title: Urinary tract abnormalities in Chinese rural children who consumed melamine-contaminated dairy products: a population-based screening and follow-up study.
abstract: BACKGROUND
  Kidney damage related to consumption of melamine-contaminated dairy products by young children in China has been described. However, no studies have reported on the population-based prevalence of kidney damage among exposed children or on the condition of affected children after follow-up.
  
  
  METHODS
  We conducted an ultrasound-based screening in September 2008 of 7933 children younger than 36 months of age who lived in a rural area in China where the dairy products most highly contaminated with melamine were sold. We monitored children who had evidence of nephrolithiasis or hydronephrosis at screening using renal ultrasonography after one, three and six months. We also collected information from the mothers of affected children about consumption of melamine-contaminated products between June and August 2008.
  
  
  RESULTS
  The overall prevalence of urinary tract abnormalities among screened children was 0.61% (95% confidence interval [CI] 0.45%-0.80%). The mean exposure dose of melamine was estimated to be 116 (range 36-220) mg per day. Of the 48 affected children, 43 (89.6%) were asymptomatic, 2 had symptoms and were hospitalized, and 3 had symptoms but treatment had been not sought for them. Of the 46 children for whom six-month follow-up information was available, renal abnormalities persisted in 5 children and resolved in the remaining 41.
  
  
  CONCLUSIONS
  Among children who underwent screening, 0.61% showed ultrasonographic evidence of nephrolithiasis or hydronephrosis. Most of the affected children were asymptomatic. The majority of the affected children recovered from the toxic effects of melamine over time without specific treatment. Renal abnormalities remained in 12% of the affected children.
authors.affiliation: Peking University Institute of Reproductive and Child Health, Beijing, China.
authors.forename: Jian-meng
authors.initials: JM
authors.lastname: Liu
authors.forename: Aiguo
authors.initials: A
authors.lastname: Ren
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Jinji
authors.initials: J
authors.lastname: Gao
authors.forename: Lijun
authors.initials: L
authors.lastname: Pei
authors.forename: Rongwei
authors.initials: R
authors.lastname: Ye
authors.forename: Quangang
authors.initials: Q
authors.lastname: Qu
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005506:Food Contamination; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000002:abnormalities / Q000000981:diagnostic imaging; D008297:Male; D008403:Mass Screening; D008892:Milk / Q000009:adverse effects* / Q000737:chemistry; D053040:Nephrolithiasis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D012424:Rural Population; D014227:Triazines / Q000009:adverse effects* / Q000032:analysis; D014463:Ultrasonography
chemical_list: D014227:Triazines; C011907:melamine