Análise espacial da taxa de detecção de casos suspeitos de síndrome congênita pelo vírus Zika, Maranhão, 2015 a 2018

RESUMO: Objetivo: Identificar padrões espaciais em casos de lactentes com alterações de crescimento e desenvolvimento relacionadas à infecção pelo vírus Zika e outras etiologias infecciosas (neste trabalho denominado de síndrome congênita pelo vírus Zika), notificados no Maranhão de 2015 a 2018 e sua relação com variáveis socioeconômicas e demográficas. Métodos: Estudo ecológico de casos suspeitos notificados de síndrome congênita pelo vírus Zika nos 217 municípios do Maranhão, Brasil. Calculou-se a autocorrelação espacial pelos índices de Moran local e global (I) univariado e bivariado da taxa de detecção de casos suspeitos de síndrome congênita pelo vírus Zika com índice de desenvolvimento humano municipal, densidade demográfica, índice de Gini e tempo de emancipação político-administrativa dos municípios. O índice de Moran local foi calculado para localizar clusters com autocorrelação espacial significativa. Resultados: Houve autocorrelação espacial na análise univariada da taxa municipal de detecção de casos suspeitos de síndrome congênita pelo vírus Zika (I=0,494; p=0,001) e, na análise bivariada, correlação positiva da taxa de detecção de casos suspeitos com índice de desenvolvimento humano municipal (I=0,252; p=0,001), densidade demográfica (I=0,338; p=0,001) e tempo de emancipação dos municípios (I=0,134; p=0,001). Não houve correlação significativa da taxa de detecção de casos suspeitos com o índice de Gini (I= -0,033; p=0,131). Cinco clusters de alta detecção de casos suspeitos foram encontrados em áreas distintas do estado. Conclusões: Os municípios com maior índice de desenvolvimento humano municipal, maior densidade demográfica e mais tempo de emancipação político-administrativa tiveram mais casos suspeitos notificados de síndrome congênita pelo vírus Zika.

Autoregressive spatial modeling of possible cases of dengue, chikungunya, and Zika in the capital of Northeastern Brazil

INTRODUCTION:

Dengue, chikungunya, and Zika are a growing global health problem. This study analyzed the spatial distribution of dengue, chikungunya, and Zika cases in São Luís, Maranhão, from 2015 to 2016 and investigated the association between socio-environmental and economic factors and hotspots for mosquito proliferation.

METHODS:

This was a socio-ecological study using data from the National Information System of Notifiable Diseases. The spatial units of analysis were census tracts. The incidence rates of the combined cases of the three diseases were calculated and smoothed using empirical local Bayes estimates. The spatial autocorrelation of the smoothed incidence rate was measured using Local Moran's I and Global Moran's I. Multiple linear regression and spatial autoregressive models were fitted using the log of the smoothed disease incidence rate as the dependent variable and socio-environmental factors, demographics, and mosquito hotspots as independent variables.

RESULTS:

The findings showed a significant spatial autocorrelation of the smoothed incidence rate. The model that best fit the data was the spatial lag model, revealing a positive association between disease incidence and the proportion of households with surrounding garbage accumulation.

CONCLUSIONS:

The distribution of dengue, chikungunya, and Zika cases showed a significant spatial pattern, in which the high-risk areas for the three diseases were explained by the variable "garbage accumulated in the surrounding environment,” demonstrating the need for an intersectoral approach for vector control and prevention that goes beyond health actions.

Spatial analysis of probable cases of dengue fever, chikungunya fever and zika virus infections in Maranhao State, Brazil

Dengue fever, chikungunya fever, and zika virus infections are increasing public health problems in the world, the last two diseases having recently emerged in Brazil. This ecological study employed spatial analysis of probable cases of dengue fever, chikungunya fever, and zika virus infections reported to the National Mandatory Reporting System (SINAN) in Maranhao State from 2015 to 2016. The software GeoDa version 1.10 was used for calculating global and local Moran indices. The global Moran index identified a significant autocorrelation of incidence rates of dengue (I=0.10; p=0.009) and zika (I=0.07; p=0.03). The study found a positive spatial correlation between dengue and the population density (I=0.31; p<0.001) and a negative correlation with the Performance Index of Unified Health System (PIUHS) by basic care coverage (I=-0.08; p=0.01). Regarding chikungunya fever, there were positive spatial correlations with the population density (I=0.06; p=0.03) and the Municipal Human Development Index (MHDI) (I=0.10; p=0.002), and a negative correlation with the Gini index (I=-0.01; p<0.001) and the PIUHS by basic care coverage (I=-0.18; p<0.001). Lastly, we found positive spatial correlations between Zika virus infections and the population density (I=0.13; p=0.005) and the MHDI (I=0.12; p<0.001), as well as a negative correlation with the Gini index (I=-0.11; p<0.001) and the PIUHS by basic care coverage (I=-0.05; p=0.03). Our results suggest that several socio-demographic factors influenced the occurrence of dengue fever, chikungunya fever, and zika virus infections in Maranhao State.

Synthesis and Properties of Lanthanide Incorporated Mesoporous Molecular Sieves

Nanostructured lanthanum and cerium incorporated MCM-41 molecular sieves were synthesized via a hydrothermal method using cethyltrimethylammonium bromide as template and trimethylammonim hydroxide as mineralizer. Characterization of these materials by X-ray diffraction and nitrogen adsorption indicates that the resulting materials possess an MCM-41-like mesoporous structure. Atomic absorption and infrared spectroscopy studies revealed the presence of La and Ce in these materials. Their BET surface areas were ca. 590 and 700 m(2)/g for La- and CeMCM-41, respectively, whereas the average mesopore diameters were in the range between 3.0 and 3.5 nm. Total acidity determined by n-butylamine adsorption showed that the samples possess from weak to strong acid sites, the strengths of which are much higher for CeMCM-41 than for LaMCM-41. Adsorption energy distributions evaluated from low pressure adsorption isotherms indicate that the amount of surface hydroxyls is also higher for the cerium containing materials. Copyright 1999 Academic Press.