title: Hong Kong Chinese school children with elevated urine melamine levels: a prospective follow up study.
abstract: BACKGROUND
  In 2008, the outbreak of kidney stones in children fed by melamine-tainted milk products in Mainland China has caused major public concern of food safety. We identified Hong Kong school children with elevated urine melamine level from a community-based school survey in 2007-08 and reviewed their clinical status in 2009.
  
  
  METHODS
  In 2007-08, 2119 school children participated in a primary and secondary school survey in Hong Kong using a cluster sampling method. Urine aliquots from 502 subjects were assayed for melamine level. High urine melamine level was defined as urine melamine/creatinine ratio >7.1 μg/mmol. Subjects with high urine melamine level were invited for clinical evaluation in 2009 including urinalysis and ultrasound imaging of the urinary system.
  
  
  RESULTS
  The age range of this subcohort was 6 - 20 years with 67% girls (335 female and 167 male subjects). The spot urine melamine/creatinine ratio of the 502 urine aliquots ranged from undetectable to 1467 μg/mmol (median 0.8 μg/mmol). Of these, 213 subjects had undetectable level (42%). We invited 47 (9%) subjects with high urine melamine level for re-evaluation and one subject declined. The median duration of follow-up was 23.5 months (interquartile range: 19.8 - 30.6 months). None of the 46 subjects (28% boys, mean age 13.9 ± 2.9 years) had any abnormality detected on ultrasound study of the urinary system. All subjects had stable renal function with a median urine albumin-creatinine ratio of 0.70 mg/mmol (interquartile range: 0.00 - 2.55 mg/mmol).
  
  
  CONCLUSIONS
  Hong Kong Chinese school children with high urine melamine levels appeared to have benign clinical course in the short term although a long term follow-up study is advisable in those with persistently high urine melamine level.
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China.
authors: Alice P S
authors: AP
authors: Kong
authors: Kai-Chow
authors: KC
authors: Choi
authors: Chung Shun
authors: CS
authors: Ho
authors: Michael H M
authors: MH
authors: Chan
authors: Chun Kwok
authors: CK
authors: Wong
authors: Eric K H
authors: EK
authors: Liu
authors: Winnie C W
authors: WC
authors: Chu
authors: Viola C Y
authors: VC
authors: Chow
authors: Joseph T F
authors: JT
authors: Lau
authors: Juliana C N
authors: JC
authors: Chan
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