Detection of cross infections by Leishmania spp. and Trypanosoma spp. in dogs using indirect immunoenzyme assay, indirect fluorescent antibody test and polymerase chain reaction.
ABSTRACT The aim of this study was to detect cross infections by Leishmania spp. and Trypanosoma spp. using enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody test (IFAT) and polymerase chain reaction (PCR). Thus, 408 blood samples were collected from dogs domiciled in Araçatuba Municipality, São Paulo State, Brazil; the dogs were of both sexes, of several breeds and aged 6 months. For Leishmania spp., 14.95 % (61 out of 408) of dogs were reactive using IFAT. Positivity was 20.10 % (82 out of 408) using ELISA and 29.66 % (121 out of 408) using PCR, with significant differences for the sex and age of these animals (p < 0.05). For Trypanosoma spp., antibody occurrence using ELISA was 10.54 % (43 out of 408), while PCR indicated 2.45 % (10 out of 408) positive dogs. Using IFAT, 10.29 % (42 out of 408) of animals were considered positive and only sex showed a significant difference (p < 0.05). In this study, 10.54 % (43 out of 408) of animals were seropositive according to ELISA for Trypanosoma spp., of which 79.07 % (34 out of 43) showed positive results in the molecular diagnosis for Leishmania spp., while of the 10.29 % (42 out of 408) positive dogs according to IFAT, 95.24 % (40 out of 42) had confirmed infection by this parasite. The obtained results demonstrate evidence of cross infections by both protozoa in the animals analysed in this study.
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ABSTRACT: Visceral leishmaniasis in Brazil is caused by Leishmania (Leishmania) chagasi and the dog is its most important reservoir. The clinical features in dogs include loss of weight, lymphadenopathy, renal failure, skin lesions, fever, hypergammaglobulinemia, hepatosplenomegaly, anemia, and, rarely, neurological symptoms. Most infected animals develop active disease, characterized by high anti-leishmania antibody titers and depressed lymphoproliferative ability. Antibody production is not primarily important for protection but might be involved in the pathogenesis of tissue lesions. An ELISA test was used to determine if there is an association between neurological symptoms and the presence of anti-L. chagasi antibodies in cerebrospinal fluid (CSF). Thirty serum and CSF samples from symptomatic mixed breed dogs (three with neurological symptoms) from a region of high incidence of visceral leishmaniasis in Brazil were examined for antibody using total parasite antigen and anti-dog IgG peroxidase conjugate. A high level of L. chagasi antibodies was observed in sera (mean absorbance SD, 1.939 0.405; negative control, N = 20, 0.154 0.074) and CSF (1.571 0.532; negative control, N = 10, 0.0195 0.040) from all animals studied. This observation suggests that L. chagasi can cause breakdown of filtration barriers and the transfer of antibodies and antigens from the blood to the CSF compartment. No correlation was observed between antibody titer in CSF and neurological symptoms.Brazilian Journal of Medical and Biological Research 05/2003; 36(4):485-9. · 1.14 Impact Factor
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ABSTRACT: A comparative study was made of eluates of the blood of dogs experimentally infected with different trypanosomatids. Using antigens prepared from promastigotes of Leishmania mexicana, L. braziliensis and L. chagasi, assessments were made by the indirect immunofluorescence test. The results showed a sensitivity of 87.5% in the diagnosis of canine visceral leishmaniasis, independent of antigen used. Cross-reactions occurred in 75% of cases of cutaneous leishmaniasis and 83.3% of dogs with chagas' disease. An epidemiological survey in an area of leishmaniasis confirmed that immunofluorescence tests on eluates of dogs' blood give cross-reactions between L. braziliensis and L. chagasi. The results suggest that such testing could be useful in public health campaigns but attention is drawn to the fact that the level of positive reactions cannot be used as an indicator of the prevalence of canine kala-azar.Revista da Sociedade Brasileira de Medicina Tropical 01/1991; 24(1):21-5. · 0.93 Impact Factor
- Revista do Instituto de Medicina Tropical de São Paulo 01/1966; 8(5):227-35. · 0.96 Impact Factor