A patient in the United States has recently died after contracting pneumonic plague, a rare but highly serious form of the disease caused by the bacterium Yersinia pestis, according to a statement from the Coconino County Health and Human Services (CCHHS).1 This is the first confirmed plague-related fatality in the county of Arizona in several years and has prompted increased public health monitoring and community awareness efforts.
CCHHS officials said the case was identified during routine disease surveillance, with the individual testing positive for the pneumonic form of the infection, which affects the lungs and can be transmitted person-to-person through respiratory droplets.
Understanding the Plague
Plague is a zoonotic disease, transmissible between animals and humans, most commonly carried by infected fleas that live on small mammals. While often associated with the historic Black Death of the 14th century, plague continues to occur sporadically in the southwestern United States, particularly in Arizona, New Mexico, and Colorado.2
The disease has three primary forms:3
- Bubonic plague: The most common form, affecting the lymphatic system and typically transmitted through flea bites.
- Septicaemic plague: Occurs when the infection spreads to the bloodstream.
- Pneumonic plague: The most severe form, involving the lungs. It can be transmitted through infected droplets, making it more dangerous and requiring rapid diagnosis and treatment.
Plague in the United States
According to the Centers for Disease Control and Prevention (CDC), an average of seven human plague cases are reported each year in the United States. The vast majority occur in rural or semi-rural areas of western states, often during warmer months when human–flea contact is more likely.4
Although modern antibiotics are highly effective against Yersinia pestis, delays in treatment can lead to serious illness or death, particularly with the pneumonic form. Health officials are urging residents and healthcare providers to remain vigilant for potential symptoms of plague, which include:4
- Sudden fever and chills
- Severe headache
- Cough and difficulty breathing (in pneumonic cases)
- Swollen, painful lymph nodes
- Gastrointestinal distress
References:
- Health Day. Arizona Resident Dies From Pneumonic Plague. 2025. Available at: https://www.healthday.com/health-news/infectious-disease/arizona-resident-dies-from-pneumonic-plague?utm_medium=email&utm_source=rasa_io&utm_campaign=newsletter (accessed 17 July 2025).
- World Health Organization. Plague. 2022. Available at: https://www.who.int/news-room/fact-sheets/detail/plague (accessed 17 July 2025).
- Mayo Clinic. Plague. 2023. Available at: https://www.mayoclinic.org/diseases-conditions/plague/symptoms-causes/syc-20351291 (accessed 17 July 2025).
- About Plague. 2024. Available at: https://www.cdc.gov/plague/about/index.html (accessed 17 July 2025).
Editor: Katey Gabrysch, Editorial Director
Disclosures: This article was created by the touchINFECTIOUS DISEASES team utilizing AI as an editorial tool (ChatGPT (GPT-4o) [Large language model]. https://chat.openai.com/chat.) The content was developed and edited by human editors. No funding was received in the publication of this article.
Cite: Rare pneumonic plague-related death sparks health advisory. touchINFECTIOUS DISEASES. 17 July, 2025.
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