Last week, a case of bubonic plague, a disease that killed tens of millions in medieval Europe, was reported in rural Oregon. Those affected received prompt treatment, and health officials believe there is “minimal risk to the community” from the spread of the disease.
Officials believe the disease is likely transmitted to individuals from sick pet cats, and although the disease is extremely rare in modern times, a few cases are reported each year. But by 2024, doctors know better how to treat the disease and prevent its spread.
Here’s what you need to know about how the disease once called the Black Death became treatable:
What is a plague?
The Black Death was an infectious disease affecting mammals caused by Yersinia pestis bacteria. It is usually spread by fleas infected with bacteria. Infection can also be acquired through inhalation of respiratory droplets after close contact with animals or humans with pneumonic plague (the most severe form of the disease). According to the Centers for Disease Control and Prevention, another way to contract plague is through “direct contact with infected tissue or fluids while handling animals that are infected or have died from plague.”
Plague symptoms can manifest themselves in many ways. Plague – the plague that Oregon residents contracted – occurs when plague bacteria enter the lymph nodes. It can cause fever, headache, weakness, and painful, swollen lymph nodes. According to the CDC, this condition is usually caused by the bites of infected fleas.
If the bacteria enter the bloodstream, symptoms of septicemic plague can occur. It may occur during the early stages of the Black Death or after it is left untreated. This form of plague causes the same fever, chills, and weakness, as well as abdominal pain, shock, and sometimes other symptoms such as bleeding on the skin and darkening of the fingers, toes, or nose. The CDC says this form comes from flea bites or handling infected animals.
Pneumonic plague, the most severe form of the disease, occurs when the bacteria enters the lungs. Pneumonic plague adds rapidly developing pneumonia to the list of plague symptoms. It is the only form of plague that can be spread from person to person through inhalation of infectious droplets.
The CDC says all forms of plague can be treated with common antibiotics, and people who seek treatment early have a better chance of making a full recovery.
Who is at risk?
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, and about 80 percent of these are the bubonic form. Most cases occur in rural areas of the western and southwestern United States.
In 2012, a central Oregon welder contracted the bubonic plague while pulling a rodent from a suffocated cat’s mouth. He survived but lost his fingertips and toes to the disease. A Colorado teen contracted a fatal infection while hunting in 2015, and Colorado officials last year confirmed at least two cases, one of which died.
Worldwide, most human plague cases in recent decades have occurred among people in rural towns and villages in Africa, particularly Madagascar and Congo, according to the Cleveland Clinic.
People can reduce the risk of plague by making their homes and outdoor living areas less attractive to rodents, clearing brush and trash piles, and keeping pet food inaccessible. Ground squirrels, chipmunks, and wood rats, among other rodents, can carry plague, so people who keep birds and squirrels may want to consider the risks if they live in an area with plague outbreaks.
Insect repellents containing DEET can also help protect people from rodent fleas while camping or working outdoors, the CDC says.
Flea control products can help prevent fleas from infesting household pets. The CDC says if your pet becomes sick, you should take it to a veterinarian as soon as possible.
Aren’t plagues from the Middle Ages?
The Black Death of the 14th century is perhaps the most notorious plague epidemic, killing up to half the population as it spread across Europe, the Middle East and North Africa. It began to wreak havoc on communities in the Middle East and Europe between 1347 and 1351, and continued to cause widespread outbreaks for about the next 400 years.
An early major plague pandemic, known as the Plague of Justinian, broke out in Rome around 541 and continued to erupt for the next several hundred years.
The third plague pandemic broke out in the Yunnan region of China in the mid-1800s and spread along trade routes, arriving in Hong Kong and Bombay some 40 years later. It eventually reached every continent except Antarctica, killing an estimated 12 million people in China and India alone, according to the Cleveland Clinic.
In the late 1800s, an effective antiserum treatment was developed. Decades later, this treatment was replaced by more effective antibiotics.
The World Health Organization says that while plague remains a serious disease, antibiotics and supportive care are effective against even the most dangerous forms of pneumonia if patients are treated promptly.
