Comparative haemato-biochemical alteration in theileriosis and babesiosis detected by duplex PCR in cattle

Abstract

Blood samples from suspected crossbred cows (327) were examined microscopically as well as confirmed by in-house standardized duplex PCR assay. Out of 327 samples, 107 (32.72%) and 17 (5.19%) samples were positive for T. annulata and B. bigemina respectively by microscopy. When the samples were screened by duplex PCR, 130 (39.75%) and 27 (8.25%) animals had single infection with T. annulata (Group I) and B. bigemina (Group II), respectively. Duplex PCR was able to detect 11% of mixed infections (Group III) compared to 2.75% by microscopy. Haemato-biochemical profile of infected animals (30 for each group) were studied and compared with each other and normal healthy group (Group IV, n=10). The infected group showed significantly decreased levels of TEC, Hb and PCV, red blood cell indices than healthy control animals indicating microcytic hypochromic anaemia. Marked thrombocytopenia was also observed in affected animals. Serum biochemistry of infected cows revealed significantly higher values of AST and low levels of blood glucose, calcium, total protein, albumin as compared to healthy animals. Group I and Group II were further sub-divided into three sub-groups based on severity of infection as latent, subclinical and clinical. No significant difference among biochemical parameters was observed between subgroups of diseased animals but there was significant decline in hematological parameters, viz. haemaoglobin, PCV and TEC. Haemato-biochemical changes were more severe in B. bigemina infected group in contrast to other groups and anaemia is becoming more severe as the disease progress due to extensive intravascular haemolysis.