The spreading of East Coast Fever into Great Bahr- El Ghazal Region, North West of South Sudan

Theileriosis is a fatal tick-borne disease caused by Theileria parva (T.parva) and affecting cattle mainly in East and Central Africa. A cross-sectional survey was conducted during June to November 2015 in 12 localities of Great Bahr- El Ghazal Region, South Sudan to investigate the prevalence of East Coast Fever in indigenous zebu (Nilotic) cattle kept under traditional management system. A total of 600 blood and 105 lymph node smears were collected from cattle. Microscopic examination of Giemsa stained blood smears revealed prevalence of 8.7% for Theileria spp piroplasms. Surprisingly, all the105 lymph node smears were negative for Theileria schizonts. In addition, out of 599 blood samples examined, 464 (77.5%) were positive for Theileria parva DNA using p104 nested polymerase chain reaction (nPCR) with significant differences (P < 0.001) between the localities of the study areas. Out of eight pooled ticks species that were identified (Amblyomma variegatum, Rhipicephalus evertsi evertsi, R. decoloratus, Hyalomma rufipes, R.annulatus, H. truncatum, R. sanguineus group and R. praetextus), one tick species (Amblyomma variegatum) was positive for Theileria parva DNA. The study concluded that T. parva is endemic in the region in spite of the absence of R. appendiculatus. Detection of T. parva DNA in A. variegatum may indicate the role of this tick species in transmission of T. parva among cattle. However, a need for further investigationemploying more samples and using more advanced techniques is highly recommended. Keywords: Epidemiology, East Coast fever; Bahr- El Ghazal; South Sudan.