Plague pandemics can be prevented by the disinfection of ships, aircraft, and persons who are known to have the plague. The classic route of transmission that leads to pandemics is the transportation of infected rodents aboard transcontinental vehicles. Since many countries have instituted rigorous disinfection practices for ships and planes, plague cases have dropped dramatically.
If a person is diagnosed with plague, most countries, including the United States, require that the governmental health agency be notified. The person is usually kept under strict quarantine until the disease is brought under control with antibiotics.
Another way to prevent plague is to control rodent and flea populations in cities. Fleas are easier to control than rodents, since most homes can be easily decontaminated. Many cities, especially in the United States, have instituted rodent-control programs aimed at decreasing the numbers of rodents that roam the streets. Since rodents also carry rabies and other deadly diseases, controlling their numbers makes sense for a variety of reasons.
Cantor, Norman F. In the Wake of the Plague: The Black Death and the World It Made. New York: Perennial, 2002.
Nelson, K.E., C.M. Williams, and N.M.H. Graham. Infectious Disease Epidemiology: Theory and Practice. Gaithersburg: Aspen Publishers, 2001.
Epstein, Richard. "A Persistent Pestilence." Geographical Magazine 63 (April 1994): 18.
Jayaramen, K.S. "Indian Plague Poses Enigma to Researchers." Nature (October 13, 1994): 547.
Mee, Charles L. "How a Mysterious Disease Laid Low Eu rope's Masses." Smithsonian (February 1990): 66.
Richardson, Sarah. "The Return of the Plague." Discover 16 (January 1995): 69.