Diagnoses of Bovine Babesiasis by Using Thin Blood Smear from Differentially Hemolysed Blood

The aim of this research was to develop a new method of detection of bovine babesiasis that is more sensitive than thick smear method. Babesiasis is a carrier state of the disease in cattle characterized by low parasitemia in peripheral blood and very difficult to detect. Diagnoses of low level infection of babesiasis is important for transmission and epidemiological studies. Serial dilution of hypotonic saline with an increment of 0.05% (from 0.3% to 0.85%) was used in this study to obtain an optimal concentration of the saline to selectively haemolysed un-infected blood. The optimal concentration is 0.5% based on criteria number of erythrocytes, morphology of erytrocytes and percentage of parasitemia found in a thin smear. Forty-two of 46 (91%) cattle were detected by haemolysed method while only 32 (69%) by thick smear and 21 (45,6%) by thin smear. In no case was haemolysed blood method-negative animal detected by thick or thin smear. Similarly, no negative result by thick smear method was positive with thin smear method. The result shows the superiority of the hemolysed blood in detecting bovine babesiosis.