Plague in the modern USA

It's 350 years since Samuel Pepys saw the Great Plague devastate London, so why are Americans still being killed today?

Plague, a disease caused by the bacterium Yersinia pestis, is one of the oldest identifiable diseases known to man. Over 2,400 years ago a plague epidemic tore through Ancient Greece killing one to two thirds of Athens's population. In the 14th century the infamous Black Death devastated the population of Europe altering the course of history and in 1665 the dreaded affliction returned to London killing 100,000, nearly a quarter of it's population. It's this outbreak, the Great Plague, that Pepys himself witnessed and we've already covered in previous blogs


Plague in London, 1665 Credit: Wellcome Library, London.
Plague in London, 1665 Credit: Wellcome Library, London.


Every school child has heard of the major outbreaks that afflicted medieval Europe, but even as recently as the nineteenth century plague pandemics were still killing millions. The lesser known Third Plague Pandemic killed around 15 million people, mainly in China and India. It's surprising that this relatively recent outbreak, on a global scale, isn't as established in the public consciousness but what many may find more surprising is that plague still persists to this day. With access to modern antibiotics plague is treatable but the disease is still endemic in Africa and parts of Asia. 

Even less people know that nearly 50 years after America first put a man on the moon it's citizens are still dying of the ancient disease. The CDC (Centers for Disease Control and Prevention) are the leading national public health institute of the United States. We spoke to them to get more info on why the USA hasn't yet eradicated plague. 

CDC figures on plague cases in the USA

Plague was first introduced into the United States in 1900, by rat–infested steamships that had sailed from affected areas, mostly from Asia. Epidemics occurred in these port cities. The last urban plague epidemic in the United States occurred in Los Angeles from 1924 through 1925. After entering the country plague then spread from urban rats to rural rodent species. Prairie Dogs, the Canada Lynx and Black-footed ferrets are particularly susceptible and it's the existence of large rural populations of these animals that allows plague to persist. Most cases of plague occur in the Western United States and its these areas that have some of the largest rodent populations. 

CDC map charting recorded occurrences of plague in the USA

According to the CDC an average of seven cases are recorded each year. In recent years, the number isn't decreasing either. In fact four deaths recorded so far in 2015 mark the highest fatality so far this century. However efforts are being made to rid rodent populations of fleas and provide vaccines against the disease. In fact plague research continues in a relatively active state, though driven less by motivation to finally eradicate the ancient disease and more by fears of its potential use as a biological weapon. 

CDC data on recent cases of Plague in the USA

To see how the Great Plague ravaged London see our new exhibition Samuel Pepys: Plague, Fire, Revolution

Does it surprise you that plague persists in the modern USA? Join the conversation on social media using #PepysShow

For more information on plague in the modern world visit the CDC website