[Leprosy surveillance in Olinda, Brazil, using spatial analysis techniques]

Modelagem espacial da hanseníase no estado da Bahia, Brasil, (2001-2015) e determinantes sociais da saúde

Resumo O trabalho analisa a distribuição espacial da hanseníase na Bahia e os determinantes sociais relacionados. Estudo ecológico com dados de hanseníase do período 2001-2015. Três indicadores epidemiológicos foram selecionados: coeficiente de detecção na população geral e em menores de 15 anos e a taxa de casos novos com grau II de incapacidade. Os indicadores foram suavizados pelo Modelo Bayesiano Empírico Local e aplicou-se estatística de Moran Global e Local. As variáveis independentes foram selecionadas a partir do Censo IBGE-2010. Regressões multivariadas foram empregadas, seguidas de regressão espacial. Observou-se distribuição heterogênea no estado, com concentração no eixo norte-oeste e região sul. Para o coeficiente de detecção geral, cinco variáveis compuseram o modelo: densidade demográfica, proporção da população urbana, renda per capita, proporção de extremamente pobres e domicílios com mais de três pessoas por dormitório. A proporção de analfabetismo compôs o modelo final para a taxa de grau II de incapacidade física. Não foram identificados determinantes da ocorrência da doença em menores de 15 anos. A modelagem utilizada contribuiu para demonstrar a heterogeneidade espacial e os determinantes sociais da doença na Bahia, colocando em evidência a complexidade do problema.

Hanseníase e carência social: definição de áreas prioritárias em estado endêmico do Nordeste brasileiro

RESUMO: Introdução: A hanseníase é uma doença que guarda estreita relação com as condições sociais e econômicas. O Brasil é o único país que ainda não alcançou a meta de eliminação da doença como problema de saúde pública. Objetivo: Este trabalho teve como objetivo analisar a associação entre a carência social dos municípios baianos e a detecção de casos novos de hanseníase na população, como instrumento para a definição de áreas prioritárias para intervenção. Metodologia: Trata-se de um estudo ecológico realizado no estado da Bahia, no período de 2001 a 2015. Variáveis analisadas: coeficiente de detecção casos novos, índice de carência social (ICS) e hanseníase em menores de 15 anos. O ICS foi construído com base em quatro variáveis: índice de performance socioeconômica, renda per capita, proporção de extremamente pobres e densidade domiciliar. Na análise espacial, foram utilizadas modelagem bayesiana empírica local e estatística de Moran global e local. Na análise estatística, foram empregados regressão multivariada, espacial e logística, cálculo do odds ratio e análise de variância. Resultados: A hanseníase apresentou distribuição heterogênea no estado, com concentração no eixo norte-oeste e sul. Dos municípios, 60,4% (n = 252) apresentaram muito baixa condição de vida. Observou-se associação entre as condições de vida e a detecção da hanseníase, com maiores coeficientes no grupo de município com melhor condição de vida (p < 0,001). Conclusão: As piores condições atuaram como um impeditivo ao diagnóstico, ao mesmo tempo que ampliaram o risco de adoecimento. As boas condições possuem efeito inverso.

Spatial approach of leprosy in the State of São Paulo, 2009-2012

BACKGROUND

Leprosy is a chronic, infectious disease that affects the skin and the peripheral nervous system and can lead to permanent disability and/or deformity.

OBJECTIVES

To identify the distribution and to quantify the spatial dependence of the detection rates of new cases of Hansen's disease in the State of São Paulo, correlating with socioeconomic variables.

METHODS

Ecological and exploratory study with data on the detection rates of new cases of Hansen's disease among residents of São Paulo State municipalities between 2009-2012. The average rate per 10,0000 inhabitants was estimated. Information on the proportion of the population with low-income and the values of the Gini index were obtained. Thematic maps were constructed with the average rates and with those obtained by the Bayesian estimator; Moran and Kernel maps were also constructed. Spatial analysis by TerraView program. An alpha of 5% was adopted.

RESULTS

In total, 7163 new cases of Hansen's disease were recorded throughout the state. The average rate per 10,000 inhabitants, was 0.71 (SD = 1.06), ranging from zero to 12.87, with higher rates in the west of the State, in the metropolitan area of the capital and the Paraiba Valley. Municipalities with high priority for intervention were located in the west and northwest of the State. There was no correlation between rates with Gini index and low income.

STUDY LIMITATIONS

Possible inconsistency of Hansen's disease notification database regarding information quantity, quality and processing.

CONCLUSIONS

This study identified the distribution and quantified the spatial dependence of the detection rates of new cases of Hansen's disease in the State of São Paulo, corroborating previous studies and serving as a subsidy to health managers.

Spatial patterns of leprosy in a hyperendemic state in Northern Brazil, 2001-2012

OBJECTIVE

To describe the spatial patterns of leprosy in the Brazilian state of Tocantins.

METHODS

This study was based on morbidity data obtained from the Sistema de Informações de Agravos de Notificação (SINAN - Brazilian Notifiable Diseases Information System), of the Ministry of Health. All new leprosy cases in individuals residing in the state of Tocantins, between 2001 and 2012, were included. In addition to the description of general disease indicators, a descriptive spatial analysis, empirical Bayesian analysis and spatial dependence analysis were performed by means of global and local Moran's indexes.

RESULTS

A total of 14,542 new cases were recorded during the period under study. Based on the annual case detection rate, 77.0% of the municipalities were classified as hyperendemic (> 40 cases/100,000 inhabitants). Regarding the annual case detection rate in < 15 years-olds, 65.4% of the municipalities were hyperendemic (10.0 to 19.9 cases/100,000 inhabitants); 26.6% had a detection rate of grade 2 disability cases between 5.0 and 9.9 cases/100,000 inhabitants. There was a geographical overlap of clusters of municipalities with high detection rates in hyperendemic areas. Clusters with high disease risk (global Moran's index: 0.51; p < 0.001), ongoing transmission (0.47; p < 0.001) and late diagnosis (0.44; p < 0.001) were identified mainly in the central-north and southwestern regions of Tocantins.

CONCLUSIONS

We identified high-risk clusters for transmission and late diagnosis of leprosy in the Brazilian state of Tocantins. Surveillance and control measures should be prioritized in these high-risk municipalities.

Spatial analysis of new cases of leprosy in the State of Espírito Santo, Brazil, between 2004 and 2009

INTRODUCTION

Leprosy in Brazil is a public health issue, and there are many regions in the State of Espírito Santo with high endemic incidence levels of leprosy, characterizing this state as a priority for leprosy programs. The aim of this study was to determine the spatial distribution of coefficients of new cases of leprosy in the State of Espírito Santo, Brazil.

METHODS

We conducted a descriptive and ecologic study based on the spatial distribution of leprosy in the State of Espírito Santo between 2004 and 2009. Data were gathered from the available records of the Espírito Santo State Health Secretary. The global and local Bayesian empirical methods were used to produce an estimate of leprosy risk, smoothing the fluctuation effects of the detection coefficients.

RESULTS

The study resulted in a coefficient adjustment of new cases in 10 towns that changed their classification, among which, 2 went from low to medium, 4 from medium to high, 3 from high to very high, and 1 from very high to hyper-endemic. An average variation of 1.02, fluctuating between 0 and 12.39 cases/100,000 inhabitants, was found in a comparative calculation between the Local Ebest value and the average coefficient of new leprosy cases in the State of Espírito Santo.

CONCLUSIONS

The spatial analysis of leprosy favors the establishment of control strategies with a better cost-benefit relationship since it reveals specific and priority regions, thereby enabling the development of actions that can interfere in the transmission chain.

Aspectos epidemiológicos da hanseníase: uma abordagem espacial

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.

Clusters of leprosy transmission and of late diagnosis in a highly endemic area in Brazil: focus on different spatial analysis approaches

OBJECTIVE

The Brazilian National Hansen's Disease Control Program recently identified clusters with high disease transmission. Herein, we present different spatial analytical approaches to define highly vulnerable areas in one of these clusters.

METHOD

The study area included 373 municipalities in the four Brazilian states Maranhão, Pará, Tocantins and Piauí. Spatial analysis was based on municipalities as the observation unit, considering the following disease indicators: (i) rate of new cases/100,000 population, (ii) rate of cases <15 years/100,000 population, (iii) new cases with grade-2 disability/100,000 population and (iv) proportion of new cases with grade-2 disabilities. We performed descriptive spatial analysis, local empirical Bayesian analysis and spatial scan statistic.

RESULTS

A total of 254 (68.0%) municipalities were classified as hyperendemic (mean annual detection rates >40 cases/100,000 inhabitants). There was a concentration of municipalities with higher detection rates in Pará and in the center of Maranhão. Spatial scan statistic identified 23 likely clusters of new leprosy case detection rates, most of them localized in these two states. These clusters included only 32% of the total population, but 55.4% of new leprosy cases. We also identified 16 significant clusters for the detection rate <15 years and 11 likely clusters of new cases with grade-2. Several clusters of new cases with grade-2/population overlap with those of new cases detection and detection of children <15 years of age. The proportion of new cases with grade-2 did not reveal any significant clusters.

CONCLUSIONS

Several municipality clusters for high leprosy transmission and late diagnosis were identified in an endemic area using different statistical approaches. Spatial scan statistic is adequate to validate and confirm high-risk leprosy areas for transmission and late diagnosis, identified using descriptive spatial analysis and using local empirical Bayesian method. National and State leprosy control programs urgently need to intensify control actions in these highly vulnerable municipalities.

Spatial analysis of leprosy incidence and associated socioeconomic factors

OBJECTIVE

To identify clusters of the major occurrences of leprosy and their associated socioeconomic and demographic factors.

METHODS

Cases of leprosy that occurred between 1998 and 2007 in São José do Rio Preto (southeastern Brazil) were geocodified and the incidence rates were calculated by census tract. A socioeconomic classification score was obtained using principal component analysis of socioeconomic variables. Thematic maps to visualize the spatial distribution of the incidence of leprosy with respect to socioeconomic levels and demographic density were constructed using geostatistics.

RESULTS

While the incidence rate for the entire city was 10.4 cases per 100,000 inhabitants annually between 1998 and 2007, the incidence rates of individual census tracts were heterogeneous, with values that ranged from 0 to 26.9 cases per 100,000 inhabitants per year. Areas with a high leprosy incidence were associated with lower socioeconomic levels. There were identified clusters of leprosy cases, however there was no association between disease incidence and demographic density. There was a disparity between the places where the majority of ill people lived and the location of healthcare services.

CONCLUSIONS

The spatial analysis techniques utilized identified the poorer neighborhoods of the city as the areas with the highest risk for the disease. These data show that health departments must prioritize politico-administrative policies to minimize the effects of social inequality and improve the standards of living, hygiene, and education of the population in order to reduce the incidence of leprosy.

Migração e hanseníase em Mato Grosso

Trabalhos de geografia médica sobre hanseníase discutem o papel da ocupação dos territórios como fundamento da permanência de focos leprógenos. No Brasil, os Estados que apresentam as mais altas taxas de detecção, historicamente, se localizam na região amazônica, o que evidencia uma desigual evolução regional da doença. Este trabalho analisa a evolução da hanseníase contextualizando os processos migratórios que ocorreram no Estado de Mato Grosso a partir da segunda metade do século XX. O crescimento econômico ocorrido no Estado nas décadas de 1970, 1980 e 1990 provocou taxas de crescimento populacional maiores que a média nacional. Os dados analisados permitem uma associação entre o crescimento e dispersão dos coeficientes de detecção da hanseníase com o processo de ocupação do território mato-grossense. Entretanto, a permanência da hanseníase em municípios da Baixada Cuiabana, assim como em outros municípios que sofreram perda de população, parece apontar a existência de contextos geográficos de diferentes vulnerabilidades à produção social da doença. A migração explicaria a instalação e evolução da hanseníase, entretanto consideramos que a manutenção da endemia pode estar associada a fatores contextuais relacionados com o ambiente.

Decentralization of leprosy control actions in the micro-region of Almenara, State of Minas Gerais

This study analyzes the decentralization process of Leprosy control actions for Family Health Strategy units in the cities of the Almenara micro-region, in the state of Minas Gerais, Brazil. This qualitative research, based on the concept "Technological Organization of Work", was carried out in nine municipalities. Semi-structured interviews and document research were used for data collection. Forty-five interviews with care providers and health managers were conducted. The data collection took place between November 2007 and February 2008. Content Analysis was utilized to study the data and results indicate that the cities present different levels of decentralization and that the process was determined based on local specifications and on the engagement of care providers and health managers. Several cities kept a reference team to provide support to primary health care. The conclusion is that the decentralization process is a strategy that proves to be useful in facing Leprosy in the micro-region.

Leishmaniose visceral no município de Várzea Grande, Estado de Mato Grosso, no período de 1998 a 2007

O presente trabalho objetivou descrever a epidemiologia e a expansão da leishmaniose visceral no município de Várzea Grande/Mato Grosso/Brasil de 1998 a 2007. Foram notificados 48 casos humanos, com taxa de incidência de até 11,7 por 100.000 habitantes, preferencialmente em crianças e adolescentes de ambos os sexos, com acentuada expansão geográfica da doença no município.

Desigualdade social, crescimento urbano e hanseníase em Manaus: abordagem espacial

OBJETIVO: Analisar a epidemiologia de hanseníase segundo a distribuição espacial e condições de vida da população. MÉTODOS: Estudo ecológico baseado na espacialização da hanseníase em Manaus (AM), entre 1998 e 2004. Os 4.104 casos obtidos do Sistema de Informações de Agravos de Notificação foram georreferenciados de acordo com a localização dos endereços em 1.536 setores censitários urbanos, por meio de quatro técnicas: correios (73,7% dos endereços encontrados); Programa de Cadastro de Logradouros (7,3%); Programa Saúde da Família (2,1%) e folhas de coleta do Instituto Brasileiro de Geografia e Estatística (1,5%). Para cálculo do coeficiente de detecção utilizou a população de 2001. Na análise espacial foi aplicado o método bayesiano empírico local para produzir uma estimativa do risco da hanseníase, suavizando o efeito da flutuação das taxas, quando calculadas para pequenas áreas. Para análise da associação entre espacialização e fatores de risco empregou-se a regressão logística, tendo como variáveis explicativas a ocorrência de casos em menores de 15 anos (indicador de gravidade) e o Índice de Carência Social construído a partir das variáveis do Censo 2000. RESULTADOS: O coeficiente de detecção apresentou-se hiperendêmico em 34,0% dos setores e muito alto em 26,7%. A medida de associação (odds ratio) referente às variáveis explicativas foi significativa. A combinação de baixa condição de vida e ocorrência em menores de 15 anos foi adotada para identificar as áreas prioritárias para intervenção. CONCLUSÕES: A análise espacial da hanseníase mostrou que a distribuição da doença é heterogênea, atingindo mais intensamente as regiões habitadas por grupos em situação de maior vulnerabilidade.

[Leprosy in Espírito Santo State, Brazil: a growing endemic?]

This study provides a trend analysis of leprosy among patients in the State of Espírito Santo, Brazil, from 1980 to 2003. Using temporal series statistical models, an upward trend was identified throughout the period in the overall detection rate (p<0.05), with an apparent stabilization at the end of the period. We also observed an upward trend for the following periods: (i) 1980-1987 in the <15 and >or=50-year age groups and for paucibacillary forms; (ii) 1988-1995 for the 15-19, 20-29, and >or=50-year groups and for multibacillary forms; and (iii) 1996-2003 in the 20-29-year group and paucibacillary forms. The indicators for evaluation of the endemic indicate: stable levels in grade 2 disability (mean of 6%); a proportion of less than 10% of cases in individuals<15 years of age; and a treatment dropout rate of approximately 6%. Prevalence showed a sharp decline. The upward trend can be explained partially by greater surveillance sensitivity, but the high proportion of individuals<15 highlights the need for studies aimed at better knowledge of residual sources of infection, especially in the household.

[Spacial analysis of Leprosy in the microregion of Almenara, MG, Brazil]

Hansen's disease is still considered a public health problem in Brazil. The objective of this ecological study is to analyze the epidemiological status of Hansen's disease in the microregion of Almenara, State of Minas Gerais, according to its spatial distribution and its relations with the socioeconomic conditions of the population. The results of this study classify the microregion as a hyperendemic area and indicate that the health services are not capable of detecting all existing cases, thus contributing to the maintenance of the disease transmission chain. The spatial analysis identified two clusters, one with detection coefficients above and the other below those expected. It is believed that the results of the study will help to establish guidelines for the development and implementation of prevention and control measures for Hansen's disease in the region.

The prevalence of previously undiagnosed leprosy in the general population of northwest bangladesh

BACKGROUND

The prevalence of previously undiagnosed leprosy (PPUL) in the general population was determined to estimate the background level of leprosy in the population and to compare this with registered prevalence and the known PPUL in different levels of contacts of leprosy patients.

METHODOLOGY AND PRINCIPAL FINDINGS

Multistage cluster sampling including 20 clusters of 1,000 persons each in two districts with over 4 million population. Physical examination was performed on all individuals. The number of newly found leprosy cases among 17,862 people above 5 years of age from the cluster sample was 27 (19 SLPB, 8 PB2-5), giving a PPUL rate of 15.1 per 10,000.

CONCLUSIONS AND SIGNIFICANCE

PPUL in the general population is six times higher than the registered prevalence, but three times lower than that in the most distant subgroup of contacts (neighbour of neighbour and social contacts) of leprosy patients in the same area. Full village or neighbourhood surveys may be preferable to contact surveys where leprosy is highly endemic.

[Spatial analysis of leprosy cases treated at public health care facilities in Brazil]

Hansen disease or leprosy is a major endemic disease in Brazil. Well-designed strategies, including decentralization of basic care, are needed to reduce its prevalence. The article begins by describing the structure and supply of services for treating leprosy cases in the country, after which it analyzes the trends in epidemiological and operational indicators, comparing the periods before and after decentralization of services to the municipal (local) level. Finally, spatial analysis allowed identifying the territorial distribution of this endemic and analyzing the pattern of geographic areas according to care provided by health facilities and its evolution. Based on the location of the geographic centers in the census tracts by place of residence, and using spatial smoothing technique based on Kernel estimation, the study constructed domain areas of care for each health facility or unit. Following municipalization of care, there was an increase in the detection and treatment by the municipalities themselves, reducing patient evasion to neighboring counties and causing changes in demand trends, with an increase in use of services by the clientele and important alterations in the epidemiological and operational indicators.

Spatial distribution of leprosy cases in Ribeirão Preto, Brazil, 2004

This cross-sectional study aimed to describe the spatial distribution of leprosy cases in Ribeirão Preto in 2004. The data collection was performed through compulsory notification records in the Epidemiological Surveillance Service of the Municipal Secretary of Health of Ribeirão Preto. The data were geo-coded through the MapInfo program version 7.8 in order to obtain the thematic map. From the 37 cases found, 62% were automatically coded, which revealed good compatibility between the database and the information in the cartographic base. The remaining 38% of the cases were geo-coded interactively. The thematic map analysis and the geo-referenced cases revealed a concentration of cases in the Northern region of the city, traditionally characterized by poor neighborhoods.

Intraurban variations in adult mortality in a large Latin American city

Urbanization is high and growing in low- and middle-income countries, but intraurban variations in adult health have been infrequently examined. We used spatial analysis methods to investigate spatial variation in total, cardiovascular disease, respiratory disease, and neoplasm adult mortality in Buenos Aires, Argentina, a large city within a middle-income country in Latin America. Conditional autoregressive models were used to examine the contribution of socioeconomic inequalities to the spatial patterning observed. Spatial autocorrelation was present in both men and women for total deaths, cardiovascular deaths, and other causes of death (Moran's Is ranging from 0.15 to 0.37). There was some spatial autocorrelation for respiratory deaths, which was stronger in men than in women. Neoplasm deaths were not spatially patterned. Socioeconomic disadvantage explained some of this spatial patterning and was strongly associated with death from all causes except respiratory deaths in women and neoplasms in men and women [relative rates (RR) for 90th vs 10th percentile of percent of adults with incomplete high school and 95% confidence intervals: 1.23 and 1.09-1.39 vs 1.24 and 1.08-1.42 for total deaths in men and women, respectively; 1.36 and 1.15-1.60 vs 1.22 and 1.01-1.47 for cardiovascular deaths; 1.21 and 0.97-1.52 vs 1.07 and 0.85-1.34 for respiratory deaths; 0.94 and 0.85-1.04 vs 1.03 and 0.87-1.22 for neoplasms; and 1.49 and 1.20-1.85 vs 1.63 and 1.31-2.03 for other deaths]. There is substantial intraurban variation in risk of death within cities. This spatial variability was present for multiple causes of death and is partly explained by the spatial patterning of socioeconomic disadvantage. Our results highlight the pervasive role of space and social inequalities in shaping life and death within large cities.

Evolução espaço-temporal dos casos de tuberculose em Ribeirão Preto (SP), nos anos de 1998 a 2002

OBJETIVO: Estabelecer a distribuição espacial da tuberculose no Município de Ribeirão Preto (SP) de 1998 a 2002, buscando verificar a dependência entre sua ocorrência e o espaço. MÉTODOS: Foi utilizada a base de dados secundários Epi-Tb da Secretaria Municipal de Saúde de Ribeirão Preto. O georreferenciamento dos casos de tuberculose foi realizado através do software MapInfo 6.5 e a análise estatística espacial através do software Spring. RESULTADOS: Por meio da análise do padrão espacial existente no decorrer dos anos estudados, foi concluído que para cada ano houve um padrão para a distribuição espacial da tuberculose em Ribeirão Preto, tendo sido identificadas áreas homogêneas de risco para a doença, embora os casos estivessem sempre concentrados em uma faixa da região noroeste do município, que consiste de bairros de classe média e/ou média baixa da população. CONCLUSÃO: Os resultados contribuíram para o conhecimento da distribuição espacial da tuberculose em Ribeirão Preto, em diferentes períodos, ressaltando a importância da categoria espaço como alternativa metodológica para auxiliar no planejamento, monitoramento e avaliação das ações em saúde, com direcionamento mais adequado das intervenções para diminuir as iniqüidades.

Análise de dados espaciais em saúde pública: métodos, problemas, perspectivas

Estudos mostram que a localização espacial dos eventos em saúde e os Sistemas de Informações Geográficas (SIG), têm papel destacado e vêm se tornando mais freqüentes na literatura da área de saúde pública. Entretanto, os métodos e software necessários ao aprofundamento desta abordagem ainda apresentam limitações devido à dificuldade de uso e desconhecimento dos pesquisadores e profissionais da área. O objetivo deste trabalho é apresentar algumas aplicações exemplares de métodos voltados para a análise de padrões espaciais de eventos em saúde, discutindo vantagens, desvantagens e aplicabilidade dos modelos propostos, particularmente no campo dos estudos ecológicos e na análise do uso de serviços de saúde, além de sistematizar o estado da arte da utilização de metodologias de análise espacial na saúde pública.

Spatial analysis of the distribution of leprosy in the State of Ceará, Northeast Brazil

The aim of this study was to describe spatial patterns of the distribution of leprosy and to investigate spatial clustering of incidence rates in the state of Ceará, Northeast Brazil. The average incidence rate of leprosy for the period of 1991 to 1999 was calculated for each municipality of Ceará. Maps were used to describe the spatial distribution of the disease, and spatial statistics were applied to explore large- and small-scale variations of incidence rates. Three regions were identified in which the incidence of leprosy was particularly high. A spatial gradient in the incidence rates was identified, with a tendency of high rates to be concentrated on the North-South axis in the middle region of the state. Moran's I statistic indicated that a significant spatial autocorrelation also existed. The spatial distribution of leprosy in Ceará is heterogeneous. The reasons for spatial clustering of disease rates are not known, but might be related to an heterogeneous distribution of other factors such as crowding, social inequality, and environmental characteristics which by themselves determine the transmission of Mycobacterium leprae.