I am on the road and haven't watched the video yet, and perhaps the point I'm about to make is addressed there. The year 2000 was a presidential election year and featured the Olympics, but was not a Leap Year because century-years that are divisible by four are not Leap Years.

I must add "Bill and Ted's Excellent Adventure" to the list.

Well, actually, Pettenkofer procured the vial of vibrio from Koch's lab, and all he got was a little diarrhea himself. By the time he received the sample from Koch, the virulence of the bacteria was likely greatly diminished, and as a wealthy man, Pettenkofer likely had a very healthy diet. Cholera bacteria will succumb very easily to stomach acids and a healthy immune system -- that's one reason Asiatic cholera is a disease of the poor. That said, Pettenkofer's ideas of sanitary saved a great many lives in the nineteenth century, especially with Asiatic cholera. They cleaned up the cities, and cholera is a disease of filth. So, there's no reason to disparage him for not endorsing germ theory. There are plenty of theories today we all endorse that will seem pretty naive in a few generations, but that doesn't demean the work we do to make the world a better place.