Desempenho do teste rápido imunocromatográfico (TRI) para o diagnóstico da leishmaniose visceral canina: comparação com outros métodos sorológicos em cães suspeitos de Cuiabá, Mato Grosso, Brasil

O teste rápido imunocromatográfico (TRI) para leishmaniose visceral canina (LVC) foi testado em cães suspeitos da área urbana de Cuiabá. O desempenho do teste foi comparado com RIFI e ELISA e, como padrão ouro, o teste parasitológico direto (TPD). A amostra com 45 cães foi selecionada pelo Centro de Controle de Zoonoses, sendo 23 (51,1%) machos, 34 (75,5%) sem raça definida e com idade estimada inferior a três anos. De acordo com os dados clínicos e os exames laboratoriais, 10 (26,3%) cães foram classificados como expostos, outros 10 (26,3%) como infectados e 18 (47,4%) como doentes. O TRI alcançou os melhores resultados quanto à sensibilidade, 62%, elevada especificidade, 87% e para os valores preditivos positivo e negativo: 83,30% e 81,48%, respectivamente, consolidado pelo coeficiente Kappa igual a 0,50, de concordância moderada. Os resultados confirmaram TRI como um bom preditor de doença e infecção para LVC.The immunochromathographic rapid test (IRT) for canine visceral leishmaniasis (CVL) was tested in suspected dogs from the urban area of Cuiabá. The performance of IRT was compared with IFT and EIE and the direct parasitological test (DPT) as the gold standard. The sample, comprising 45 dogs, was selected by the Zoonosis Control Center. Twenty (51%) were male and thirty-four (75.5%) were both mongrel and had an estimated age of less than three years old. According to clinical data and lab tests: 10 (26.3%) dogs have been classified as exposed or infected and 18 (47.4%) as sick. IRT has achieved the best result for sensibility, 62%, high specificity, 87% and for positive and negative predictive values: 83.3% and negative 81.48%, respectively, reinforced by a k coefficient equal to 0.50, representing substantial agreement

Ultrastructural Changes and Death of Leishmania infantum

The search for new treatments against leishmaniasis has increased due to high frequency of drug resistance registered in endemics areas, side effects, and complications caused by coinfection with HIV. Morinda citrifolia Linn., commonly known as Noni, has a rich chemical composition and various therapeutic effects have been described in the literature. Studies have shown the leishmanicidal activity of M. citrifolia; however, its action on the parasite has not yet been elucidated. In this work, we analyzed leishmanicidal activity and ultrastructural changes in Leishmania infantum promastigotes caused by M. citrifolia fruit juice treatment. M. citrifolia fruit extract showed a yield of 6.31% and high performance liquid chromatography identified phenolic and aromatic compounds as the major constituents. IC50 values were 260.5 µg/mL for promastigotes and 201.3 µg/mL for intracellular amastigotes of L. infantum treated with M. citrifolia. Cytotoxicity assay with J774.G8 macrophages showed that M. citrifolia fruit juice was not toxic up to 2 mg/mL. Transmission electron microscopy showed cytoplasmic vacuolization, lipid inclusion, increased exocytosis activity, and autophagosome-like vesicles in L. infantum promastigotes treated with M. citrifolia fruit juice. M. citrifolia fruit juice was active against L. infantum in the in vitro model used here causing ultrastructural changes and has a future potential for treatment against leishmaniasis

Seroprevalence and associated epidemiologic variables with canine visceral leishmaniasis in endemic area, São Luis, Maranhão State, Brazil

Este trabalho teve como objetivos determinar a soroprevalência e as variáveis epidemiológicas associadas com a infecção de Leishmania spp. em cães de cinco localidades no Distrito do Tirirical no município de São Luís, Maranhão. Foram visitadas 72 moradias, perfazendo uma amostra de cem cães domiciliados, e aplicados questionários com o objetivo de determinar os fatores que poderiam estar relacionados com a ocorrência da infecção. Utilizaram-se como variáveis: proximidade da moradia com a mata, existência de criação/abrigo de animais de produção e de animais silvestres, sexo, idade, raça, além de exame clínico do animal, com observação da presença de sinais clínicos compatíveis com a doença. A análise sorológica demonstrou que 67 amostras apresentaram-se positivas para Leishmania spp. Os sinais clínicos observados foram linfadenopatia localizada, alopecia, pelo opaco, emagrecimento, úlceras cutâneas, descamação furfurácea, ceratoconjuntivite, e onicogrifose. Animais das localidades Cruzeiro de Santa Bárbara e Cajupari, ambas localizadas próximas de matas, têm 3,4 e 12,0 vezes mais chances de serem soropositivos para Leishmania spp. do que aqueles das outras localidades estudadas. Não se verificou correlação entre as outras variáveis estudadas e soropositividade para Leishmania spp.This work aimed to determine the seroprevalence and epidemiological variables associated to Leishmania spp. infection in dogs from five locations of Tirirical District, in São Luís, Maranhão State, Brazil. Seventy-two houses were visited and samples of one hundred dogs were taken. A questionnaire was applied in order to investigate the possible factors related to the Leishmania infection. The following variables were used: forest proximity from the residence, livestock of domestic animals or shelter of wild animals, sex, age and breed. Clinical examination was also performed looking for clinical signs compatible to the infection. The serological analysis revealed that 67 samples were reactive. The clinical signs observed were focal lymphadenophaty, alopecia, weight loss, cutaneous ulcers, skin desquamation, keratoconjuntivitis and onycogrifosis. Animals from Cruzeiro de Santa Bárbara and Cajupari, both locations near the forest, have 3.4 and 12.0 more chances of being reactive to Leishmania spp. than the ones in the other studied locations. No statistical relation was found between seropositive dogs and any other variables.À Universidade Estadual do Maranhão, pela concessão de bolsa de Iniciação Científica (programa BIC/UEMA), no período de novembro de 2006 a novembro de 2007. À FAPEMA, pela concessão de Bolsa de Apoio Técnico no período de fevereiro de 2008 a fevereiro de 2009

Infection of retinal epithelial cells with L. amazonensis impacts in extracellular matrix proteins

One of the manifestations of leishmaniases is eye injuries which main characteristics are the injury of the anterior chamber of the eye and the resistance to specific treatments. the retinal pigment epithelial (RPE) cells participate in pathogen-induced intraocular inflammatory processes. We investigated Leishmania amazonensis-RPE cells relationship and its impact in laminin and fibronectin production. Using RPE cell (ARPE-19), we demonstrated that L. amazonensis adhere to these cells in the first hour of infection, whereas parasite internalization was only observed after 6 h. Seventy-two hours after infection, vacuoles with parasites debris were observed intracellularly, and no parasite were observed intra- or extracellularly at the 96 h, suggesting that Leishmania can infect ARPE-19 cells although this cells are able to clear the infection. Fibronectin and laminin were associated with L. amazonensis-ARPE-19 interaction. Confocal analysis showed no substantial alterations in fibronectin presence in ARPE-19-infected or ARPE-19-noninfected cells, whereas laminin levels increased three times 10 h after L. amazonensis infection. After this time, laminin levels decreased in infected cells. These results suggest that L. amazonensis-ARPE-19 infection induces increased production of laminin in the beginning of infection which may facilitate parasite-host cell interactions.Instituto Oswaldo CruzFiocruz MS, Inst Oswaldo Cruz, Lab Imunomodulacao & Protozool, BR-21040900 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc

SOROPREVALÊNCIA E VARIÁVEIS EPIDEMIOLÓGICAS ASSOCIADAS À LEISHMANIOSE VISCERAL CANINA EM ÁREA ENDÊMICA NO MUNICÍPIO DE SÃO LUÍS, MARANHÃO, BRASIL

This work aimed to determine the seroprevalence and epidemiological variables associated to Leishmania spp. infection in dogs from five locations of Tirirical District, in São Luís, Maranhão State, Brazil. Seventy-two houses were visited and samples of one hundred dogs were taken. A questionnaire was applied in order to investigate the possible factors related to the Leishmania infection. The following variables were used: forest proximity from the residence, livestock of domestic animals or shelter of wild animals, sex, age and breed. Clinical examination was also performed looking for clinical signs compatible to the infection. The serological analysis revealed that 67 samples were reactive. The clinical signs observed were focal lymphadenophaty, alopecia, weight loss, cutaneous ulcers, skin desquamation, keratoconjuntivitis and onycogrifosis. Animals from Cruzeiro de Santa Bárbara and Cajupari, both locations near the forest, have 3.4 and 12.0 more chances of being reactive to Leishmania spp. than the ones in the other studied locations. No statistical relation was found between seropositive dogs and any other variables

Awareness of visceral leishmaniasis and its relationship to canine infection in riverside endemic areas in Northeastern Brazil

IntroductionAn awareness of visceral leishmaniasis (VL) is necessary to encourage the population to participate in prevention and control in collaboration with more efficient, centrally organized health programs. The aim of this study was to evaluate the awareness of the riverside population regarding VL and the association between awareness and the prevalence of canine visceral leishmaniasis (CVL).MethodsIn total, 71 people living in riverside areas in the City of Mossoró in State of Rio Grande do Norte participated of the study, and 71 dogs were tested for CVL by polymerase chain reaction (PCR). Association analysis of several variables related to knowledge of the riverside population regarding CVL positivity was performed, yielding odds ratios (OR) and 95% confidence intervals (CI), and significance was determined using chi-square (χ2) and Fisher's exact tests.ResultsAmong individuals whose dogs tested positive for CVL, 60% did not know the cure for CVL, and these subjects were three times more likely to have a dog test positive for CVL than those who were aware the cure for CVL. Knowledge of CVL cure was the only variable that remained in the logistic model after the successive removal of variables, with an adjusted OR of 3.11 (95%CI: 1.1-8,799; p=0.032).ConclusionsInsufficient awareness regarding VL in riverside areas with CVL-positive dogs was associated with increased rates of canine infection, which suggests that changes in habits and the adoption of attitudes and preventive practices may contribute to the control and prevention of this disease. This study reinforces the need to invest in better health education programs regarding VL