US annual plague average revised without explanation

A total of 131 cases were recorded nationally between 2000 and 2025, 17 of which were fatal, the CDC’s database says The US Centers for Disease Control and Prevention (CDC) has updated its estimate of annual human plague infections in the country, lowering it from seven to five.

On Wednesday, the CDC amended its Plague Maps and Statistics page, which now states: “An average of five human plague cases are reported each year in the United States.” The previous version, dated March 2025, cited seven cases annually, although its own year-by-year data already showed an average of approximately five.

The agency has not provided an explanation for the revision.

According to the CDC’s current data, there were a total of 131 plague cases across the US between 2000 and 2025, 17 of which were lethal.

The highest number of cases dates back to 2006 (17) and 2015 (16).

In the latter case, four people died – the highest annual death toll during the period.

Read more US-funded biolabs project ‘overwhelmingly’ focused on Russia – ex-CIA analyst The previous figure of seven is likely derived from a different historical period.

An April 2026 study by CDC researchers found that 196 human plague cases were reported between 1991 and 2018 – exactly seven annually on average.

According to the CDC, plague first reached the US in 1900 aboard rat-infested steamships, sparking outbreaks in port cities.

The last urban epidemic occurred in Los Angeles in 1924-1925.

Since then, infections have largely been confined to rural western regions, particularly New Mexico, Arizona, and Colorado, as well as parts of California, Oregon, and Nevada.

Read more US publishes docs on ‘dangerous’ Ukrainian biolabs The disease is caused by the Yersinia pestis bacterium, which circulates among rodents and fleas.

More than 80% of US cases involve bubonic plague, which does not spread directly between humans and is typically contracted through infected flea bites or contact with infected animals.

Only pneumonic plague, which affects the lungs, can spread from person to person through respiratory droplets, typically requiring close contact.