登革热疫点22年后的血清流行病学调查

目的了解曾发生登革热流行的旧疫区健康人群抗登革病毒的抗体水平及分布。方法在1986年曾爆发Ⅱ型登革热疫情的黄埔区鱼珠街一带，对2周内无临床症状的健康人群横断面采样，收集血清，ELISA法检测血清中抗登革病毒IgG抗体，并和非疫点健康人群抗登革病毒IgG抗体阳性率进行比较。RT—PCR法检测抗体阳性者血清中登革病毒。结果登革热疫点健康人群抗登革病毒IgG抗体阳性率为23.3％，非疫点健康人群抗登革病毒IgG抗体阳性率为3．8％，两者差异有统计学意义（P〈0．01）；登革热疫点人群抗体阳性率与年龄成正相关，0～20、21～30、31—40、41～50、51—60、61～70和70岁以上各年龄组的抗体阳性率分别为3．8％、5．8％、9．1％、26．5％、27．7％、32．5％和35．1％。30岁以下年龄组与31～40岁年龄组、31～d0岁年龄组与41～60岁年龄组、41-60岁年龄组与61岁年龄组间的抗登革病毒IgG抗体阳性率差异分别具有统计学意义（P〈0．05）。登革热疫点和非疫点15岁以下中小学生滤纸血样标本中均未检测到抗登革病毒IgG抗体。RT—PCR法未检测到抗体阳性者血清中有登革病毒。结论登革热疫点人群抗登革病毒IgG阳性率明显高于非疫点人群，疫点人群抗体阳性率随年龄增长而上升，提示登革热疫点在登革热疫情后，登革病毒可能在蚊媒体内存在低密度的循环。

Seroepidemiological Investigation of Dengue Fever in Guangzhou

Objective To study the level of anti-dengue virus antibody among residents living in the area that had the previous history of dengue fever epidemic.Methods Serum samples were collected from the asymptomatic residents living at Yuzhu street where dengue fever outbreak was recorded in 1986. Control serum samples were collected from the healthy subjects living in other areas of Huangpu that had no previous record of dengue fever outbreak. Anti-dengue IgG in serum sample was measured by ELISA method. Viral RNA was detected by RT-PCR. Results In contrast with the normal control subjects （3.8%）,23.3% of the subjects living at Yuzhu street was seropositive for dengue virus（P〈0.01 ）. The percentage of seropositive individual was correlated with the increase in the age group age 0 to 20 （3.8%）, 21 to 30 （5.8%）, 31 to 40 （9.1%）, 41 to 50 （26.5%）, 51 to 60（27.7%）, 61 to 70（32.5%）and〉70 （35.1%）]. Anti-dengue virus IgG was not detected in all study and control subjects with the age below 15. Conclusion Residents, especially the elderly, living at Yuzhu street had a significantly higher level of anti-dengue virus IgG antibody. This area may still be the endemic area of dengue fever.