Zika virus (ZIKV) is a mosquito-borne flavivirus associated with a febrile illness as well as severe complications, including microcephaly and Guillain-Barré Syndrome. Antibody cross-reactivity between flaviviruses has been documented, and in regions where ZIKV is circulating, dengue virus (DENV) is also endemic, leaving the potential that previous exposure to DENV could alter clinical features of ZIKV infection. To investigate this, we performed a retrospective case-control study in which we compared Canadian travellers who had been infected with ZIKV and had serological findings indicating previous DENV or other flavivirus exposure (n = 16) to those without any previous exposure (n = 44). Patient samples were collected between February 2016 and September 2017 and submitted to Public Health Ontario for testing. ZIKV infection was determined using real-time RT-PCR and antibodies against DENV were identified by the plaque-reduction neutralization test. The mean time from symptom onset to sample collection was 5 days for both groups; the magnitude of viremia was not statistically different (Ct values: 35.6 vs. 34.9, p-value = 0.2). Clinical scores were also similar. Our findings indicate that previous DENV or other flavivirus exposure did not result in greater viremia or a higher illness score.

中文翻译：

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在被寨卡病毒感染的一小群加拿大旅行者中，黄病毒抗体的存在并不会导致更多的症状。

寨卡病毒（ZIKV）是一种由蚊子传播的黄病毒，与高热病以及严重的并发症（包括小头畸形和格林-巴利综合征）相关。黄病毒之间的抗体交叉反应性已有文献记载，在ZIKV流行的地区，登革热病毒（DENV）也是地方性流行，因此以前接触DENV可能会改变ZIKV感染的临床特征。为了对此进行调查，我们进行了一项回顾性病例对照研究，在该研究中，我们比较了曾感染ZIKV且血清学发现表明曾接触过DENV或其他黄病毒（n = 16）的加拿大旅行者与未曾接触过nav（44）的加拿大旅行者）。在2016年2月至2017年9月之间收集了患者样本，并提交给安大略省公共卫生进行测试。使用实时RT-PCR确定ZIKV感染，并通过噬斑减少中和试验鉴定抗DENV的抗体。两组从症状发作到样本采集的平均时间为5天；病毒血症的程度没有统计学差异（Ct值：35.6 vs. 34.9，p值= 0.2）。临床分数也相似。我们的发现表明，以前接触DENV或其他黄病毒没有导致更高的病毒血症或更高的疾病评分。