Arizona Confirms First Fatal Pneumonic Plague Case Since 2007 Linked to Cat Exposure

Key points

• A young adult male in Coconino County, Arizona, died less than eight hours after admission to an emergency department in July 2025, becoming the state's first pneumonic plague fatality since 2007.
• The patient presented with abdominal pain, chest pain, and a dry cough; initial diagnoses considered hantavirus or bacterial pneumonia, but he deteriorated despite empiric antibiotic treatment.
• Preliminary lab results, including blood culture growth and Gram stain findings, raised suspicion for Yersinia pestis two days after death, prompting immediate public health action.
• Forty-six potentially exposed individuals, including household members, coworkers, and hospital staff, received a seven-day course of oral ciprofloxacin as postexposure prophylaxis; none became ill.
• The patient had occupational exposure to two domestic cats with respiratory symptoms five and four days before his illness onset, suggesting inhalation transmission from the animals.
• Final confirmation of Yersinia pestis via PCR and culture was achieved 10 days after the patient's death, but early intervention based on clinical and preliminary lab data prevented further cases.

Background

Arizona has reported only eight human plague cases between 2000 and 2024, with Yersinia pestis endemic among rodents in northern regions. The 2020 Navajo County case highlighted delays in diagnosis, whereas this 2025 case demonstrates improved rapid response. Recent global concerns, such as the disputed fatal plague diagnosis in Siberia, underscore the ongoing relevance of plague surveillance, though this Arizona case is unrelated to that incident.

Why it matters

This case underscores the critical role of clinical suspicion and preliminary diagnostic testing in triggering timely public health interventions in plague-endemic areas. It highlights the risk of zoonotic transmission from domestic cats and the effectiveness of postexposure prophylaxis in preventing outbreaks. Healthcare providers in endemic regions must remain vigilant for severe respiratory illness in patients with animal exposure, while laboratory safety protocols are essential to prevent misidentification and occupational exposure.

What to watch

Public health authorities will continue to monitor the 46 exposed individuals for any late-onset symptoms, though none have reported illness. The CDC and Arizona Department of Health Services will likely reinforce guidelines for veterinary and medical personnel regarding personal protective equipment when handling ill animals or suspected plague specimens. No further cases have been reported as of the publication date.