Occurrence of Cross-Reaction Between Canine Visceral Leishmaniasis and Chagas Disease by Enzyme-Linked Immunosorbent Assay (ELISA), Indirect Immunofluorescent Antibody Test (IFAT) and Immunochromatographic Dipstick Test
M.F. Zanette1; V.M.F. Lima1; M.D. Lauenti2 ; J.P. Vides1; D.L. Silva1; C.N.Rossi1; F.A. Ikeda-Garcia1; F.A. Rosa1; L.S.V. Sobrinho1; D.C. Costa1; S.H.V. Perri1; A.A.Camacho3; M. Marcondes1
Visceral leishmaniasis, also known as Kalazar, is an anthropozoonosis with world distribution in tropical and subtropical areas of the world. It is caused by a protozoan placed in the order Kinetoplastida, family Trypanosomatidae and genus Leishmania that infects dogs and a wide variety of vertebrates. Serodiagnosis is the most valuable tool for its diagnosis. However, the specificity of the serological tests may be harmed due to the occurrence of cross-reaction among diseases caused by others Trypanosomatidae, such as Trypanosoma cruzi. Thus, the aim of this work was to determine the occurrence of cross-reaction between Trypanosoma cruzi and Leishmania chagasi antigens, by ELISA, indirect immunofluorescent antibody test (IFAT) and immunochromatographic dipstick test. The ELISA and indirect immunofluorescence assay were performed using L. chagasi promastigote antigen while the immunochromatographic test employed rK39 antigen. The study was carried out with a group of 14 naturally and experimentally T. cruzi infected dogs. Of the 14 sera samples tested for visceral leishmaniasis, nine (64,3%) were positive by ELISA, six (42,9%) were positive by indirect immunofluorescence assay and all of them were found to be negative by immunochromatographic test (Table 1). Based on the results of this study, among the three methods assessed, the immunochromatographic dipstick test using the rK39 antigen was the best option due to the ability to distinguish successfully patients infected by T. cruzi from those infected by L. chagasi.