Infectivity of Theileria annulata in Hyalomma ticks of Eastern Terai districts, Nepal

The study was conducted to assess the prevalence of Theileria infection in Hyalomma tick vectors collected from cattle host to record the natural infection level of theilerial parasite in the field condition. A total of 174 male and 298 female of Hyalomma marginatum issaci ticks were collected from three districts Sunsari, Morang and Jhapa of Eastern Terai of Nepal during 2004-2005. These Hyalomma ticks were dissected and their salivary glands were stained with Methyl Green Pyronin (MGP) stain. 472 Hyalomma ticks were screened and 114 (24.15%) were found positive for Theileria. The percent of Theileria positive ticks were 8.62, 27.35 and 20.63 from Sunsari, Morang and Jhapa respectively. The prevalence, abundance and intensity of Theileria annulata infection were higher in female Hyalomma ticks (27.18%, 6.61 and 24.31 respectively) than male Hyalomma ticks (18.97%, 3.60 and 19.00 respectively).