In 2012, an extraordinary rise in Puumala infections causing nephropathia epidemica (NE) was observed in southern Austria. We investigated differences in epidemiology, clinical presentation, laboratory results, treatment parameters, and outcome between patients in 2012 and previous years (2007-2011). All patients diagnosed with Puumala virus infections between 2007 and 2012 using a point of care Puumala IgM test at the microbiology laboratory, Department of Internal Medicine, Medical University of Graz, were included. In 2012, 42 and in 2007-2011 a total of 40 patients were diagnosed with NE. In 2007-2011, patients presented more frequently with arthromyalgias (25% vs 7%, p = 0.027), while lower back pain was reported more often in 2012 (21% vs 5%, p = 0.029). Other symptoms occurred at the same rate. In 2012, patients were diagnosed significantly faster (time from first contact with a physician to diagnosis 1.3 ± 0.2 vs 2.7 ± 0.4 days, p = 0.01). Significantly fewer patients required haemodialysis in 2012 (2.4% vs 20%, p = 0.01). There were no significant differences in laboratory parameters between the two groups. In the peak year 2012, patients were diagnosed faster and fewer patients required haemodialysis possibly because of the earlier diagnosis and earlier onset of therapy.