ABSTRACT
Background: Dengue fever is a rapidly spreading viral infection. The incidence of dengue fever cases in Kerala is still rising from the year 2006 onward in spite of several measures. The pattern of dengue fever distribution is not uniform in all the districts. Only some districts are reporting a high number of cases in every year. Based on this background, the present study conducted to observe and analyze the spatial distribution pattern of dengue fever incidence in Kerala state. Objectives: The objectives of the present study are to assess the spatial auto-correlation of dengue fever incidence in Kerala state and to identify the significant spatial clusters having a high or low incidence of dengue fever in Kerala state. Materials and Methods: The present study is a retrospective observational study using the secondary data of Kerala state. Year wise incidence of dengue fever cases in each district was measured. Since 2011, hierarchical maps of the incidence of dengue fever in different districts were created using QGIS software. Spatial auto-correlation of dengue fever incidence in every year was tested using GeoDa software. Global Moran’s i value was measured in each year, local indicators of spatial association maps prepared to observe the spatial distribution of dengue fever incidence in Kerala. Results: Incidence of dengue fever cases is in increasing trend in every district, but in the year 2014 and 2018, the incidence was decreased compared to the previous year. Among all the years, 2013, 2016, and 2017 showed significant positive global spatial auto-correlation. Kollam district is showed a high-high spatial pattern. Low-low cluster areas were observed in North Kerala from 2011 to 2013 and in central Kerala in the years 2016 and 2018. Conclusion: Spatial distribution of dengue fever incidence is not uniform every year. Kollam district significantly reporting the high incidence and surrounded by high incidence districts. Kannur, Malappuram, Palakkad, Wayanad, Thrissur, and Ernakulam districts significantly reporting the low incidence of dengue fever and they were surrounded by low incidence districts. This type of analysis helps identify areas where control efforts can be intensified strategically thus optimizing resources Larger studies can be conducted at subnation or nation level, to eliminate the border issues between states and for better identification of local spatial clusters of dengue fever incidence.
ABSTRACT
Background: Infant mortality rate (IMR) is globally identified by the policymakers as the marker of health of a population. Objectives: This study aimed to detect the change in hotspots of IMR in Indian states from the year 2000 to 2012, identify hotspots of IMR at district level in selected states from each of the six regions of India and determine the potential predictors of IMR after accounting for spatial autocorrelation. Methods: Ecological study design was used to analyze state and district level data on IMR of India. For the first objective, the data were obtained from Sample Registration System. For the second objective, we classified India into six regions and selected a state in each region that had the highest IMR. The district level data on IMR and potential predictors were obtained from surveys, namely, Annual Health Survey, District Level Household and Facility Survey and Census. Spatio-temporal hotspots of IMR were examined using local indicators of spatial association statistic. Spatial regression was used to identify the potential predictors of IMR after accounting for spatial autocorrelation. Results: Temporal hotspots of IMR were found in the central part of India. Spatial hotspots were identified in districts of Uttar Pradesh. A negative association of IMR existed with female literacy rate, mothers receiving antenatal checkup (%), and people living in urban areas (%). Conclusion: IMR continues to be a problem in the states that have previously shown to be poor performing. Certain districts within these states need emphasis for focused activities.
ABSTRACT
The Media Luna lake-spring was selected as representative of all thermal or no thermal springs in the zone of Valley of Rioverde, a semi-arid vegetation in the North-eastern of Mexico. This system is inhabited by 11 fish species, of which six are native. Four of the native species are endemic to the region and threatened due to touristic pressure and to the introduction of exotic species. The objectives were to determine the characteristics that influence the spatial distribution of the fish species, to analyze their spatial distribution patterns, and to describe the relationships between the different species. The general aim was to establish some basis for the conservation of these fish communities and their habitat. Several sessions were initiated in 1992 through direct observation. Later, between 1998 and 1999 five systematically seasonal sampling sessions were conducted (54 subaquatic transects/session). Finally, the data was updated by sampling in summer 2002 and winter 2006. Through the analysis was performed only for endemics of the region, like Ataeniobius toweri Meek, Cualac tessellatus Miller, Cichlasoma bartoni Bean and C. labridens Pellegrin, in at least one life stage, showed correlation with habitat variables or with other species. For these species, patterns of spatial aggregation and association with other species were observed. These results show a certain degree of specialization of endemic species to some microhabitat characteristics, as well as a significant interaction with other native species which they coexist. In addition, some significant relations between endemic and alien species suggest an antagonist relation. Management actions focused in the touristic use of the spring represent the main threat for these species, followed by an adequate management of exotic species. This study provides basis for future responsible management of these wetlands, where tourism and conservation can be combined. Rev. Biol. Trop. 58 (1): 413- 426. Epub 2010 March 01.
Este estudio se enfocó en los peces de un sistema dulceacuícola en el noreste de México, donde habitan seis especies nativas (cuatro endémicas amenazadas) y cinco exóticas. El objetivo fue establecer los patrones que determinan la distribución espacial, así como las interrelaciones de las especies. Los datos se basan en sesiones de observación directa desde 1992; entre 1998 y 1999 se llevó a cabo un muestreo sistematizado mediante transectos subacuáticos en cinco sesiones estacionales (54 transectos/ sesión), con sesiones adicionales en 2002 y 2006. Sólo las especies endémicas de la región: Ataeniobius toweri, Cualac tessellatus, Cichlasoma bartoni y C. labridens, en al menos un estadio de vida, mostraron correlación significativa con variables del hábitat o con otras especies. También mostraron patrones de agregación y asociación con otras especies nativas o introducidas. Existe especialización de los endémicos a las condiciones de su microhábitat, así como interacciones significativas con otras especies. Acciones inadecuadas para promover el turismo representaron la mayor amenaza por destrucción del hábitat, endémicos tales como A, toweri y C. bartoni enfrentan solapamiento con especies introducidas, sobre todo en sus sitios de crianza. Este estudio aporta bases para un manejo responsable de estos humedales, donde turismo y conservación pueden combinarse.