An Ebola outbreak that began in the Democratic Republic of the Congo has spread into neighboring Uganda and could become one of the largest Ebola outbreaks on record — raising concerns about the world’s ability to detect and respond to emerging infectious diseases amid reductions in public health capacity.
While the risk to Americans remains low, the outbreak comes as North America is hosting the largest FIFA World Cup in history — a 39-day event expected to draw millions of international visitors traveling across dozens of cities in the United States, Canada and Mexico.
Jennifer Layden, MD, PhD, associate dean for practice and professor at the Bursky School of Public Health at Washington University in St. Louis, has spent much of her career responding to emerging public health threats. As Illinois’ state epidemiologist and chief medical officer, she led statewide outbreak response efforts and oversaw disease surveillance programs, fielding reports ranging from measles outbreaks to suspected Ebola cases. She later became the founding director of the Centers for Disease Control and Prevention’s Office of Public Health Data, Surveillance and Technology, where she led the agency’s data modernization initiative.
Here, Layden discusses the outbreak and the public health systems designed to detect and respond to emerging threats.
What makes the Ebola outbreak particularly difficult to contain?
Stopping an Ebola outbreak is incredibly hard work, and this one is especially challenging because of delayed detection and how widespread the outbreak had become before it was reported. There also are tensions and conflicts within the affected regions, likely underdiagnosis of cases and the absence of an approved therapeutic or vaccine for the strain involved.
An on-the-ground response to an outbreak like this is both an art and a science. The science requires identifying cases, conducting investigations, tracing contacts, isolating infected individuals, educating communities, protecting healthcare workers and providing compassionate care.
The art involves diplomacy, communication, community engagement and earning the support of affected communities. The people doing this work on the ground are local and international public health heroes.
Should Americans be worried about the Ebola outbreak?
I think about this in a few ways. We can and should be worried about the outbreak because of what it signals about the risk for infectious disease outbreaks across the globe and here in the U.S. Every time we see an outbreak like this, it reminds us that infectious diseases remain a real — and growing — threat. Disruption to our public health systems, inadequate funding to support robust surveillance and maintain a resilient public health workforce, coupled with changing climate, deforestation, widespread global travel, among other things, makes such threats real.
We can also be worried about such outbreaks because of the profound devastation they have for vulnerable communities.
And then there is worry at the personal health risk level. Right now, the risk to Americans who have not traveled or been in the impacted regions recently is very low.
Why is the current risk to Americans low?
Ebola is not something that naturally occurs in the U.S. People contract Ebola through direct contact with body fluids of someone with symptomatic Ebola, or through contaminated objects.
Right now, there is no evidence of that here in the U.S. And our public health systems are taking a very aggressive approach to limiting travel, screening returning travelers, monitoring individuals when there is a known exposure, among other things.
How are public health agencies monitoring the World Cup?
Preparation for an event as large as the World Cup extends far beyond public health agencies. It involves coordination across multiple levels of government as well as hospitals, businesses, transportation systems, emergency management teams and event organizers.
One important approach is the use of emergency operations centers, which bring key stakeholders and responsible parties together, providing robust situational awareness, clarity on roles and standing procedures for responding to issues as they arise.
In the United States, the World Cup elevates the concern for all sorts of outbreaks. Public health leaders need to ensure they are monitoring and preparing for the full range of health challenges. With more travelers and large crowds gathering in close proximity, there is always a risk of disease transmission. More common threats, such as foodborne outbreaks, are often the greater concern.
What information helps public health officials assess outbreak risk?
The central question is: Does this disease pose a risk to my community?
To answer that, they need to understand the disease burden. How many cases are there? Do we have a good handle on the outbreak, or is it being significantly underreported? They need to understand the disease dynamics: How rapidly is it spreading? How is it transmitted? Is it spreading person to person, or through a particular exposure such as food or water? How long does it take for symptoms to appear, and when are people contagious?
Just as important are questions about detection and preparedness. If a case appeared in my community, where would it likely show up first? Would it be a returning traveler? Would that person go to an emergency department? What information should we be monitoring so we can identify a case as quickly as possible?
Leaders also need to know whether healthcare systems are prepared to safely manage and care for patients and whether there is a risk of further transmission in those settings. These situations are often fluid, and information is frequently incomplete. That’s why communication is so critical — communication with government leaders, coordination with healthcare partners and ongoing communication with community members.
How do officials prioritize threats such as Ebola and rising measles cases?
Public health agencies don’t focus exclusively on one disease. Instead, they focus on signals that could indicate an emerging health threat.
One tool is syndromic surveillance, which monitors patterns in emergency department visits and urgent care visits. Another is event-based surveillance, which uses information from multiple sources, including artificial intelligence (AI) and advanced analytics, to look for signals in media and social media.
Many diseases are already required to be reported to state and local health departments, allowing officials to continuously monitor for unusual patterns in case numbers or geographic spread.
Rather than preparing for a single disease, public health agencies build systems designed to detect and respond to a wide range of threats, including known diseases such as Ebola and measles, as well as emerging threats that may not yet be on anyone’s radar.
