Goncalez T T, Sabino E C, Murphy E L, Chen S, Chamone D A F, McFarland W
Fundacão Pro-Sangue/Hemocentro de São Paulo, São Paulo, Brazil.
Vox Sang. 2006 Apr;90(3):170-6. doi: 10.1111/j.1423-0410.2006.00743.x.
Previous studies have shown that volunteer, community-recruited donors have a higher prevalence of human immunodeficiency virus (HIV) infection in São Paulo, Brazil, than replacement donors. One hypothesis which may explain this unexpected finding is that some individuals donate blood because they are seeking HIV testing. The objective of this study was to characterize test-seeking blood donors and to determine whether they are at higher risk for HIV infection compared with other donors.
Subjects presenting for blood donation were asked to participate in a study assessing their motivations (including test seeking) to donate, as measured by perceiving donation as a means to obtain infectious disease test results. Participants completed the standard blood bank predonation screening questions plus our additional survey, and were tested for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphocytotrophic virus (HTLV) I/II, syphilis and Chagas' disease. As a result of anticipated low statistical power to directly measure the association between test-seeking motivation and HIV infection, we tested for herpes simplex virus type 2 (HSV-2) as a marker of sexual risk for HIV. Our survey includes accepted donors as well as persons whose risk-behaviour histories would result in their exclusion from donation according to routine screening procedures.
Of 1,720 potential blood donors randomly selected and approached, 1,600 (93.0%) participated. Overall, 141 (8.8%) were classified as test seekers; 15.6% of these were HSV-2 positive. The proportion of test seekers was the same among community-recruited and replacement donors. Test seekers had a higher prevalence of HSV-2 [adjusted odds ratio (AOR) 1.66; 95% confidence interval (CI): 1.06-2.59] adjusting for age, gender and prior donation. The association was significant among community-recruited blood donors whose previous donation was more than 1 year ago (i.e. 'lapsed donors') (AOR 2.55; 95% CI: 1.20-5.44). Test seekers were not more likely to be rejected from blood donation as a result of health reasons, self-reported HIV risk-related behaviour, or by their own confidential unit exclusion. We found no difference in HSV-2 prevalence between persons accepted for donation (15.7%) and those rejected because of self-reported sexual risk (16.7%).
We did not detect a difference in the proportion of test seekers across different types of blood donors; however, we did detect an association between HSV-2 infection and test seeking, especially among community-recruited lapsed blood donors. Of note, questions on test-seeking behaviour detected donors with increased prevalence of HSV-2, but the self-reported sexual risk behaviours currently used for deferral criteria did not. Incentives to get tested at sites other than blood banks may decrease the residual risk of HIV in the blood supply.
先前的研究表明，在巴西圣保罗，通过社区招募的志愿者献血者中人类免疫缺陷病毒（HIV）感染率高于替代献血者。一种可能解释这一意外发现的假说是，一些人献血是因为他们想进行HIV检测。本研究的目的是对寻求检测的献血者进行特征描述，并确定与其他献血者相比，他们感染HIV的风险是否更高。
要求前来献血的受试者参与一项研究，评估他们献血的动机（包括寻求检测），通过将献血视为获取传染病检测结果的一种方式来衡量。参与者完成了血库标准的献血前筛查问题以及我们额外的调查，并接受了HIV、乙型肝炎病毒（HBV）、丙型肝炎病毒（HCV）、人类T细胞嗜淋巴细胞病毒（HTLV）I/II、梅毒和恰加斯病的检测。由于直接测量寻求检测动机与HIV感染之间关联的统计效力预计较低，我们检测了2型单纯疱疹病毒（HSV-2）作为HIV性传播风险的标志物。我们的调查包括被接受的献血者以及根据常规筛查程序因其风险行为史而被排除献血的人员。
在随机挑选并接触的1720名潜在献血者中，1600名（93.0%）参与了研究。总体而言，141名（8.8%）被归类为寻求检测者；其中15.6%的人HSV-2呈阳性。在社区招募的献血者和替代献血者中，寻求检测者的比例相同。在对年龄、性别和既往献血情况进行调整后，寻求检测者HSV-2的感染率更高[调整后的优势比（AOR）为1.66；95%置信区间（CI）：1.06 - 2.59]。在既往献血超过1年的社区招募献血者（即“过期献血者”）中，这种关联显著（AOR为2.55；95%CI：1.20 - 5.44）。寻求检测者因健康原因、自我报告的与HIV风险相关行为或因自身机密单位排除而被拒绝献血的可能性并不更高。我们发现被接受献血者（15.7%）和因自我报告的性传播风险而被拒绝献血者（16.7%）之间HSV-2感染率没有差异。
我们未发现不同类型献血者中寻求检测者比例的差异；然而，我们确实发现HSV-2感染与寻求检测之间存在关联，尤其是在社区招募的过期献血者中。值得注意的是，关于寻求检测行为的问题检测出HSV-2感染率较高的献血者，但目前用于延期标准的自我报告的性传播风险行为却未检测出。在血库以外的地点进行检测的激励措施可能会降低血液供应中HIV的残余风险。
