感染登革病毒后抗体产生规律及应用于暴发疫情的血清学诊断

目的了解感染登革病毒后特异性抗体产生规律,指导基层实验室应用血清抗体检测方法对暴发疫情的早期病例作出正确诊断,为控制暴发提供实验室依据。方法采集福建省1次暴发登革热疫情中的发热病人和密切接触者血清标本441份,以及恢复期血清22份,用捕获法ELISA检测登革IgG和IgM抗体,并结合病例的流行病学资料进行分析。结果根据本研究规定的病例判定标准,441例中登革热感染者为228例。其中,IgM抗体检出226例,IgG抗体检出119例。226例IgM抗体阳性标本中,IgG抗体同时阳性的为118份;119例IgG阳性标本中,IgM抗体阴性1例;两者均阴性的标本中用RT-PCR方法检测出1例。22份恢复期血清两类抗体检测均为阳性。绝大部分病例集中在10～70岁,病例的职业分布较广,男女比例为1∶1.53。结论登革病毒感染后特异性IgM抗体在发病早期即可检出,并可维持至少一个半月,但个别病例发病早期IgM可能为阴性;IgG抗体随病程的延长,其检出率逐步增高,至发病后50 d,其检出率可达95%左右。本研究结果抗体产生规律同以往研究结果一致,可为基层实验室开展登革热血清学检测和病例诊断提供参考。

Rule of antibody production in dengue virus infection and its application in the laboratory of dengue fever outbreak

To ascertain the rule of specific antibody production in dengue virus infection so as to making the early diagnosis of dengue fever cases in the outbreak of dengue fever by means of laboratory methods, serum samples from 441 patients or the close contacts in a dengue fever outbreak of Fujian province and 22 convalescent serum samples were collected to detect the production of specific IgM and IgG antibodies by using the captures ELISA assay. Combined with the data from field case survey, the results were analyzed. According to the case definition set in this study,228 cases were confirmed. Among these cases,226 cases were proved to be IgM-positive,while 119 cases to be IgG positive. Of the IgM-positive cases, 118 cases were showed to be IgG-positive simultaneously. In 119 IgG-positive samples, only one sample was showed to be IgM-negative. For the samples which were both negative for IgM and IgG, RT-PCR assay was used to detect the specific nucleic acid of which one sample was found to be positive in this assay. Twenty two convalescent serum samples were all positive to these two types of antibodies. Most cases of patients aged from 10 to 70. Among the confirmed cases, their occupations were diverse and the gender ratio was 1 ： 1.53. After dengue virus infection the viral IgM antibody was detectable from onset of disease to at least one and half month later. The IgG antibody prevalence was low at early stage of disease, but it escalated late on and its detection rate raise up to 95% after 50 days later. Only few individuals developed IgM antibodies to the detectable level at early stage of disease. It is evident that the rule of antibody production in dengue virus infection is consistent to the previous reports and can be used to instruct the antibody test-based laboratory diagnosis of dengue fever in the disease outbreak.