Molecular detection of Babesia bigemina and Babesia bovis in carrier cattle by duplex polymerase chain reaction (PCR)

Babesiosis is a highly important disease in the world, caused by the intraerythrocytic protozoan parasites of the genus Babesia. A wide range of domestic and wild animals and occasionally man are affected by this disease, which is transmitted by ticks and has a worldwide epidemiological distribution. While the major economic impact of babesiosis is on the cattle industry, infections also occurs in other domestic animals, including horses, sheep, goats, pigs and dogs. Study targeted the carrier cattle infected with Babesia bigemina and Babesia bovis, as they are difficult to detect because of the low numbers of parasites that occur in peripheral blood. However, diagnosis of low-level infections with the parasite is important for studying the transmission and standardizing epidemiological studies. Using the Polymerase Chain Reaction (PCR) to amplify a portion of the gene from the parasite, and tested the ability of this method to detect carrier cattle. A study was conducted to detect the Babesia in blood samples through PCR described which could differentiate Babesia bigemina and Babesia bovis by using specific primer in carrier cattle. Blood samples of 100 cattle were randomly analyzed with PCR assay 29 (29.0%) out of 100 blood samples were positive for babesiosis in which 18% were positive for Babesia bigemina and 11% were positive for Babesia bovis, while the Light Microscopy detected only 18 (18%) out of the same samples. The samples found positive by LM were reconfirmed during the PCR assay but no sample was found to be having both Babesia bigemina and Babesia bovis infections simultaneously. Thus it is concluded that PCR is a reliable molecular diagnostic technique to detect low level of infections in carrier animals in a population and thus could be used as an effective screening tool for the control and eradication of disease.