Clinical, hematobiochemical and phylogenetic studies of bubaline malaria in Indian water buffaloes (Bubalus bubalis)

The present study was conducted to investigate the clinical profile, hematobiochemical alterations, and confirmation of Plasmodium bubalis infection by PCR and sequence analysis, as well as to detect Plasmodium bubalis and human Plasmodium species using a lateral flow assay targeting the Plasmodium lactate dehydrogenase (pLDH) antigen in domestic Indian water buffaloes (Bubalus bubalis). Out of 56 suspected cases, five (8.93%) buffaloes were found positive for P. bubalis infection by PCR, while blood smear examination could detect only three (5.36%) buffaloes positive for P. bubalis infection. Moreover, the human rapid diagnostic test (RDT) targeting the pLDH antigen showed negative results for both P. bubalis and human Plasmodium species. The infected buffaloes showed clinical signs such as fever, tachycardia, tachypnoea and icteric or pale conjunctival mucous membranes. The important hematobiochemical changes observed in infected buffaloes includes marked anaemia, thrombocytopenia, hyperbilirubinemia and hypoalbuminemia. Sequence and evolutionary phylogenetic analyses revealed, for the first time, the prevalence of Plasmodium bubalis Type I infection in domestic Indian water buffaloes. The characteristic clinical signs, haemato-biochemical alterations, microscopic and molecular findings will be useful for early diagnosis and therapeutic management of bubaline malaria.