三峡库区当地人群日本血吸虫IgG抗体特征研究

Baseline Study on the Characteristics of Antibody Level Against Schistosoma japonicum in the Three Gorges Reservoir Areas

目的掌握三峡库区当地人群抗日本血吸虫特异性抗体本底分布特征,探讨库区人群抗血吸虫特异性抗体的影响因素。方法选择三峡库区中段万州区的当地居民为研究对象,用统一的调查表进行个案调查,采集2～3ml静脉血,检测人群血吸虫特异性抗体(IgG)。结果调查633人,人群血吸虫抗体水平几何平均数(OD均值)为0.0145,抗体阳性率为3.32%(21/633);男性OD均值为0.0140,女性为0.0150,二者间差异无统计学意义(t=0.543,P=0.587)。男性阳性率为3.103%,女性3.499%,差异无统计学意义(!2=0.076,P=0.782)。70岁以上组OD均值最高(0.0252),10～19岁组最低(0.0058),年龄组与OD均值呈明显的相关(r=0.224,P=0.000);学生OD均值显著低于家庭妇女(P=0.0000)、农民(P=0.0000)和工人(P=0.0000);学历与OD均值存在明显的相关(r=0.199,P=0.000),学历越高,OD值呈下降趋势;抗体水平全频率分布曲线均呈"L"型,OD均值小于0.03者占63.8%,小于0.07者分别为91.3%。多因素逐步回归分析表明,职业(t=2.3221,P=0.0211)和人均年收入(t=-2.2724,P=0.0240)与抗体水平显著相关。结论三峡库区人群日本血吸虫特异性抗体水平低,呈非流行区人群分布特征;三峡库区存在潜在的影响人群血吸虫特异性抗体水平的因素;建议进一步健全三峡库区血吸虫病监测体系,针对重点人群,开展健康教育,预防和控制血吸虫病在三峡库区发生和流行。

Objective To analyze the baseline study on the characteristic of anti-schistosome antibody and the risk factors of infection with S. japonicum in local inhabitants in the Three Gorges Reservoir areas （TGR）. Methods The local inhabitants in Wanzhou district of the middle part of TGR were investigated. Each case was interviewed and 2-3 ml of blood sample was collected for the detection of anti-schistosome antibody level by ELISA. Results 633 people were investigated. The Geometric Mean of OD value （OD-value） of anti-schistosome antibody level was 0.0145 and the positive rate was 3.32%（21/633）. The OD-value of male was 0.014 and the positive rate was 3.103%. The OD-value of female was 0.015 and the positive rate was 3.499%. The OD-value （t=0.543, P=0.587） and positive rate （X2=0.076, P=0.782） had no significant difference between male and female. The highest OD-value was in the age group of over 70 years （0.0252） and the lowest was in the age group 10-19 years （0.0058）. The OD value was correlated with age （r= 0.224, P=0.000）. The OD-value of students was lower than that of housewives （P=0.0000）, the farmer （P=0.0000） and the worker （P=0.0000）. There was significant difference in OD-value among people with different education background （r=0.199, P=0.000）. There was a tendency on OD-value declining with education level. The curve of full frequency distribution of antibody level was an ＂L＂ figure. The proportion of OD value under 0.03 was 63.8%. The proportion under 0.07 was 91.3%. The results from the multivariate stepwise regression analysis indicated that there was significant difference with antibody level between different occupations （t=2.322, P=0.021 ） and different annual income （t=-2.272, P=0.024）. Conclusion The antibody level against S. japonicum infection in the TGR was low which is same as the level of population in non-endemic region. The potential social-behavior factors may affect schistosomiasis transmission. So the monitoring system of schistosomiasis should be improved and health education should be carried out in key populations to prevent infection from S. japonicum in the TGR.