SURVEILLANCE METHODS FOR VIRUSES IN FOODS1

Abstract

Viruses contaminate foods and sometimes cause illnesses in consumers. Methods have been needed for detection of foodborne viruses both in routine field samples and in samples associated with outbreaks of disease. Viruses are detected by inoculating living hosts such as tissue cultures or laboratory animals. Food samples, made fluid if necessary, can be inoculated directly into the test host. This approach has resulted in several isolations of viruses from field samples of foods. If greater sensitivities are desired, larger samples must be tested. This usually requires that the sample be concentrated before inoculation into the test host, and concentration can be performed only if food solids in the suspension are at a minimum. A family of methods has been developed for extraction and detection of enteroviruses from food samples. More recently, a procedure for dislodging enteroviruses from food surfaces has been devised. These procedures do not possess all of the desired properties of an ideal test method. In particular, they cannot detect all of the viruses known to be transmitted in foods. They do offer the possibility that several samples could be tested per day, with good sensitivity, at a moderate cost per sample. The means for routine surveillance of foods for virus contamination are at hand. Growing points for further development of surveillance methods are discussed.