Prevalência, avaliação clínica e imunológica de cães (Canis familiaris) (Linnaeus, 1758) naturalmente infectados por Leishmania (Leishmania) chagasi (Cunha & Chagas, 1937) provenientes do município de Tamandaré, região litoral Sul do Estado de Pernambuco, Brasil

Abstract

Canine Visceral Leishmaniasis (CanL) in Brazil is caused by Leishmania (Leishmania) chagasi and it has been reported in some cities. The goal of this research was to verify the prevalence, analyze the spatial correlation between CanL and environmental factors, evaluate and compare the levels of cytokine (IL-12, IFN-γ, IL-2 and IL-4) expressions by Realtime-PCR in different tissues/organs and also determination of hematological and biochemical patterns in dogs naturally infected by L. (L.) infantum/chagasi and also evaluate the levels of Leishmania chagasi specific IgG2antibodies in symptomatic and asymptomatic dogs naturally infected using CPX2. First of all the dogs fromTamandare county, Pernambuco, Brazil were investigated for clinical signs related to Canine Visceral Leishmaniasis (CanL) and sera were analyzed by ELISA test for anti-Leishmania antibodies. According to serology, the positive and negative cases in were each assigned coordinates through the use of a handheld GPS. The cases were plotted throughout the county, and the points were loaded into arcGIS and the layers were analyzed using “Moran’s I Spatial Autocorrelation” to distinguish clustering based on the variables vegetation and hydrology. Later the evaluation of cytokine levels (IL-12, IFN-γ, IL-2 and IL-4) was made by Realtime-PCR in different tissues/organs from adult dogsnaturally infected by L. (L.) infantum/chagasi, and determination of hematological and biochemical parameters in symptomatic and asymptomatic dogs and after of CanL was performed. The serological survey showed 20.40% of animals were positive to serological test and 80.1% of positive dogs were asymptomatic animals. On the other hand the correlations between all points and environmental factors, such vegetation and hydrology were found to beclustered with less than 1% likelihood due to random chance. Symptomatic animals showed increased expression of IL-12 IFN-y, IL-2 and IL-4 when compared with healthy dogs. Asymptomatic animals and dogs that had been subject to treatment against CanL revealed significant augments of IL-4. Significantly increased in lymph nodes of IL-12 and IL-2 expression was observed in asymptomatic dogs. Treated animals showed significant high levels of IL-12 in bone marrow when compared with healthy, symptomatic and asymptomatic dogs. The determination of hematological and biochemical parameters in symptomatic and asymptomatic dogs and after of CanL showed that dogs of symptomatic group exhibited not only clinical signs compatible withleishmaniasis but also normocytic and normochromic anaemia, hypergammaglobulinemia and increase of blood urea. The results of the CPX2 ELISA showed 41.01%) of dogs were positive to IgG2 antibodies, but cross reaction with non-leishmaniasis disease was observed. As the dogs is the reservoir in Brazil and the canine infection precedes the human cases, these findings indicate that control measures must be apply in dog population from Tamandaré County in order to prevent human cases.