Tick-borne diseases in Tajikistan : anaplasmosis, babesiosis and theileriosis

Abstract: Tajikistan is situated in central Asia and is the poorest of 15 former Soviet republics. Sixty percent of the people in the country live below poverty line. Over seventy percent of the households in Tajikistan own cattle, and healthy animals are therefore very important to reduce poverty in the country. Tick-borne diseases (TBDs) directly and indirectly cause a significant reduction in income and hamper the growth of the whole agricultural sector, which is especially serious in livestock dependent systems. Due to difficulties in estimating income losses caused by TBDs these problems are often neglected. The direct effect of tick infestation is reduction of the value of hides because of tick marks. Indirect effects are diseases transmitted by ticks that cause losses in production of milk and meat, and illness and deaths among affected cattle. Anaplasmosis, babesiosis and theileriosis are diseases in cattle transmitted by ticks in large parts of the world, including Central Asia. Few studies have been made on the spread of and damage caused by these diseases in the area. The aim of this study was to investigate occurrence of Anaplasma marginale and Babesia bigemina, which cause anaplasmosis and babesiosis, in dairy cattle in western Tajikistan and to study risk factors relevant for controlling these diseases. Blood samples were collected from 294 cattle at seven governmental units and three private units. The samples were analyzed for presence of antibodies against A. marginale och B. bigemina. Divergence in seroprevalence between groups considering age, breed, governmental/private units, region, number of ticks and pasture/no pasture were also investigated. The overall seroprevalence among the sampled animals was 14% for A. marginale and 18% for B. bigemina. No statistically significant risk factors affecting seroprevalence were identified, but there was a clear numerical difference in seroprevalence between governmental and private units. The seroprevalence was higher among cattle sampled at private units compared to governmental. The cause of this numerical difference is unclear, but could be due to different grazing- and prophylaxis routines at governmental and private units. To appoint the cause of this difference in seroprevalence further studies are needed where possible risk factors are investigated one at a time.