William Schaffner | Professor of Preventive Medicine, Department of Health Policy; Professor of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
Citation: Microbiol Infect Dis AMJ. 2026; https://doi.org/10.33590/microbiolinfectdisamj/738858S4
During your early days as a CDC Epidemic Intelligence Service (EIS) officer in Rhode Island, USA, you investigated municipal outbreaks, ranging from Salmonella to seasonal flu. How did that field training shape your approach to building hospital infection control systems?
My commitment to epidemiology surprised me because it began in an unlikely fashion. I had just completed an internal medicine residency as well as clinical and research training in infectious diseases at Vanderbilt University Medical Center in Nashville, Tennessee, USA. It was now time for me to fulfil my national service obligation (Selective Service, ‘the draft’) that all young men had back in the 1960s. Because of my interest in infectious diseases, it had been suggested that I apply to the US Public Health Service rather than serving in the army. To my surprise and delight, I was accepted and reported for duty at the CDC as a new EIS officer. Each cadre of novice EIS officers were immersed in the principles and practice of investigative field epidemiology, transforming clinicians who had focused on the illness of single patients into public health physicians who worked to ensure the health of entire communities.
After initial training, I was assigned to work in the Rhode Island Department of Health, where I found a variety of challenges and opportunities. I investigated an outbreak of shigellosis in a summer riding camp, hepatitis B among intravenous drug users, residual measles in a highly immunized population, and anthrax in a mill worker. Smallpox was still a matter of concern, and I led a program of smallpox vaccination among hospital workers and was able to participate in a WHO-sponsored evaluation of its smallpox elimination program in rural India.
All the lessons I learned doing field epidemiology could be applied when I returned to Vanderbilt to establish a hospital infection control program. Among them: it all starts with surveillance. You have to define the problem before you can fix it. Interventions depend upon collaboration with people who work in all areas of the hospital, and an atmosphere of working together to achieve goals is likely to be successful. I saw hospital (now healthcare) infection control as public health, applied to the healthcare workplace.
Your investigation into neonatal Pseudomonas putida infections showed that even rare environmental bacteria can cause serious hospital outbreaks. When an unusual pathogen appears, what should microbiology teams prioritize when trying to identify the source?
The most successful investigation of outbreaks results from close collaboration of epidemiologists and microbiologists. Today, microbiologists can use whole genome sequencing to securely identify bacterial isolates from both patients and environmental sources as being identical, thus providing strong confirmatory evidence of the source of an outbreak.
Biofilms on urinary catheters and central lines remain a major cause of hospital-acquired infections. How has our understanding of biofilms changed the way hospitals prevent infections linked to medical devices?
Biofilms are communities of bacteria that attach to a surface and enclose themselves in a sticky protective ‘cocoon’. This makes the bacteria harder to kill with antibiotics and disinfectants. Biofilms can form on foreign objects in the body such as intravenous and urinary catheters and implants. Rigorous sterilization of implants and disinfection of endoscopes, as well as meticulous maintenance of catheters, contribute to reducing the risk of contamination and the formation of biofilms, and consequently reduce the risk of healthcare-associated infections.
Long-term active surveillance shows that the mortality rate for bacteremic pneumococcal disease in elderly adults has remained stuck near 20% for decades, despite modern ICU care. Why do these infections remain so difficult to treat, and what can HCPs do to improve outcomes?
Despite modern ICU care and effective antibiotics, the mortality rate for pneumococcal sepsis, particularly in older adults, remains stubbornly high. The reasons for this are multiple. First, the frailty of older persons who have multiple chronic medical conditions puts them at increased risk. Further, there may be delayed diagnosis; what can appear to be a minor illness in older persons can suddenly become much more serious and difficult to treat. Lastly, the inflammatory response evoked by the infection can itself be destructive, leading to severe disease.
All the more reason to emphasize prevention! The pneumococcal vaccine is strongly recommended for everyone age 50 years and older. We need to do better in getting this vulnerable population vaccinated.
You have emphasized that influenza can affect more than the respiratory system and may temporarily increase the risk of heart attack and stroke. What causes this increased cardiovascular risk, and why should clinicians be aware of it?
After recovering from the acute illness caused by influenza, middle-aged and older persons are at an increased risk for heart attacks and strokes for several weeks. This increased risk is thought to be caused by residual chronic inflammation involving small blood vessels after the acute illness subsides.
Once again, this is a strong argument for prevention. The influenza vaccine has been shown to provide a measure of protection against these cardiovascular events, along with its well-known prevention of severe acute influenza.
Adult vaccination rates remain much lower than pediatric vaccination rates. How could pharmacists, physician assistants, and nurse practitioners play a greater role in improving adult vaccine uptake?
Improving adult immunization remains an ongoing multifactorial challenge. This is all the more important because a growing number of vaccines is available for adults. Vaccination is not just for kids anymore; it should be part of the routine medical care of every adult.
Both the medical community and the general public need more education about the benefits of vaccines for adults. Fortunately, pharmacists are playing a substantial and increasing role in providing adult vaccinations. There still are substantial funding issues regarding this essential preventive measure for adults. If they could be addressed, then efforts to improve adult immunization would accelerate.
Infectious diseases is facing recruitment challenges, with many young doctors discouraged by workload and administrative pressures. What changes to medical training could make the specialty more attractive to future clinicians?
I am sure there are several aspects of training that might be improved to attract young people into infectious diseases, a most exiting specialty that ranges from molecular events to global epidemiology. However, the proverbial elephant in the room is compensation. The payment for services provided by the infectious diseases specialist must improve.
Looking ahead to the next decade, which pathogen or form of antimicrobial resistance concerns you most, and what should be done now to prepare for it?
Several things concern me at the moment: 1) the loss of trust in public health; 2) spreading vaccine skepticism; and 3) the lack of a global vision of public health in the US. All can conspire to turn back the clock on progress that has been achieved and will be difficult to regain. There is no magic solution. All of us in infectious diseases and public health are optimistic that we can improve health for the next generation. We must reinforce that optimism with resilience and persistence in the expectation that the arc of events will bend toward justice and a healthier world tomorrow.
