Geographic variation in the incidence of Legionnaires' disease in Scotland

The major sources of infection for Legionnaires' Disease, identified by study of outbreaks, are hot water systems and cooling towers. However, most cases are not part of outbreaks and, for these, the source of infection is rarely traced. The principle aim of this study was to help understand the source of non-outbreak infection by examining the epidemiology of the disease in Scotland.Of the. recognised cases which met the study casedefinition, 366 were ill between 1978 to 1986 giving a mean annual incidence rate of 7.9 per million. The annual incidence varied in Scotland (range 3.1 to 20.2) and within health boards. Geographical variations were demonstrated by health board, by city and within cities, particularly for non-travel infection. For example, the cumulative incidence rate per million for non-travel, non-outbreak disease in Greater Glasgow Health Board (GGHB) was 130 compared to 45 for the whole of Scotland, and 11, 33 and 50 in Tayside, Lanarkshire and Lothian Health Boards respectively. Of 16 postcode sectors with a high incidence of disease in Scotland, 14 were in GGHB. In GGHB, the residence of nontravel, non-outbreak cases (but not of travel-related ones) was clustered in central areas. Previously unrecognised clustering was also found in other health boards.These variations were not fully explained by differences in the population's exposure to diagnostic tests, as indicated by the number of serology tests reguested by Scottish hospitals; the diagnostic service and approach of bacteriology laboratories; and the approach of hospital consultants to the diagnosis of Legionnaires' Disease. Differences in host susceptibilty, as reflected by socio-economic status and the incidence of other respiratory disease, were small and did not explain the variation.In the City of Glasgow, many cooling towers were not maintained in accord with recommendations and posed a theoretical risk of infection. The location of residence of non-travel cases was associated with the location of premises with cooling towers, the incidence of non-travel Legionnaires' Disease being more than three times higher in areas of Glasgow within 0.5 kilometres of a cooling tower than in areas more than one kilometre away.The best explanation for these observations is that cooling towers were a major source of non-travel, nonoutbreak infection. Hence, for the investigation and prevention of such infection, the emphasis should be on cooling tower maintenance. Close surveillance of apparently sporadic disease is recommended as the basis for disease control and future research

Differences in all-cause hospitalisation by ethnic group: a data linkage cohort study of 4.62 million people in Scotland, 2001–2013

Background: Immigration into Europe has raised contrasting concerns about increased pressure on health services and equitable provision of healthcare to immigrants /ethnic minorities. We assessed hospital use by ethnic group in Scotland. Methods: We anonymously linked Scotland?s Census 2001 records for 4.62 million people, including their ethnic group, to National Health Service general hospitalisation records for 2001-2013. We used Poisson regression to calculate hospitalisation rate ratios (RRs) in 14 ethnic groups, presented as percentages of the White Scottish reference group (RR=100), for males and females separately. We adjusted for age and socio-economic status and compared those born in the United Kingdom or the Republic of Ireland (UK/RoI) with elsewhere. We calculated mean lengths of hospital stay. Results: 9,789,975 hospital admissions were analysed. Compared to the White Scottish, unadjusted RRs for both males and females in most groups were about 50-90, e.g. Chinese males 49 (95% CI 45-53) and Indian females 76 (71-81). The exceptions were White Irish males, 120 (117-124) and females 115 (112-119) and Caribbean females, 103 (85-126). Adjusting for age increased the RRs for most groups towards or above the reference. Socio-economic status had little effect. In many groups, those born outside the UK/RoI had lower admission rates. Unadjusted mean lengths of stay were substantially lower in most ethnic minorities. Conclusions: Use of hospital beds in Scotland by most ethnic minorities was lower than by the White Scottish majority, largely explained by their younger average age. Other countries should use similar methods to assess their own experiences