What is one example of the author keeping a lively tone even while discussing a disease?

The author uses technical language when defining the name "bovine spongiform encephalopathy."
The author explains how "[i]t takes a long time for the cow to show symptoms" after it is infected by the disease.
The author connects prions to humans by saying it is "very similar to other proteins in the brain."
The author humanizes the prion with playful language by saying "[i]f it manages to burrow into a corner."