In a stark reminder of the enduring nature of the deadly Plague, a man in New Mexico died in March after being hospitalized with the disease, while another individual in Oregon was diagnosed with bubonic plague in February, potentially contracted from their pet cat. The Plague, known historically as the Black Death, caused an estimated 50 million deaths in Europe during the Middle Ages.

The Plague, caused by the bacterium Yersinia pestis, is transmitted through fleas that reside on rodents, primarily found in rural areas of the western United States, particularly in states like Arizona, California, Colorado, and New Mexico. The disease is extremely rare but still exists today, with an average of seven human cases reported each year to the U.S. Centers for Disease Control and Prevention (CDC) in these regions.

Symptoms of the Plague typically manifest within one to seven days after infection and include painful and swollen lymph nodes, known as bubos, in areas such as the groin, armpit, or neck, accompanied by fever, chills, and coughing. While humans usually contract the Plague through flea bites or by handling infected animals, cats can directly infect humans, and dogs can carry infected fleas to their owners. Moreover, the disease can also be spread through inhaling droplets from the cough of an infected person or animal.

Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, highlighted that the persistence of the Plague is due to the presence of an animal reservoir. Infected animals and their fleas serve as long-term carriers of the bacteria, making it challenging to eliminate the disease entirely.

Although Plague cases are reported globally, more instances occur in certain parts of Africa and Asia. The World Health Organization (WHO) reported a total of 3,248 cases worldwide from 2010 to 2015, resulting in 584 deaths. The most endemic countries for the disease are the Democratic Republic of the Congo, Madagascar, and Peru.

There are three types of Plague: bubonic, septicemic, and pneumonic. The bubonic form accounts for over 80% of cases in the United States and can progress to the more severe pneumonic form if left untreated. Pneumonic Plague, which affects the lungs, poses a direct risk of human-to-human transmission and was responsible for a large outbreak in Madagascar in 2017, leading to thousands of cases and hundreds of deaths.

While the Plague remains a serious illness, the availability of modern antibiotics has turned it into a treatable disease, as long as it is diagnosed early. Prompt administration of antibiotics, particularly streptomycin, can prevent complications and death. The case-fatality ratio for untreated bubonic Plague ranges from 30% to 60%, while untreated pneumonic Plague is always fatal, according to the WHO.

In terms of prevention, it is crucial to eliminate rodent nesting areas around homes and recreational spaces by removing brush, rock piles, trash, and excess firewood. In the case of sick or dead animals, it is advised to report the sightings to law enforcement or local health officials and avoid handling them directly, unless wearing gloves. Individuals living in endemic areas should use insect repellent containing DEET to prevent flea bites and regularly treat their pets for fleas. Moreover, it is recommended not to sleep with pets, as this increases the risk of contracting the disease. Lastly, pets should not be allowed to hunt or roam in rodent habitats, such as prairie dog colonies.

While the Plague may still exist, understanding its transmission methods and taking precautionary measures can significantly reduce the risk of infection. With timely medical attention and appropriate antibiotic treatment, the once-devastating disease can now be effectively managed.