BACKGROUND Zika virus (ZIKV) is a mosquito-borne virus that is also transmitted sexually; however, the epidemiological relevance of ZIKV sexual transmission in endemic regions is unclear. METHODS We performed a household-based serosurvey in Northeast Brazil to evaluate the differential exposure to ZIKV and chikungunya virus (CHIKV) among households. Individuals who participated in our previous arboviral disease cohort (indexes) were recontacted and enrolled, and their household members were newly enrolled. RESULTS The relative risk of sexual partners being ZIKV-seropositive when living with a ZIKV-seropositive index participant was significantly higher, whereas this was not observed among nonsexual partners of the index. For CHIKV, both sexual and nonsexual partner household members living with a CHIKV-seropositive index had a significantly higher risk of being seropositive. In the nonindex-based dyadic and generalized linear mixed model analyses, the odds of sexual dyads having a concordant ZIKV plaque reduction neutralization test result was significantly higher. We have also analyzed retrospective clinical data according to the participants' exposure to ZIKV and CHIKV. CONCLUSIONS Our data suggest that ZIKV sexual transmission may be a key factor for the high ZIKV seroprevalence among households in endemic areas and raises important questions about differential disease from the 2 modes of transmission.

中文翻译：

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巴西东北部寨卡病毒的后续家庭血清调查：指标患者的性接触具有最高的血清阳性风险。

背景寨卡病毒 (ZIKV) 是一种蚊媒病毒，也可通过性传播；然而，ZIKV 性传播在流行地区的流行病学相关性尚不清楚。方法 我们在巴西东北部进行了一项以家庭为基础的血清调查，以评估家庭之间对 ZIKV 和基孔肯雅病毒 (CHIKV) 的差异暴露。参与我们以前虫媒病毒疾病队列（指数）的个人被重新联系并登记，他们的家庭成员是新登记的。结果 当与 ZIKV 血清阳性指数参与者一起生活时，性伴侣为 ZIKV 血清阳性的相对风险显着更高，而在该指数的非性伴侣中未观察到这一点。对于 CHIKV，具有 CHIKV 血清阳性指数的性伴侣和非性伴侣家庭成员的血清阳性风险显着更高。在基于非指数的二元和广义线性混合模型分析中，具有一致 ZIKV 斑块减少中和测试结果的性二元的几率显着更高。我们还根据参与者对 ZIKV 和 CHIKV 的暴露情况分析了回顾性临床数据。结论 我们的数据表明，ZIKV 性传播可能是流行地区家庭中 ZIKV 血清阳性率高的一个关键因素，并提出了关于两种传播方式的鉴别疾病的重要问题。具有一致 ZIKV 斑块减少中和测试结果的性二元组的几率显着更高。我们还根据参与者对 ZIKV 和 CHIKV 的暴露情况分析了回顾性临床数据。结论 我们的数据表明，ZIKV 性传播可能是流行地区家庭中 ZIKV 血清阳性率高的一个关键因素，并提出了关于两种传播方式的鉴别疾病的重要问题。具有一致 ZIKV 斑块减少中和测试结果的性二元组的几率显着更高。我们还根据参与者对 ZIKV 和 CHIKV 的暴露情况分析了回顾性临床数据。结论 我们的数据表明，ZIKV 性传播可能是流行地区家庭中 ZIKV 血清阳性率高的一个关键因素，并提出了关于两种传播方式的鉴别疾病的重要问题。