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Renal screening in children after exposure to low dose melamine in Hong Kong: cross sectional study

BMJ 2008; 337 doi: (Published 19 December 2008) Cite this as: BMJ 2008;337:a2991
  1. Hugh S Lam, assistant professor1,
  2. Pak C Ng, chairman and professor of paediatrics1,
  3. Winnie C W Chu, professor2,
  4. William Wong, consultant1,
  5. Dorothy F Y Chan, specialist1,
  6. Stella S Ho, senior radiographer2,
  7. Ka T Wong, consultant2,
  8. Anil T Ahuja, chief of service2,
  9. Chi K Li, chief of service1
  1. 1Department of Paediatrics, The Chinese University of Hong Kong
  2. 2Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong
  1. Correspondence to: H S Lam, 6/F Clinical Sciences Building, Department of Paediatrics, Prince of Wales Hospital, Sha Tin, New Territories, Hong Kong hshslam{at}
  • Accepted 8 December 2008


Objective To investigate the renal outcomes of children after exposure to low dose melamine in Hong Kong.

Design Cross sectional study.

Setting Special assessment centres, Hong Kong.

Participants 3170 children (1422 girls and 1748 boys) aged 12 years or less referred from territory-wide primary care clinics after daily consumption for one month or more of milk products tainted with melamine.

Main outcome measures Presence of renal stones and haematuria.

Results One child had a confirmed renal stone, seven were suspected of having melamine related renal deposits, and 208 (6.6%) were positive for blood in urine by reagent strip. A proportion of these children were followed up at the special assessment centre, but only 7.4% of those positive for blood on reagent strip were confirmed by microscopy, suggesting an overall estimated prevalence of less than 1% for microscopic haematuria.

Conclusions No severe adverse renal outcomes, such as acute renal failure or urinary tract obstruction, were detected in children after exposure to low dose melamine. Our results were similar to territory-wide findings in Hong Kong. Even including the seven children with suspected renal deposits, the prevalence of suspected melamine related abnormalities on ultrasonography was only 0.2%. None of these children required specific treatment. The prevalence of microscopic haematuria was probably overestimated by the reagent strip. These data suggest that large scale and urgent screening programmes may not be informative or cost effective for populations who have been exposed to low dose melamine.


  • HSL and PCN contributed equally to this article. We thank our research team, So Hung Kwan, Ngai Hoi Yan, Simmy Yeung, and Jessie Mak, who helped organise and enter a large amount of data within a short period.

  • Contributors: HSL and PCN drafted the manuscript and made substantial revisions. CKL, WW, and WCWC helped revise the manuscript. PCN, DFYC, WW, and CKL designed the screening programme at the special assessment centre. SSH, KTW, WCWC, and ATA designed the ultrasound follow-up service. WW, CKL, DFYC, KTW, ATA, SSH, and WCWC coordinated the screening service and provided the core paediatric and ultrasonographical data on which the manuscript is based. HSL is guarantor.

  • Funding: The government of the Hong Kong Special Administrative Region provided out of hours pay to staff working extra time during screening. The researchers were independent of the funders.

  • Competing interests: None declared.

  • Ethical approval: In light of the severe adverse renal outcomes associated with consumption of melamine tainted milk products in children on the mainland of China, an expert committee appointed by the government of the Hong Kong Special Administrative Region endorsed a screening programme comprising urinalysis, renal ultrasonography, and blood tests for renal function. There were no adverse health risks from the renal ultrasound scans and urinalysis, and only 1 ml of whole blood was taken for plasma urea and creatinine determination. Participants were free to join the programme and therefore implied consent was assumed for the assessments and no formal written consent was required. The data presented in this report were obtained from the participants who attended our centre and are anonymised. Ethical approval for analysis and publication of the screening programme results was granted by the joint The Chinese University of Hong Kong—New Territories East Cluster Clinical Research Ethics Committee after retrospective review.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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