Diagnosis of rabies in buffaloes: comparison of clinico-pathological, immunohistochemical and immunofluorescent techniques

Abstract

The present study was envisaged to compare the sensitivity of detection of rabies virus antigen by application of Fluorescent Antibody Technique on fresh impression smear (Direct-FAT) and that on formalin fixed nervous tissue (IndirectFAT), histopathology and immunohistochemistry (IHC) in the species which is highly significant for the economics of the dairy farmer i.e. buffalo. A total of 28 cases of buffaloes suspected for rabies were presented. Out of 28 cases, 18 (64.28%) cases were positive by direct-FAT, indirect-FAT, IHC and 60.71% (17/28) by demonstration of negri bodies and thus, histopathology revealed 94.4% sensitivity in comparison to direct- FAT. While as, indirect-FAT, and IHC revealed 100% sensitivity in comparison to direct-FAT. Percentage of neurons positive for Negri bodies by H and E and IHC were 59.35% and 78.88% and average number of Negri bodies detected per neuron by H & E and IHC were 1.8 and 3.01, respectively. Important clinical signs in rabid animals were anorexia, circling/Head pressing, behavioural change and bellowing. Thus, it is concluded that rabies detection in animals can be accomplished from diagnosis of rabies from fixed brain tissues which offers same sensitivity as detection of rabies in impression smears.