Detection of Theileria and Anaplasma spp. in carrier buffaloes (Bubalus bubalis) by polymerase chain reaction in Tamil Nadu, India

A total of 150 heparinised blood samples and equal number of blood smears were collected from buffaloes in three agro-climatic zones of Tamil Nadu viz., Cauvery delta, North - western and Southern zones to detect Theileria and Anaplasma by blood smear examination and Polymerase Chain Reaction. The blood smear examination revealed that none of animals were found to harbour any haemoprotozoan parasites. Whereas PCR detected Theileria and Anaplasma in 26.9% and 48.0%, and 10% and 15% of the animals, respectively in north- western zone and Cauvery delta, however no animal from south zone was detected positive for any protozoan. Besides, mixed infection of Theileria and Anaplasma was recorded in 8 (5.3%) animals. The analysis of data collected to determine the risk factors associated with occurrence of haemoprotozoan parasites revealed that the pure breed Murrah showed higher percentage of Theileria and Anaplasma positivity (30.7% and 46.1%) than non - descriptive breed (8.7% and 16.0%). The percentage of positivity of haemoprotozoan parasites was found to be higher among animals of 1 year, followed by 2 years and > 4 years of age.