Plague in the United States and Worldwide: Maps and Statistics

Plague first came to the United States in 1900, aboard rat-infested steamships from affected regions, and caused epidemics in port cities. The last urban plague epidemic in the country struck Los Angeles in 1924–1925. From city rats the disease spread to rural rodents and became established across much of the West, and since then it has appeared as scattered cases in rural areas.

Where U.S. cases occur

Most human cases are acquired in two regions:

• northern New Mexico, northern Arizona and southern Colorado; and
• California, southern Oregon and far western Nevada.

Since the mid-20th century, U.S. plague has typically occurred in the rural West; cases in the East have involved people who traveled from the West or were exposed in laboratories.

Reported human plague cases in the United States, 1970–2023. CDC

How many and who

In recent decades, an average of seven human cases have been reported each year, ranging from none to 17. More than 80% have been the bubonic form. Plague has affected people of every age, from infants to a 96-year-old, but half of cases are in people aged 12 to 45. It occurs in both sexes, historically slightly more often in men, probably because of outdoor activities that raise their risk.

Human plague cases, fatal and non-fatal, United States, 2000–2023. CDC

Around the world

More recent plague epidemics have occurred in Africa, Asia and South America, but since the 1990s most human cases have been in Africa. Almost all cases in the last 20 years have been among people living in small towns, villages or farming areas rather than in larger towns and cities.

Sources

• Centers for Disease Control and Prevention, "Plague: Maps and Statistics": https://www.cdc.gov/plague/maps-statistics/index.html
• A world map on the source page is labeled with two different periods and is not reproduced.