Diana Gómez-Barroso

Oesophageal cancer mortality in Spain: a spatial analysis

Oesophageal carcinoma is one of the most common cancers worldwide. Its incidence and mortality rates show a wide geographical variation at a world and regional level. Geographic mapping of age-standardized, cause-specific death rates at a municipal level could be a helpful and powerful tool for providing clues leading to a better understanding of its aetiology. This study sought to describe the geographic distribution of oesophageal cancer mortality for Spains 8077 towns, using the autoregressive spatial model proposed by Besag, York and Mollié. Maps were plotted, depicting standardised mortality ratios, smoothed relative risk (RR) estimates, and the spatial pattern of the posterior probability of RR being greater than 1. Important differences associated with area of residence were observed in risk of dying from oesophageal cancer in Spain during the study period (1989–1998). Among men, excess risk appeared across the north of the country, along a band spanning the length of the Cantabrian coastline, Navarre, the north of Castile & León and the north-west of La Rioja. Excess risk was likewise observed in the provinces of Cadiz and part of Seville in Andalusia, the islands of Tenerife and Gran Canaria, and some towns in the Barcelona and Gerona areas. Among women, there was a noteworthy absence of risk along the mid-section of the Cantabrian seaboard, and increases in mortality, not observed for men, in the west of Extremadura and south-east of Andalusia. These major gender- and area-related geographical differences in risk would seem to reflect differences in the prevalence of some well-established and modifiable risk factors, including smoking, alcohol consumption, obesity and diet. In addition, excess risks were in evidence for both sexes in some areas, possibly suggesting the implication of certain local environmental or socio-cultural factors. From a public health standpoint, small-area studies could be very useful for identifying locations where epidemiological research and intervention measures ought to receive priority, given the potential for reducing risk in certain places.BackgroundOesophageal carcinoma is one of the most common cancers worldwide. Its incidence and mortality rates show a wide geographical variation at a world and regional level. Geographic mapping of age-standardized, cause-specific death rates at a municipal level could be a helpful and powerful tool for providing clues leading to a better understanding of its aetiology.MethodsThis study sought to describe the geographic distribution of oesophageal cancer mortality for Spains 8077 towns, using the autoregressive spatial model proposed by Besag, York and Mollié. Maps were plotted, depicting standardised mortality ratios, smoothed relative risk (RR) estimates, and the spatial pattern of the posterior probability of RR being greater than 1.ResultsImportant differences associated with area of residence were observed in risk of dying from oesophageal cancer in Spain during the study period (1989–1998). Among men, excess risk appeared across the north of the country, along a band spanning the length of the Cantabrian coastline, Navarre, the north of Castile & León and the north-west of La Rioja. Excess risk was likewise observed in the provinces of Cadiz and part of Seville in Andalusia, the islands of Tenerife and Gran Canaria, and some towns in the Barcelona and Gerona areas. Among women, there was a noteworthy absence of risk along the mid-section of the Cantabrian seaboard, and increases in mortality, not observed for men, in the west of Extremadura and south-east of Andalusia.ConclusionThese major gender- and area-related geographical differences in risk would seem to reflect differences in the prevalence of some well-established and modifiable risk factors, including smoking, alcohol consumption, obesity and diet. In addition, excess risks were in evidence for both sexes in some areas, possibly suggesting the implication of certain local environmental or socio-cultural factors. From a public health standpoint, small-area studies could be very useful for identifying locations where epidemiological research and intervention measures ought to receive priority, given the potential for reducing risk in certain places.

Municipal mortality due to thyroid cancer in Spain

BackgroundThyroid cancer is a tumor with a low but growing incidence in Spain. This study sought to depict its spatial municipal mortality pattern, using the classic model proposed by Besag, York and Mollié.MethodsIt was possible to compile and ascertain the posterior distribution of relative risk on the basis of a single Bayesian spatial model covering all of Spains 8077 municipal areas. Maps were plotted depicting standardized mortality ratios, smoothed relative risk (RR) estimates, and the posterior probability that RR > 1.ResultsFrom 1989 to 1998 a total of 2,538 thyroid cancer deaths were registered in 1,041 municipalities. The highest relative risks were mostly situated in the Canary Islands, the province of Lugo, the east of La Coruña (Corunna) and western areas of Asturias and Orense.ConclusionThe observed mortality pattern coincides with areas in Spain where goiter has been declared endemic. The higher frequency in these same areas of undifferentiated, more aggressive carcinomas could be reflected in the mortality figures. Other unknown genetic or environmental factors could also play a role in the etiology of this tumor.

Spatio-temporal analysis of tuberculosis in Spain, 2008-2010.

BACKGROUND The characteristics of respiratory tuberculosis (TB) favour the appearance of clusters of cases in space and time. It is important for public health authorities to know which clusters occur randomly and which merit further investigation. OBJECTIVE To detect spatial and spatio-temporal clusters of respiratory TB in Spain during the period from 1 January 2008 to 31 December 2010. MATERIALS AND METHODS Retrospective spatio-temporal study of respiratory TB cases reported to Spains National Epidemiological Surveillance Network from 2008 to 2010, at a municipal level. We used the purely spatial and space-time Scan statistic estimators. All analyses were adjusted for age and sex. RESULTS The spatial cluster analysis detected 28 significant clusters and the spatio-temporal cluster analysis detected 20 significant clusters. The most likely spatial cluster comprised seven municipalities in the Greater Barcelona Area. Most space-time clusters were situated in the same area, and were detected between 1 April 2008 and 31 March 2009. CONCLUSION The distribution of TB clusters as shown by the proposed models furnishes a spatial pattern of the distribution of the disease. The two methods used can be a useful tool for analysing the distribution of respiratory TB in Spain.

DISTRIBUCIÓN ESPACIAL DE LA TUBERCULOSIS EN ESPAÑA MEDIANTE MÉTODOS GEOESTADÍSTICOS

Fundamentos: La incidencia de tuberculosis (TB) se ha asociado a factores, epidemiologicos y sociales. En Espana, la TB es una enfermedad de declaracion obligatoria e individualizada. Las tasas de TB respiratoria experimentan un descenso constante en los ultimos anos. El objetivo es valorar la asociacion entre la morbilidad por TB respiratoria y variables socioeconomicas y epidemiologicas asi como su distribucion espacial mediante metodos geoestadisticos. Metodo: Las tasas de incidencia se estandarizaron por edad y sexo con datos de la Red Nacional de Vigilancia (2006). Las variables socioeconomicas incluidas son: condicion socioeconomica, nivel de estudios, tasa de hacinamiento, densidad de poblacion, tasa de inmigracion estandarizada por sexo, tasa de analfabetismo, tasa de paro, gasto medio en euros por persona. Las variables epidemiologicas incluidas han sido la tasa de SIDA y la tasa de incidencia de gripe. Se realizo un analisis multivariable mediante un Modelo Lineal Generalizado poisson. Se aplico la tecnica geoestadistica cokringing ajustada por las variables estadisticamente significativas para ver la distribucion espacial de riesgo. Resultados: Las variables estadisticamente significativas son la tasa de hacinamiento, tasa de inmigracion, tasa de analfabetismo, tasa de paro, gasto medio euros por persona, tasa de gripe y tasa de sida. La tecnica geoestadistica muestra una variabilidad espacial del riesgo y una concentracion del riesgo en el noroeste y sureste de la peninsula. Conclusiones: Los resultados permiten afirmar que el metodo Cokriging es una herramienta util para representar la distribucion espacial del riesgo. Existe asociacion entre variables socioeconomicas, epidemiologicas y TB en Espana.

Non-imported malaria in non-endemic countries: a review of cases in Spain

Spain declared the elimination of malaria in 1964. In non-endemic areas, the overwhelming majority of malaria cases are acquired abroad, and locally acquired infections are rare events. In Spain, malaria is a statutorily notifiable disease. During these fifty years more than ten thousand malaria cases have been reported, and about 0.8% of them did not have a history of recent travel. In this report, it was carried out a review of the ways in which malaria can be transmitted in non-endemic areas and a short description of the Spanish cases, aggregated by their transmission mechanisms. Four cases contracted malaria by mosquito bites; there were two autochthonous cases and two of “airport malaria”. The other 28 cases were: congenital malaria cases, transfusion-transmitted malaria, post-transplant cases, nosocomial transmission and cases in intravenous drug users. In addition, in 1971 there was an outbreak of 54 cases due to exposure to blood or blood products. So, while malaria usually is an imported disease in non-endemic areas, it should not be excluded in the differential diagnosis of persons who have fever of unknown origin, regardless of their travel history.

Using hospital discharge database to characterize Chagas disease evolution in Spain: there is a need for a systematic approach towards disease detection and control.

After the United States, Spain comes second in the list of countries receiving migrants from Latin America, and, therefore, it is the European country with the highest expected number of infected patients of Chagas disease. We have studied the National Health System’s Hospital Discharge Records Database (CMBD) in order to describe the disease evolution from 1997 to 2011 in Spain. We performed a retrospective descriptive study using CMBD information on hospitalizations including Chagas disease. Data was divided in two periods with similar length in time: 1997-2004 and 2005-2011. Hospitalization rates were calculated and clinical characteristics were described. We used multivariable logistic regression to calculate adjusted odds-ratio (aOR) for the association between various conditions and being hospitalized with organ affectation. A total of 1729 hospitalization records were identified. Hospitalization rates for the two periods were 18 and 242.8/100000 population, respectively. The median age was 35 years (range 0-87), 74% were female and the 16-45 age-group was mostly represented (69.8%). Overall, 23.4% hospitalizations included the diagnosis of Chagas disease with organ complications. Being male [aOR: 1.3 (1.00-1.77)], aged 45 and 64 years [aOR: 2.59 (1.42-4.71)], and a median hospitalization cost above 3,065 euro [aOR: 2.03 (3.73-7.86)] were associated with hospitalizations with organ affectation. Since 2005, the number of detected infections increased in Spain. The predominant patients’ profile (asymptomatic women at fertile age) and the conditions associated with organ affectation underlines the need for increased efforts towards the early detection of T cruzi.

Climatic Factors and Influenza Transmission, Spain, 2010–2015

The spatio-temporal distribution of influenza is linked to variations in meteorological factors, like temperature, absolute humidity, or the amount of rainfall. The aim of this study was to analyse the association between influenza activity, and meteorological variables in Spain, across five influenza seasons: 2010–2011 through to 2014–2015 using generalized linear negative binomial mixed models that we calculated the weekly influenza proxies, defined as the weekly influenza-like illness rates, multiplied by the weekly proportion of respiratory specimens that tested positive for influenza. The results showed an association between influenza transmission and dew point and cumulative precipitation. In increase in the dew point temperature of 5 degrees produces a 7% decrease in the Weekly Influenza Proxy (RR 0.928, IC: 0.891–0.966), and while an increase of 10 mm in weekly rainfall equates to a 17% increase in the Weekly Influenza Proxy (RR 1.172, IC: 1.097–1.251). Influenza transmission in Spain is influenced by variations in meteorological variables as temperature, absolute humidity, or the amount of rainfall.

Spatial pattern of legionellosis in Spain, 2003-2007

OBJECTIVES To analyze the spatial pattern of legionellosis in Spain for men and women during the period 2003-2007 and to identify spatial clustering of risk. METHODS We identified the spatial pattern of the distribution of legionellosis rates based on calculation of rates by municipality through the direct method. Smoothing of these rates was performed by the Empirical Bayes method for studying the spatial pattern of disease for both sexes. We used Morans index to analyze spatial autocorrelation rates globally. To calculate local rates, the Local Morans Index [known as local indicators of spatial association (LISA)], was used to analyze the clusters of municipalities with the highest risk. RESULTS After smoothing the risk, the highest rates (over 50 per 100,000 inhabitants) were grouped in the eastern Mediterranean coastal areas and the north of the mainland, as well as in the Mediterranean islands. Morans index smoothed rates were 0.15 for men and 0.23 for women. The spatial clusters of statistically significant higher rates calculated by the LISA index were distributed in the north and east for both sexes. CONCLUSIONS These methods of spatial analysis allow patterns of disease distribution to be identified. All the methods used yielded similar results. These techniques are a complementary tool for epidemiological surveillance of infectious diseases.

Patrón espacial de la legionelosis en España, 2003-2007

OBJECTIVES To analyze the spatial pattern of legionellosis in Spain for men and women during the period 2003-2007 and to identify spatial clustering of risk. METHODS We identified the spatial pattern of the distribution of legionellosis rates based on calculation of rates by municipality through the direct method. Smoothing of these rates was performed by the Empirical Bayes method for studying the spatial pattern of disease for both sexes. We used Morańs index to analyze spatial autocorrelation rates globally. To calculate local rates, the Local Morans Index [known as local indicators of spatial association (LISA)], was used to analyze the clusters of municipalities with the highest risk. RESULTS After smoothing the risk, the highest rates (over 50 per 100,000 inhabitants) were grouped in the eastern Mediterranean coastal areas and the north of the mainland, as well as in the Mediterranean islands. Morans index smoothed rates were 0.15 for men and 0.23 for women. The spatial clusters of statistically significant higher rates calculated by the LISA index were distributed in the north and east for both sexes. CONCLUSIONS These methods of spatial analysis allow patterns of disease distribution to be identified. All the methods used yielded similar results. These techniques are a complementary tool for epidemiological surveillance of infectious diseases.

Mediterranean spotted fever rickettsiosis in Italy, 2001–2015: Spatio-temporal distribution based on hospitalization records

The Mediterranean spotted fever (MSF) rickettsiosis is the predominant rickettsial disease among the spotted fever group (SFG) rickettsiae in the Mediterranean countries and North Africa. Its causative agent is Rickettsia conorii, although, SFG rickettsiosis - cases due to Rickettsia monacensis, Rickettsia massiliae and Rickettsia aeschlimannii were also described. A retrospective study based on hospital discharge records with a diagnosis of SFG rickettsiosis was carried out to describe the spatial pattern, the trend of the disease, and the epidemiological characteristics of persons hospitalized in the period 2001-2015. Standardized hospitalization ratios were calculated at municipal level using the European population. Smoothed maps were produced using a localised smoothing Poisson model. The mean annual standardized hospitalization rate was 1.36/100,000 person years (95%CI: 1.34; 1.39). Rates showed strong summer seasonality and tended to decrease over time. During the study period, 28.89% of municipalities had smoothed standardized hospitalization ratios greater than 1 and 14.01% above 20. Higher standardized hospitalization ratios were found in areas along the Tyrrhenian coast, especially in the south of Calabria and in the islands of Sardinia and Sicily, where the disease is of public health relevance.