On a quiet evening in late February 2020, a phone call came that would soon echo across the global public health landscape. The voice on the line delivered a directive familiar to generations of disease detectives: deployment was imminent, the team assembling at the CDC’s Roybal campus in Atlanta and the mission—though not yet fully detailed—was clear. This moment, recounted in recent reflections on a milestone anniversary, captures the enduring readiness of the Epidemic Intelligence Service (EIS), the U.S. Centers for Disease Control and Prevention’s renowned two-year fellowship program that trains physicians, scientists, and epidemiologists in rapid outbreak response.
As the EIS marks its 75th anniversary in 2025, its legacy looms large in an era defined by recurring health threats—from novel coronaviruses to resurgent measles and antimicrobial resistance. Founded in 1951 under the leadership of CDC pioneer Dr. Alexander Langmuir, the program was conceived during the early Cold War as a defensive mechanism against biological threats. Langmuir, often called the father of modern epidemiology, envisioned a corps of “shoe leather epidemiologists” trained to deploy swiftly wherever disease emerged, combining field investigation with laboratory science to trace outbreaks to their source.
Today, the EIS continues to embody that original mission. Each year, approximately 80 individuals are selected from a competitive pool of applicants—including medical doctors, veterinarians, nurses, and PhD scientists—to undergo intense training in epidemiology, biostatistics, and public health practice. Following a summer of coursework at CDC headquarters, EIS officers are assigned to state and local health departments, federal agencies, or international partners, where they conduct real-world investigations under expert supervision. Their work has been instrumental in identifying the sources of foodborne illnesses, tracking the spread of vaccine-preventable diseases, and responding to natural disasters and humanitarian crises.
The program’s impact extends far beyond U.S. Borders. EIS alumni have contributed to global eradication efforts, including the worldwide elimination of smallpox and the near-eradication of polio. In recent decades, EIS officers have played key roles in responding to Ebola outbreaks in West Africa, the Zika virus epidemic in the Americas, and the COVID-19 pandemic, where they supported contact tracing, vaccine distribution planning, and variant surveillance. Their presence in over 80 countries through CDC’s global health security agenda underscores the program’s evolution into a vital instrument of international health diplomacy.
What distinguishes the EIS is not only its technical rigor but its culture of service and humility. Officers are trained to listen first—to clinicians, to community health workers, to affected populations—before drawing conclusions. This approach has fostered trust in communities often wary of public health interventions, particularly during politically charged outbreaks. As Dr. Richard Besser, former acting CDC director and EIS alumnus, noted in a 2020 reflection, “The strength of the EIS lies not just in its science, but in its ability to connect data to human stories.”
The 75th anniversary was marked in April 2025 with a scientific conference held at the CDC’s headquarters in Atlanta, bringing together current officers, alumni spanning seven decades, and public health leaders. Sessions highlighted historical investigations—from the 1955 influenza outbreak to the 2014–2016 Ebola crisis—although also addressing emerging challenges such as climate-driven disease spread and the health impacts of misinformation. The event served as both a tribute to past achievements and a recommitment to the principles that have guided the EIS since its inception: speed, accuracy, and an unwavering focus on protecting public health.
Looking ahead, the EIS faces new pressures in an age of information overload and declining trust in institutions. Yet its core methodology—grounded in shoe-leather epidemiology, rapid data collection, and iterative hypothesis testing—remains as relevant as ever. As global travel, urbanization, and ecological disruption increase the likelihood of zoonotic spillover, the need for trained disease detectives who can operate across borders and disciplines has never been greater.
The EIS’s 75-year journey reminds us that while pathogens evolve, the fundamentals of outbreak response endure: vigilance, preparation, and the courage to run toward the threat when others are fleeing. For those who wear the EIS badge, the call to serve is not just a professional duty—We see a continuation of a legacy built on science, service, and the quiet determination to make the world safer, one investigation at a time.