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.

A leishmaniose visceral (LV) é um grande desafio para a saúde pública no Brasil, particularmente nos estados onde é endêmica. O objetivo deste estudo foi verificar a relação da densidade populacional de flebotomíneos com as variáveis ambientais (temperatura, precipitação de chuva e umidade relativa do ar) em bairros urbanos de Mossoró, Rio Grande do Norte. Os flebotomíneos foram capturados com armadilhas CDC instaladas mensalmente no intra e peridomicílio de três casas. A análise dos dados foi baseada no teste Qui-quadrado e na regressão linear. Foram capturados 7.347 flebotomíneos, sendo 93,85% Lutzomyia longipalpis e 6,15% Lutzomyia evandroi. Os flebotomíneos foram encontrados mais comumente no peridomicílio e nenhuma diferença significativa entre o número de machos e fêmeas foi observada. As variáveis estação chuvosa, bem como a umidade relativa e precipitação de chuva, associadas ou isoladas, não influenciou a densidade populacional dos flebotomíneos. No entanto, a alta temperatura afetou essa densidade de forma negativa. Portanto, este estudo específico em áreas endêmicas é importante, porque as agências de Saúde Pública podem usar essas informações para um planejamento adequado das medidas de controle de vetores LV.

Visceral leishmaniasis (VL) is a major public health challenge in Brazil, especially in states where it is endemic. The aim of this study was to investigate the relationship of sand fly population density with environmental variables (temperature, rainfall and relative humidity) in urban areas of the city of Mossoró, Rio Grande do Norte, Northeastern Brazil. Sand flies were captured with Center Disease Control (CDC) traps installed monthly in the intra and peridomicile of three houses. Data analysis was based on the chi-square test and linear regression. A total of 7,347 sand flies were captured, being 93.85% Lutzomyia longipalpis and 6.15% Lutzomyia evandroi. Sand flies were more commonly found in the peridomicile and there was no difference between the number of males and females. The variables rainy season as well as relative humidity and rainfall, alone or together, did not have an effect on sand fly population density. However, high temperatures had a negative effect. The study of the behavior of sand flies in specific units of endemic areas can provide input to public health authorities for planning appropriate VL vector control measures.

No Brasil, o crescimento urbano da leishmaniose visceral (LV) está associado com a adaptação do seu vetor, Lutzomyia longipalpis, aos ambientes modificados pelo homem. Este estudo relata a vigilância entomológica de L. longipalpis e os efeitos das variáveis ambientais sobre a sua densidade populacional. Os flebotomíneos foram capturados no município de Mossoró, Rio Grande do Norte, no Nordeste do Brasil, a partir de janeiro de 2005 a dezembro de 2006. Duas armadilhas tipo CDC foram colocadas mensalmente durante quatro noites consecutivas no peridomicílio das casas escolhidas. A análise dos dados foi baseada no teste Qui-quadrado e regressão linear. Um total de 2.087 flebotomíneos foram capturados, dos quais 99,86% foram L. longipalpis. Mais fêmeas do que machos foram capturados (p < 0,05). Na análise mensal das variáveis ambientais a temperatura, umidade relativa e a chuva não tiveram impacto significativo sobre a densidade populacional de L. longipalpis. No entanto, houve diferenças sazonais: aproximadamente 70% dos flebotomíneos foram capturados durante a estação chuvosa (p < 0,05). Assim, L. longipalpis, a espécie predominante, representa um risco à saúde pública. Portanto, devido à maior prevalência no período chuvoso, recomendamos intensificar as medidas de controle da LV antes e durante este período para reduzir o risco de transmissão da doença.

Urban increase of visceral leishmaniasis (VL) in Brazil is associated with the adaptation of its vector, Lutzomyia longipalpis, to environments modified by humans. The present study reports the results of an entomological monitoring of L. longipalpis and the effect of environmental variables on its population density. Sandflies were captured in the municipality of Mossoró, State of Rio Grande do Norte, Northeastern Brazil, from January 2005 to December 2006. Two CDC light traps were placed monthly for four consecutive nights in the peridomicile of selected households. Data analysis was based on the chi-square test and linear regression. A total of 2,087 sandflies were captured, 99.86% of which were L. longipalpis. A higher proportion of females were captured (p < 0.05). Monthly analysis of the variables temperature, relative humidity and rainfall did not show a significant influence on population density. However, there were seasonal differences: approximately 70% of sand flies were captured during the rainy season (p < 0.05). The predominant species, L. longipalpis, is present in substantial number, representing a public health risk. Therefore, because of higher prevalence during the rainy season, we recommend intensified VL control measures before and during this season to reduce the risk of disease transmission.

O presente estudo objetivou descrever alguns fatores relacionados à positividade de cães para leishmaniose visceral, em área endêmica do Estado do Rio Grande do Norte. Foram analisados 198 cães, dos quais 62 foram recrutados de propriedades rurais e 136 de residências urbanas. O diagnóstico foi realizado através dos testes de imunofluorescência indireta e imunoadsorção enzimática. Dos cães analisados, 45% dos positivos eram provenientes da área rural e 35% da área urbana. Analisando a função dos animais, a prevalência foi de 50% dos cães de guarda nas áreas rural e de 43% na área urbana. Quanto aos cães que tinham contato com outros cães de origem rural ou urbana, a prevalência observada de foi 54% e 32%, respectivamente. No que se refere ao sexo, as fêmeas da zona rural foram mais prevalentes. Estes resultados sugerem uma atenção maior sobre o papel destes animais como reservatório dessa zoonose, como também na urbanização da leishmaniose visceral e o inquérito epidemiológico desta doença, no qual estas informações poderão contribuir para o planejamento de estratégias de controle do cão como reservatório doméstico.

This study aimed at describing several factors related to positive testing of dogs for visceral leishmaniasis, in an endemic area of the state of Rio Grande do Norte. Sera of 198 dogs were analyzed, 62 from rural properties and 136 from urban residences. Diagnosis was performed through indirect immunofluorescence and enzyme-linked immunosorbent assay. Forty five percent of positive dogs were from the rural area and 35% came from the urban area. Concerning the analysis of dogs' function, the watchdogs showed greater prevalence, with 50% prevalence in the rural area and 43% in the urban area. With regard to contact with other dogs and origin in rural or urban areas, the prevalence was 54% and 32% respectively. In relation to gender, females from the rural area were more prevalent. These results suggest more attention should be paid to dogs as reservoirs for this zoonosis, as well as their important role in the urbanization of Leishmaniasis and in epidemiological survey of the disease. These data can contribute to the planning of strategies for control, targeting dogs as domestic reservoirs.