Avaliação da infectividade parasitária a Lutzomyia longipalpis por xenodiagnóstico em cães tratados para leishmaniose visceral naturalmente adquirida

Clinical evolution of equine leishmaniasis with self-limiting cutaneous disease caused by Leishmania infantum in northeastern Brazil: A case report

Leishmania infantum infections have long been described in humans and dogs worldwide, but characterization of equine cases remains scarce. We describe the clinical evolution of a natural L. infantum infection to contribute to the diagnostic knowledge and epidemiology of equine leishmaniasis (EL). An auction-acquired four-year-old Mangalarga Marchador mare from Pernambuco state, presented a few subcutaneous nodules on the head and neck upon arrival at the purchaser's stud at Bahia state, in November of 2019. They progressed to multiple ulcerated and non-ulcerated nodules and spread to both right limbs in seven weeks. Hematology revealed anemia, lymphocytosis, monocytosis, and elevated plasma fibrinogen. Histopathology of the biopsied nodules identified a granulomatous dermatitis with macrophages containing Leishmania amastigotes. PCR detected Leishmania in skin lesions, but not in blood or spleen aspirate samples; ITS1 PCR-RFLP and DNA sequencing confirmed L. infantum species. A topical antiseptic and insect-repellent therapy and a monthly follow-up were established. All lesions improved progressively, without specific anti-Leishmania treatment, and 14 months later there was a consistent resolution. This first description of EL by L. infantum in an endemic area is relevant to emphasize the need for epidemiological studies, and to enhance clinicians' awareness for differential diagnosis.

Spatial distribution of canine Leishmania infantum infection in a municipality with endemic human leishmaniasis in Eastern Bahia, Brazil

Efforts to control a zoonotic disease such as visceral leishmaniasis (VL) caused by Leishmania infantum can be successful if they rely on comprehensive data on animal infection. In Bahia state, Brazil, human VL is endemic, yet some areas have no epidemiological data on canine L. infantum infection and canine leishmaniasis (CanL) to date. We aimed to perform an epidemiological study describing the spatial distribution and characterizing canine L. infantum infection in two districts of the municipality of Muritiba, where human cases have occurred. Brazilian official serodiagnostic protocol (ELISA and immunochromatographic tests), PCR and clinical examination were performed in 351 owned dogs. A seroprevalence of 15.7% (55/351) was found, and L. infantum identified in 88.8% (32/36) of PCR tested samples. Spatial distribution of positive dogs indicated infection in both urban and rural districts. There was no association between seropositivity and sex or breed, but dogs older than 2 years were 3.8 times more likely to be seropositive (95% CI 1.57 - 9.18) than younger dogs. Among seropositive dogs, 80% (44/55) had clinical manifestations of CanL: 75% (33/44) presented dermatopathy, 50% (22/44) emaciation, and 29.5% (13/44) ophthalmopathy. This is the first report on canine seroprevalence and natural L. infantum infection in Muritiba, Bahia.

Detection of allopurinol and oxypurinol in canine urine by HPLC/MS-MS: Focus on veterinary clinical pharmacokinetics

Allopurinol is the most commonly used drug for the treatment of hyperuricemia in people, and in view of the risks of fatal hypersensitivity in patients with renal dysfunction, doses based on the glomerular filtration rate are proposed. In veterinary medicine, allopurinol is used in the treatment of canine leishmaniasis (CanL) caused by Leishmania infantum owing to the drug action of inhibiting the parasite's RNA synthesis. However, renal dysfunction frequently ensues from disease progression in dogs. The purpose of the present study was to standardize and validate a sensitive high-performance liquid chromatography-mass spectrometric (HPLC-MS/MS) method to determine the concentration of allopurinol and its active metabolite oxypurinol in canine urine for clinical pharmacokinetic investigation. Urine samples of eleven (11) dogs with naturally occurring CanL and in the maintenance phase of the treatment with alopurinol were used. For the chromatographic analysis of urine, the mobile phase consisted of a solution of 0.1 % formic acid (88 %) in 10 mM ammonium acetate. Separation of allopurinol and oxypurinol occurred in a flow of 0.8 mL/min on a C8 reverse phase column 5 μm, and acyclovir was the internal standard. The HPLC-MS/MS method was validated by reaching the limits of detection and quantification, reproducibility and linearity. The lower limit of quantification achieved by the method was 10 μg/mL for both allopurinol and oxypurinol. Calibration curves were prepared in blank urine added with allopurinol at concentrations of 10-1000 μg/mL, and oxypurinol at 10-200 μg/mL. Coefficients of variation of less than 15 % between intracurrent and intercurrent accuracy values were observed for both allopurinol and oxypurinol. Urine test samples remained stable after being subjected to freeze-thaw cycles and remaining at room temperature for 4 h. The method proved to be adequate to quantify allopurinol and oxypurinol in urine samples from dogs under treatment.

[Control of canine visceral leishmaniasis by euthanasia: estimated effect based on a survey and mathematical modeling]

Visceral leishmaniasis is an emerging and neglected disease that is currently expanding to urban areas. The incidence of human disease is related to canine infection. Araçatuba and Birigui are municipalities (counties) in the state of São Paulo, Brazil, with 8-10% seroprevalence of canine infection and that employ control strategies targeting the canine reservoir, based on serological survey and culling of seropositive dogs. Using data from these control programs to parameterize mathematical models, this study assessed the efficacy of these activities. We estimated that current control is capable of reducing the incidence of canine visceral leishmaniasis (CVL) by approximately 20%. Assuming continuous control and three times the current serological survey activities in Araçatuba and Birigui, culling dogs with a positive CVL diagnosis would be effective for the control of canine infection. Although theoretically possible, in practice the control of CVL with the currently recommended strategies is insufficient, since it would require overcoming the difficulties in these activities, such as lack of material, human, and financial resources, besides associated ethical and legal issues.