Melamine-tainted milk product-associated urinary stones in children

Zheng Wang, Hong Luo, Wenwei Tu, Hui Yang, Wilfred Hing Sang Wong, Wing Tak Wong, Ka Fu Yung, Nan Zhou, Jingti Zhang, Xiaoqing Li, Zerong Wang, Wenjun Guo, Dezhi Mu, Fanghong Li, Meng Mao, Yu Lung Lau

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)


Background: An outbreak of urinary stones related to consumption of melamine-tainted milk products (MTMP) occurred in China in 2008. The aim of the present study was to evaluate such children to identify their clinical features and risk factors. Methods: Renal ultrasound was performed for 7328 children who presented to a Sichuan teaching hospital between 13 September and 15 October 2008 due to concern of such stones. Clinical data, family information, feeding history and urinary stones were analyzed. Results: Of the 7328 children, 189 (2.58%) had ultrasound findings of urinary stones, and 51 were admitted. Age (mean ± SD) was 27.4 ± 25.5 months, and 101 were male and 88, female. The odds ratio (OR) for urinary stones for infants and young children (1-3 years) as compared to older children (>3 years), was 2.42 (95% confidence interval [CI], 1.64-3.56; P < 0.0001) and 1.95 (95%CI, 1.31-2.89; P < 0.0011), respectively. Independent risk factors associated with urinary stones included consumption of MTMP with melamine at >5500 mg/kg (OR, 13.3; 95%CI, 6.8-26.1, P < 0.0001) as compared to that with melamine at <200 mg/kg, and younger father (P = 0.0006). On logistic regression, the only risk factor associated with inpatient care was lower family income per person (OR, 4.4; 95%CI, 1.2-15.9, P = 0.02). Repeat ultrasound for 51 children at mean follow up of 15.3 ± 8.9 days found that 33 passed out all stones, which was associated with a larger number of smaller stones (P = 0.003). Urinary stones contained melamine and uric acid, but no cyanuric acid. Conclusions: MTMP-associated urinary stones were more frequent in young children and more severe in children from poorer families.
Original languageEnglish
Pages (from-to)489-496
Number of pages8
JournalPediatrics International
Issue number4
Publication statusPublished - 1 Aug 2011
Externally publishedYes


  • cyanuric acid
  • melamine
  • milk
  • uric acid
  • urinary stones

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health


Dive into the research topics of 'Melamine-tainted milk product-associated urinary stones in children'. Together they form a unique fingerprint.

Cite this