Nephropathia epidemica in Finland: a retrospective study of 126 cases.

A total of 126 (99 males, 27 females) serologically confirmed hospital-treated adult cases of nephropathia epidemica (NE) were studied. The initial diagnosis suggested by the referring physician was correct in only 28%. Some rare clinical manifestations of NE were observed; acute myopericarditis in 3 patients and encephalitis in 1. Pulmonary involvement due to vascular congestion was observed in 16% and liver involvement in 34% of the patients. Thrombocytopenia was present in 75%, leukocytosis in 50% and anemia in 50%. Erythrocyte sedimentation rate (ESR) was 2-108 (mean 38) mm/h and C-reactive protein (CRP) 0-126 (mean 52) mg/l. Proteinuria was observed in 94%, hematuria in 58% and pyuria in 28%. Electrolyte abnormalities (hyponatremia, hypokalemia, hypocalcemia, hyperphosphatemia) were all common but rarely serious. Serum lipid changes caused by the acute infection and renal failure included very low total and HDL-cholesterol as well as high triglyceride levels. Renal function was transiently impaired in 94% of the patients and 7 needed transient dialysis therapy. All recovered.