陕西省姜片吸虫病疫源地生物生长区的研究

本文报告陕西省姜片吸虫病疫源地生物生长区的研究。首先叙述和疫源地范围有关的宿主动物、中间宿主扁卷螺和病原体姜片吸虫的分布情况。然后对疫源地范围内姜片吸虫病流行过程的特点进行了分析,追索到生物生长区的自然条件和社会条件上去。最后确定了陕西省姜片吸中病疫源地的界线。和其他疫病的疫源地一样,研究这一疫源地的范围也取决于地理屏障和疫病流行过程的特点两方面。汉中地区的地形、水文、温度和湿度决定了扁卷螺在该地区可以越冬,因而可以形成攀生地多决定了扁卷螺在该地区的季节动态和猪姜片吸虫病的季节动态,亦即流行过程的季节性特点;包括姜片吸虫虫卵从四月份开始发育,五月份起开始有毛勤,在水内感染扁卷螺,六月.份起扁卷螺内开始发现自然感染,七月至九月份水草上囊勤集结最多,八月至十月份是一猪姜片吸虫严重感染时期。安康专区由于社会因素无姜片吸虫病的存在。陕西省姜片吸虫病疫源地的范围相当于陕西省省级自然区划的陕南秦岭山地地区,落歼阔叶与常绿阔叶混交林黄褐土和棕褐土地带IA:南秦岭中山省的汉中专区部分。疫源地的界线如下: (1)北部界线,佛坪、留坝一线以秦岭高山区为地理屏障.(2)南部界线:镇巴、宁强一线,以甲山山脉为地理屏障。 (3)东部界线:相当于安康专区宁陕、石泉、紫阳各县的西部县界。 (4)西部界线:暂定以陕西东部和甘肃省接界处为界线,等待今后甘肃陇南姜片吸虫病的调查工作资料来加以证实或修正.

STUDIES ON THE BIOTOPE OF THE SHANSI FASCIOLOPSIASIS NIDUS

The paper presents the results of studies on the biotope of the Shansi Fasciolopsiasis nidus. The geographical distribu- tion of the host animals, the vector animals-the Planorbids and the trematodes were reviewed, as these are related to the scope of the nidus. The peculiarities of the course of infection were then analyzed with a discussion on both the natural and the social conditions of the biotope. The boundaries of the Shansi Fasciolopsiasis nidusm were finally ascertained. The scope of the nidus, just like that of any other nidi, depends on the geographical relieves and the peculiarities of the course of infection. The topography, hydrology, temperature and humidity of the Hangchung district-has made the following facts possibie: 1) The Planorbids at the diatrict can survive the winter season and hence there are abundant breeding places of the Planorbid snails at the district. 2) There are prevailing at that district certain seasonal dynamic patterns not only of the Planorbid snails but also of the Fasciopsis flukes of swine. The seasonal peculiarities of the course of iofection include that the eggs of Fasciolopsis buski begin to develop in April, that they are found with miracidia which infect Planorbid snails in water at the beginnig of May, that the planorbid snails are found to be attached with metacercariae mostly from July to September, and finally that the pigs are most seriously infected with Fasciolopsis buski in August to October. Because of social reasons, the An-Kang district, a district neighbor to the Hangchung district, is free from Fasciolopsis buski. The scope of the Shansi Fasciolopsiasis nidus corresponds to the Hangchung district of "the Southern Shansi Medium-Mountain Natural Province" which may be found on the map of the Shansi natural regionalization. The boundaries of the nidus are: (1) The northern boundary: A line drawn from Fu-Ping to Liu-Pa, with Ching-Ling High Mountain Area as the geographical relief. (2) The southern boundary: A line drawn from Ching-Pa to Ning-Chang, with Pa-Shan mountain chain as the geographical relief. (3) The eastern boundary: Corresponds to a line drawn from the western boundaries of Ning-Shang, Se-Ching and Zi-Yang, all of An-Kang district. (4) The western boundary: For the time being, it is supposed to be corresponding to the western boundarv of the Hangchung district. It should be confirmed or revised after a survey on Fasciolopsis buski at the southern part of the Kansu province.