Low Swee-Ling, Lam Sally, Wong Wing-Yan, Teo Diana, Ng Lee-Ching, Tan Li-Kiang
Am J Trop Med Hyg. 2015 Jul;93(1):40-45. doi: 10.4269/ajtmh.14-0671. Epub 2015 May 26.
Routine national notifications of dengue cases typically do not reflect the true dengue situation due to large proportion of unreported cases. Serosurveys, when conducted periodically, could shed light on the true dengue infections in the population. To determine the magnitude of dengue infections of the adult population in Singapore following the outbreak in 2007, we performed a cross-sectional study on blood donor samples from December 2009 to February 2010. The residual blood of 3,995 donors (aged 16-60 years) was screened for the presence of dengue-specific immunoglobulin G (IgG) and IgM using enzyme-linked immunosorbent assay (ELISA) kits. The age-weighted IgG prevalence of residents was 50.8% (N = 3,627, 95% confidence interval [CI] = 49.4-52.3%). Dengue IgG prevalence increased with age, with the lowest in 16-20 years age group (16.1%) and the highest in 56-60 years age group (86.6%). Plaque reduction neutralization test (PRNT) on samples of young resident adults (aged 16-30 years) revealed lower prevalence of neutralizing antibodies to each serotype, ranging from 5.4% to 20.3% compared with the older age groups. The level of exposure to dengue among the young adults is relatively low despite the endemicity of the disease in Singapore. It partially explains the population's susceptibility to explosive outbreaks and the high incidence rate among young adults.
由于大量病例未报告，全国常规登革热病例通报通常无法反映真实的登革热疫情情况。定期开展的血清学调查能够揭示人群中真实的登革热感染情况。为确定2007年疫情爆发后新加坡成年人群的登革热感染程度，我们于2009年12月至2010年2月对献血者样本进行了一项横断面研究。使用酶联免疫吸附测定（ELISA）试剂盒对3995名年龄在16至60岁之间的献血者的剩余血液进行筛查，以检测登革热特异性免疫球蛋白G（IgG）和免疫球蛋白M（IgM）的存在情况。居民的年龄加权IgG患病率为50.8%（N = 3627，95%置信区间[CI] = 49.4 - 52.3%）。登革热IgG患病率随年龄增长而升高，在16至20岁年龄组中最低（16.1%），在56至60岁年龄组中最高（86.6%）。对年轻成年居民（年龄在16至30岁之间）的样本进行的蚀斑减少中和试验（PRNT）显示，与年龄较大的组相比，针对每种血清型的中和抗体患病率较低，范围为5.4%至20.3%。尽管登革热在新加坡呈地方性流行，但年轻成年人中的登革热暴露水平相对较低。这部分解释了该人群对爆发性疫情的易感性以及年轻人中的高发病率。
