Spatial analysis of the relationship between mortality from cardiovascular and cerebrovascular disease and drinking water hardness.

Previously published scientific papers have reported a negative correlation between drinking water hardness and cardiovascular mortality. Some ecologic and case-control studies suggest the protective effect of calcium and magnesium concentration in drinking water. In this article we present an analysis of this protective relationship in 538 municipalities of Comunidad Valenciana (Spain) from 1991-1998. We used the Spanish version of the Rapid Inquiry Facility (RIF) developed under the European Environment and Health Information System (EUROHEIS) research project. The strategy of analysis used in our study conforms to the exploratory nature of the RIF that is used as a tool to obtain quick and flexible insight into epidemiologic surveillance problems. This article describes the use of the RIF to explore possible associations between disease indicators and environmental factors. We used exposure analysis to assess the effect of both protective factors--calcium and magnesium--on mortality from cerebrovascular (ICD-9 430-438) and ischemic heart (ICD-9 410-414) diseases. This study provides statistical evidence of the relationship between mortality from cardiovascular diseases and hardness of drinking water. This relationship is stronger in cerebrovascular disease than in ischemic heart disease, is more pronounced for women than for men, and is more apparent with magnesium than with calcium concentration levels. Nevertheless, the protective nature of these two factors is not clearly established. Our results suggest the possibility of protectiveness but cannot be claimed as conclusive. The weak effects of these covariates make it difficult to separate them from the influence of socioeconomic and environmental factors. We have also performed disease mapping of standardized mortality ratios to detect clusters of municipalities with high risk. Further standardization by levels of calcium and magnesium in drinking water shows changes in the maps when we remove the effect of these covariates.

Measles outbreak in Andalusia, Spain, January to August 2011.

On 7 January 2011, a six year-old child living in a Roma community near Seville, southern Spain, was hospitalised with measles. Contact tracing identified a probable index case with onset of symptoms on 20 December 2011 and several unreported cases among children under the age of 15 years in the same town. The outbreak initially spread in districts in the city of Seville with a high proportion of Roma residents, and later to other cities and towns in Andalusia. While some towns experienced wide spread of the disease with significant clusters of cases, most of the affected locations saw non-clustered cases or very few secondary cases. The outbreak resulted in 1,759 confirmed or probable cases of which 393 (19%) required hospitalisation. Measles virus of genotype D4 was diagnosed in more than half of the cases. Significant differences (p<0.0001) by age group were found between clustered and non-clustered cases. The highest proportion of clustered cases occurred in the age group of 5-14 yearolds, while the highest proportion of non-clustered cases was seen in those older than 29 years. The last confirmed case related to this outbreak was reported on 20 August 2011.