Reply to Park et al.: Human ectoparasite transmission of plague during the Second Pandemic is still plausible.

In their letter, Park et al. (1) raise several concerns and question our conclusion (2) that human ectoparasites could have caused plague epidemics during the Second Pandemic.First, Park et al. (1) state that our study cannot provide evidence that human ectoparasite transmission was more likely than a mixed pneumonic and rat-flea transmission. We have acknowledged this limitation in our discussion, where we wrote that “we did not model mixed transmission routes, and this makes it difficult to fully assess the contribution of pneumonic plague, which commonly occurs during bubonic outbreaks.” They assert that this scenario is “highly plausible.” We note that while secondary pneumonic infections are common, primary pneumonic transmission through … [↵][1]1To whom correspondence may be addressed. Email: k.r.dean{at}ibv.uio.no, n.c.stenseth{at}ibv.uio.no, or boris.schmid{at}gmail.com. [1]: #xref-corresp-1-1