CANINE VISCERAL LEISHMANIASIS CASE INVESTIGATION IN THE JACARE REGION OF NITEROI, RIO DE JANEIRO, BRAZIL

SUMMARY American visceral leishmaniasis is a vector-borne zoonosis in expansion in Brazil. Dogs are the main urban reservoir. Departing from a case of canine visceral leishmaniasis (CVL) in Jacaré, Niterói, Rio de Janeiro State, an epidemiological canine and entomological study was performed to assess the extension of the disease at the location. Sample was collected around the case and the dogs identified by serological tests (rapid double platform immunochromatographic exams, immunoenzymatic assay/ELISA, indirect immunofluorescence/IFAT). The parasitological diagnosis was performed in animals positive in at least one of these tests. The entomological study was carried out by using light traps and manual collection. The associations between canine variables and outcome (ELISA and IFAT reagents) were assessed by the chi-square test and adjusted by multivariate logistic regression for those associations with p < 0.1 in the bivariate analysis. Seventeen cases of CVL were detected among 110 evaluated dogs (prevalence of 15.5%). Presence of ectoparasites (OR 6.5; 95% CI 1.1-37.4), animals with clinical signs (OR 9.5; 95% CI 1.2-76.6), and previous cases of CVL in the same house (OR 17.9; 95% CI 2.2-147.1) were associated with the outcome. Lutzomyia longipalpiswas not detected. Our results are indicative of an ongoing transmission in the area

Abundance of Lutzomyia longipalpis in urban households as risk factor of transmission of visceral leishmaniasis

Urban occurrence of human and canine visceral leishmaniasis (VL) is linked to households with characteristics conducive to the presence of sand flies. This study proposes an ad hoc classification of households according to the environmental characteristics of receptivity to phlebotominae and an entomological study to validate the proposal. Here we describe the phlebotominae population found in intra- and peridomiciliary environments and analyse the spatiotemporal distribution of the VL vector Lutzomyia longipalpis of households receptive to VL. In the region, 153 households were classified into levels of receptivity to VL followed by entomological surveys in 40 of those properties. Kruskal-Wallis verified the relationship between the households’ classification and sand fly abundance and Kernel analysis evaluated L. longipalpis spatial distribution: of the 740 sand flies were captured, 91% were L. longipalpis; 82% were found peridomiciliary whilst the remaining 18% were found intradomiciliary. No statistically significant association was found between sandflies and households levels. L. longipalpis counts were concentrated in areas of high vulnerability and some specific households were responsible for the persistence of the infestation. L. longipalpis prevails over other sand fly species for urban VL transmission. The entomological study may help target the surveillance and vector control strategies to domiciles initiating and/or maintaining VL outbreaks

Serological, parasitological and molecular tests for canine visceral leishmaniosis diagnosis in a longitudinal study

One of the measures to control visceral leishmaniosis (VL) in Brazil is the identification and culling of the canine reservoir. There is much controversy concerning this strategy, including the proper identification of positive dogs and the fact that the host-parasite relationship changes over time make it more challenging. A dynamic cohort of 62 dogs was followed every three months using serological and parasitological examinations and PCR. Positivity by PCR was higher than by serology and by parasitological examinations and showed a tendency to decrease over time, while serology tended to increase after six months. Concomitant positivity in all tests was observed in 10.4% of the samples, and negativity in 29.1%. Overall sensitivity ranged from 43.6 to 64.1%, and was not uniform over time. The proportion of dogs with or without clinical signs was not different by cytology or PCR but PCR was able to identify a larger number of asymptomatic dogs compared to ELISA and immunochromatography. PCR can be useful for surveillance of areas where cases of canine VL have not yet been detected and in which control strategies can be implemented to limit the spread of the disease. Despite the advance in diagnostic tools CVL diagnosis remains a challenge

Fatores de risco peridomiciliares e conhecimento sobre leishmaniose visceral da população de Formiga, Minas Gerais

Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil.Universidade do Estado de Minas Gerais. Fundação Educational Divinópolis. Divinópolis, MG, Brazil.Universidade do Estado de Minas Gerais. Fundação Educational Divinópolis. Divinópolis, MG, Brazil.Centro Universitário de Formiga. Formiga, MG, BrazilFundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil/Universidade do Estado de Minas Gerais. Fundação Educational Divinópolis. Divinópolis, MG, Brazil.Introdução: As leishmanioses representam uma importante carga de doença nos países tropicais, apresentando índices significativos de morbimortalidade nos locais onde ocorrem, incluindo o Brasil. Nesse contexto, a participação popular nas ações profiláticas pode ser determinante para o êxito das estratégias de controle. Objetivo: Por isso, o presente estudo teve o objetivo de investigar o conhecimento da população sobre as leishmanioses e a ocorrência de fatores de risco peridomiciliares associados à população no município de Formiga, Minas Gerais. Métodos: Foi realizado um inquérito domiciliar com uma amostra de 427 indivíduos entre maio e julho de 2011. Resultados: Apenas 7,5% dos moradores mostraram conhecimento sobre as leishmanioses, sendo principalmente as mulheres (OR = 3,15; IC95% 1,30 - 7,65). A prevalência de riscos peridomiciliares foi de 95%. Associação estatisticamente significativa foi encontrada entre maior escolaridade e menos fatores de risco peridomiciliares (OR = 0,45; IC95% 0,28 - 0,72) e entre o local de residência e maior número desses fatores de risco (OR = 1,84; IC95% 1,19 - 2,85). Conclusão: Os resultados demonstram que há baixo nível de conhecimento sobre as leishmanioses por parte da população. Além disso, a maioria dos respondentes está sujeita a algum fator de risco peridomiciliar, fato que pode contribuir para a manutenção do ciclo da doença no município.Introduction: Leishmaniasis represents an important burden of diseases in tropical countries, with significant levels of morbidity and mortality where they occur, including in Brazil. In this context, popular participation in prophylactic actions can be decisive for the success of the control strategies. Objective: For this reason, this study aimed at investigating the population's knowledge concerning leishmaniasis and the occurrence of peridomiciliary risk factors associated with the population of Formiga, Minas Gerais. Methods: A household questionnaire with a sample of 427 individuals was conducted between May and July 2011. Results: Only 7.5% of the residents presented knowledge regarding leishmaniasis, most of them being women (OR = 3.15; 95%CI 1.30 - 7.65). The prevalence of peridomiciliary risks was 95%. A statistically significant association was found between higher education levels and less peridomiciliary risk factors (OR = 0.45; 95%CI 0.28 - 0.72) and between the place of residence and a higher number of risk factors (OR = 0.84; 95%CI 1.19 - 2.85). Conclusion: The results demonstrate that the population has low levels of knowledge about leishmaniasis. Moreover, the majority of respondents are subject to some peridomiciliary risk factor, which may contribute to the maintenance of the disease cycle in the city