Hot spots of leprosy in the endemic area of São Luís, Maranhão State, Northeastern Brazil.

BACKGROUND: Despite the decreasing of leprosy cases in Brazil, its occurrence remains high in certain Brazilian cities. The aim of the study was to analyze the spatial pattern of leprosy in São Luís, capital of Maranhão State, Northeastern Brazil. METHODOLOGY: An ecological study was carried out based on secondary data from leprosy cases and contacts reported in the Notification of Injury Information System in2015, and information on residency domiciles in three districts in the city. RESULTS: A positive correlation was found between the leprosy cases and the average number of residents per household, and households with open sewage, garbage accumulated, with street identification, persons without income, dependents and the poor. A negative correlation between cases and households with a sidewalk, literate people and 60 years old or more were identified. The seropositivity of contacts examined using the ML Flow test was of 23.19%. The disease presents a heterogeneous spatial pattern, with hyperendemic clusters. CONCLUSIONS: The spatialization of both leprosy cases and contacts and the identification of areas presenting the highest concentration of the disease in each district is important and constitutes an important tool to subsidize disease-control actions.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing.

OBJECTIVE: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. METHODS: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). RESULTS: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. CONCLUSIONS: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing / Desempenho de testes para o diagnóstico de tuberculose pulmonar em populações indígenas no Brasil: a contribuição do Teste Rápido Molecular

ABSTRACT Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

RESUMO Objetivo: Avaliar a acurácia do teste rápido molecular como ferramenta diagnóstica e estimar a incidência de casos pulmonares positivos entre a população indígena. Métodos: Estudo epidemiológico baseado em dados secundários. Foi calculada a incidência de casos de tuberculose pulmonar positiva entre 1° de janeiro de 2011 e 31 de dezembro de 2016, e o desempenho da baciloscopia e do teste rápido molecular no diagnóstico de tuberculose pulmonar, em comparação à cultura de escarro (teste padrão). Resultados: Foram incluídos 4.048 casos de indígenas considerados sintomáticos respiratórios, que forneceram amostras de escarro para análise. Destes, 3,7%, 6,7% e 3,7% apresentaram resultados positivos para baciloscopia, cultura e teste rápido molecular, respectivamente. A incidência média de tuberculose pulmonar foi de 269,3/100 mil habitantes. A sensibilidade do teste rápido molecular, em relação à cultura, foi 93,1% e a especificidade foi 98,2%. A baciloscopia apresentou sensibilidade 55,1% e especificidade 99,6%. Conclusões: O teste rápido molecular pode ser útil em áreas remotas, com recursos limitados e incidência de tuberculose elevada, como as aldeias indígenas nas áreas rurais do país. Ademais, o teste rápido molecular apresenta como principais vantagens o fácil manuseio, os resultados rápidos e a possibilidade de identificar a resistência à rifampicina. Em conjunto, esses atributos facilitam o início do tratamento precoce, contribuindo para reduzir a transmissão em comunidades reconhecidamente vulneráveis à infecção e à doença.

Geographic weighted regression: applicability to epidemiological studies of leprosy.

INTRODUCTION: Geographic information systems (GIS) enable public health data to be analyzed in terms of geographical variability and the relationship between risk factors and diseases. This study discusses the application of the geographic weighted regression (GWR) model to health data to improve the understanding of spatially varying social and clinical factors that potentially impact leprosy prevalence. METHODS: This ecological study used data from leprosy case records from 1998-2006, aggregated by neighborhood in the Duque de Caxias municipality in the State of Rio de Janeiro, Brazil. In the GWR model, the associations between the log of the leprosy detection rate and social and clinical factors were analyzed. RESULTS: Maps of the estimated coefficients by neighborhood confirmed the heterogeneous spatial relationships between the leprosy detection rates and the predictors. The proportion of households with piped water was associated with higher detection rates, mainly in the northeast of the municipality. Indeterminate forms were strongly associated with higher detections rates in the south, where access to health services was more established. CONCLUSIONS: GWR proved a useful tool for epidemiological analysis of leprosy in a local area, such as Duque de Caxias. Epidemiological analysis using the maps of the GWR model offered the advantage of visualizing the problem in sub-regions and identifying any spatial dependence in the local study area.

Geographic weighted regression: applicability to epidemiological studies of leprosy

Abstract: INTRODUCTION: Geographic information systems (GIS) enable public health data to be analyzed in terms of geographical variability and the relationship between risk factors and diseases. This study discusses the application of the geographic weighted regression (GWR) model to health data to improve the understanding of spatially varying social and clinical factors that potentially impact leprosy prevalence. METHODS: This ecological study used data from leprosy case records from 1998-2006, aggregated by neighborhood in the Duque de Caxias municipality in the State of Rio de Janeiro, Brazil. In the GWR model, the associations between the log of the leprosy detection rate and social and clinical factors were analyzed. RESULTS: Maps of the estimated coefficients by neighborhood confirmed the heterogeneous spatial relationships between the leprosy detection rates and the predictors. The proportion of households with piped water was associated with higher detection rates, mainly in the northeast of the municipality. Indeterminate forms were strongly associated with higher detections rates in the south, where access to health services was more established. CONCLUSIONS: GWR proved a useful tool for epidemiological analysis of leprosy in a local area, such as Duque de Caxias. Epidemiological analysis using the maps of the GWR model offered the advantage of visualizing the problem in sub-regions and identifying any spatial dependence in the local study area.

Geographical heterogeneity in the analysis of factors associated with leprosy in an endemic area of Brazil: are we eliminating the disease?

BACKGROUND: The leprosy transmission chain is very complex and, in order to intervene in this transmission, more must be known about the factors linked to falling ill. There are doubts as to the influence of population size, population density and the disease's magnitude in detection rate trends. This paper aimed to identify factors associated with detection of leprosy in an endemic municipality of Rio de Janeiro State, Brazil. METHODS: This ecological study in Duque de Caxias municipality, Rio de Janeiro State, Brazil, used neighbourhoods (bairros) as the unit of analysis. Selecting new cases of leprosy detected from 1998 to 2006, the analysis examined clinical, socioeconomic and service variables using a Poisson log-Normal model. RESULTS: In the municipality overall, 2572 new cases were detected, a rate of 3.70 cases/10,000 inhabitants. The results describe a heterogeneous distribution of cases and rates in the municipality. The final model displayed a significant association with indeterminate clinical form (ß = 2.599), proportion of homes with running water (ß = -2.334) and presence of a decentralised health care unit (ß = 0.524). CONCLUSION: Although the results indicate progress towards elimination of the disease in the municipality, high rates continue to be detected in municipal sub-regions. The following question can thus be posed: over how wide a geographical area could the disease be thoroughly eliminated, given this heterogeneity within a small municipality?

[Epidemiological aspects of leprosy: a spatial approach]. / Aspectos epidemiológicos da hanseníase: uma abordagem espacial.

The objective of this study was to identify spatial patterns in the occurrence of leprosy in Duque de Caxias, a municipality (county) with high endemicity for the disease in the State of Rio de Janeiro, Brazil. The authors selected all new leprosy cases reported to the Brazilian National Database on Diseases of Notification (SINAN) from 1998 to 2006. The analysis was performed according to three-year periods, followed by spatial analysis according to the local empirical Bayesian method and calculation of global (Moran) and local (LISA) spatial autocorrelation. The analysis showed marked improvement in the epidemiological situation associated with earlier diagnosis. There was a reduction in the proportion of cases with grade II leprosy, from 13.6% to 8.6% (p = 0.04), and increased detection of cases with the indeterminate form, from 10.3% to 18% (p = 0.00). Spatial analysis identified a cluster in the South-Northwest of the municipality, not directly related to the actions or decentralization campaign, proving to be an important tool for identifying critical areas for the endemic and assessing the impact of strategic measures to combat the disease.

Aspectos epidemiológicos da hanseníase: uma abordagem espacial / Epidemiological aspects of leprosy: a spatial approach

O objetivo foi identificar o padrão espacial da ocorrência da hanseníase em Duque de Caxias, município de alta endemicidade da doença no Estado do Rio de Janeiro, Brasil. Foram selecionados todos os casos novos de hanseníase registrados no banco do Sistema de Informação de Agravos de Notificação (SINAN), entre 1998 e 2006. Realizou-se análise por período subdividido a cada três anos, seguido de análise espacial por meio da estimativa bayesiana empírica local e do cálculo da autocorrelação espacial global (Moran) e local (LISA). A análise mostrou melhora acentuada do quadro epidemiológico, com o diagnóstico mais precoce. Houve redução da proporção de casos com grau II de 13,6% para 8,6% (p = 0,04). Verificou-se aumento da detecção de casos com forma indeterminada, de 10,3% para 18% (p = 0,00). A análise espacial identificou cluster na faixa sul-noroeste, não relacionado diretamente às ações de campanhas ou descentralização, mostrando ser uma ferramenta importante para identificação de áreas críticas da endemia e para avaliação do impacto das ações estratégias de combate à doença.

The objective of this study was to identify spatial patterns in the occurrence of leprosy in Duque de Caxias, a municipality (county) with high endemicity for the disease in the State of Rio de Janeiro, Brazil. The authors selected all new leprosy cases reported to the Brazilian National Database on Diseases of Notification (SINAN) from 1998 to 2006. The analysis was performed according to three-year periods, followed by spatial analysis according to the local empirical Bayesian method and calculation of global (Moran) and local (LISA) spatial autocorrelation. The analysis showed marked improvement in the epidemiological situation associated with earlier diagnosis. There was a reduction in the proportion of cases with grade II leprosy, from 13.6% to 8.6% (p = 0.04), and increased detection of cases with the indeterminate form, from 10.3% to 18% (p = 0.00). Spatial analysis identified a cluster in the South-Northwest of the municipality, not directly related to the actions or decentralization campaign, proving to be an important tool for identifying critical areas for the endemic and assessing the impact of strategic measures to combat the disease.

[Hansen's disease, social conditions, and deforestation in the Brazilian Amazon]. / Hanseníase, condições sociais e desmatamento na Amazônia brasileira.

OBJECTIVE: To analyze the association between social and environmental indicators and the Hansen's disease new case detection rate (HNCDR) in the Brazilian Amazon. METHODS: This ecological study was based on the new cases of Hansen's disease reported to the Brazilian Disease Surveillance System SINAN in 2006. Analyses were performed considering 105 micro-regions formed by adjacent municipalities with economic and social similarities. HNCDRs per 10 000 people were calculated. Independent variables were total area deforested (km(2)) in each micro-region until 2006; proportion of people living in households with rudimentary septic tanks; proportion of people living in households with water supply from wells; and human development index (HDI) in 2000. Local empirical Bayes smoothing was applied to HNCDR. Analyses were carried out to determined correlations and differences between means (analysis of variance) for a significance level of 5%. The Kernel technique was used to investigate the geographic distribution of events of interest for all the study indicators. RESULTS: A positive correlation was observed between HNCDR and total deforested area (r = 0.50; P < 0.000) and percent of households with rudimentary septic tanks (r = 0.49; P < 0.000). HDI was inversely correlated with HNCDR: the higher the HDI, the lower the HNCDR (r = -0.36; P < 0.000). Considering the entire region, proportion of households with water from wells was not associated with NCDR. CONCLUSIONS: The Hansen's disease new case detection rate, which reflects the magnitude of disease, is associated with social conditions and land settlement practices in the Brazilian Amazon.

Hanseníase, condições sociais e desmatamento na Amazônia brasileira / Hansen's disease, social conditions, and deforestation in the Brazilian Amazon

Objetivo: Analisar a associação entre indicadores sociais e ambientais e o coeficiente de detecção de hanseníase (CDH) na Amazônia brasileira. Métodos: Neste estudo ecológico, foram selecionados os registros de casos novos de hanseníase no ano de 2006 da base de dados do Sistema de Informação de Agravos de Notificação (SINAN) e calculados os CDHs por 10 000 habitantes. As análises foram realizadas considerando-se 105 microrregiões formadas por municípios adjacentes com semelhanças econômicas e sociais. As variáveis independentes foram área total (km²) desmatada nas microrregiões até 2006; proporção de residentes em domicílios com fossa rudimentar; proporção de residentes em domicílios abastecidos com água de poço; e índice de desenvolvimento humano (IDH) do ano de 2000. O coeficiente CDH foi suavizado pelo método Bayesiano empírico local. As análises foram conduzidas por meio de correlação e diferenças de médias (ANOVA) com nível de significância de 5 por cento. A técnica de Kernel foi utilizada para investigar a distribuição geográfica dos eventos de interesse para todos os indicadores analisados. Resultados: Verificou-se correlação positiva dos CDHs com o total de área desmatada (r = 0,50; P < 0,000) e a proporção de domicílios com fossa rudimentar (r = 0,49; P < 0,000). O IDH apresentou comportamento inverso ao CDH - quanto maior o IDH, menor o CDH (r = -0,36; P < 0,000). A variável proporção de domicílios com abastecimento de água de poço não apresentou associação com o CDH quando analisada toda a região. conclusões: O coeficiente de detecção de hanseníase, que representa a magnitude da doença, está associado aos indicadores de condições de vida e ao modo de ocupação territorial da Amazônia.

Objective: To analyze the association between social and environmental indicators and the Hansen's disease new case detection rate (HNCDR) in the Brazilian Amazon. Methods: This ecological study was based on the new cases of Hansen's disease reported to the Brazilian Disease Surveillance System SINAN in 2006. Analyses were performed considering 105 micro-regions formed by adjacent municipalities with economic and social similarities. HNCDRs per 10 000 people were calculated. Independent variables were total area deforested (km²) in each micro-region until 2006; proportion of people living in households with rudimentary septic tanks; proportion of people living in households with water supply from wells; and human development index (HDI) in 2000. Local empirical Bayes smoothing was applied to HNCDR. Analyses were carried out to determined correlations and differences between means (analysis of variance) for a significance level of 5 percent. The Kernel technique was used to investigate the geographic distribution of events of interest for all the study indicators. Results: A positive correlation was observed between HNCDR and total deforested area (r = 0.50; P < 0.000) and percent of households with rudimentary septic tanks (r = 0.49; P < 0.000). HDI was inversely correlated with HNCDR: the higher the HDI, the lower the HNCDR (r = -0.36; P < 0.000). Considering the entire region, proportion of households with water from wells was not associated with NCDR. Conclusions: The Hansen's disease new case detection rate, which reflects the magnitude of disease, is associated with social conditions and land settlement practices in the Brazilian Amazon.