The prion is a new addition to the rogue’s gallery of infection agents. Unlike a virus that cannot survive outside a living body, prions may lodge in dead meat for unknown periods, and strike even after flesh has been cooked. Cases of mad cow disease have brought this frightening matter to light. Bird meat has been known to contain bacteria, fungi and protozoa. These pathogens are relatively easy to control through the use of chemical biocides. However an infection threat from bird meat has seemed unlikely until now, since the animals are dressed, cooked and eaten hours if not days after slaughter. What if a chicken leg, breast or other part contains prions? Our knowledge of prions in birds is sketchy. The implications of consuming meat of diseased birds are simply not known. Prions are associated with fatal diseases in big game such as deer, and have been discovered in fish as well. Where will all this end?
Mad cow disease has changed meat production and its international trade forever. Each animal that shows signs of nerve defect or brain damage is isolated. Preceding generations are traced as a matter of abundant precaution. Countries are careful not to source beef from foreign sources where monitoring and quarantine practices are suspect. Logically, we should extend these measures to poultry, piggeries and fish farms. However the logistics are daunting, and how can you tell if a fish feels a bit under the weather anyhow? The situation in most of Asia is more complicated: animals are allowed to roam free, taken to graze and slaughtered without effective regulation. US Customs do not allow people arriving from abroad to bring in edible substances, but how can such conditions be universally enforced? Can we make sure that every backpack is free of that sandwich, or that meals left unconsumed in an airliner do not make their way to a soup kitchen?