جستجوی مقالات مرتبط با کلیدواژه « همبستگی اسپیرمن » در نشریات گروه « عمران »

Foot-and-Mouth (FMD) is a viral and contagious disease that endangers both domestic and wild animals and this disease has caused a lot of social and economic damage to the livestock industry in Iran. Considering the endemism of this disease in Iran, the main purpose of this study is to investigate the temporal trend, discover spatial and spatio-temporal clusters and determine the impact of environmental factors and model the disease in order to better understand the spatio-temporal epidemiology of FMD in Iran. In this study, data related to the incidence of disease as well as environmental variables including meteorological variables, vegetation and topography of the region were used. This study was performed on 12442 cases of registered diseases in the years 1396-1387 in the city for the whole of Iran. First, general auto correlation indices including Moranchr('39')I index, General G index and Ripleychr('39')s K index were used to investigate the distribution of the spatial pattern of the disease. Local Moran and the Gatis-Ord G* index were used to detect hot and cold spots. Then, with the help of the points of occurrence and time of the disease, spatial and spatio-temporal clusters of the disease were discovered. Spearmanchr('39')s correlation and linear regression analysis were used to evaluate the type and severity of correlation between environmental parameters and disease incidence. The results showed that the maximum incidence is in spring (44%) and the minimum incidence is in summer (15%). The months of Ordibehesht, Farvardin, Khordad and Dey, with a total of 6650 cases, were the most riskful months of the year, respectively. Autocorrelation tests showed the distribution of FMD clusters for every 10 years studied. The results of the local Moran index and the Gatis-Ord G* showed that the foci of this disease are still active in Iran and parts of Semnan, Tehran, Markazi, Fars, Lorestan, Khorasan Razavi and East Azerbaijan provinces are hot spots of FMD. In spatial scan, 8 clusters were identified, which confirmed the results of Moran and the Gatis-Ord G* index. In the spatio-temporal scan, 5 clusters were discovered that were consistent with the results of the spatial scan. Spearman analysis showed that there is a positive correlation between the incidence of the disease and vegetation, which is decreasing from the beginning to the end of the year and has a negative relationship in winter. Also, a positive and increasing correlation was observed with wind speed and precipitation from the beginning to the end of the year. In addition, a positive correlation between the incidence of the disease and altitude and a negative relationship with the direction of the slope was calculated. Linear regression analysis was also used to evaluate the effect of variables, which resulted in confirming Spearman correlation outputs. The results of the model showed that vegetation and topography are the most important environmental factors that affect the prevalence of snow fever in the region. The results of this study identify areas that are at higher risk and need more planning and attention to control the disease.

Epidemic diseases are a public health concern that has many economic costs and health problems. The geographical distribution of these diseases is a spatial and temporal process. By understanding the process and identifying the factors that affect it, we can take an effective step in preventing and treating these diseases. Brucellosis is one of the most important zoonotic diseases in Iran. To better understand the epidemiology of this disease in northern Iran, the main objectives of this study are to review the annual and monthly trends, to identify spatial and space-time clusters, and to determine the impact of ecological variables. The study was conducted on 6895 patients from April 2009 to March 2017. Data of disease incidence with environmental data including average temperature, maximum temperature, minimum temperature, number of freezing days, humidity, precipitation, evaporation, wind speed, vegetation, elevation, slope and aspect in Golestan, Mazandaran and Gilan provinces as Monthly collected. Global Moran's I was used to investigate spatial autocorrelation. Spatial scan, local moran’s I and space-time scan were used to identify clusters. Spearman correlation was used to study the effect of ecological parameters. The results showed that brucellosis was clustered in northern Iran. The incidence was maximum in the summer (34%) and at least in winter (16%). The months of May, June, July and August were the most susceptible months with a total of 3396 patients. In Local Moran's I, the cities of Minudasht, Kurdkuy, Bandar Ghaz and Galughah were identified as high-high, the cities of Lahijan, Astaneh Ashrafieh and Rasht as low-low and the shaft town was identified as high-low region. In the spatial scan, 10 classes were discovered, most of which were located in Golestan and Mazandaran, and only one was in Gilan. The first and most dangerous classes were in Golestan province. In a space-time scan, 4 classes were identified. The results obtained from the Moran index and spatial scan and space-time scan were confirmed by each other. Spearman showed a positive correlation between incidence of disease with evaporation, aspect, maximum temperature, height and mean temperature, and negative correlation with precipitation, moisture and vegetation. This study shows that in the north of Iran, we see an increase in the incidence of this disease from west to east. Brucellosis is higher in spring and summer in mountainous regions with warm and dry weather. This information can be used for the control strategy used by decision-makers in the field of health.