Expert: John Locke - 4/9/2007

Question
Jared Diamond in Guns, Germs and Steel, (p.198)refers to the "virus causing laughing sickness (kuru) in the New Guinea highlands" and says it is passed by children "licking their fingers" after touching infected brains of victoms which have not yet been cooked. Can prions be considered a virus? Is Diamond wrong or merely speaking casually for a non-scientific audience?

Answer
Edwyn, thank you for using AllExperts and I'd be happy to answer your question.

To put it briefly, no, prions are not similar enough to viruses to accurately consider them the same thing. Viruses consist of a protein coat surrounding a core of DNA or RNA; they insert that genetic material into a host cell, which in turn causes the production of new viruses. Prions contain no nucleic acid; indeed, they are made entirely of protein, hence the name ("prion" is taken from the term proteinacious infectious particle). Like viruses, they also create additional copies of themselves; this catalytic ability is a function of their shape, although the mechanism is not known exactly--it's a current avenue of research.

To be fair to Diamond, I have not read Guns, Germs, and Steel, and cannot say for certain whether he made a deliberate or accidental error. However, I can say this: kuru is a very unusual disease, between its method of transmission (the consumption of brains can indeed spread the disease), the infectious agent (prion), and the symptoms (mainly neurological effects, which include uncontrollable laughter and personality changes). Diamond, who I do understand researches his work very thoroughly, would almost certainly have come across the fact that kuru is a prion disease. Whether he chose not to include this is a fact that, unfortunately, falls beyond my scope here.