Melamine-Contaminated Powdered Formula and Urolithiasis in Young Children. N. Guan and Others http://content.nejm.org/cgi/content/short/360/11/1067 Full text available The recent epidemic of melamine-contaminated formula in China has been associated with urinary tract stones. The authors of this study screened 589 consecutively enrolled children; 421 had received formula contaminated by melamine. In all, 50 had urinary stones, 112 were suspected to have stones, and 427 did not have stones. Affected children lacked typical signs and symptoms of urolithiasis. Exposure to melamine-contaminated formula and prematurity were associated with the presence of stones.