Analysis of methods for the diagnosis of microfilaraemia in buffaloes and cattle

For detecting the microfilariae in blood of buffaloes and cattle, four diagnostic methods were employed. Considering the modified Knott's as standard (100%), the comparative efficacy of distilled water haemolysis method (100%), thick blood smear examination (76.70%) and wet blood film examination (69.90%) were in the decreasing order of merit. For morphological study, Giemsa and JSB staining techniques were employed, out of which JSB was observed to be rapid and cheap technique. Microfilariae detected in all the 103 positive cases were ensheathed, long, slender with blunt anterior and tapering posterior ends. Morphological features like median projecting knob of cephalic end, indistinct small cephalic space, obliquely placed nerve ring, more intermingled nuclei, long caudal sheath space were also observed. Micrometry revealed mean length and width of 249.82±1.61 μm and 8.05±0.10 μm, respectively. The cephalic space, central viscus and caudal sheath space were 6.66±0.34 μm, 20.10±0.71 μm and 24.72±1,63 μm long, respectively. Based on the above morphological characteristics, the microfilariae recovered in the current study were presumed to be Setariacervi.