The Centers for Disease Control and Prevention (CDC) publishes a webpage which gives excellent summary information on government powers to enforce isolation and quarantine.

First, the definitions.

Isolation separates sick people with contagious disease from people who are not sick. Quarantine separates and restricts the movement of people exposed to contagious disease to determine if they become sick.

The federal government derives its powers to isolate and quarantine from the Commerce Clause of the Constitution.

Under section 361 of the Public Health Service Act (42 U.S. Code § 264), the Secretary of Health and Human Services is authorized to take measures to prevent the entry and spread of communicable diseases from foreign countries into the United States and between states.

The day to day administration of this authority is delegated to the CDC.

What is the CDC allowed to do? Quite a lot, actually. CDC is authorized to detain, medically examine, and release persons arriving into the United States and traveling between states who are suspected of carrying these communicable diseases.

When alerted about an ill passenger by airplane pilot or ship captain, CDC may detain passengers and crew as necessary to investigate whether the cause of the illness on board is a communicable disease.

The list of communicable diseases which can trigger federal isolation and quarantine are

• Cholera
• Diphtheria
• Infectious TB
• Plague
• Smallpox
• Yellow fever
• Viral hemorrhagic fevers
• Severe acute respiratory syndromes
• Flu that can cause pandemic

Federal isolation and quarantine are authorized by Executive Order of the President. The President can update this list by Executive Order.

Next, states are empowered to control the spread of disease within its borders. State laws can enforce isolation and quarantine. In most states, breaking a quarantine is a criminal misdemeanor. (Breaking a federal quarantine order is punishable by fines and imprisonment…)

The federal government may accept state and local assistance in enforcing a federal quarantine. The federal government may assist local authorities in preventing spread of communicable disease. A nice summary of state statutes affecting isolation and quarantine can be found here. As but one example, in North Carolina, The State Health Director and a local health director are empowered to exercise quarantine and isolation authority. Regarding, police power and limitations. Quarantine or isolation can be imposed for 30 days. The individual so restricted can challenge the order in superior court. The period of restriction can be increased a further 30 days if still necessary for protection of public health by petition to the superior court.

The last time large scale isolation and quarantine was enforced for communicable disease was Spanish Flu pandemic in 1918-1919. In 1963, a passenger arriving into the United States was placed under a federal quarantine order as a suspected case of smallpox. In 2007, a traveler with drug-resistant TB was placed in isolation.

During the 2003 outbreak of SARS, CDC did not issue isolation or quarantine orders. However, CDC did conduct active surveillance, visual screening of passengers, and handed out Travel Health Alert notices.

According to a survey conducted for the Trust for America’s Health in 2007, “nearly 9 out of 10 Americans say they would abide by a voluntary quarantine and stay home in the case of an outbreak of a pandemic flu. Willingness to accept this type of quarantine exists across the public at high levels. Among the 10 percent who say they would not adhere to the government’s request of a voluntary quarantine, most indicate that they could not stay at home due to fears of losing needed income (64 percent) or losing their jobs altogether (39 percent).”