This study was undertaken to correlate the clinical features and pathologic changes noted during the initial and later stages of fatal typhoid illness. Five cases who died during the initial stage of the illness (< 2 weeks from onset) had altered mental status, tachypnea, and tachycardia. Three had shock and elevation of serum creatinine values. Autopsies of all five revealed hyperplastic Peyer's patches, features of adult respiratory distress syndrome, and megakaryocytosis. Five other cases died during the later stage of the illness (> or= 2 weeks after onset). They had a left shift in peripheral blood leukocyte count. Autopsies revealed deep ileal ulcerations with or without perforation and peritonitis and intercurrent pneumonia. Three of them had disseminated intravascular coagulation. Further studies are warranted to understand the mediators of shock and tissue injuries during the initial period of the illness.