Leishmaniose visceral canina: dois casos autóctones no município de Florianópolis, estado de Santa Catarina / Canine visceral leishmaniasis: two autochthonous cases in Florianópolis municipality, Santa Catarina State, Brazill

ABSTRACT

Background: Brazil faces an expansion and urbanization of American visceral leishmaniasis with human and canine cases in several metropolises. This report describes two cases of autochthonous canine visceral leishmaniasis in the city of Florianópolis, state of Santa Catarina, classified as an area previously without disease transmission. Case Five dogs from Canto dos Araçás, Lagoa da Conceição, Florianópolis municipality, which had no history of displacement to other municipalities, were studied by collecting clinical specimens in an attempt to isolate the parasite and to confirm the infection by Leishmania. For sampling the animals were sedated and after local shaving, asepsis and anesthesia with lidocaine HCl 2%, two fragments of apparently healthy skin of the scapular region with the aid of a 3 mm punch were obtained. The two fragments were placed in sterile saline plus antibiotics and antifungal agents solution to attempt the isolation of the parasite in NNN culture medium plus Schneider's medium. In addition to the collection of skin fragment, animals underwent bone marrow (BM) needle aspiration, obtained from the manubrium of the sternum, using a 20 mL syringe with 40x12 mm needle and aspiration biopsy of popliteal lymph nodes using Valeri citoaspirador 10 mL syringe and 25x8 mm needle, both performed after local shaving, asepsis and anesthesia with 2% lidocaine. The material collected from punctures biopsies was also seeded in an attempt of isolating the parasites. Among the five examined animals, in three cases promastigotes were isolated, two of which through the cultivation of skin fragments and one through a punctured sample of the lymph node. In two cases isoenzymatic characterization and identifying parasites such as Leishmania chagasi could be performed. Discussion: The LVC findings in Florianópolis, Santa Catarina generates great concern due to lack of knowledge of the actual spread of the disease, transmission dynamics in this area, knowledge of the vector, wild reservoirs and even in relation to the canine population exposed, for the first time, to Leishmania chagasi. These peculiar conditions may contribute to the onset of an abrupt expansion of the disease, differently from endemic regions. This fact can also be observed in many other cities in Brazil, mainly due to the development and expansion of road networks and the popularity of air travel, which increases the transit of people and their pets thereby increasing the risk of dispersion, not only of LVC, as of other infectious diseases to non-endemic areas. Another important point which causes dispersion of the LVC is related to some owners' attempt to get around the main control method, which is euthanasia for positive dogs, and end up moving their animals to areas where there is no endemic canine serological survey, endangering the population of these areas. The use of some tools could avoid this type of dispersal, as the tighter control of the movement of dogs from endemic areas, implementation of mandatory serological diagnosis and mandatory reporting of positive canine cases. Moreover, educational measures to educate dog owners and veterinarians from the public and private sectors would also help in trying to minimize this problem. In this sense, it is extremely important that the entomological and epidemiological surveillance aimed at LVC are deployed and implemented in free areas, aiming at detecting the presence of vector and/or canine enzootic diseases before installing the anthropozoonotic cycle, allowing unprecedented action aimed at preventing the occurrence of disease in humans, or even prepare the health services and the population to fight the problem.