Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Department of Occupational and Environmental Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
BMC Infect Dis. 2019 Apr 24;19(1):338. doi: 10.1186/s12879-019-3946-y.
A severe dengue epidemic occurred in 2015 which resulted in over 22,000 laboratory-confirmed cases. A cross-sectional seroprevalence study was conducted during the ending phase of this epidemic to evaluate the true incidence of dengue virus (DENV) infection and the level of herd immunity.
Adult residents in three administrative districts with high dengue incidence were recruited; workers in two districts with intermediate dengue incidence were also recruited for comparison. DENV-specific IgM and IgG were tested using commercial enzyme-linked immunosorbent assays. DENV RNA was detected using commercial quantitative real-time reverse transcriptase polymerase chain reaction assay. Univariate and multivariate logistic regressions were performed to identify risk factors for recent and past DENV infection.
The overall seroprevalence of anti-DENV IgM and IgG in 1391 participants was 6.8 and 17.4%, respectively. The risk of recent DENV infection increased with age, with the elderly having the highest risk of infection. Living in areas with high incidence of reported dengue cases and having family members being diagnosed with dengue in 2015 were also independent risk factors for recent DENV infection. One sample was found to have asymptomatic viremia with viral load as high as 10 PFU/ml.
Comparing the seroprevalence of anti-DENV IgM with the incidence of reported dengue cases in 2015, we estimated that 1 out of 3.7 dengue infections were reported to the surveillance system; widespread use of rapid diagnostic tests might contribute to this high reporting rate. The results also indicate that the overall herd immunity remains low and the current approved Dengvaxia® is not quite suitable for vaccination in Taiwan.
2015 年发生了一场严重的登革热疫情，导致超过 22000 例实验室确诊病例。在该疫情的末期进行了一项横断面血清流行率研究，以评估登革病毒（DENV）感染的真实发病率和群体免疫力水平。
招募了三个高登革热发病率行政区的成年居民；还招募了两个中登革热发病率行政区的工作人员进行比较。使用商业酶联免疫吸附测定法检测 DENV 特异性 IgM 和 IgG。使用商业定量实时逆转录聚合酶链反应检测 DENV RNA。使用单变量和多变量逻辑回归来确定近期和过去 DENV 感染的危险因素。
在 1391 名参与者中，抗 DENV IgM 和 IgG 的总体血清流行率分别为 6.8%和 17.4%。近期 DENV 感染的风险随年龄增长而增加，老年人感染风险最高。居住在报告登革热病例高发地区和 2015 年有家庭成员被诊断患有登革热的人也是近期 DENV 感染的独立危险因素。有一个样本检测出无症状病毒血症，病毒载量高达 10 PFU/ml。
将抗 DENV IgM 的血清流行率与 2015 年报告的登革热病例发生率进行比较，我们估计 3.7 例登革热感染中有 1 例报告给监测系统；快速诊断检测的广泛使用可能导致这种高报告率。结果还表明，总体群体免疫力仍然较低，目前批准的 Dengvaxia® 不太适合在台湾接种。
