BackgroundVisceral leishmaniasis (VL) is an infectious disease with a variety of clinical signs. The main form of parasite transmission to humans and other mammalian hosts is through the bite of infected arthropod females with Lutzomyia longipalpis serving as the main vector in the Americas. Dogs are the main urban domestic reservoirs of the parasite and the main source of vector infection due to their high prevalence in endemic areas and the large number of parasites in the skin of infected animals. Although miltefosine has been used in Europe since 2002 for treatment of VL infected dogs, in the Americas the treatment of dogs has not been recommended. Therefore, this study aimed to evaluate efficacy of miltefosine observing a reduction of clinical signs in infected dogs and the infectiveness to the vector by Leishmania (L.) infantum.MethodsTo our knowledge, this is the first controlled study using qPCR and xenodiagnosis to evaluate the efficacy of miltefosine (Milteforan®, Virbac) as a single treatment in Brazil. Thirty-five adult dogs with canine visceral leishmaniasis (CVL), confirmed by clinical and laboratory tests, were included in this study. They received miltefosine at a dose of 2 mg/kg every 24 h for 28 days. The dogs were observed over a three-month period, during which clinical evaluations based on a scoring system were conducted at pre-established times. Parasite load was assessed by cytology and real-time polymerase chain reaction (qPCR). Transmissibility to the vector was evaluated by xenodiagnosis.ResultsAt the end of the period, the following were observed: (i) the remission of clinical signs with a reduction in clinical scores for 94.2% of the animals; (ii) a statistically significant reduction (98.7%) in parasitic load by qPCR; and (iii) a reduction in infectivity to sand flies. After treatment, 74.2% of the animals remained or had become non-infectious.ConclusionsOur study indicates that the use of miltefosine administered orally for 4 weeks contributes to a clinical improvement and reduction in infectivity of dogs to L. infantum.

On 26 October 2012, veterinary medicine clinicians and researchers, members of Brasileish - Study Group about Animal Leishmaniasis - met at the Regional Council of Veterinary Medicine of Minas Gerais, in the city Belo Horizonte, in order to discuss many aspects of the situation of canine visceral leishmaniasis (CVL) in Brazil. In the face of recent national and international scientific evidence, we, the members of Brasileish, have elaborated some recommendations for the management and control of CVL in Brazil.

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A leishmaniose é uma importante zoonose parasitária, tendo os flebotomíneos como vetores biológicos. Por ser uma doença de epidemiologia complexa, outros artrópodes têm sido apontados como possíveis transmissores da enfermidade, especialmente nas áreas onde existem surtos da doença sem a presença do Lutzomyia spp. O objetivo deste estudo foi avaliar a ocorrência da infecção natural de Culex quinquefasciatus por Leishmania spp. em áreas endêmicas para leishmaniose humana e animal. Os insetos foram capturados em duas associações protetoras dos animais, uma delas situada no município de Andradina e a outra em Ilha Solteira-SP, utilizando armadilhas luminosas. Os mosquitos capturados foram mortos por congelamento e separados em grupos identificados com o local de origem e a espécie. Os insetos do gênero Culex sp.  foram separados e macerados formando um pool em solução fisiológica estéril 0,9%, congelados e enviados para análise laboratorial por meio da técnica de reação em cadeia da polimerase (PCR). Amplificação positiva para Leishmania chagasi foram encontradas em 12,5% (2/16) das amostras provenientes da cidade de Ilha Solteira, SP. Este é o primeiro relato da infecção natural de mosquitos Culex sp. por protozoários do gênero Leishmania chagasi em todo o mundo.

The municipality of Ilha Solteira, São Paulo, Brazil is an endemic area of leishmaniasis. At the Companhia Energética de São Paulo (CESP) Wild Animal Center of Ilha Solteira, two bush dogs (Speothos venaticus) showed clinical signs of this disease. The amastigote form of Leishmania was detected in lymph-node smears taken by fine-needle biopsy. In addition, serum samples from both animals, screened with an enzyme-linked immunosorbent assay (ELISA), were positive for anti-Leishmania antibodies. Moreover, tissue samples from one of the bush dogs were evaluated for the presence of Leishmania DNA by means of a polymerase chain reaction (PCR). DNA of the parasite was indeed detected in the tissue samples of the liver and the lymph nodes; however, no DNA from the parasite was detected in samples of the skin and spleen. These findings confirm a Leishmania infection in bush dogs (S. venaticus).