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9. The Ebola Sentinel: A Legal Analysis of US Pandemic Preparedness

Published onMar 28, 2020

It was not until August 8, 2014—four months after identification of the first probable cross-border spread from Guinea to Liberia—that the World Health Organization (WHO) director-general, Margaret Chan, convened an emergency committee and declared the outbreak of Ebola virus disease (EVD) in West Africa a public health emergency of international concern (PHEIC). The declaration of a PHEIC has particular status under international law. Firstly, it indicates that an epidemic constitutes a sufficient public health risk to other countries through the international spread of the disease, ideally driving WHO member states to provide technical and financial assistance to control and prevent the spread of the outbreak. Secondly, a PHEIC enables the director-general to issue nonbinding temporary recommendations advising countries of the health measures they should—or should not—take in responding to the infectious disease outbreak.

Accompanying the declaration of the PHEIC were temporary recommendations advising non-West African countries against implementing international travel or trade restrictions. In particular, Director-General Chan advised against visa bans and increased screenings at airports for people traveling from West Africa, except for actual EVD cases and their contacts. In addition, she reiterated the importance of respecting civil liberties in implementing any health measures.

The WHO director-general’s powers to respond to a potential PHEIC are contained within the International Health Regulations (2005) (IHR). Revised after the 2002–2003 SARS outbreak, the IHR aim to prevent, detect, and control the international spread of infectious disease while ensuring that countries do not take measures that unnecessarily interfere with international travel and trade. Unlike other international laws that require countries to sign and ratify a treaty for it to be legally binding, the IHR are automatically binding upon WHO member states—including the United States.1

While the WHO’s delay in declaring a PHEIC has been widely criticized, it parallels the limited attention the outbreak was receiving in developed countries, including the United States. While only on the other side of the Atlantic Ocean, the political and media coverage in the United States of the Ebola outbreak in West Africa was limited until July 2014, when two American health care workers were infected and repatriated to the United States for medical treatment.

The US response to the 2013–2016 EVD outbreak provides salient lessons on the state of pandemic preparedness of US political and legal systems. Only four cases were diagnosed within the United States,2 yet EVD is the sentinel that has demonstrated that US pandemic preparedness is not necessarily a question of whether the law is adequate, but rather how incorrectly used legal powers and conflicts between federal and state priorities can hamper the legal frameworks that aim to protect the public’s health.

This chapter examines three instances that exemplify the Ebola sentinel in US public health legal preparedness: 1) border closures; 2) border screenings; and 3) quarantine and isolation measures. The chapter then briefly considers possible solutions to the gaps in the US pandemic preparedness legal response.

Foundations of United States Public Health Law

The US Constitution is the supreme law of the United States of America. The scope of the public health powers at all levels of US government—federal, state, and local—are limited by protections of fundamental civil liberties under the Constitution. Under the Fourth and Fourteenth Amendments, neither the federal nor state governments may deprive a person of their life, liberty, or property without the due process of the law—meaning access to a fair, orderly, and just judicial procedure. The Constitution grants express powers to the federal government, concurrent powers held by both the federal and state governments, and powers reserved solely for the states. This division forms the primary basis for the complexities of the US public health legal regime.

The primary source of the federal government’s public health power is derived from its exclusive powers to regulate commerce between states and with foreign nations under the Commerce Clause.3 This gives the federal government the power to make laws with respect to preventing and controlling the spread of infectious diseases between states or from foreign countries into the United States.4 In contrast, states derive their law-making powers for public health from their inherent “police powers” and reserved under the Tenth Amendment to the Constitution. States’ police powers enable them to regulate behavior and enforce order within their territory for the protection and maintenance of the health, safety, or welfare of their citizens. This broad power forms the legal legitimacy for states to take measures for public health or to delegate aspects of their public health police powers to local governments, as well as to request assistance from federal authorities.

International borders are the traditional legal boundaries of a nation’s sovereignty and were therefore the logical focus of many public health measures and laws aimed at preventing the spread of Ebola into and within the United States.

Border Closures

Despite the WHO director-general’s temporary recommendations to the contrary, a number of countries unaffected by Ebola implemented border closure measures.5 On October 8, 2014, 27 Members of Congress—including three Democrats—wrote to President Obama requesting that the State Department impose a travel ban on citizens of Liberia, Sierra Leone, and Guinea until the end of the outbreak.6 The requested travel ban included suspension of visas already issued and denying entry to the United States. The authors of the letter called on President Obama not to “pass the buck” to the WHO, “an organization of unelected bureaucrats and political appointees of foreign countries” with “no duty to protect the lives and well-being of Americans.”7 In response, President Obama released a video message to the nation, urging Americans not to “give into hysteria or fear,” noting that “trying to seal off an entire region of the world—were that even possible—could actually make the situation worse.”8

Border closures are protectionist measures from long-gone, pre-globalization eras with limited effectiveness that have the potential to impede the supply of medical necessities and trained health care workers to most-affected regions.9 In addition, visa bans may result in potentially infected individuals changing their travel strategies in an attempt to evade border controls, undermining public health measures.10 In a globalized world, such actions risk increasing the likelihood of the international spread of infectious disease. While the epicenter of the 2013–2016 EVD outbreak remained in the West African region, it was pivotal to ensure that vital food and medical supplies as well as trained health care workers were able to travel to affected areas. Travel bans resulted in commercial airlines reducing or ceasing flights, hampering the flow of aid and health care workers to the region, raising concerns that health care workers would not volunteer to assist given fears that they would not be able to return to the United States after working with patients with EVD.11 The call for President Obama to close US borders in response to the outbreak demonstrates how domestic legal power and authority may conflict with international regimes. While the president had the domestic legal power to enact such bans (through the State Department and Department of Homeland Security), such measures would likely breach the United States’s legal obligations under the IHR.12 This was indeed the case for both Australia and Canada, which breached their obligations under the IHR when they imposed visa bans for nations with widespread and persistent Ebola transmission, namely Liberia, Guinea, and Sierra Leone.13 Despite these breaches, there is currently no enforcement regime—such as legal sanctions—beyond international political pressure to hold countries accountable for breaches of IHR obligations.14

Border Screenings

Following the identification of the first imported Ebola case into the United States in October 2014 (Mr. Thomas Duncan), the Centers for Disease Control and Prevention (CDC) and the United States Department of Homeland Security’s Customs and Border Protection (CBP) commenced enhanced entry screening at five major US airports: New York’s JFK and Newark International Airports, Dulles International Airport in Washington, DC, Hartsfield-Jackson Atlanta International Airport, and Chicago O’Hare International Airport.15 These five airports were estimated to handle 94 percent of all travelers to the United States who had recently been in Guinea, Liberia, or Sierra Leone.16 Upon arrival from these countries, CBP officers screened travelers with questions about symptoms and any potential exposure to Ebola, as well as checked their temperature using noncontact thermometers and conducted visual observations of other Ebola symptoms. If an individual self-reported or measured a fever or other symptoms, or if they had been in a situation where exposure may have occurred, CPD referred the person to CDC public health officers at the airport for further assessment (discussed below). These noninvasive screening methods are permissible health measures at points of entry under the IHR and legitimate public health measures under domestic law.17

Despite this, the effectiveness of border screening in identifying possible EVD cases was limited, as it relied on infected individuals either exhibiting symptoms or self-declaring possible exposures to EVD. For example, even if border screening had been in place, it is possible that they would not have detected Mr. Duncan’s illness, as he was not exhibiting symptoms and may have been unaware of or chosen not to self-declare potential exposures.18 The most valuable opportunity border screening provided was the provision of education and establishing active monitoring for cases that subsequently developed in the United States, such as New York doctor Craig Spencer.19 It is important to note, however, that as a medical doctor who had worked with EVD patients in Guinea, it is likely that border screening was not necessary for effective monitoring and follow-up for Dr. Spencer.20 Despite the immense cost, border screening may be used as a political tool to reassure the public that the government is in control of the disease. However, the limited effectiveness of border screening in detecting EVD cases ultimately undermined any reassurance such measures gave to the public.21 For future infectious disease outbreaks, the use of border screening measures—while legally available and perhaps politically preferable—must be carefully tailored, with the realistic limits of the process communicated to the public so as to not undermine broader public health efforts.

Quarantine and Isolation

While often used interchangeably—including in public health legislation—quarantine and isolation technically reference separate health strategies.22 Quarantine involves restricting the movement of individuals who have been exposed, or potentially exposed, to infectious disease during its period of communicability during the incubation period.23 Isolation, however, is the separation of individuals known to be infected—determined through testing and physical examination—for the period of communicability.24 A range of legal powers exists for quarantine and isolation in the United States, from local governments—acting with delegated state power—to the federal jurisdiction. While the constitutionality of these powers have been affirmed over the course of more than a century, the 2013–2016 EVD epidemic demonstrated the ease by which such powers can become politicized, revealing possible future weaknesses in the use of quarantine and isolation powers during an infectious disease outbreak (see chapter 16 for a detailed analysis).

Unlike other federations,25 the United States federal government does not have an express constitutional power to make laws with respect to quarantine and isolation. Rather, the Constitution’s Commerce Clause empowers the US Secretary of Health and Human Services, under the Public Health Services Act, to take measures to prevent the entry and spread of communicable diseases between states and from foreign nations into the United States.26 The day-to-day operation of this power is delegated to the CDC, which can authorize quarantine and isolation measures to prevent the introduction, transmission, and spread of certain communicable diseases into the United States from foreign countries27—or to prevent the spread of certain communicable diseases from one state into another, including where the CDC believes that measures taken by a state are insufficient.28 These measures apply only to certain communicable diseases as determined by an executive order of the president, including Ebola.29 The CDC does not typically use its federal authority for quarantine, however, historically leaving decisions on individual quarantines to states.30

Within their respective territories, states have the general authority under their police powers to enact public health measures, including quarantines.31 The exact content of quarantine powers is determined by state legislation. As a result, there is significant variance between states in the scope and procedures for imposing quarantine, including in some instances delegation of quarantine powers to local public health authorities.

Despite this authority, states are bound by the Fourteenth Amendment to the US Constitution to ensure the individuals subjected to the exercise of quarantine powers are provided with due process—both procedurally and substantively—and ensure equal protection through their nondiscriminatory application. As a result, given the significant limitations on an individual’s liberty, the proper execution of quarantine powers must satisfy substantive due process tests,32 including the requirement that quarantine be “reasonable.”33 However, more than a century of public health law and federal CDC guidelines that may help define “reasonableness” risk being ignored by the executive or legislative branches of government when politics, misinformation, and infectious disease mix.

During the 2013–2016 EVD outbreak, the CDC issued detailed guidelines on public health measures states and local authorities should take in identifying and monitoring possible EVD cases, which—even in high risk cases—did not recommend the use of traditional quarantines. Table 9.1 sets out key aspects of the CDC’s recommended health measures, implemented with the assistance of the CBP, for asymptomatic individuals.34

Table 9.1 CDC Recommended health measures for asymptomatic individuals during the 2013–2016 EVD outbreak

Exposure category

Included individuals

Public health measures required

High risk

• direct exposure to blood or bodily fluids of a symptomatic Ebola patient without appropriate PPE (such as through needle stick injury, splashes to eyes, nose, or mouth, or bodily fluids directly on skin.
• direct contact with a dead body without appropriate PPE in an intense transmission country (Liberia, Guinea, Sierra Leone).
• lived in the same household and provided direct care to a symptomatic patient deemed to be at high risk of infection

• direct active monitoring (daily fever and symptom monitoring through direct observation).
• no travel on public or long-distance transport.
• self-exclusion from public gatherings and the workplace.
• quarantine not required: non-congregate activities permitted provided a 3-foot distance from other people kept (e.g., jogging in a park).

Some risk

• direct contact with a symptomatic patient in an intense transmission country while wearing PPE (e.g. as health care workers)

• direct active monitoring
• any restrictions on movement to be assessed, on a case-by-case basis while still allowing non-congregate public activities with a 3-foot distance.

Low (but not zero) risk

• brief direct contact, without appropriate PPE, with person with EVD in the early stages of the disease.
• brief proximity to person with EVD without appropriate PPE

• travelers: active monitoring (daily fever and symptom monitoring without direct observation)
• health care workers: direct active monitoring
• No further restrictions.

No identifiable risk

• contact with asymptomatic Ebola patient or their contacts
• potential exposure to EVD more than 21 days previously
• travelers in countries without widespread EVD transmission

No restrictions

Despite the detail of these guidelines, a number of states ignored the CDC and Department of Homeland Security guidelines and procedures and used their legal powers to impose their own quarantine procedures.35 Over the course of October and November, state government officials in California,36 Connecticut,37 Florida,38 Georgia,39 Illinois,40 Maine,41 Maryland,42 New Jersey,43 and New York44 announced policies of varying degrees, but all exceeded the federal CDC guidelines. In New York and New Jersey, mandatory 21-day quarantines were imposed for health care workers returning from countries with intense EVD transmission, who would typically fall under the CDC’s “some risk” category.45

On October 24, 2014, nurse Kaci Hickox returned to the United States after working for Médecins Sans Frontières in Sierra Leone. According to court documents,46 upon her arrival at Newark Airport, New Jersey, Ms. Hickox was detained, and despite an initial temperature check showing no elevated temperature and clearance from the CDC, the New Jersey Department of Public Health (DPH) placed Ms. Hickox under mandatory, involuntary quarantine through the use of an Administrative Public Health Order, issued at the discretion of the New Jersey state’s DPH. As an asymptomatic health care worker with only some risk of exposure, these measures appear to exceed the CDC’s guidelines and may have amounted to an unreasonable exercise of the state’s legal powers. Three days later, Ms. Hickox was released and allowed to travel to her home state of Maine. Unlike in New Jersey, under Maine state law quarantine orders must be issued by a court.47 The commissioner of the Maine DPH applied for a court order to impose a mandatory quarantine order on Ms. Hickox. The Maine District Court rejected the application for a mandatory quarantine on the grounds that the state had not met its burden of proof that such a measure was necessary, but upheld the requirement for direct active monitoring (consistent with the CDC’s guidelines).48 As the differences in these two states demonstrate, the legal authority to order a quarantine can have a significant impact, with the oversight provided by the judiciary having a crucial role in this case. Civil rights actions can also serve an important role in deterring possible overreach by states in using their public health powers. On October 22, 2015—exactly one year after departing Sierra Leone—Kaci Hickox lodged a civil rights action against New Jersey Governor Christie and other officials alleging violations of her Constitutional rights, including her Fourteenth Amendment rights. If successful, this case may provide a legal deterrent to the future imposition of mandatory quarantines beyond the scope of the CDC’s guidelines.

As the 2013–2016 EVD outbreak demonstrated, despite the existence of strong federal and state public health law powers, differing understandings of state law can derail an effective global and public health response. As the Hickox case demonstrates, interpretations of existing state public health powers can vary greatly from the legal reality once tested by a court. State political leaders must ensure that they understand the extent of their legal powers, and if necessary, revise and clarify state legislation. In addition, state and federal priorities are likely to vary greatly. During the 2013–2016 EVD outbreak, the US federal government’s priorities included protecting national health by stopping the outbreak in West Africa; its international legal obligations; and foreign policy considerations. These priorities are unlikely to match states’ much narrower priority of protecting the health or addressing the concerns of their citizens. In addition, even these same priorities will have varying policy goals for each state, resulting in vastly different outcomes. An effective domestic legal and public health response requires consistency as well as flexibility. Two possible approaches—one hardline, one collaborative—may provide this: preemption and cooperative agreements.


Federal preemption is the invalidation of a state law due to a conflict with a federal law under the Supremacy Clause of the US Constitution. One of the main justifications for preemption is the need for uniformity between federal and state laws.49 For example, state quarantine laws that govern interstate movement have been preempted insofar as they conflict with federal laws.50

Understandably, the use of federal preemption can be controversial. Congress attempts to prevent inadvertent federal preemption of state laws by including anti-preemption clauses in legislation. The Public Health Services Act contains an anti-preemption clause, but is limited in its application. State public health measures—such as mandatory quarantines—above the federal regulation may not be interpreted as in conflict with federal laws, but rather setting a higher standard above the federal minimum. Yet if the state law essentially acts as an obstacle to federal laws, it may conflict and therefore be preempted.51 It is feasible that given the broader national health security aims of the federal government, the effectiveness of the CDC’s federal regulations were undermined by state laws during the US Ebola pandemic response, legitimizing a federal preemption argument. States are, however, unlikely to welcome federal preemption of their pandemic response laws. Furthermore, a hardline approach and legal conflict between states and the federal government may further undermine federal-state cooperation necessary for the US domestic pandemic response.

Cooperation Agreements

Some federations use cooperation agreements in an attempt to preempt the legal and political dynamics that might arise due to threats to public health security, by establishing a framework for clear, fast, and informed decision making during disease outbreaks that may quickly spread nationally.52 While not a formal delegation of power from the states to the federal government, state and federal governments agree to coordinate and cooperate in their responses to public health crises. Such documents can include an agreement that states defer to the advice of a federal regulatory body—such as the CDC—in scientific or technical matters. It could also include model public health legislation for states to implement at their discretion and subject to their own democratic processes. While this is not a formal delegation of power, and states retain their sovereignty to withdraw from the agreement or parts of the agreement, this nonbinding collaborative approach may provide certainty for matters such as recommended health measures. In exchange, the federal government may provide forms of support to states such as funding or coordination assistance without resorting to legislative emergency powers. While it is unlikely that complete agreement would be reached across all 50 of the US states, given the possibilities of top-down, hard-line options such as preemption available to the federal government, a cooperative agreement would help facilitate the necessary discussion for clearer federal and state laws for US public health preparedness.


The US federal and state legal responses to the 2013–2016 EVD outbreak were substantially varied, and political pressure risked undermining the United States’s important role as a leader in strengthening the IHR and global health security. Even where legitimate legal powers existed, the Ebola outbreak served as a sentinel for their potential use to achieve narrow goals, potentially undermining national public health and security. While the spread of Ebola in the United States was limited, in preparation for future infectious disease outbreaks, state and federal government priorities and legal authorities should be aligned for a more coordinated and effective response. Although the federal government may be able to use federal preemption to enforce this, such an approach should be judiciously considered. Alternative models—such as a cooperative agreement or model laws—may provide a solution or, at the very least, facilitate the necessary discussion for clearer and more efficient US public health legal preparedness.

Copyright © 2016 Massachusetts Institute of Technology. (All rights reserved.)

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