Giuseppe
Emeritus
Public health issue - Public health impact on EU citizens of the melamine contamination of dairy products in China. [ECDC]
Provisional ECDC Public Health Impact Assessment - Public health impact assessment date: 1 October 2008.
Source and date of request: EC, in preparation for a Health Security Committee teleconference, 25 September 2008.
Public health issue - Public health impact on EU citizens of the melamine contamination of dairy products in China.
Event background information
On 10 September 2008, Promed issued a request for information concerning 14 cases of kidney stones in infants hospitalized in Gansu province, China, in the past two months(1).
On September 21, Chinese authorities reported 39 965 cases of kidney stones in infants, including three deaths related to the consumption of melamine-contaminated powdered infant formula.
On this date, 12 892 were hospitalized, 104 with severe illness.
Most of these cases (82%) affected children under 2 years of age.
A large melamine contamination of milk containing products including infant formula was reported from China.
The levels of contamination is varying but reaching high levels among certain producers.
Contaminated food items include infant formula, liquid milk, frozen yoghurt dessert and coffee drinks.
Media report about other milk and dairy products to be contaminated, including ice-cream, chocolate cookies and candies.
In addition to Hong Kong and Taiwan in China, food safety agencies of several other countries have identified contaminated products sold locally originating from China: Singapore, New-Zealand, Indonesia, South Korea, Vietnam and Canada(2).
Contaminated products were also exported to Bangladesh, Burundi, Myanmar, Gabon and Yemen.
Media in the EU have reported that milk originating from China have been found in Spain and Portugal(3).
Ireland has withdrawn from selling points identified as contaminated by New Zealand health authorities(4).
On 17 September, China has recalled tons of milk powder produced by Sanlu Co since March 2008.
The importation in the EU of milk products from China is prohibited by the EU legislation since 2002.
However, certain amounts of composite products (i.e. products which contain at the same time a processed product of animal origin and a product of non-animal origin) containing processed milk components might have reached the EU in the past, including candies, biscuits, chocolate, toffee or cakes.
On 26 September, the European Commission extended this ban to all Chinese composite products containing milk or milk products, intended for particular nutritional use of infants and young children made for infants that could contain traces of milk powder(5).
As a result, systematic tests (threshold 2.5 ppm) will be performed on Chinese products containing more than 15% of milk products, and on all consignments of such composite products whose amount of milk product content can not be established.
The tolerable daily intake (TDI) of melamine is 0.5 mg/kg body weight in the EU(6).
Above such a dose, possible health effects may occur, especially when repeatedly consumed.
Health effects of melamine
Melamine, when associated with cyanuric acid, a structural analogue of melamine which may be found as an impurity of melamine(7), can cause renal failure by production of insoluble melamine cyanurate crystals in renal tubules and/or calculi in kidneys, ureter, urethra or the urinary bladder.
Calculi are a mixture of melamine, protein, uric acid and phosphate and are distinct from other kidney stones. They are radiolucent stones and give a negative image on urinary tract x-ray. Usually there is bilateral affection of the genito-urinary system. Ultrasound investigation reveals bilateral renal enlargement with increased echo. Furthermore, in the urine sediment crystals may be found with a characteristic double refraction in microscopy. Further details on differential diagnosis and ultrasound and x-ray findings can be obtained from the WHO page referenced in this paragraph.
Although there is sufficient evidence for melamine carcinogenicity under conditions which produce bladder calculi in animals, this evidence is still lacking in humans(8).
The following symptoms have been observed in infants affected by the melaminecontaminated infant formula in China (WHO):
? Unexplained fever arising from urinary tract infections/bacteraemia secondary to urine stasis resulting from obstruction; ? Unexplained crying in infants, especially when urinating, possible vomiting ? Macroscopic or microscopic haematuria; ? Acute obstructive renal failure: oliguria or anuria; ? Stones discharged while passing urine. For example, a baby boy with urethral obstruction with stones normally has dysuria; ? High blood pressure, oedema, painful when knocked on kidney area.
Urolithiasis in infants is an uncommon disease. However, the background level in the EU indicates that several hundred urolithiasis are occurring every year in the EU, affecting children under 5 years of age, and most probably not related to melamine exposure.
Assessment for exposure of EU citizen through food products
The European Food Safety Authority published on 24 September a statement(9) indicating that the estimated exposure does not raise concerns for the health of adults in Europe should they consume chocolates and biscuits containing contaminated milk powder.
Children with a mean consumption of biscuits, milk toffee and chocolate made with such milk powder would also not generally exceed the tolerable daily intake (TDI). However, in worst case scenarios with the highest level of contamination, children with high daily consumption of milk toffee, chocolate or biscuits containing high levels of milk powder would exceed the TDI. Children who consume both such biscuits and chocolate could potentially exceed the TDI more than threefold.
However, EFSA noted that it is presently unknown whether such high level exposure scenarios may occur in Europe.
In ECDC's view, the risk would be higher for children in the event of the presence in the EU of counterfeit or illegally imported milk products. The risk associated with absorbing ?tolerable? melamine doses in humans with compromised renal function or haemo-concentration is undocumented.
In particular, specific groups of EU citizens may have been and/or still be at higher risk of having been exposed to contaminated products:
? Visitors to China in the recent months; ? Export of contaminated products to EU overseas territories may have happened and therefore there might be a risk for citizens of these territories; ? Children who have been recently adopted from China and were exposed to contaminated infant formula with Chinese origin, are at risk for the disease, if still exposed to infant formula originating from China; ? Travellers to and residents in China should currently be aware of the possibility of contamination of dairy products still sold in China, including milk, milk products and infant formula until the extent of the contamination is fully ascertained by Chinese authorities.
Assessment of public health impact of potential exposure
Even though there were indication of potential contamination as early as in the late 2007, the period of potential exposure can be considered since March 2008, when contaminated batches have been produced. The assessment of the public health impact of potential exposure of EU citizens to contaminated food products during this period should therefore focus on children less than 10 years of age (the oldest case reported in Honk Kong) even though most of the cases were below three years of age.
The assessment can be done:
? Retrospectively by checking hospital discharge data (or other appropriate sources e.g. emergency consultation registers) for ICD 10 codes related to renal failure and urolithiasis, for infants under the age of 10, as most cases in China were in this age group. The relevant ICD 10 codes include N17, N19, N20, N21 and N23. Thus this review should cover the period March 2008
onwards. Data retrieved should be compared to historical baseline data;
? Prospectively, by informing health care providers in paediatric wards of the clinical presentation of the disease. Children, less than 10 years of age, who presents with symptoms or signs of urolithiasis or acute renal failure and where other potential causes of kidney stones have been excluded by differential diagnosis, should be ascertained for melamine exposure, by administering a food exposure questionnaire and if appropriate by testing for melamine and notified to health authorities if melamine exposure is confirmed.
CONTACT: support@ecdc.europa.eu
References
1 Promed: infant kidney stones - china: Gansu, milk powder suspected, request for information (http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,73896)
2 Asia: Contaminated chocolate http://news.bbc.co.uk/2/hi/asia-pacific/7641317.stm
3 http://www.eleconomista.es/europa/n...os-chinos-enestablecimientos-de-Portugal.html - http://www.elpais.com/articulo/20080926elpepunac_12/Tes/
4 http://www.fsai.ie/alerts/fa/fa_08/fa20080925.asp
5 European voice: EU bans Chinese baby products containing milk powder
http://www.europeanvoice.com/articl...aby-products-containing-milkpowder/62476.aspx
6 EC, 1986. Report of the Scientific Committee for Food on certain monomers of other starting substances to be used in the manufacture of plastic materials and articles intended to come into contact with foodstuffs. Seventeenth series. Opinion expressed on 14 December 1984. Available at url: (http://ec.europa.eu/food/fs/sc/scf/reports/scf_reports_17.pdf)
7 WHO: Melamine and Cyanuric acid: Toxicity, preliminary risk assessment and guidance on levels in food http://www.who.int/foodsafety/fs_management/Melamine.pdf
8 Melamine [108-78-1], IARC monograph Vol. 73; 1999 - http://www.inchem.org/documents/sids/sids/108781.pdf
9 Statement of EFSA on risks for public health due to the presences of melamine in infant milk and other milk products in China. (http://www.efsa.europa.eu/EFSA/Statement/contam_ej_807_melamine.pdf?ssbinary=true)
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Original text: http://ecdc.europa.eu/en/files/pdf/Health_topics/Melamine_Health_Impact_Assessment _081001.pdf
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Provisional ECDC Public Health Impact Assessment - Public health impact assessment date: 1 October 2008.
Source and date of request: EC, in preparation for a Health Security Committee teleconference, 25 September 2008.
Public health issue - Public health impact on EU citizens of the melamine contamination of dairy products in China.
Event background information
On 10 September 2008, Promed issued a request for information concerning 14 cases of kidney stones in infants hospitalized in Gansu province, China, in the past two months(1).
On September 21, Chinese authorities reported 39 965 cases of kidney stones in infants, including three deaths related to the consumption of melamine-contaminated powdered infant formula.
On this date, 12 892 were hospitalized, 104 with severe illness.
Most of these cases (82%) affected children under 2 years of age.
A large melamine contamination of milk containing products including infant formula was reported from China.
The levels of contamination is varying but reaching high levels among certain producers.
Contaminated food items include infant formula, liquid milk, frozen yoghurt dessert and coffee drinks.
Media report about other milk and dairy products to be contaminated, including ice-cream, chocolate cookies and candies.
In addition to Hong Kong and Taiwan in China, food safety agencies of several other countries have identified contaminated products sold locally originating from China: Singapore, New-Zealand, Indonesia, South Korea, Vietnam and Canada(2).
Contaminated products were also exported to Bangladesh, Burundi, Myanmar, Gabon and Yemen.
Media in the EU have reported that milk originating from China have been found in Spain and Portugal(3).
Ireland has withdrawn from selling points identified as contaminated by New Zealand health authorities(4).
On 17 September, China has recalled tons of milk powder produced by Sanlu Co since March 2008.
The importation in the EU of milk products from China is prohibited by the EU legislation since 2002.
However, certain amounts of composite products (i.e. products which contain at the same time a processed product of animal origin and a product of non-animal origin) containing processed milk components might have reached the EU in the past, including candies, biscuits, chocolate, toffee or cakes.
On 26 September, the European Commission extended this ban to all Chinese composite products containing milk or milk products, intended for particular nutritional use of infants and young children made for infants that could contain traces of milk powder(5).
As a result, systematic tests (threshold 2.5 ppm) will be performed on Chinese products containing more than 15% of milk products, and on all consignments of such composite products whose amount of milk product content can not be established.
The tolerable daily intake (TDI) of melamine is 0.5 mg/kg body weight in the EU(6).
Above such a dose, possible health effects may occur, especially when repeatedly consumed.
Health effects of melamine
Melamine, when associated with cyanuric acid, a structural analogue of melamine which may be found as an impurity of melamine(7), can cause renal failure by production of insoluble melamine cyanurate crystals in renal tubules and/or calculi in kidneys, ureter, urethra or the urinary bladder.
Calculi are a mixture of melamine, protein, uric acid and phosphate and are distinct from other kidney stones. They are radiolucent stones and give a negative image on urinary tract x-ray. Usually there is bilateral affection of the genito-urinary system. Ultrasound investigation reveals bilateral renal enlargement with increased echo. Furthermore, in the urine sediment crystals may be found with a characteristic double refraction in microscopy. Further details on differential diagnosis and ultrasound and x-ray findings can be obtained from the WHO page referenced in this paragraph.
Although there is sufficient evidence for melamine carcinogenicity under conditions which produce bladder calculi in animals, this evidence is still lacking in humans(8).
The following symptoms have been observed in infants affected by the melaminecontaminated infant formula in China (WHO):
? Unexplained fever arising from urinary tract infections/bacteraemia secondary to urine stasis resulting from obstruction; ? Unexplained crying in infants, especially when urinating, possible vomiting ? Macroscopic or microscopic haematuria; ? Acute obstructive renal failure: oliguria or anuria; ? Stones discharged while passing urine. For example, a baby boy with urethral obstruction with stones normally has dysuria; ? High blood pressure, oedema, painful when knocked on kidney area.
Urolithiasis in infants is an uncommon disease. However, the background level in the EU indicates that several hundred urolithiasis are occurring every year in the EU, affecting children under 5 years of age, and most probably not related to melamine exposure.
Assessment for exposure of EU citizen through food products
The European Food Safety Authority published on 24 September a statement(9) indicating that the estimated exposure does not raise concerns for the health of adults in Europe should they consume chocolates and biscuits containing contaminated milk powder.
Children with a mean consumption of biscuits, milk toffee and chocolate made with such milk powder would also not generally exceed the tolerable daily intake (TDI). However, in worst case scenarios with the highest level of contamination, children with high daily consumption of milk toffee, chocolate or biscuits containing high levels of milk powder would exceed the TDI. Children who consume both such biscuits and chocolate could potentially exceed the TDI more than threefold.
However, EFSA noted that it is presently unknown whether such high level exposure scenarios may occur in Europe.
In ECDC's view, the risk would be higher for children in the event of the presence in the EU of counterfeit or illegally imported milk products. The risk associated with absorbing ?tolerable? melamine doses in humans with compromised renal function or haemo-concentration is undocumented.
In particular, specific groups of EU citizens may have been and/or still be at higher risk of having been exposed to contaminated products:
? Visitors to China in the recent months; ? Export of contaminated products to EU overseas territories may have happened and therefore there might be a risk for citizens of these territories; ? Children who have been recently adopted from China and were exposed to contaminated infant formula with Chinese origin, are at risk for the disease, if still exposed to infant formula originating from China; ? Travellers to and residents in China should currently be aware of the possibility of contamination of dairy products still sold in China, including milk, milk products and infant formula until the extent of the contamination is fully ascertained by Chinese authorities.
Assessment of public health impact of potential exposure
Even though there were indication of potential contamination as early as in the late 2007, the period of potential exposure can be considered since March 2008, when contaminated batches have been produced. The assessment of the public health impact of potential exposure of EU citizens to contaminated food products during this period should therefore focus on children less than 10 years of age (the oldest case reported in Honk Kong) even though most of the cases were below three years of age.
The assessment can be done:
? Retrospectively by checking hospital discharge data (or other appropriate sources e.g. emergency consultation registers) for ICD 10 codes related to renal failure and urolithiasis, for infants under the age of 10, as most cases in China were in this age group. The relevant ICD 10 codes include N17, N19, N20, N21 and N23. Thus this review should cover the period March 2008
onwards. Data retrieved should be compared to historical baseline data;
? Prospectively, by informing health care providers in paediatric wards of the clinical presentation of the disease. Children, less than 10 years of age, who presents with symptoms or signs of urolithiasis or acute renal failure and where other potential causes of kidney stones have been excluded by differential diagnosis, should be ascertained for melamine exposure, by administering a food exposure questionnaire and if appropriate by testing for melamine and notified to health authorities if melamine exposure is confirmed.
CONTACT: support@ecdc.europa.eu
References
1 Promed: infant kidney stones - china: Gansu, milk powder suspected, request for information (http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,73896)
2 Asia: Contaminated chocolate http://news.bbc.co.uk/2/hi/asia-pacific/7641317.stm
3 http://www.eleconomista.es/europa/n...os-chinos-enestablecimientos-de-Portugal.html - http://www.elpais.com/articulo/20080926elpepunac_12/Tes/
4 http://www.fsai.ie/alerts/fa/fa_08/fa20080925.asp
5 European voice: EU bans Chinese baby products containing milk powder
http://www.europeanvoice.com/articl...aby-products-containing-milkpowder/62476.aspx
6 EC, 1986. Report of the Scientific Committee for Food on certain monomers of other starting substances to be used in the manufacture of plastic materials and articles intended to come into contact with foodstuffs. Seventeenth series. Opinion expressed on 14 December 1984. Available at url: (http://ec.europa.eu/food/fs/sc/scf/reports/scf_reports_17.pdf)
7 WHO: Melamine and Cyanuric acid: Toxicity, preliminary risk assessment and guidance on levels in food http://www.who.int/foodsafety/fs_management/Melamine.pdf
8 Melamine [108-78-1], IARC monograph Vol. 73; 1999 - http://www.inchem.org/documents/sids/sids/108781.pdf
9 Statement of EFSA on risks for public health due to the presences of melamine in infant milk and other milk products in China. (http://www.efsa.europa.eu/EFSA/Statement/contam_ej_807_melamine.pdf?ssbinary=true)
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Original text: http://ecdc.europa.eu/en/files/pdf/Health_topics/Melamine_Health_Impact_Assessment _081001.pdf
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