One flea bite and the bacteria Yersinia pestis is turned loose in another fresh victim. Sudden fever, bleeding organs and black, dying limbs inevitably followed for millions of people during the Middle Ages. Hundreds of years before the advent of modern antibiotics -- drugs used to halt infections and kill bacteria -- no cure existed for the plague that decimated populations worldwide. However, plague-fighting methods laid the groundwork for modern health care and disease prevention.

Concoctions, Potions, Remedies

Attempts to counteract the disease might seem strange by today's modern medical standards. Potions were brewed with gold, or laced with arsenic, mercury, or even horn claimed to be ground from mythical unicorns. Middle age apothecaries offered theriac, concocted of chopped snake and various other ingredients. Dung, urine, liver, hooves, brains or animal lungs were also added to supposed antidotes. A Portuguese doctor named Diogo Afonso offered a recipe for badger powder: Add the blood of a drunken badger (intoxicated with a specially prepared wine) to spices and heat, then combine it with a paste of the badger's body parts -- to be mixed with wine or vinegar and consumed within a year.

The Bubo: Attacking Plague Infection

Doctors used several invasive procedures to save plague victims. Those with Bubonic plague developed buboes, painfully swollen lymph nodes in which the bacteria multiplied. Bloodletting or lancing the buboes directly was one technique intended to draw out the sickness, although some practitioners advocated for bleeding the vessels of the hands instead. Leeches were also used to remove infected blood. Another procedure called "cupping" involved heating a cup placed over the bubo to create suction and draw out the poison.

Supernatural Aid

Religious ideas about the cause of the plague played a powerful role in medieval times, especially considering doctors' inability to eradicate the disease. Muslim beliefs of the period taught that the plague was an act of God, and forbade fleeing from infected regions. Christians formed penitent groups that journeyed between towns, to seek mercy from an angry God. Their acts of repentance included public flagellation, striking themselves with a whip of three knotted thongs, each tipped with sharp metal in the shape of a cross. People in European countries also lashed out against religious minorities and strangers, most notably extreme violence against Jewish communities.

Laws to Fight Disease

For government officials, controlling the movement of possibly infected people was a key step in slowing the plague's advance. Rare pneumonic plague is the most serious of the three forms, spread by inhaling infected droplets of blood or mucous. Bubonic or pneumonic infection may also occur when the septicemic -- characterized by blackened, dying tissues of the nose, fingers and toes -- reaches the lungs. During the Black Death in 1348, Venetian authorities required boat passengers to spend 30 to 40 days in isolation before entering Italian ports -- a practice still known as a quarantine, and an integral part of modern outbreak prevention. Other Italian cities enacted trade, travel and funeral restrictions; Milan authorities even sealed up three plague houses -- with the occupants still inside.