Clinical and serological aspects of visceral leishmaniasis in Northeast Brazilian dogs naturally infected with Leishmania chagasi

• Published in: Veterinary parasitology 2005-02, Vol.127 (3), p.227-232
• Main Authors: Almeida, M.A.O., Jesus, E.E.V., Sousa-Atta, M.L.B., Alves, L.C., Berne, M.E.A., Atta, A.M.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Protozoan - blood; antibody detection; antibody formation; blood protein disorders; blood proteins; Brazil; canine visceral leishmaniasis; Clinical signs and laboratory markers; Dog Diseases - blood; Dog Diseases - diagnosis; Dog Diseases - immunology; Dog Diseases - parasitology; Dogs; Emaciation - parasitology; Emaciation - veterinary; enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - veterinary; epidemiological studies; fluorescent antibody technique; Fluorescent Antibody Technique, Indirect - veterinary; Hypergammaglobulinemia - parasitology; Hypergammaglobulinemia - veterinary; Hypoalbuminemia - parasitology; Hypoalbuminemia - veterinary; immunoglobulin G; Leishmania chagasi; Leishmania donovani; Leishmaniasis, Visceral - blood; Leishmaniasis, Visceral - diagnosis; Leishmaniasis, Visceral - veterinary; Natural canine visceral leishmaniasis; natural infections; Sensitivity and Specificity; seroprevalence; signs and symptoms (animals and humans); Skin Ulcer - parasitology; Skin Ulcer - veterinary; symptoms; visceral leishmaniasis
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2004.10.010

Human visceral leishmaniasis is endemic in the northeast of Brazil, where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. In this study, we evaluated the clinical signs of canine visceral leishmaniasis (CVL), serum protein profile and the antileishmanial IgG antibody production in 86 dogs living in northeast endemic areas of leishmaniasis. Thirty dogs from a leishmaniasis-free area were used as a control group. The major clinical signs of CVL seen were emaciation and skin ulcers (80%), followed by onychogryphosis and conjunctivitis (73%). Depilation was observed in 60% of animals while lymphadenomegaly, splenomegaly, liver enlargement or kidney involvement was less frequent (≤20%). VL seropositive dogs presented with serum hyperproteinemia, hypoalbuminemia, hypergammaglobulinemia and decreased albumin/globulin ratio. A lower sensitivity and higher specificity was observed for promastigote indirect fluorescent antibody test (IFAT) (83 and 100%, respectively) compared with enzyme-linked immunosorbent assay (ELISA) (94 and 90%), which uses a crude extract of Leishmania. There was a positive correlation between IFAT and ELISA titers of antileishmanial IgG antibodies (Spearman test, P < 0.05), which was augmented in CVL dogs. This study found that the determination of serum protein, A/G ratio and the use of two different leishmanial serological tests like IFAT and ELISA are essential in CVL screening.