The Plague in Yosemite National Park

As many of you know, parts of Yosemite national Park closed this passed week because of several cases of the plague. For most, the plague comes with the stigma of being an extremely deadly disease. But for others, the plague spells out a quite fascinating story of infectious disease. Secretions by the enterobacteria Yersinia pestis cause the symptoms of the plague; the enterobacteria itself lives inside cells and is easily spread between different species of mammalian hosts. Perhaps we should take a moment to appreciate the rarity of a bacteria like this, not too many can infect so many different species like Y. pestis can. Even more so, it’s presence has been recorded throughout history and all over the world. Nowadays, the case of the plague is easily treated with a course of antibiotics, yet its presence is still enough to close a national park. Why?

photo by K. Dahlhausen
photo by K. Dahlhausen

Keeping humans away from the area of the outbreak will decrease the number of cases in humans, but the plague will still be there in infected host such as rodents and fleas which are quite abundant in Yosemite. Officials are spraying the area of the outbreak with insecticide; this will decrease the transmission by fleas but doesn’t control the transmission between the mammalian hosts. There doesn’t seem to be an effective way to combat a disease that has stood the test of time and geography. Does this mean that the park will be closed forever? Probably not, but it brings up an interesting question of how we will deal with infectious disease epidemics in the future. Let’s just hope that an antibiotic resistant strain of the plague doesn’t evolve anytime soon.

Leave a Reply

Katherine Dahlhausen

Katie Dahlhausen is a PhD student in Jonathan Eisen’s lab and is interested in the biogeography and mechanisms of antibiotic resistance. Find out more at her Twitter feed .