DETECTION OF VIRUS OR VIRUS-SPECIFIC NUCLEIC-ACID IN FOODSTUFF OR BIOPRODUCTS - HAZARDS AND RISK ASSESSMENT

There are two possibilities for virus contamination of foodstuff and b ioproducts of animal origin: i) the presence of endogenous virus as a result of an acute or subclinical infection of animal raw material use d for food processing or ii) contamination of food in the course of pr ocessing or thereafter. The latter must be considered as the highest r isk for human consumers since the viral contamination mostly is caused by virus shedding people and the transmitted viruses are obligate hum an pathogens. Food from animals consumed as raw material (e.g. oysters ) is listed in a high risk category concerning viral contamination (e. g. hepatovirus). Virus contamination of bioproducts such as vaccines, blood products or biological material used in surgery and for transpla ntations also is more hazardous because the application of contaminati ng virus usually occurs by circumvention of the natural barrier system s of the body. Moreover, in many cases immunosuppressed people are tre ated with bioproducts. Due to an enclosing shield of high protein and lipid content in food and bioproducts viruses are well protected again st physical and chemical influences, however most preparation procedur es for food are destructive for viruses. The detection of pseudorabies virus and pestivirus in biological fluids was tested using polymerase chain reaction (PCR), reverse transcriptase (RT)-PCR and cell culture propagation. PCR is a powerful method to detect viral nucleic acid wh ereas the detection of infectious virus in cell cultures is more limit ed, e. g. due to protein and lipid destroying conditions. Virus contam ination of bioproducts should be considered as a hazard no matter whic h method has been used for its detection. Examples are given about the contamination of cell lines and vaccines.