How can plague be prevented?

1. People who live, work, or play in areas with active plague infection in wild rodents should take these precautions:

• Eliminate food and shelter for rodents around homes, work places, and certain recreation areas, such as picnic sites or campgrounds where people congregate. Remove brush, rock piles, junk, and food sources, including pet food.
• Allow health authorities to use appropriate and licensed insecticides to kill fleas during plague outbreaks in wild animals.
• Treat pets (cats and dogs) for flea control regularly.
• Avoid sick or dead animals, and report such animals to the health department. Hunters and trappers should wear rubber gloves when skinning animals.
• Use insect repellents when outdoors in areas where there is a risk of flea exposure.

2. Preventive treatment with antibiotics is recommended for: 1) people who are bitten by fleas during a local outbreak or who are exposed to tissues or fluids from a plague-infected animal; 2) people living in a household with a bubonic plague patient, since they may also be exposed to infected fleas; and 3) people in close contact with a person or pet with suspected plague pneumonia. Close contacts defined as face-to-face contact or being in the same closed space, such as a room or vehicle.

3. People who travel to countries where plague occurs should take these additional precautions:

• Avoid exposure to fleas from diseased rats. The risk of being bitten by infected fleas is especially high after large numbers of plague-infected rats have died. Therefore, avoid places that are infested with rats or where large numbers of rats have reportedly died.
• If travel to such areas is essential, apply insect repellent containing DEET to legs and ankles. Also apply repellents and insecticides to clothes and outer bedding according to manufacturers' instructions.
• Take preventive antibiotics if the risk of exposure is high.

Ref: http://www.dhpe.org/infect/plague.html