Widely known as the Black Death, the bubonic plague pandemic that swept across much of Europe, the Middle East, and North Africa in the 14th century claimed approximately 50 million lives. Yet although it’s what most of us think of when we hear the word “plague,” the Black Death wasn’t the first bubonic plague outbreak, and it certainly wouldn’t be the last.
The bubonic plague was first recorded during the reign of Byzantine Emperor Justinian in the sixth century A.D. Although it made its most devastating appearance in the 1340s and 1350s, the plague has never been eradicated, cropping up many times throughout the centuries.
The plague is a bacterial infection spread by fleas and ticks, which can pass it directly to humans or via infected animals like cats, rabbits, rats, and other rodents. Plague can also be spread via infected bodily fluids and respiratory droplets. The plague can take several forms: bubonic, septicemic, and pneumonic, with all three types originating from the same bacterium, Yersinia pestis.
The United States experienced a bubonic plague epidemic for the first time in 1900, when an outbreak in Asia passed from Hong Kong to other port cities, eventually reaching Honolulu and then San Francisco, likely passed on by infected rats stowing away on steamships. The first plague victim in California was Wong Chut King, a 41-year-old San Francisco lumberyard owner. Yet officials initially refused to accept that Wong had died of plague, even after physician Joseph J. Kinyoun identified the Yersinia pestis bacterium during his autopsy.
The epidemic would ultimately claim at least 119 lives in the United States before it was finally halted in 1904 by improved public health measures. Kinyoun, a pioneer in bacteriology and infectious disease prevention, would go on to establish the Hygienic Laboratory, which later became the National Institutes of Health (NIH).
The plague that spread in California in 1900 is thought to be the predecessor of the strain that still exists in the western United States, leading to around seven human cases every year.
The modern plague:
- Of the three types of plague, bubonic plague is the most common. It is characterized by swollen lymph nodes, high fever, chills, headaches, weakness, and abdominal and limb pain. When left untreated, it can turn into the septicemic plague or, most seriously, pneumonic plague, which infects the lungs and is almost always fatal without treatment.
- Nearly all U.S. cases of bubonic plague occur in the rural West, in places like northern New Mexico and Arizona, southern Colorado, California, and Oregon, and western Nevada. It’s also found in other countries, most notably Peru, Madagascar, and the Democratic Republic of the Congo.
- In addition to a highly effective antibiotic treatment, there’s also a plague vaccine, though this is generally reserved for healthcare and lab workers and isn’t available in the United States.
