PCR OUTPERFORMS MICROSCOPY IN DETECTING LOW GRADE HAEMOPROTOZOAN INFECTIONS: A COMPARATIVE STUDY OF BABESIA SPP. AND CYTAUXZOON SPP. IN DOMESTIC AND CAPTIVE WILD FELIDS FROM REWA, INDIA

Abstract

This study investigated the occurrence of Babesia spp. and Cytauxzoon spp. in domestic and captive wild felids in Rewa, Madhya Pradesh, India, and evaluated the haematobiochemical alterations associated with them. Over a period of six months (July–December 2025), blood samples were collected from 50 felids (32 domestic cats, 18 captive wild felids including tigers, leopards, and lions). Samples were analyzed for hemoprtotozoa using Giemsa stained blood smear microscopy and PCR targeting the 18S rRNA gene (for Babesia spp.) and ITS-2 gene (for Cytauxzoon spp.). Haematological and  biochemical  profiling  of  all  the  felids  under  study  was  done. Microscopy detected only one cytauxzoon positive case (2.0%) in a white tiger and no babesia infections in any of the felids. In contrast, PCR revealed a significantly higher detection rate (12.0%; n=6), identifying Babesia spp. in four felids (one wild felid, three domestic cats) and Cytauxzoon spp. in two felids (one white tiger, one domestic cat). PCR demonstrated superior sensitivity (16.67% vs. 100% specificity), with a statistically significant difference for overall detection (p=0.0498), for Cytauxzoon spp. (p=0.557) and for Babesia spp. (p=0.0413). Clinically, babesia- positive domestic cats showed mild haematological changes, while the wild felids remained largely asymptomatic. Cytauxzoon- positive domestic cat and the white tiger exhibited severe anaemia, thrombocytopenia, leukopenia, elevated liver enzymes, and acute renal failure, with the domestic cat succumbing within 48 hours and the tiger after three months despite rigorous treatment. The study concludes that PCR is indispensable for accurate surveillance of haemoprotozoan infections in felids, and that regular surveillance is needed to prevent mortalities in highly endangered species.