Trans-sialidase neutralizing antibodies detection in Trypanosoma cruzi infected domestic reservoirs.

SARTOR P; CARDINAL MV; OROZCO MM; GÜRTLER RE; LEGUIZAMÓN MS

CLINICAL AND VACCINE IMMUNOLOGY

AMER SOC MICROBIOLOGY

Año: 2011 vol. 18 p. 984 - 989

1556-6811

The detection of Trypanosoma cruzi infection in domestic dogs and cats is relevant to evaluate human transmission risks and the effectiveness of the insecticide spraying campaigns. However, conventional serology (CS) presents cross-reactivity in serafrom infections with Leishmania spp. parasites. Here we employed the trans-sialidase inhibition assay (TIA) for the diagnosis of T. cruzi infection in 199 dog and 57 cat serum samples from endemic areas. TIA is based on the antibody neutralization of a recombinant trans-sialidase, an enzyme not detected in the co-endemic Leishmania spp or T. rangeli parasites. T. cruzi infection was also evaluated by indirect immunofluorescence, indirect hemagglutination, enzyme-linked immunosorbent assay, immunochromatographic dipstick test and xenodiagnosis. Sera from 30 dogs and 15 cats from non-endemic areas and 5 dogs with visceral leishmaniasis were non-reactive by TIA. In dog and cat serum samples, co-positivity between TIA and CS was 91% and 95% whereas co-negativity was 98% and 97%, respectively. Xenodiagnosis- positive dogs and cats serum samples were also reactive by TIA (co-positivity 97% and 83%respectively). TIA was reactive in samples (2 dogs, 1 cat) CS-negative and was able to resolve as negative. CS-inconclusive results in two cats serum samples. Our study first describes the development of trans-sialidase neutralizing antibodies in naturally infected dogs and cats. High co-negativity with CS, the absence of trans-sialidase neutralization in dog sera from non-endemic areas and from dogs with visceral leishmaniasis supports TIA specificity. TIA assay may be a useful epidemiological tool for T. cruzi detection in the main domestic reservoir.