Comparative evaluation of flotation techniques for the detection of soil borne parasites

Efficacy of the three conventional flotation techniques in recovering the parasitic forms from soil samples was compared after screening both naturally contaminated and experimentally seeded soil samples. Out of 200 soil samples screened from different locations of Rayalaseema region of Andhra Pradesh, parasitic stages were isolated in 62 (31.0 %), 32 (16.0 %) and 16 (8.0 %) samples by O'Lorcain (J Helminthol, 68:237-241,1994), Kazakos (Am J Vet Res 44:896-900, 1983) and Santarém et al. (Rev Inst Med trop Sao Paulo 51(3):163-167, 2009) methods, respectively. One hundred and forty-four soil samples were seeded with two different concentrations (100/200) of the eggs of Toxocara spp., Ascaris spp. and Ancylostoma spp. and oocysts of Eimeria spp. and were processed by these techniques. Irrespective of parasitic species or concentration, the mean recovery rate of parasitic stages obtained was above 50 ± 4.32, above 33.67 ± 5.084 and below 22.33 ± 2.37 percent by O'Lorcain (1994), Kazakos (1983) and Santarém et al. (2009) methods, respectively. O'Lorcain (1994) method was found better than the other methods for the isolation of soil borne parasitic stages but none of these methods were found to be cent per cent sensitive.