Sociodemographic and environmental analysis for the occurrence of anti-Leptospira antibodies in dogs of Teresina, Piauí, Brazil.

Leptospirosis is a worldwide zoonosis whose transmission is interlinked by multiple factors in the man-animal-ecosystem interface. This study aimed to evaluate the risk factors for the occurrence of anti-Leptospira antibodies in dogs in the capital Teresina (PI), and to determine their spatial distribution. Five hundred fifty-eight dog blood samples were submitted to the Microscopic Serum Agglutination (MSA) test.

The sero-conversion and evaluation of renal alterations in dogs infected by Leishmania (Infantum) chagasi.

This study investigated the sero-conversion period in which dogs from endemic areas test positive for visceral leishmaniasis (VL) as well as the early post-infection period in which renal alterations are observed. Dogs that were initially negative for Canine Visceral Leishmaniasis (CVL) were clinically evaluated every three months by serological, parasitological and biochemical tests until sero-conversion was confirmed, and six months later a subsequent evaluation was performed. Samples of kidney tissues were processed and stained with Hematoxylin and Eosin (H&E), Periodic Acid Schiff (PAS) and Masson's trichrome stain and lesions were classified based on the WHO criteria.

Immunoactivation and immunopathogeny during active visceral leishmaniasis.

Visceral leishmaniasis is caused by protozoan parasites of the Leishmania donovani complex. During active disease in humans, high levels of IFN-gamma and TNF-alpha detected in blood serum, and high expression of IFN-gamma mRNA in samples of the lymphoid organs suggest that the immune system is highly activated. However, studies using peripheral blood mononuclear cells have found immunosuppression specific to Leishmania antigens; this poor immune response probably results from Leishmania antigen-engaged lymphocytes being trapped in the lymphoid organs.