The plague is an infection caused by bacteria. It mainly affects rodents, but fleas carried on the backs of rats can transmit the disease to people, once a person is infected, they can infect others very rapidly. The plague causes fever, painful swelling of the lymph glands and causes skin spots that are red at first and then turn to black.
Bubonic Plague is often fatal in three to four days without treatment. The plague is perhaps best known for ravaging Europe and Asia in the 14th Century. The outbreak was called 'Black Death' because of the black spots it produced. In winter the disease seemed to disappear, but only because fleas were dormant then. Each spring it returned, attacking and killing millions more. Over the course of five years, Bubonic Plague killed 25 million Europeans, 1/3 of Europe's entire population. Bodies were left in deserted houses for years, because people were so terrified of the disease. Smaller outbreaks continued for hundreds of years in Europe.
Still today the plague exists in rodents around the world. Dr. David Waagner, an Infectious Disease Specialist at Texas Tech University, says you're greatest risk of contracting the disease is coming into contact with an infected rodent. "This organism is not like small pox. It doesn't only exist in laboratories. You can identify this organism in rodents in the southwestern United States. We see cases of bubonic plague naturally occurring from people who have had rodent exposure. It's transmitted by flea bites," says Dr. Waagner.
Today, the plague can be treated. It does not respond to penicillin, but other antibiotics are effective. A vaccine can also prevent it. Also today, up to 12 cases are reported each year in Texas alone, and still one out of seven who get the disease die from it even with treatment.