Environmental-medical and sanitary-zoological investigation on the land leech biohazard spreading at the southern area of Boso Peninsula.

1. 通过对陆地水蛭种群的连续定点调查，发现它们的活动期向冬季中期延长，12月和1月就有几只水蛭被捕获，并产卵3个卵团。分析了水蛭发生暴发的原因：(1)镇上鹿的出现和游荡；(2)水蛭天敌的稀少；(3)1984年适宜水蛭繁殖的天气条件。在77种被检测的食肉动物中，有4种昆虫被确定为水蛭的天敌，但由于与水蛭接触的机会较少，对实际消灭水蛭的作用不大。吸血水蛭的症状是局部出血（出血时间延长，失去凝血），持续约1小时，随后瘙痒，偶有硬结，用石膏敷，用1%以上单宁酸棉治疗有效。在吸血的人和哺乳动物血液中产生抗陆水蛭抗体，并随吸血次数的增加而增加。这种抗体减轻了局部出血并杀死了水蛭。这些抗体值甚至在17年前被血蜱的另一个亚种感染的病例中也检测到。事实证明，鹿是陆地水蛭的合适宿主，它们的四肢上携带着几十只水蛭，它们的第三和第四趾之间有一种中空的炎性肿瘤，水蛭就在肿瘤的中空中进入。陆地水蛭的数量是通过抗体的杀伤作用在免疫上加以控制的。一些地面行走的鸟类是水蛭的安全载体，因为它们是水蛭的首选，但很少产生抗水蛭的抗体。烟叶热水萃取物和硫酸烟碱是田间消灭水蛭的有效物质，烟叶盐粉或烟灰和蚊香是杀灭皮肤上水蛭的有效物质，这些物质对水蛭是致命的。少

1. As the result of continuous fixed point investigation on the land leech population, their active period prolonged toward mid winter, and several individuals of the leech were collected even in December and January and they spawned 3 egg masses.2. As the causes of this explosive occurrence of the land leech, (1)appearance and wandering of deers in the town, (2)scarce existence of natural enemies of the land leech, and(3)weather condition in 1984 that was suitable for the leech propagation were listed.3. As the natural enemies of the land leech, 4 species of insect were confirmed among 77 species of carnivorous animals tested, but they are hardly useful to practically exterminate the leech because of less chances to meet with the leeches.4. Symptoms induced by bloodsucking of the leech are local bleeding (caused by prolonged bleeding time and loss of coagulation) lasting for about 1 hour, followed by itching and occasional induration, and the application with plaster and treatment wit … More h 1% tannic acid cotton are effectual.5. Anti-land leech antibody was produced in the blood of bloodsucked humans and mammals and increased with the frequency of bloodsucking. This antibody lightens the local bleeding and kills the leech. These antibody values were detected even in cases affected more than 17 years ago by another subspecies of Haemadipsa.6. It was proven that deers act as if the proper host of the land leech and carry several tens of the leeches on their extremities and that they have a kind of hollowed inflammatory tumors between the 3rd and the 4th toes, within the hollow of the tumors a leech enters.7. The population of the land leech is controlled immmunologically by killing effect of the antibody.8. Some ground walking birds will be safe carrier of the land leech because they are prefered by the leech but hardly produce anti-land leech antibody.9. Hotwater extract of tobacco and nicotin sulfate are effectual for field extermination of the leech and salt powder or ashes of tobacco and mosquito coil are fitted to removal of the leech on the skin, and these substances are lethal to the leech. Less