Most dengue virus (DENV) infections remain asymptomatic. This increases the risk of DENV transfusion transmission (TT‐DENV) during outbreaks. We evaluated DENV viremia in 8475 blood donations assembled in minipools for the presence of DENV RNA. The tested samples were obtained between February and May, 2016, during a large DENV outbreak in Ribeirão Preto city, northeast region of the São Paulo State, Brazil. The DENV RNA + samples were serotyped and screened for DENV NS1. We also tested a significant number of plasma samples (n = 372) to estimate the DENV seroprevalence among blood donors in the region. We detected three DENV RNA + samples in the tested blood donations (n = 3/8475, 0.04%). From these, two samples were further serotyped as DENV‐1 and one sample as DENV‐2. All DENV RNA positive samples were negative for anti‐DENV IgG, indicating the presence of primary acute infection. Moreover, two of the DENV RNA + samples were also NS1 antigen positive (antigenemia). The anti‐DENV IgG seroprevalence among blood donor population was 50.8% (n = 189/372). Our results are in accordance with the presence of DENV primary infection in blood donors which can lead to transfusion transmission of the infection to recipients. Measures to exclude such donors should be adopted to prevent TT‐DENV.

中文翻译：

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2016 年巴西圣保罗州爆发期间登革热 RNA 检测和献血者血清阳性率

大多数登革热病毒（DENV）感染仍然无症状。这增加了爆发期间 DENV 输血传播（TT-DENV）的风险。我们评估了 8475 份献血中的 DENV 病毒血症，这些献血被收集在小池中，以确定 DENV RNA 的存在。测试样本是在 2016 年 2 月至 5 月期间在巴西圣保罗州东北部地区里贝朗普雷图市大规模 DENV 爆发期间获得的。对 DENV RNA + 样本进行血清分型并筛选 DENV NS1。我们还测试了大量血浆样本（n  = 372），以估计该地区献血者中的 DENV 血清流行率。我们在检测的献血中检测到了 3 个 DENV RNA + 样本（n  = 3/8475，0.04%）。其中，两个样本进一步被血清分型为 DENV-1，一个样本被进一步血清分型为 DENV-2。所有 DENV RNA 阳性样本的抗 DENV IgG 均为阴性，表明存在原发性急性感染。此外，其中两个 DENV RNA + 样本也呈 NS1 抗原阳性（抗原血症）。献血人群中抗 DENV IgG 血清阳性率为 50.8% ( n  = 189/372)。我们的结果与献血者中存在登革热病毒原发感染一致，这可能导致感染通过输血传播给受血者。应采取措施排除此类捐赠者以预防 TT-DENV。