Abstract: Objective To investigate the seroprevalence of immunoglobulin G (IgG) antibodies in dengue cases nine years after being infected with dengue virus and associated factors, and to provide a scientific basis for dengue prevention and control. Methods A seroprevalence survey was conducted on dengue cases from a dengue outbreak (dengue virus-3) in Yiwu, Zhejiang province, China, 2009. Serum samples were collected from them from May to August, 2018 for dengue virus IgG antibody detection by ELISA. The distribution of dengue virus IgG antibodies in the serum samples was calculated, and associated factors for positive dengue virus IgG antibodies were analyzed. Results A total of 126 serum samples from dengue cases were collected and the mean seroprevalence of dengue virus IgG antibodies was 79.37% (100/126). The seroprevalence of males and females was 75.00% (30/40) and 81.40% (70/86), respectively, showing no significant difference (χ²=0.682, P=0.409). The seroprevalence in the groups aged 1-, 21-, 41-, and ≥ 61 years were 100%, 94.12%, 85.42%, and 67.86%, respectively; there was a significant difference in the seroprevalence of dengue virus IgG antibodies between the four groups (χ²=9.161, P=0.027). The seroprevalence of dengue virus IgG antibodies in apparent infection cases was significantly higher than that in inapparent infection cases (89.11% vs 40.00%, χ²=29.511, P=0.000). Conclusion Dengue virus IgG antibodies are detectable in dengue cases nine years after infection. The seroprevalence of dengue virus IgG antibodies in apparent cases is significantly higher than that in inapparent cases.

Key words: Dengue, Seroprevalence, Antibody

摘要： 目的 了解登革热病例感染登革热病毒（DENV）9年后IgG抗体阳性情况及影响因素，为登革热预防控制提供科学依据。方法 以2009年浙江省义乌市一起登革热（DENV-3）暴发疫情中的感染者为调查对象，于2018年5－8月采集登革热既往感染者血清，采用ELISA法检测DENV IgG抗体，计算样本中DENV IgG抗体分布情况，并分析IgG抗体阳性的相关因素。结果 共采集登革热既往感染者血清标本126份，DENV IgG抗体阳性率平均为79.37%（100/126）；男性和女性感染者中DENV IgG抗体阳性率分别为75.00%（30/40）和81.40%（70/86），差异无统计学意义（χ²=0.682，P=0.409）；1～、21～、41～和≥61岁年龄组血清登革热IgG抗体阳性率分别为100%、94.12%、85.42%和67.86%，差异有统计学意义（χ²=9.161，P=0.027）；病例和隐性感染者DENV IgG抗体阳性率分别为89.11%和40.00%，差异有统计学意义（χ²=29.511，P=0.000）。结论 DENV感染9年后感染者体内DENV IgG抗体仍广泛存在，且病例的阳性率明显高于隐性感染者。

关键词: 登革热, 血清阳性率, 抗体