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This study examines the prevalence of, and risk factors for, diabetic retinopathy in Asian Indian, Chinese, and Creole Mauritians in whom there is an increasing prevalence of non-insulin-dependent diabetes mellitus (NIDDM). As part of a population-based survey on the Indian Ocean island of Mauritius in 1992, glucose tolerance was classified using a 75-g oral glucose tolerance test on 6,553 persons. Subjects with newly diagnosed (n = 358) or known diabetes (n = 388), and a random sample of one in four subjects with impaired glucose tolerance (n = 165), had stereoscopic 45 degrees retinal photographs taken of three fields in the right eye after mydriasis. Photographs were graded according to a modified version of the Airlie House criteria. The prevalence of nonproliferative and proliferative retinopathy was: 14.5% and 0.3%, respectively, in newly diagnosed diabetic subjects; 42.0% and 2.3%, respectively, in known diabetic subjects; and 9.1% and 0%, respectively, in persons with impaired glucose tolerance. Muslim Indians had the lowest prevalence of retinopathy (10.8% and 34.0% for new and known diabetes, respectively), but after adjusting for other factors, this was significantly different only to Creoles (18.8% and 53.8%, respectively). Univariate analysis revealed significant differences between diabetic subjects with and without retinopathy in mean age, body mass index, fasting and 2-hour plasma glucose levels, systolic and diastolic blood pressure, fasting triglycerides, serum creatinine, and urinary albumin levels. For known diabetes, mean duration of diabetes and the proportion using insulin were also greater in those with retinopathy. Multivariate analysis using logistic regression confirmed that increasing duration of diabetes, fasting plasma glucose, systolic blood pressure, and urinary albumin concentration, and decreasing body mass index, were independently associated with retinopathy. The high prevalence of diabetic retinopathy observed in all major ethnic groups in Mauritius portends a serious public health problem, given the relative recency of the NIDDM epidemic in that country and the limited resources for laser photocoagulation. Strategies to minimize this problem among those already known to have diabetes should include strict control of plasma glucose and blood pressure.

SUMMARYBetween April and August 2005 Christchurch, New Zealand experienced an outbreak of Legionnaires' disease. There were 19 laboratory-confirmed case including three deaths.Legionella pneumophilaserogroup 1 (Lpsg1) was identified as the causative agent for all cases. A case-control study indicated a geographical association between the cases but no specific common exposures. Rapid spatial epidemiological investigation confirmed the association and identified seven spatially significant case clusters. The clusters were all sourced in the same area and exhibited a clear anisotropic process (noticeable direction) revealing a plume effect consistent with aerosol dispersion from a prevailing southwesterly wind. Four out of five cases tested had indistinguishable allele profiles that also matched environmental isolates from a water cooling tower within the centre of the clusters. This tower was considered the most probable source for these clusters. The conclusion would suggest a maximum dispersal distance in this outbreak of 11·6 km. This work illustrated the value of geostatistical techniques for infectious disease epidemiology and for providing timely information during outbreak investigations.