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VA Researchers Who Served: Dr. Mark Riddle

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VA Sierra Nevada Health Care System

June 4, 2020

 Dr. Mark Riddle, a Navy Veteran, is the associate chief of staff for research and a physician at the VA Sierra Nevada Health Care System.
Dr. Mark Riddle, a Navy Veteran, is the associate chief of staff for research and a physician at the VA Sierra Nevada Health Care System.

Dr. Mark Riddle, a Navy Veteran, is the associate chief of staff for research and a physician at the VA Sierra Nevada Health Care System.

Dr. Mark Riddle, a Navy Veteran, is the associate chief of staff for research and a physician at the VA Sierra Nevada Health Care System. In a research career of two decades, he has specialized in the global impact of infectious and gastrointestinal diseases, population-based epidemiological study design and execution, population health, health economics and analysis, and biomarker discovery, among other key areas. He also serves as a professor and the associate dean of clinical research at the University of Nevada, Reno. He served 21 years in the Navy and received a series of honors, including the Meritorious Service Medal.



What motivated you to join the military?

It was mostly because of financial reasons. I was born and raised in California and worked very hard as an undergraduate at the University of California, Davis, where I earned degrees in zoology and human development, to try to get into medical school. Unfortunately, when I was applying, California was the main importer of medical students across the country. I didn’t get into any California schools. But I often think life happens for a reason, and I ended up going out of state to medical school at Tulane University in New Orleans. I come from a middle-class family and lost my father when I was 19 and in college. I, as well as my parents, lacked the means to pay for private medical school. I borrowed my first year but quickly did the math and realized I didn’t want to be strapped with huge debt upon graduation. Therefore, I moved toward the health professions scholarship program and chose the Navy. I liked sailing and marine biology and the network of Navy overseas labs that would become part of my Navy medicine career path.



What inspired your research career?

I originally thought I wanted to be a pediatric surgeon. But I realized the importance of work-life balance. At the same time, I became enamored with tropical medicine and global health given the strength of the program at Tulane University. While in medical school, I completed my master’s degree in public health and had some formative experiences working overseas. I began to see that my potential life-long impact on the health of people could be much greater as a researcher in infectious diseases than as a hospital- or office-based physician. This perspective, combined with the Department of Defense’s (DOD) world class research in infectious diseases, as well as my enjoyment of the global travel experience, set me toward a path of research in the Navy.



Did you have mentors who inspired you in life, the military, or your research career?

I’ve had many mentors in my life. Dr. Chuck Rosson, the father of my best friend growing up, was a cardiothoracic surgeon. Very early on, I got to be exposed to medicine as a teenager going on rounds and scrubbing in to watch his surgeries. That was formational. Also, for a kid like myself from a middle-class household, his simple encouragement for pursuing a career in medicine was important. In high school, I had some very impactful science teachers, Mr. Utley and Mr. Shrock. I now realize they were very influential in my early development and interest in mammalian biology and physiology. During my undergraduate career, I had formative research experiences under Dr. Kappagoda, a very generous cardiac researcher, as well as many faculty members at the marine biology laboratory in Bodega Bay in California, where I did a semester of study.

I have also had many mentors in my military career. The executive officer of the artillery battalion in which I served as a general medical officer taught me what it meant to be an officer and a leader. Many DOD vaccine research leaders encouraged my growth as a clinical vaccinologist and a leader of research programs. Deans and professors have helped shape my academic research career. I’ve been fortunate. I’ve also had the chance to work directly with corpsmen, medics, and military service members in deployed environments. That has continually inspired my drive to bring innovation and solutions to the many problems our servicemen and women face when the go in harms way.  Finally, I probably owe most of my success to my mom and dad. From them, I learned humility, hard work, and empathy—the three core values and guiding aspects of my life.

Dr. Mark Riddle as a professor in and chair of the department of preventative medicine and biostatistics at the Uniformed Services University in 2017.
Dr. Mark Riddle as a professor in and chair of the department of preventative medicine and biostatistics at the Uniformed Services University in 2017.

Dr. Mark Riddle as a professor in and chair of the department of preventative medicine and biostatistics at the Uniformed Services University in 2017.



When and where did you serve in the military? Describe your military experience.

My military career has taken me across the United States and on overseas deployments. Upon graduating from Tulane University in 1997, I transferred to Navy Medical Center San Diego for a transitional internship. After that, I completed fleet medical forces school and was assigned to the 1st Marine division at Camp Pendleton in California in a very rewarding tour as a battalion surgeon. In 2000, I transferred to the Uniformed Services University in Maryland to finish my training in general preventative medicine and public health. While in residency, I was accepted into the doctorate of public health program. Next, I was assigned to the Naval Medical Research Center in Maryland in the enteric disease department and was promoted to lieutenant commander. While I was working as a research medical officer, an opportunity in 2003 to be the head of the epidemiology center and public health preparedness at the Washoe County district health department in Reno, Nevada, lured me away from life in uniform. My year there was a learning experience.

But I was quickly drawn back to the Navy. I recommissioned and became head of an epidemiology division at a U.S. Navy medical research unit in Cairo, Egypt. I engaged in many operational surveillance efforts in Turkey, Egypt, Qatar, and Djibouti, such as a six-week mission to support Angola’s ministry of defense in a 2005 Marburg hemorrhagic fever virus outbreak. In 2006, I transferred back to the Naval Medical Research Center and rose through the ranks to become head of the DOD bacterial diarrhea vaccine research program. I also deployed on assignments to Djibouti, Honduras, and Kenya in support of clinical field trials. Most recently, I chaired the department of preventative medicine and biostatistics at the Uniformed Services University, where I led programs that trained future uniformed and non-uniformed public health professionals.



What kinds of research are you involved in? How does it potentially impact Veterans?

I focused most of my research in the Navy on vaccine development and antibiotic therapy for deployment-associated acute gastrointestinal infections that are very common and debilitating. This work included conducting many early human FDA-regulated vaccine trials, as well as single-dose antibiotic clinical field trials. Those trials culminated in the creation of the first military guidelines for diarrhea management in deployment, as well as guidelines for the American College of Gastroenterology and the International Society of Travel Medicine.

I work with and lead teams to better understand the chronic consequences of these gastrointestinal infections—an area that is highly relevant to the Veteran population. We’ve learned that there’s major risk in developing chronic health problems of the gastrointestinal and rheumatological systems that can be triggered by acute intestinal infections while being deployed overseas or in garrison. I lead research teams to better define this disease and to discover the fundamental biology and mechanisms that explain how these chronic health problems are triggered. This is a very exciting area of research that I hope to continue while I’m at VA.



Did your military experience inspire you to pursue a career as a VA researcher? Is your military experience connected in some way to your VA research?

Absolutely. Being a Veteran and having many Veteran colleagues is a strong motivator to discover new ways to help those who have served in harms way. My research in chronic gastrointestinal effects associated with service during my military career is directly related to my interests in VA research moving forward.



How do you feel about the possibility of making life better for Veterans through your research?

That’s what keeps me going. I believe in the process and promise of science to solve the toughest problems.



Does being a Veteran give you a greater emotional tie to the work you’re doing or more insight into Veterans’ needs?

I would say yes. I feel that I can in some ways connect with Veterans when I’m asking them to enroll in a study by discussing shared experiences and understanding. 



Based on your life experiences to date, what do you believe are the keys to success? What motivational tips would you share?

Being humble, hard-working, and smart. There’s so much we don’t know about medicine and science, and the hardest problems require teams of people. Knowing you don’t have all the answers and that you need help is key to success and requires one to be humble. Research takes grit. It’s not a 9 to 5 job and requires extra nights and weekends to accomplish the mission. Research takes time. Developing an idea, writing a proposal, obtaining funding, writing a protocol, executing a study, analyzing the data….it all takes time and thus requires a long vision and a tolerance for delayed gratification and hard work. As I mentioned, good research takes teams of professionals. Sometimes, you are a member of a team, sometimes you lead a team. Knowledge about science and research methods will only get you so far. The rest of success requires you to know how to communicate with others, motivate, develop self-awareness, and retain a positive attitude. You must be smart, but not necessarily book smart.



What’s the next step for you in your VA career?

As the new associate chief of staff for research for a small program at the Sierra Nevada VA, I’ve worked for the last nine months to develop a strategic plan that will take research to the next level. This is the first strategic plan that our VA medical center has ever had. The main goals  that are outlined in our new plan are to grow the number of staff engaged in clinical research from across the entire spectrum of health professions and services in VA; initiate and expand a portfolio of independent investigator-driven research; create an environment and training programs where well-rounded health-professionals are cultivated and capable in competency-driven research knowledge and skills; and increase collaborative research engagements with community, academic, and VA partners. Over the next four years, I hope to achieve as many of the goals that we’ve identified.

I also hope to establish my own research program in the area of functional bowel disorders among Veterans. At present, generalization of limited diagnostic and therapeutic strategies across a heterogeneous prevalent patient population impedes the ability to provide effective personalized care in irritable bowel syndrome and other functional gastrointestinal disorders. I hope to develop a research program with the help of others that identifies diagnostic tools, safe and effective therapies, and clinical-physiologic traits of an organism that ultimately guide treatments based on distinct pathways of disease.


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