Four facts about plague in New Mexico

New Mexico recently reported its first human plague case since 2021, but plague has been in the state for decades and New Mexico accounts for many of the human plague cases in the U.S.

Here are four facts about plague in New Mexico:

1. In the Western U.S., rats are not the biggest spreaders of plague.

While black rats and brown rats are the most important plague hosts globally, in the Western U.S. ground squirrels play a bigger role in amplifying the disease, according to a New Mexico Department of Health report.

2. Plague has been in New Mexico since the 1930s.

The first human case of plague in New Mexico was reported in 1949, but plague was found in prairie dogs in 1938, according to an NMDOH report.

3. Feline plague has been in N.M. since the 1970s.

The first confirmed case of plague in a New Mexican cat was reported in 1977 after the cat bit and infected a Cibola County boy, according to an NMDOH report. Since 1977, 407 domestic cats in the state have had confirmed or probable cases of plague.

4. The 1980s were a peak for human plague cases in New Mexico.

In the 1980s, New Mexico had 104 cases of plague, the most cases of any decade, according to NMDOH data. The 1970s saw 60 cases of human plague in the state, the second highest number of any decade. Recent decades have had much lower numbers, with 22 human cases in the 2010s.