BACKGROUND:
Melamine is an industrial chemical used primarily as
plastics stabilizer and fire retardant. On September 11, 2008, melamine-contaminated milk products were reported to be responsible for
urinary tract calculi in infants and children in China. This study aimed to investigate the
prevalence,
lesions,
risk factors, clinical features, and management of children fed with the melamine-contaminated milk products. METHODS: A total of 15 577 infants and children fed with the milk products were screened at our hospital.
Ultrasonography was performed in all the infants and children. For those found with
urinary tract calculion
ultrasonography, urnalysis was done. Among them, 846 with detailed data screened from September 17 to 25 were enrolled for further analysis in this study. They were divided into calculus group (326 children) and non-calculus group (520 children) according to the results of
ultrasonography. They included 429 boys and 417 girls,
aged from 1 month to 5 years (
median, 18 months). Their clinical and laboratory data,
ultrasonograms, and treatment results were analyzed. RESULTS: Of the 15 577 children screened, 562 (3.61%) had
urinary tract calculi. The rate was closely related to the
melamine concentration in patients fed with formula. In 846 children with detailed data enrolled in this analysis, weight and
head circumference
Z scores in the calculus group were lower than those in the non-calculus group (P=0.048, P=0.046). Long duration of formula feeding, high
melamine contained formula, and minimal
water intake were the
risk factors for calculi (P<0.05, respectively). Of 326 children with calculi, 281 had small calculiless than 0.5 cm in diameter, 227 had multiple calculi, and 34 had
urinary tract distention. Moreover, diffuse
renal lesions,
renal failure and
ascites were noted in 4, 3 and 2 patients, respectively. After 1-month treatment with
sodium bicarbonate and
Chinese traditional medicine, calculi disappeared in 49 of 54 outpatients. In 41 inpatients, 5 had calculi removed operatively and 36 had calculi minimized. CONCLUSIONS: Melamine-contaminated milk products induced
urinary tract calculi, which have a good response to conservative therapy. Long-term follow-up of infants and children fed with melamine-contaminated milk products is required, and food safety should be supervised increasingly for the health of children.
