Risk factors for death and changing patterns in leptospirosis acute renal failure.

The risk factors for death and changes in clinical patterns in leptospirosis (Weil's disease) have not been well studied. We retrospectively studied 110 patients with Weil's disease hospitalized in Brazil between 1985 and 1996. Univariate statistical analysis showed that nonsurvivors were older than survivors, and had higher frequency of oliguria, cardiac arrhythmia, dyspnea, and pulmonary rales. Logistic regression showed that the only independent factor associated with death was oliguria (odds ratio [OR] = 8.98). The presence of arthralgia (OR = 4.71), dehydration (OR = 6.26), dyspnea (OR = 17.7), and pulmonary rales (OR = 9.91) increased after 1994. These data suggest that in Weil's disease the clinical patterns have changed and the presence of oliguria is a risk factor for death.