湖北省水牛巴贝斯虫病调查研究 Ⅴ.镰形扇头蜱经卵传递牛巴贝斯虫的证实

AN INVESTIGATION OF BABESIOSIS IN BUFFALOES IN HUBEI PROVINCE 5. THE EXPERIMENTAL DEMONSTRATION OF THE TRANSOVARIAN TRANSMISSION OF BABESIA BOVIS By RH1PICE- PHALUS HAEMAPHYSALOIDES HAEMAPHYSALOIDES

1986年从病牛身上摘下饱血雌蜱,经实验室饲养,孵化为第二代成蜱,人工越冬。于1987年将上述蜱100只接种于已去脾23天的一岁龄健康水牛,以后每天从该牛身上取蜱查其唾液腺。结果在吸血期间,始终查到梨形虫体,其平均大小为1.3×0.68微米。接种后第4天,牛血中开始出现巴贝斯虫,至第19天,红细胞感染率高达9.6％,单梨形虫体大小为0.84～2.64×0.42～1.22微米,双梨形虫体大小为0.64～1.64×0.37～0.97微米,以后逐渐下阵。该牛出现体温升高)41.6℃)、严重贫血(血红蛋白量2克,红细胞压积14％,红细胞总数177万/毫米~3)、黄疸及精神萎顿等症状。上述结果表明,该牛感染了巴贝斯虫病,由此证实镰形扇头蜱是经卵传递巴贝斯虫,其感染阶段是成蜱。

The engorged female ticks of Rhi. haemaphysaloides haemaphysaloides were collected from a buffalo, affected with babesiosis, in April, 1986. A number of adult ticks of second generation were harvested in laboratory after 3-4 months.These ticks survived over winter in a cave in the field from Nov., 1986 to Apr., 1987. 100 survived ticks ( both males and females)were placed on to two ears of a one year old healthy buffalo, splenectomized 23 days earlier, for infection on April 21 .1987. Then ticks on the buffalo were picked up every day. The salivary glands of these ticks were smeared and stained with Giemsa's stain for exa mining pyriform body of B. bovis. The pyriform body in salivary glands and B. bovis in peripheral blood were found on day 2 and 4 post-infection respectively. The infection rate of erythrocytes reached peak (9.6%) on day 19 pastinfecfion and then declined. The buffalo showed high body temperture ( up to 41.6 C ) , depression, anemia ( HG 2g, PCV 14%, RBC 177,000/mm3) and icterus. These results showed that the buffalo had infected with babesiosis. It is proved that Rhipicephalus haemaphysaloides haemaphysaloides transmits B. bovis to buffalo by tran-sovary and its infection stage is adult tick.