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Urinary tract abnormalities in Chinese rural children who consumed melamine-contaminated dairy products: a
Jian-meng Liu1, Aiguo Ren, Lei Yang
1Peking University Institute of Reproductive and Child Health, Beijing, China.
Insights
A 2008 China study found 0.61% of young children had kidney abnormalities after consuming melamine-contaminated dairy. Most cases resolved without treatment, but 12% showed persistent renal issues.
Area of Science:
- Pediatric Nephrology
- Toxicology
- Public Health Surveillance
Background:
- Melamine contamination in dairy products has been linked to pediatric kidney damage in China.
- Previous studies lacked data on the prevalence and outcomes of kidney damage in exposed children.
Purpose of the Study:
- To determine the population-based prevalence of kidney damage in children exposed to melamine-contaminated dairy.
- To assess the clinical condition and follow-up outcomes of affected children.
Main Methods:
- Ultrasound-based screening of 7933 children under 36 months in a high-exposure rural area.
- Renal ultrasonography follow-up at one, three, and six months for children with abnormalities.
- Maternal interviews to gather data on melamine-contaminated product consumption.
Main Results:
- Overall prevalence of urinary tract abnormalities was 0.61% (95% CI 0.45%-0.80%).
- Mean melamine exposure was 116 mg/day; 89.6% of affected children were asymptomatic.
- Renal abnormalities persisted in 12% of children at six-month follow-up.
Conclusions:
- 0.61% of screened children exhibited ultrasonographic evidence of nephrolithiasis or hydronephrosis.
- Most affected children were asymptomatic and recovered without specific treatment.
- A significant minority (12%) experienced persistent renal abnormalities post-melamine exposure.
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.
Interpretation:
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.
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