张家川县绵羊血液原虫病的调查与防治

对甘肃省张家川县绵羊蜱媒血液原虫病进行了流行病学调查。结果发现 ,绵羊体表寄生蜱类 5种 ,即青海血蜱 (Haemaphysalisqinghaiensis)、长角血蜱 (H .longicornis)、革蜱 (Dermacentorspp .)、草原革蜱 (D .nuttalli)和微小牛蜱 (Boophilusmicroplus) ,其中青海血蜱为传播媒介优势种。绵羊泰勒虫 (Theileriaovis)感染率为 6 2 .2 % ,无形体 (Anaplasmaovis)感染率为 16 .7% ,且有双重感染的病例。体表喷洒药物灭蜱试验表明 ,5 0mg/L倍特对蜱类的半数致死时间 (LT50 )为 4 .91h ,用药后 3d体表残留活蜱数为 3.4± 2 .2只 ,14d后再次染蜱数为 4 9.7± 12 .0只 ,羊只血液原虫病感染率由38.1%降至 8.8% (P <0 .0 1) ,红细胞染虫率由 11.6 %± 6 .9%降至 5 .4 %± 2 .1% (P >0 .0 1)。

Investigation and control of blood protozoonoses in sheep

An epidemiological investigation of blood protozoonoses in sheep was carried out in (Zhangjia-) chuan County of Gansu Province. The results were as follows. There were five species of ticks parasitizing in surfaces of sheep bodies in the county,i.e.Haemaphysalis qinghaiensis, H.longicornis,Dermacentor spp.,D.nuttalli and Boophilus microplus. H.qinghaiensis was main tick vector. Infection rates of Theileria ovis and Anaplasma ovis were 62.2% and 16.7% respectively, besides there were some double infection cases of T.ovis with A.ovis. The test of killing ticks by sprinkling the Butox solution on sheep body surfaces showed that LT (50) of 50 mg/L Butox was 4.91 h. The averages of living tick quantities in the sheep body surfaces were 3.4 and 49.7 ticks per sheep on day 3 and 14 after the Butox was administrated to the sheep, respectively. The infection rate of blood protozoonoses in the sheep decreased significantly from (38.1%) on day 3 post-administration to 8.8% on day 14 post-administration (P<0.01), and correspondingly the infection rate in erythrocytes of the sheep decreased significantly from 11.6% to 5.4%(P>(0.01).)