I had to deal with this in Ecuador about a decade ago. I had to always carry around a health certificate showing I was vaccinated against yellow fever or they w

I had to deal with this in Ecuador about a decade ago. I had to always carry around a health certificate showing I was vaccinated against yellow fever or they wouldn't let me enter the eastern Oriente (Amazon) region. I think it was a good idea. Too bad there's no vaccine against bot flies :(