Colorado health officials are currently investigating a suspected case of the plague in a human, a rare bacterial infection infamous for causing devastation in 14th century Europe. Despite its historical reputation, the plague is now effectively treated with antibiotics.
The Centers for Disease Control and Prevention report an average of seven human plague cases annually in the U.S., with a recent case in Oregon involving a person likely infected by their sick cat.
The bubonic plague, which spreads naturally among rodents like prairie dogs and rats, is the most common form of the bacterial infection. It causes painful swelling of lymph nodes, known as buboes, mainly in the groin, armpit, and neck. If left untreated, bubonic plague can progress to septicemic or pneumonic plague.
Symptoms of the plague include swollen lymph nodes, high fever, chills, headaches, and pain in the abdomen, legs, and arms.
Plague is transmitted through the bites of infected fleas that spread the bacteria between rodents, pets, and humans. Additionally, it can be contracted by touching infected bodily fluids or through respiratory droplets of a patient with pneumonic plague.
The most dangerous form is pneumonic plague, with an untreated fatality rate close to 100%. Areas in the U.S. where plague cases occur most commonly are rural regions of northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon, and far western Nevada.
While the plague has not been eradicated, advancements in prevention and treatment have been made. Early antibiotic treatment can cure the plague if administered promptly.
Prevention measures include keeping rodent-attracting debris away from homes, ensuring pets are up to date on flea treatments, and using insect repellent with DEET when outdoors to ward off disease-spreading pests.
Although a vaccine exists, it is only recommended by the World Health Organization for high-risk individuals like laboratory and healthcare workers, and it is not available in the U.S. Research is ongoing to determine the vaccine’s efficacy against different forms of the plague. Developing a trial for a plague vaccine poses ethical and logistical challenges, particularly due to the rarity of the bubonic form and the limited market demand.