Oregon residents were diagnosed with bubonic plague.Here’s everything you need to know about the disease

Officials in Central Oregon this week reported a case of Black Death in a resident who may have contracted the disease from a sick pet cat.

Public health officials said medication has been provided to infected residents and their close contacts, and there is believed to be no risk to people in the community. The cat was also treated but did not survive.

Plague was not common, but it was not unheard of in the American West, with a few cases occurring every year. It is different from Alaska pox, a recently discovered rare disease that killed a man in Alaska last month.

Here’s some information about what plague is, who is at risk, and how a disease that was once a harbinger of death became treatable.

What is a plague?

Plague is an infectious disease that can affect mammals. It is caused by the Yersinia pestis bacterium carried by rodents and fleas. Sunlight and dryness can kill plague bacteria on surfaces, according to the Centers for Disease Control and Prevention. People and pets suspected of having plague are often treated with antibiotics and sometimes other medical measures.

Plague symptoms can manifest themselves in many ways. Bubonic 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 by inhaling 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.

Am I at risk of contracting plague?

According to the 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 welder in central Oregon contracted the disease while pulling a rodent from a choking cat’s mouth. He survived but lost fingertips and toes to the disease. A Colorado teen contracted a fatal infection while hunting in 2015, and Colorado officials confirmed at least two cases last year, including one death.

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 by clearing brush and trash heaps and keeping pet food inaccessible. Ground squirrels, chipmunks, and wood rats, as well as 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 them 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.

(This story has not been edited by News18 staff and is published from Yonhap News Agency-The Associated Press)