[mewzilla]

If you'd like to geek out, your answer may be found here...

A refined model of how Yersinia pestis produces a transmissible infection in its flea vector

Ick.

[mewzilla]

Oh, and it turns out Alaskapox is some new orthopox virus. And gee, there have been a number of novel orthopox viruses appearing on the scene the last few years.

Hmmmmm....

From 1998...

Naturally Occurring Orthopoxviruses: Potential for Recombination with Vaccine Vectors

Conspiracy theory...

...or spoiler?

[Dr. Franklin]

If you'd like to geek out, your answer may be found here...
A refined model of how Yersinia pestis produces a transmissible infection in its flea vector Ick.

Asserting that fleas spread plague doesn't prove that lice don't. Lice are known to spread disease:
Trench fever