Comparison of serological assays for the diagnosis of canine visceral leishmaniasis in animals presenting different clinical manifestations

• Published in: Veterinary parasitology Vol. 146; no. 3; pp. 235 - 241
• Main Authors: Ferreira, Eduardo de Castro, de Lana, Marta, Carneiro, Mariângela, Reis, Alexandre Barbosa, Paes, Daniela Vieira, Silva, Eduardo Sérgio da, Schallig, Henk, Gontijo, Célia Maria Ferreira
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 31-05-2007
• Subjects: agglutination tests; Animals; cross reaction; Diagnosis; Dog Diseases - blood; Dog Diseases - diagnosis; Dogs; Ehrlichia canis; enzyme-linked immunosorbent assay; epidemiological studies; Female; fluorescent antibody technique; immunologic techniques; Leishmania braziliensis; Leishmaniasis, Visceral - blood; Leishmaniasis, Visceral - diagnosis; Leishmaniasis, Visceral - veterinary; Male; Sensitivity and Specificity; serodiagnosis; Serologic Tests - veterinary; Serological assays; signs and symptoms (animals and humans); Toxoplasma gondii; Trypanosoma cruzi; Visceral leishmaniasis; Brazil; Diagnosis; Serological assays; Visceral leishmaniasis; Dogs
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2007.02.015

Three serological methods, indirect fluorescent immunoassay (IFI), enzyme-linked immunosorbent assay (ELISA) and direct agglutination test (DAT) that are commonly employed in the diagnosis of canine visceral leishmaniasis (CVL), have been assessed. A total of 234 domestic dogs, drawn from an area in the municipality of Belo Horizonte, Minas Gerais, Brazil, endemic for visceral leishmaniasis, were submitted to clinical and parasitological examinations and serological assay. Sera collected from confirmed non-infected dogs (
n
=
20), and from dogs with other parasitic diseases including
Trypanosoma cruzi (
n
=
7),
Leishmania braziliensis (
n
=
5),
Toxoplasma gondii (
n
=
5) and
Ehrlichia canis (
n
=
3), were also included in the study. IFI presented a lower sensitivity (72%) than ELISA (95%), although the specificities of these assays were low (52 and 64%, respectively) and both exhibited cross-reactivity with sera from dogs infected with
T. cruzi,
L. braziliensis and
E. canis. In contrast, DAT exhibited a high sensitivity (93%) and a high specificity (95%) and cross-reacted with only one serum sample derived from an
E. canis-infected dog. The reproducibilities of the ELISA and DAT assays were excellent, whilst that of IFI was considered to be acceptable. The results produced by ELISA and DAT were in complete agreement, those between ELISA and IFI were at an acceptable level of agreement, whilst the concurrence between the IFI and DAT results were either acceptable or poor depending on the clinical conditions of the group of dogs examined. Since there is no readily accessible method for the diagnosis of CVL that offers 100% specificity and sensitivity, the choice of technique employed must depend on the aim of the investigation.