ABSTRACT
Objective To investigate the spatial distribution characteristics and patterns of congenital syphilis in China,and to make suggestions and recommendations for precise prevention of motherto-child transmission of syphilis.Methods The geographic information system software ArcGIS 10.0 was used to conduct exploratory spatial data analysis on the basis of congenital syphilis cases reported from 31 provinces,autonomous regions and municipalities directly under the central government in 2010 and 2015.Results In 2015,a total of 7 251 congenital syphilis cases were reported,which decreased by 40.00％ compared with the case number in 2010 (12 084 cases).The global spatial autocorrelation analysis revealed a positive spatial autocorrelation in the number of reported cases at the county level in China between 2010 and 2015,with Global Moran's I indices of 0.46 and 0.37,respectively.The degree of spatial clustering of congenital syphilis was lower in 2015 than in 2010.The local spatial autocorrelation analysis was further performed to output the hot-spot mappings of congenital syphilis at the county level in 2010 and 2015.In 2010,207 hot-spot counties with a high number of congenital syphilis cases (＞ 12 cases) were identified,and these counties were mainly distributed in 3 core areas including southwest China (Chongqing,eastern Sichuan and northern Guizhou),eastern China (southern Jiangsu,Zhejiang and northern Fujian),and southern and central China (Guangxi,Guangdong and mid-east Hunan).In 2015,72 hot-spot counties with a high number of congenital syphilis cases (＞ 12 cases)were identified,and mainly distributed in 5 core areas including northwest China (western Xinjiang),mid-east Qinghai,southwest and central China (Sichuan,Chongqing,Guizhou and Hunan),eastern China (Jiangsu,Anhui),and southern China and eastern China (Guangdong and Fujian).Conclusions In Zhejiang,Shanghai,Guangdong,Guangxi,Sichuan and Chongqing,the number of hot-spot counties with a high reported congenital syphilis cases was significantly lower in 2015 than in 2010,suggesting that the prevention of mother-to-child transmission of syphilis had achieved a primary success.At present,hot-spots counties with a high number of congenital syphilis cases are mainly distributed in western Xinjiang,mid-east Qinghai,Sichuan,Chongqing,Guizhou and so on,Therefore,the prevention of mother-to-child transmission of syphilis should be strengthened in these areas.
ABSTRACT
A análise exploratória de dados espaciais, empregada para identificação de arranjos urbano-regionais entre os municípios brasileiros, mostrou-se adequada a estudos de conjuntos amplos de unidades observacionais (áreas), possibilitando resultados reveladores de dinâmicas territoriais e de padrões de correlações espaciais entre municípios. Associada a informações de centralidade (rede de cidades), conectividade (sistema viário principal) e densidade dos movimentos pendulares da população, evidenciou conjuntos mais amplos do que as aglomerações urbanas apontadas em estudos precedentes. Tais conjuntos correspondem a morfologias que transcendem as tradicionais aglomerações definidas por manchas contínuas de ocupação entre mais de um município, constituindo-se em categorias espaciais ainda mais complexas do ponto de vista de concentração populacional, econômica e funcional e densidade de deslocamentos de pessoas. Este artigo coloca em discussão o uso dessa técnica de análise, suas possibilidades e limitações.
El análisis exploratorio de datos espaciales, empleado para la identificación de ordenamientos urbano-regionales entre municipios brasileños, se mostró adecuado para estudios de conjuntos amplios de unidades observacionales (áreas), posibilitando resultados reveladores de dinámicas territoriales y patrones de correlaciones espaciales entre municipios. Asociado a informaciones sobre centralidad (red de ciudades), conectividad (sistema vial principal) y densidad de los movimientos pendulares de población, evidenció conjuntos más amplios que las aglomeraciones urbanas apuntadas en estudios precedentes. Tales conjuntos corresponden a morfologías que transcienden las tradicionales aglomeraciones definidas por manchas continuas de ocupación de más de un municipio, constituyéndose en categorías espaciales todavía más complejas desde el punto de vista de la concentración poblacional, económica y funcional, y de densidad de desplazamientos de personas. Este artículo pone en tela de juicio el uso de esa técnica de análisis, sus posibilidades y limitaciones.
Exploratory analysis of spatial data, carried out to identify different regional urban arrangements between Brazilian municipalities, proved to be useful for studies on various areas of observation. This makes it possible to arrive at important findings related to territorial dynamics and patterns of spatial correlations between municipalities. This analysis, associated with information on centrality (networks of cities), connectivity (general street and highway systems) and density of pendular movements of the population, showed groupings that extend beyond the large urban agglomerations found in earlier studies. These newer types of groupings correspond to morphologies that transcend traditional agglomerations defined by continuous urban sprawls that involve more than one municipality. They consist of spatial categories that are even more complex from the point of view of demographic, economic and functional concentrations and in terms of the density of human displacements. This article brings up the discussion of the use of this analysis technique, together with its possibilities and limitations.