Epidemiology of ticks and tick-borne diseases in Ethiopia: Future research needs and priorities.

Livestock and livestock products play an important role in the socio-economic development of Ethiopia. There is a growing demand for meat, milk and eggs to improve the nutritional status of the population. Hides and skins are important components of the agricultural sector in generating foreign export earnings. Draft animals provide power for cultivation of many peasant agricultural holdings. Moreover, livestock help as a source of security and supplementary cash income for rural agricultural households. Improved dairy animals are increasing in numbers and there are now estimated to be 100,000 head of Bos taurus/B. indicus crosses which are the basis of the attempts by the government to strengthen dairying in both the commercial and smallholder sectors. All these cattle are at risk from the effects of ticks and tick-borne diseases (TBD). Anaplasmosis, babesiosis, cowdriosis and theileriosis (Theileria mutans), together with a range of vector tick species, have been demonstrated to be important, and streptothricosis (Dermatophilus congolensis infection) is becoming more important. Although East Coast fever (T. parva infection) and its vector Rhipicephalus appendiculatus have not been found, the relatively uncontrolled passage of livestock from the southern Sudan ensures a considerable risk. (Norval et al 1991). Losses from tick damage to hides and skins were claimed in 1979 to be in the region of one million Ethiopian Birr (US$ 500,000) per annum (Radley 1980), but are likely to be much higher. An estimate of the yearly cost of acaricides in 1989 was 3 million Birr (US$ 1.5 million) (Newson 1991). When other losses such as deaths, reduced growth rate and reduced milk production are added, economic losses due to ticks and tick-borne diseases are highly significant. Ticks are controlled mainly by the application of acaricides. A national policy on ticks and tick-borne diseases control was recently drafted and submitted to the government for approval. The objective of this paper is to review the available information, including that recently collected, on the occurrence of ticks, tick-borne diseases and the control strategies practised in Ethiopia.