Tutoring biology, diseases are mentioned. The tutor names perhaps the most contagious one.
Measles is potentially the most contagious disease among humans. In particular, all children in a natural, unvaccinated population will catch it.1
When I was a kid, I heard about measles, but didn’t catch it. I believe I was immunized against it at some point. I never hear about it now, likely because children are typically vaccinated.
Measles can be fatal, by complication to pneumonia or swelling of the brain.
1Mader, Sylvia S. Inquiry into Life, 11th ed. Toronto: McGraw Hill, 2006.
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.