A 37-year-old Belgian patient presented with acute nephropathia epidemica (NE) shortly after a camping holiday in southern France. Unusual symptoms were initial noncardiogenic lung involvement, followed by severe acute renal failure, acute acalculous cholecystitis, presence of immunoblasts in the bone marrow, and hemolytic anemia, presenting as hemolytic uremic syndrome. Positive immunoglobulin (Ig) A and rising IgG titers against Puumala hantavirus (PUUV) were detected, but IgM remained negative on days 8 and 20. The results of reverse-transcriptase-polymerase chain reaction performed on day 8 were positive for PUUV. This is the first report of an iatrogenically IgM-negative hantavirus case due to the selective removal of heavyweight molecules during plasma exchange via the centrifugation technique. This is also the first report of proven NE from the Mediterranean part of France.