What does the word "eradicate" mean in the context of infectious disease? Short thread. (1/n)

It means to completely eliminate an infectious agent or disease from the planet and it can only be done with agents that don't infect non-human animals (i.e., that don't exist in an animal reservoir). (2/n)

So far we have only achieved that with one virus -smallpox virus. There are only an additional two viruses for which we can do that, and those are poliovirus and measles virus. (3/4)

It would be impossible to eradicate any other virus that we know of, because they all circulate in animal reservoirs. (End)