Bubonic plague is spread by fleas infected with Yersinia pestis, and its main symptoms include swollen lymph nodes and fever.

Pneumonic plague is airborne and its main symptoms include high fever, cough and chest pain.

The Black Death was a plague epidemic in Europe in the 14th century that killed millions of people.

Pandemics in the 19th and early 20th centuries occurred mainly in Asia and Africa.

Yersinia pestis commonly lives in rodents, such as mice and squirrels, and is transmitted to humans by fleas.

Symptoms of bubonic plague include fever, swollen lymph nodes, nausea and vomiting.

Symptoms of pneumonic plague include high fever, cough, difficulty breathing, chest pain and feeling tired.

Preventive measures include using insect sprays, rodent removal, and vaccinations.

Treatment includes antibiotics and supportive care.

In recent years, plague outbreaks have been brought under control in some countries, but local epidemics still exist.

International organizations and governments continue to focus on the spread of plague and control measures.