donors had a Chagas deferral. When contacted, seven reported risk (e.g., travel or residence in an endemic area, vector exposure) and six were anti-T. cruzi tested with one radioimmunoprecipitation assay (RIPA) positive. Six others had answered the question incorrectly. The remaining 21 could not be contacted but from the donor record it could be determined that 13 were Hispanic ethnicity or Spanish speaking and/or provided specific details of Chagas risk or disease.
In 12 years, only 28 potentially infected donors were identified using the Chagas question. Limited testing data suggest that few of these would have had serologic evidence of prior infection. In contrast, nearly 5 years of anti-T. cruzi screening identified 488 RIPA-positive donors, none of whom answered "yes" to the Chagas question. According to estimates in this study, the value of retaining the questionnaire in addition to testing translates to preventing the collection of 0.4 infected donors per billion. Thus, the Chagas history question has no meaningful value.
美国食品药品监督管理局当前的指南规定，必须询问所有献血者是否有恰加斯病病史。
我们确定了2000年1月至2011年8月期间因恰加斯病病史而被延期献血的所有美国红十字会献血者。试图联系所有被延期的献血者，并邀请他们回来进行抗克鲁斯锥虫检测。2007年1月之后，所有接受检测的献血者（无恰加斯病病史）都进行了抗克鲁斯锥虫检测。
在这12年期间（约8800万次献血者登记），有34名献血者因恰加斯病被延期。在联系后，7人报告有风险（如在流行地区旅行或居住、接触传播媒介），6人进行了抗克鲁斯锥虫检测，其中1人放射免疫沉淀试验（RIPA）呈阳性。另外6人回答问题错误。其余21人无法联系到，但从献血者记录中可以确定，13人是西班牙裔或说西班牙语，和/或提供了恰加斯病风险或疾病的具体细节。
在12年里，通过询问恰加斯病问题仅识别出28名可能感染的献血者。有限的检测数据表明，其中很少有人会有既往感染的血清学证据。相比之下，近5年的抗克鲁斯锥虫筛查识别出488名RIPA阳性献血者，他们对恰加斯病问题均回答“否”。根据本研究的估计，除检测外保留问卷的价值在于每10亿次可防止采集到0.4名感染的献血者。因此，恰加斯病病史问题没有实际意义。
