Quarantine occurs when people, animals, or plants are isolated or their movements restricted to prevent the spread of infection. The period of quarantine depends on the amount of time necessary for protection against the spread of a particular disease. The word quarantine comes from the Latin quadraginta, meaning 40. In early times, officials held a ship outside of port for 40 days if they suspected it carried infection among its passengers or freight.
International quarantine.
All people entering a country from foreign areas are subject to quarantine. The officer in command of a ship or airplane is required to report illnesses or deaths on board to officials at the port of entry. People infected with certain diseases may be detained, placed in isolation, or denied entry.
In the United States, the Centers for Disease Control and Prevention (CDC) is the agency responsible for developing and enforcing quarantine regulations. The CDC may apply quarantine restrictions in cases of cholera, diphtheria, infectious tuberculosis, plague, severe acute respiratory syndrome (SARS), smallpox, viral hemorrhagic fevers, yellow fever, and certain types of influenza. Quarantine regulations in Canada are administered by the Public Health Agency of Canada. The World Health Organization, an agency of the United Nations, helps national health agencies develop quarantine laws.
Plant and animal quarantine.
Harmful insect pests and disease organisms have been brought into the United States and Canada by diseased plants and animals. The governments of both nations have laws that provide for the inspection of all plants and animals entering the country. Some states have quarantines to keep out diseased plants and animals or insect pests. Local areas may be quarantined to prevent the spread of such animal diseases as foot-and-mouth disease, which affects livestock.