Ruth A. Etzel1, M.D., Ph.D., Dorr G. Dearborn, Ph.D., M.D.

Case Western Reserve University, Cleveland, Ohio 44106

In 1994, we investigated a geographic cluster of 10 cases of acute idiopathic pulmonary hemorrhage among infants in Cleveland, Ohio. Our matched case-control study demonstrated that infants with this condition were more likely than control infants to live in homes with toxigenic Stachybotrys chartarum and other fungi in the indoor air. The risk appeared to increase when both S. chartarum and environmental tobacco smoke were present in the home. Since the completion of the 1994 investigation, 27 additional infants in the Cleveland area have been diagnosed with acute idiopathic pulmonary hemorrhage. Of the 37 infants, 30 were African-American infants, all of whom lived in a limited geographic area of eastern metropolitan Cleveland, an area of older housing stock. Twelve deaths with extensive idiopathic pulmonary hemosiderosis have been identified, including seven originally thought to be due to Sudden Infant Death Syndrome (SIDS).

To determine how common this problem might be, we actively solicited reports of idiopathic pulmonary hemorrhage in infants from pediatricians throughout the United States. We have received physician reports of an additional 101 cases of acute idiopathic pulmonary hemorrhage among infants under 1 year of age. This paper reviews the risk factors for this condition and discribes the ongoing surveillance efforts.