Plague in the USA: Colorado

Public health officials in Colorado reported a fatal case of plague in Archuleta County on 25 September 2023. It is not known how the person became infected. This was the second case of plague in Colorado this year. The first was reported in Montezuma County in June 2023.

Plague is a severe bacterial infection which spreads to humans mainly by the bite of infected fleas, or from having close contact with infected animals or people. It is rare in the USA but is known to occur in wild rodents, espcially priairie dogs.

Advice to travellers

Plague is rare in international travellers. The risk is highest in those visiting endemic regions who come into close contact with local wildlife, particularly rats or other rodents or who are in a healthcare environment. Activities which may increase this risk include:

• camping, or staying in very basic rural accommodation
• walking, hiking or working outdoors
• hunting or participating in activities which involve close contact with wildlife
• caring for a sick person who may be infected with pneumonic plague, which spreads from person to person

Travellers should be advised to:

• practice good insect bite avoidance: insect repellents should protect against flea bites
• avoid close contact with sick or dead animals
• avoid crowded areas in regions where pneumonic plague has recently been reported
• follow appropriate infection prevention and control guidance in a healthcare environment
• seek prompt medical attention if they develop symptoms and is a risk they may have been exposed to plague

No vaccine is available for plague. Progression of the disease may be prevented with appropriate antibiotic treatment.

For further information, see the TRAVAX Plague page.