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Series/Report no.RIVM report 330371008
MetadataShow full item record
TitleQuantitative risk profile for viruses in foods
Translated TitleKwantitatief risicoprofiel voor virussen in voedsel
PubliekssamenvattingNet als bacteriën kunnen virussen in voedsel risico's vormen voor de volksgezondheid. Over virussen is echter minder bekend. Het RIVM heeft daarom in kaart gebracht welke kennis beschikbaar is of juist ontbreekt om de volksgezondheidsrisico's te kunnen schatten (risicoprofiel). Hiervoor zijn drie virussen uitgelicht die via voedsel naar mensen kunnen worden overgedragen: hepatitis A-virussen in schelpdieren, norovirussen op verse groenten en fruit, en hepatitis E-virussen in varkensvlees. De inventarisatie is in opdracht van de Nederlandse Voedsel- en Warenautoriteit gemaakt.
In het algemeen blijkt dat het tot nu toe lastig is om het aantal virussen op producten op een betrouwbare manier te kunnen schatten. Dit komt gedeeltelijk omdat de methoden om de virussen aan te tonen sterk verschillen. Om de gezondheidsrisico's te kunnen inschatten is kennis over het aantal virussen juist nodig. De kans dat iemand ziek wordt is namelijk groter naarmate het aantal producten dat besmet is groter is, of wanneer het aantal virussen per product hoger is. De tekortkomingen van de methoden worden in dit rapport aangegeven en enkele aanbevelingen worden gedaan om de berekeningen van het aantal virussen realistischer te maken.
Verder is geïnventariseerd welke factoren de kans vergroten dat voedsel besmet raakt tijdens de productie of de verwerking ervan. Bij rauwe of kwetsbare producten, zoals oesters, of verse groenten en fruit, is het immers niet mogelijk om de virussen eenvoudig onschadelijk te maken door voedsel te koken.
Bevindingen onderzochte virussen
Specifieker is het bij het norovirus belangrijk te achterhalen hoeveel virussen op groente en fruit terechtkomen via het irrigatiewater. Een andere mogelijke bron is via de handen of gereedschap tijdens de oogst en verwerking. Voor het hepatitis E-virus is het van belang te weten hoeveel varkens tijdens de slachtfase de infectie doormaken en zo besmette producten leveren. Als zij de hepatitis E-infectie eerder doormaken, is de besmetting voorbij en vormt dit geen risico meer voor de consument. Ook is inzicht nodig in de aantallen hepatitis E-virussen per product. Wat de schelpdieren betreft, is het relevant om te weten hoeveel virussen in het oppervlaktewater zitten waarin ze worden gekweekt, en in welke mate deze virussen in de schelpdieren achterblijven.
Viruses, similar to bacteria, can pose a risk to human health when present in food, but comparatively little is known about them in this context. In a study aimed at the health risks posed by viruses in food products, the RIVM has inventoried both current knowledge and pertinent information that is lacking. The inventory, which is presented in this report as a so-called risk profile, focuses on three viruses that can be transmitted to humans through food consumption. These are the hepatitis A viruses in shellfish, noroviruses in fresh fruits and vegetables and hepatitis E viruses in pork. The study was commissioned by the Dutch Food and Consumer Product Safety Authority.
he general finding is that to date it has been difficult to obtain a reliable estimation of the number of viruses in food products. This is partly due to large differences in the methodologies currently used to detect viruses in food products. However, accurate information on the number of viruses in a food product is crucial to a reliable estimate of the health risk. The probability that any one person becomes infected increases with an increasing number of contaminated products, or with an increasing number of viruses per product. The shortcomings of the methods currently used to make such estimations are identified in this report, and recommendations are made for improvements that will enable a more realistic determination.
Factors that increase the likelihood of food becoming contaminated with viruses during production or processing were also studied. For raw or fragile products, such as oysters, or fresh fruits and vegetables, viruses are not inactivated by heating because the foods are not cooked before consumption.
Specific findings on the studied viruses
With respect to fresh produce, it is important to estimate how many noroviruses come into direct contact with the fruits and vegetables through the irrigation system. Another possible but important source that needs to be characterized is the transfer of viruses from hands or tools to the food product during harvesting and/or processing. For hepatitis E virus, it is important to know how many pigs are infected at the time of slaughter as this could result in contaminated pork products. If the hepatitis E virus infection occurs months before slaughter, the pigs would likely have recovered by the time of slaughter and the products would not represent a health risk to the consumer. It is also important to determine the number of hepatitis E viruses per product. In terms of shellfish, it is relevant to know how many viruses are present in the surface waters in which they are cultured and the extent to which they remain in the shellfish up to the moment of consumption.
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