Having dismantled the U.S. Agency for International Development and decimated the CDC's global health capacities, the Trump administration has resorted to a blunt instrument to protect the American public from the Bundibugyo ebolavirus outbreak rapidly escalating across the Democratic Republic of Congo: shutter our borders.
The State Department's plan to establish a 50-bed Ebola quarantine and triage facility at Laikipia Air Base in Nanyuki, Kenya, appeared to collapse following intense public protests and a court order requiring the government to suspend construction. Yet, construction continued. In MedPage Today I explained everything wrong with the offshore quarantine plan. More recently, on July 13, the CDC issued an emergency order to extend a ban of virtually all foreign nationals who were in Congo, Uganda, or South Sudan in the past 21 days from flying into the U.S. The same day, the Trump administration in effect extended the ban to cover American citizens in Congo from flying into the U.S. by placing them on a "do-not-board" (DNB) list.
The problem is that border closures don't work. The World Health Organization urges against travel restrictions, and they violate U.S. treaty obligations under the International Health Regulations. Further, while U.S. citizens possess a constitutional right to return home, the administration argues that this restriction is legally permissible. In my expert legal opinion, it is not.
The DNB List
The DNB list was jointly established by the CDC and DHS in 2007 to prevent individuals, including U.S. citizens, with active or suspected severe, quarantinable diseases (like tuberculosis or Ebola) from utilizing commercial air travel. During the 2014-2016 West African Ebola epidemic, the CDC expanded the criteria to include individuals with or believed to have been exposed to an infectious disease that presents a public health threat. Applying this restriction for the duration of the Ebola disease's 21-day incubation period aligns with standard CDC and TSA protocols.
Since its inception, hundreds of individuals have been placed on the list. In its first decade, the vast majority of these cases (over 99%) involved active, infectious pulmonary tuberculosis; it has also been used for measles, COVID-19, and mpox.
The 2007 DNB list was prompted by the case of Andrew Speaker. Speaker traveled to Europe for his honeymoon despite CDC warnings that he had multi-drug-resistant tuberculosis. While abroad, subsequent laboratory tests indicated his condition might be extensively drug-resistant tuberculosis. The CDC cautioned him against boarding commercial flights due to the public health risk. However, Speaker flew to Montreal and drove across the U.S. border.
Constitutional and Legal Challenges
It is not hard to understand why individuals who are "high-risk" or have an active infection would be denied the right to board a commercial aircraft. But that is not at all what is happening in the new Ebola order. Implementing a blanket geographic ban on all U.S. citizens, regardless of documented individual exposure, is unprecedented, represents a substantial expansion of federal authority, and is likely to face immediate constitutional challenges.
First, prohibiting citizens from returning to the U.S. based purely on their geographic location violates the Fifth Amendment's requirement of due process of law. Under a blanket geographic ban, the government is making no individualized assessment of risk to the public -- such as a specific diagnostic test or a documented close interaction with an Ebola-infected person. Blanket bans are nothing more than arbitrary deprivations of personal liberty.
Second, the DNB order is a de facto banishment of citizens for 21 days. While the government may argue that citizens are only being blocked from commercial flights (not the country itself), this is a distinction without a difference. For a U.S. citizen in a landlocked or distant country like Congo, blocking commercial aviation effectively traps them abroad. This violates a citizen's fundamental constitutional right to return home, as established in the 1898 Supreme Court case, United States v. Wong Kim Ark, which the Court recently reaffirmed in upholding birthright citizenship. The Supreme Court also affirmed a citizen's right to return home in the Court's 1958 decision in Kent v. Dulles.
Third, public health interventions that limit personal liberties must adhere to the principle of using the least restrictive means. In this case, less restrictive alternatives are available, such as routing travelers through designated U.S. airports for screening (which the CDC is already doing for non-citizen travelers in the Congo, Uganda, and South Sudan) or implementing a 21-day quarantine on U.S. soil. Forcing citizens to remain out of the country rather than managing their quarantine domestically is likely to be viewed by courts as overly broad, exceeding the limits of executive authority during emergencies.
Public Health Consequences
Beyond its legal deficiencies, this policy risks transferring public health responsibility to foreign nations with limited medical infrastructure. It may incentivize travelers to conceal their itineraries, and it could severely hinder the recruitment of U.S. healthcare and humanitarian workers who are critical to containing the outbreak at its source.
The order currently affects more than two dozen Americans scheduled to return, including a U.S. humanitarian worker who has tested positive for the Bundibugyo strain. While this individual was evacuated to Germany, the travel ban leaves other Americans stranded without access to resource-intensive private evacuations, forcing them to rely on local, resource-constrained systems. And some, it appears, will be quarantined in the hastily constructed facility on the U.S. military base in Kenya. Seven Americans with the humanitarian aid organization Samaritan's Purse, none of whom show any symptoms of Ebola, have been quarantined there, their employer revealed last week.
By restricting the travel of critical personnel, the new policy endangers U.S. citizens and cripples the global Ebola response -- blocking vital assistance in contact investigations, healthcare, and humanitarian relief.
Rather than implementing sweeping travel bans that strain international cooperation and legal boundaries, the U.S. should rely on proven domestic screening, quarantine, and treatment protocols. Moreover, travel bans can't replace the hard work of public health testing and surveillance on the ground in the outbreak zone.
True biosecurity is achieved not by shutting the door on our citizens and our frontline responders, but by supporting them with the full, uncompromised resources of the domestic and global health system.