Bubonic Plague Death in Arizona 2025: First Since 2007

Arizona recorded its first human death from pneumonic plague in nearly two decades in July 2025, a stark reminder that Yersinia pestis still circulates in American wildlife. The Coconino County resident died the same day symptoms appeared, highlighting how rapidly the disease can overwhelm treatment despite modern medicine.

Location: Coconino County, Arizona · Date Confirmed: July 2025 · Disease Form: Pneumonic plague · County First Since: 2007 · US Cases Yearly: 1-17 reported

Arizona’s first pneumonic plague death in nearly 20 years occurred in Coconino County in July 2025, confirming the bacterium remains active in the state’s wildlife despite decades of absence from human fatality records.

How did the person in Arizona get the plague?

Coconino County officials confirmed on July 11, 2025, that a resident died from pneumonic plague caused by Yersinia pestis bacteria. The patient sought care at Flagstaff Medical Center and died the same day despite resuscitation efforts. Rapid diagnostic testing confirmed the infection, according to UNMC Health Security.

County officials have not released the patient’s identity or exposure history out of respect for the family. The death is unrelated to a prairie dog die-off reported in the Townsend Winona area northeast of Flagstaff, officials emphasized. Public health investigators are reviewing potential wildlife exposures, but no definitive source has been identified.

The risk to the general public remains low, according to Coconino County health officials. Yersinia pestis transmits to humans primarily through infected flea bites or direct contact with infected animals—rodents like squirrels and prairie dogs serve as natural reservoirs in the American Southwest.

The pattern across both Coconino County deaths points to direct wildlife contact as the most probable transmission route, even without an obvious die-off event.

When was the last case of the bubonic plague in the US?

The United States records roughly 1 to 17 plague cases annually, with an average of about seven per year, according to CDC data cited by multiple sources. These cases cluster in the Southwest—New Mexico, Arizona, Colorado, and California—where Yersinia pestis circulates among wildlife populations.

Coconino County’s previous plague death occurred in 2007 and also involved direct contact with a dead animal. That case was confirmed by Northern Arizona Healthcare, matching records from Vax-Before-Travel. The 2025 death marks the first pneumonic plague fatality in the county in almost two decades.

Nationwide, human-to-human plague transmission has not occurred in the United States since 1924, when the last documented case of person-to-person spread was recorded. The last major urban epidemic in the US unfolded in Los Angeles from 1924 to 1925.

Annual incidence

• US average: 7 cases per year (CDC)
• Typical range: 1-17 annually
• Southwest states account for most cases
• Human-to-human transmission: zero since 1924

What animal carries the bubonic plague today?

Rodents serve as the primary wildlife reservoir for plague in North America. Squirrels, prairie dogs, chipmunks, and mice can carry Yersinia pestis, typically through flea bites. When infected fleas bite humans, bubonic plague develops at the bite site, causing painfully swollen lymph nodes called buboes.

“Yersinia pestis is transmitted to animals via bites from infected fleas; human-to-human transmission risk is very low,” CIDRAP reported, citing CDC guidance. The pathogen can also spread through contact with tissues or fluids from infected animals, which explains why handling dead wildlife poses documented danger.

In the American Southwest, prairie dog colonies and squirrel populations in forested and semi-rural areas represent the highest-risk environments. The Townsend Winona prairie dog population northeast of Flagstaff experienced a die-off in 2025, though health officials confirmed the Coconino County death is unrelated to that event.

Flea vectors

• Oropsylla montana (prairie dog flea) — primary US vector
• Xenopsylla cheopis (oriental rat flea) — historically linked to urban epidemics
• Transmission occurs when fleas bite infected host then bite human

What are symptoms of pneumonic plague?

Pneumonic plague attacks the lungs, producing severe respiratory symptoms that distinguish it from bubonic plague. Early signs include fever, chills, headache, and weakness—similar to many infections. The disease progresses rapidly, developing into cough, chest pain, and bloody or watery mucus.

Without treatment, pneumonic plague can cause respiratory failure within two to four days. “Untreated bubonic plague can progress to septicemic plague in bloodstream, then secondary pneumonic plague,” KNAU reported, quoting Northern Arizona University researchers. The pneumonic form is the most dangerous because it can spread person-to-person through respiratory droplets.

Antibiotics including streptomycin and gentamicin effectively treat plague when administered promptly. “Plague can be treated effectively with antibiotics if detected early,” CIDRAP noted. The Arizona patient’s rapid death despite hospital care suggests the infection had progressed too far before medical intervention.

Progression

• Day 1-2: fever, chills, headache, malaise
• Day 2-4: cough, chest pain, difficulty breathing
• Day 4+: respiratory failure, septic shock possible

Differences from bubonic

• Bubonic: swollen lymph nodes (buboes), less often fatal
• Pneumonic: lung infection, higher mortality without treatment
• Septicemic: bloodstream infection, can accompany either form

The window between symptom onset and life-threatening progression is measured in hours, not days, making rapid response critical for survival.

Can you still get the plague today?

Plague has never disappeared from the United States. The 2025 Arizona death demonstrates that Yersinia pestis continues circulating in American wildlife, occasionally spilling over to humans. Roughly seven Americans contract plague annually, according to CDC surveillance data.

“It’s really rare in the U.S. Typically in a year we’ll have 5 to 10 cases, human cases in the U.S,” said Dave Wagner, director of Northern Arizona University’s Pathogen and Microbiome Institute, in an interview with KNAU. Wagner’s team conducts ongoing research into plague vaccine development, funded by the US Department of Defense.

Globally, plague remains endemic in parts of Africa, Asia, and South America. Madagascar reports the highest annual human case counts worldwide. No plague vaccine is currently licensed for general use in the United States, though research continues with DoD support.

Prevention steps

• Avoid rodent habitats, especially dead animals
• Use insect repellent containing DEET on skin and clothing
• Keep pets flea-free with veterinary-approved preventives
• Seal homes to prevent rodent entry

For residents of plague-endemic areas, prevention through flea control and wildlife avoidance offers the only reliable protection against a disease that moves faster than most people expect.

Was the Black Death 100% fatal?

The Black Death that killed an estimated 30 to 60 percent of Europe’s population in the 14th century was devastating—but not universally fatal. Survivors existed then as now, driven by immune resistance, less virulent bacterial strains, and access to better nutrition and care. Historical records show some regions and individuals weathered the pandemic better than others.

Modern medicine has fundamentally changed the equation. Antibiotics like streptomycin, gentamicin, and doxycycline effectively cure plague when administered early. The CDC reports that proper treatment reduces bubonic plague mortality from 50-90 percent (untreated) to roughly 16 percent. Pneumonic plague remains more dangerous—mortality reaches 40 to 90 percent without treatment—but drops substantially with prompt antibiotic therapy.

The 2025 Arizona case illustrates both the progress and limits of modern medicine. The patient received hospital care at Flagstaff Medical Center and died the same day, suggesting the infection overwhelmed treatment before antibiotics could take effect. For those who seek care within hours of symptom onset, survival remains highly probable.

Modern vs. past

• 14th century Black Death: 30-60% mortality untreated
• Current US plague with treatment: approximately 16% mortality
• Pneumonic plague without treatment: 40-90% mortality
• Key variable: speed of antibiotic administration

For anyone spending time in Arizona’s forests and rural areas, the message is concrete: avoid contact with dead rodents, keep pets flea-free, and treat fever after outdoor exposure as a medical emergency. Plague bacteria have survived for millennia in American wildlife, and the 2025 death proves they still occasionally claim human lives.