Flach E J, Ouhelli H
Département de Parasitologie, Institute Agronomique et Vétérinaire Hassan II, Rabat-Instituts, Morocco.
Vet Parasitol. 1992 Sep;44(1-2):51-65. doi: 10.1016/0304-4017(92)90143-w.
A longitudinal study of tropical theileriosis was performed on 12 farms in the Doukkala region of Morocco during 1990. Adult Hyalomma detritum detritum were collected between March and early October and a peak in numbers was observed at the end of June. Nineteen percent (24/127) were infected with Theileria species and, amongst these, over 50% had five or more sporoblasts in their salivary glands (range 1-151). Hyalomma d detritum larvae and nymphs were found on cattle between September and early December with the highest numbers in late October. The prevalence of T. annulata piroplasm carriers at the beginning of the year was 48.5% (47 positive out of 97) and there were 14 new infections during the disease season (March to September) of which five developed into clinical cases. The incidence rates of new infection and clinical disease were 0.156 and 0.056 per animal-season, respectively. Differences were observed between age categories of cattle in both tick and parasite infections. A significantly lower number of adult H.d. detritum were collected from calves than from adult cattle. The prevalences of piroplasm carriers before the disease season were 0%, 36% and 76%, respectively, in (a) calves which had been born since the previous disease season, (b) calves born before then and (c) adults. However, the incidence rates of infection and disease for uninfected animals in the two categories of calves were approximately the same: 0.299 and 0.378 new infections, and 0.085 and 0.126 clinical cases per animal-season for (a) and (b), respectively. The date predicted for the appearance of adult H.d. detritum, based on published tick development times and local temperature records, was within 2 weeks of the study visit when the highest number of adults were collected from cattle. However, the date predicted for the appearance of larvae was 6 weeks earlier than the observed peak populations and may indicate that H.d. detritum delays either egg laying in the summer or larval host searching in the autumn.
1990年，在摩洛哥杜卡拉地区的12个农场对热带泰勒虫病进行了一项纵向研究。在3月至10月初收集成年微小扇头蜱，6月底观察到数量达到峰值。19%（24/127）的蜱感染了泰勒虫属，其中超过50%的蜱唾液腺中有5个或更多的子孢子（范围为1 - 151个）。在9月至12月初在牛身上发现微小扇头蜱的幼虫和若虫，10月底数量最多。年初环形泰勒虫梨形虫携带者的患病率为48.5%（97头中有47头阳性），在疾病季节（3月至9月）有14例新感染，其中5例发展为临床病例。新感染和临床疾病的发病率分别为每动物季节0.156和0.056。在蜱和寄生虫感染方面，观察到不同年龄类别的牛之间存在差异。从小牛身上收集到的成年微小扇头蜱数量明显低于成年牛。在疾病季节之前，梨形虫携带者的患病率在以下三类牛中分别为0%、36%和76%：（a）自上一个疾病季节以来出生的小牛，（b）在此之前出生的小牛，（c）成年牛。然而，两类小牛中未感染动物的感染率和发病率大致相同：（a）和（b）每动物季节的新感染率分别为0.299和0.378，临床病例率分别为0.085和0.126。根据已发表的蜱发育时间和当地温度记录预测的成年微小扇头蜱出现日期，与研究访问中从牛身上收集到最多成年蜱的时间相差在2周内。然而，预测的幼虫出现日期比观察到的种群峰值早6周，这可能表明微小扇头蜱要么在夏季延迟产卵，要么在秋季延迟寻找幼虫宿主。
