河南省基本消除丝虫病后残存微丝蚴血症者传播作用的研究

目的探讨基本消除丝虫病后残存微丝蚴血症者在不采取任何病原防治措施下的传播作用。方法选择柘城县张庄村为观察点,病原学监测和蚊媒监测采取常规方法,血清学检测采用IFAT、ELISA、Dot-ELISA(查抗体)和ICT(查循环抗原)方法,同时进行居民防蚊情况调查。结果1990年残存微丝蚴血症者39人,人群微丝蚴率2.01%(39/2040),2000年微丝蚴血症者全部转阴,人群微丝蚴率降为0;1990、1991和1994年检测人群丝虫抗体阳性率和抗体阳性者的几何平均滴度均逐渐下降,1998年检测92名12岁以下儿童血中丝虫循环抗原均为阴性;淡色库蚊幼丝虫自然感染率逐年下降,自1997年未再发现感染蚊;1990~2002年当地居民经济收人逐渐增加,普遍采取防蚊措施。结论基本消除丝虫病后,随居民经济和文化水平的逐渐提高,防病意识的不断增强以及防蚊措施的加强,即使未采取任何干预措施,残存微丝蚴血症者也不能引发丝虫病流行,丝虫病传播已经被阻断。

STUDY ON THE ROLE OF THE RESIDUAL MICROFILAREMIA CASES IN THE TRANSMISSION OF FILARIASIS IN CONTROLLED AREAS OF HENAN PROVINCE

Objective To explore the role of residual microfilaremia cases in the transmission of filariasis, in the areas where were not adopted by any control measures after filariasis was basically controlled in Henan Province. Methods Zhangzhuang Village in Zhecheng City was selected as observed site. Parasitological and entomological surveys use traditional methods, serological survey use IFAT, ELISA, Dot-ELISA to detect anti-filarial antibody and ICT to detect circulating filarial antigen, at same time investigation of measures on preventing mosquito was also carried out. Results In 1990, 39 residual microfilaremia cases were found and the microfilaremia rate was 2.01%(39/2040) among population in the observed site; in 2000, all residual microfilaremia cases naturally turned negative and the microfilaremia rate of population dropped to 0. From 1990 to 1994, the positive rate of anti-filarial antibody of people kept with falling down, and in 1998 the positive rate of filarial circulating antigen was 0 in 92 children under 12 years. From 1990 to 1997, the natural infection rate of filarial larvae in C. pipens pallens drops year-by-year and after 1997 the mosquito with filarial larvae was not found again. From 1990 to 2002, the income of local people increased gradually and the measures on preventing mosquito were adopted more and more widely. Conclusion Though any control measure was not taken among the residual microsfilaremia cases, they have lost the transmission potential of filariasis, the transmission of filariasis has been interrupted.