At NEFEDA, we believe in the power of personalized care to create the strongest bond possible between caregivers and patients. That’s why we’ve assembled teams of exceptional endocrinologists, physician assistants, nurses, and educators. Each has a wealth of experience plus a passion for patient well-being. NEFEDA’s unique approach means you benefit from the expertise of an entire team focused on you.
Meet NEFEDA's CareTeams

Salwa Ayad, M.D.
Dr. Salwa S. Ayad joined NEFEDA in 2006 after relocating from Alexandria, Egypt. She is a graduate of the Collège de la Mère de Dieu. Dr. Ayad brings a spirit of innovation coupled with an old-fashioned approach to providing patients with personal attention. Physicians like Dr. Ayad are why the experts consider NEFEDA a genuine “world-class” practice. She is married with three children, and when not at work, she enjoys cooking, traveling, and the great outdoors. Her patients enjoy a great doctor when she is working.
Ronnie Bateh, DPM
A proud native, Dr. Bateh attended Jacksonville University before enrolling at the University of California, San Francisco’s College of Podiatric Medicine, completing his residency at St. Vincent’s Medical Center.
When he joined NEFEDA, Dr. Bateh made history as the first podiatrist in the nation to be incorporated into an endocrinology group, a pioneering move that has been an overwhelming success. When not helping patients, Dr. Bateh enjoys spending time outdoors.
When he joined NEFEDA, Dr. Bateh made history as the first podiatrist in the nation to be incorporated into an endocrinology group, a pioneering move that has been an overwhelming success. When not helping patients, Dr. Bateh enjoys spending time outdoors.
Jennifer Becker, PA-C
Jennifer Becker is a board-certified Physician Assistant and Diabetes Care and Education Specialist. She earned her Master of Medical Science degree at Nova Southeastern University. Jennifer's own Type 1 diabetes diagnosis gives her a particular interest in diabetes care. She is a Certified Tandem insulin pump trainer and proficient with the latest technologies. Other areas of interest include weight management and hormonal balance. Jennifer enjoys running, kayaking, learning French and walks with her German Shepherd.
Cassandra Burt-Ernst, PA-C
Cassandra graduated from physician assistant school at Emory University with a Master of Medical Science degree. Jacksonville has been home since 1996. She has extensive experience in pulmonary care, family practice, internal medicine, and critical care. As a valued member of the team since 2008, she plays an active role in medical research at NEFEDA. Cassandra appreciates the opportunity she has been given to improve quality of life for her patients.
Cort Little,
PA-C
Cort Little is a Certified Physician Assistant with a Master of Medical Science degree from Nova Southeastern University. Cort is committed to fostering strong patient-provider relationships. His interests include Type 2 diabetes management, the integration of technology in diabetes care, and cortisol disorders. He is an active member of several professional societies. Outside of work, Cort enjoys board games, escape rooms, and spending time with his partner and their cats, Kelvin and Joules.
Troy Ellis,
PA-C
Troy Ellis is a Certified Physician Assistant. Troy earned his Master of Medical Science at Nova Southeastern University in 2019. He is dedicated to empowering patients and building trust. In his free time, Troy enjoys time with his family and friends, hiking, traveling, and exploring the Jacksonville culinary scene.
Steve Parker, PA-C
Steve Parker, PA-C, has specialized in diabetes and thyroid disorders for more than 20 years. Before becoming a Physician Assistant, he worked as an EMT/Paramedic and participated in several diabetes research studies. His passion for medicine led him to the Medical College of Georgia, where he graduated summa cum laude. He has volunteered extensively in the community and is recognized as a caring and compassionate healthcare provider.
John Gary Evans, M.D.
Dr. John Gary Evans has led dozens of clinical trials as NEFEDA’s principal investigator. He completed his medical degree and residency at the University of Maryland School of Medicine. Dr. Evans is known for his kindness and genuine desire to listen. Dr. Evans enjoys time with his wife and three daughters, tennis, fishing and, especially chess. Winning at chess and helping patients each involve expert strategy. Dr. Evans's patients will be the first to tell you his individualized plans make an immense difference in their lives.
Akshaya Kambhatla, M.D.
Dr. Akshaya Kambhatla joined NEFEDA in 2024 after returning to Florida from Mobile, Alabama. Known for her compassionate and patient-centered approach, Dr. Kambhatla is dedicated to enhancing her patients’ lives. With expertise in a wide range of endocrine disorders, Dr. Kambhatla specializes in the treatment of diabetes, thyroid cancer, hyperthyroidism, adrenal disorders, and calcium disorders.
J. Sample Magee, M.D.
During his more than 30 years of service, Dr. J. Sample Magee has watched NEFEDA emerge as one of America’s largest private endocrinology practices. Dr. Magee graduated from the University of Pennsylvania, completed his residency at the University of Miami, and a fellowship at Yale University. Dr. Magee treats every patient as an individual with unique needs, requiring a customized plan for care. It is a formula that has made Dr. Magee one of the most trusted and admired practitioners on the First Coast.
Miguel Roura, M.D.
Dr. Miguel Roura is a graduate of the Dominican Republic’s CETEC University, completed his internal medicine residency at New York Medical College, and a fellowship in endocrinology at the University of Florida. Certified in Internal Medicine, Endocrinology, and Metabolism by the American Board of Internal Medicine, Dr. Roura has been an investigator for clinical trials since 1991. He is a member of the American Medical Association, Duval County Medical Society, and American College of Endocrinology.
Anil Shrestha, M.D.
Dr. Anil Shrestha joined NEFEDA in 2016. After completing his medical degree in his native country of Nepal, he did his residency in Internal Medicine at Long Island College Hospital in Brooklyn, New York, and his fellowship in Endocrinology at Beth Israel Medical Center in New York City. Dr. Shrestha is Board Certified in Internal Medicine and Endocrinology. He enjoys spending his free time with his wife and two daughters, and is a history and trivia buff.
Ricardo Silva, M.D.
Dr. Ricardo Silva earned his medical degree from Puerto Rico’s Universidad Central del Caribe, Cayey School of Medicine, and completed an internal medicine residency at Michigan State University. Dr. Silva joined NEFEDA after an endocrinology fellowship at the University of Florida. He has been principal investigator and sub-investigator for dozens of clinical trials. Dr. Silva also lectures to community physicians and has served as Chief of the Section of Endocrinology at Baptist Medical Center. Fully bilingual, Dr. Silva has the privilege of serving our Spanish-speaking patients.
Senan Sultan, M.D.
Dr. Sultan earned his medical degree in Syria. While studying there, he also volunteered, providing underprivileged children with free health care and screenings. He then travelled to Europe where Dr. Sultan did rotations in Germany and France. Coming to the U.S., Dr. Sultan completed his residency at the prestigious Cleveland Clinic, one of America’s premier health care organizations. Dr. Sultan next practiced as a hospitalist in Georgia before completing a fellowship at the University of Florida and joining NEFEDA in 2010.
David Sutton, M.D.
One of our founders and a Jacksonville native, Dr. David Sutton is as likely to be recognized at a local eatery as in the clinic. Dr. Sutton earned his Doctor of Medicine from Wake Forest University and completed his residency at the University of Florida. Dr. Sutton has been a clinical trial investigator in hypopituitarism since 1997. Dr. Sutton excels at helping patients feel excited about their future. “If it weren’t for him, we never could have had our two children. We owe him everything,” said one of Dr. Sutton’s longtime patients.
Stacey Kelly, APRN
Stacey Kelly earned her Master of Nursing in Critical Care from Emory University and her acute care nurse practitioner degree from the University of Florida. She began specializing in primary care and endocrinology while employed at the US Embassy in Bangkok, Thailand. ANCC Board Certified, Stacey helps train NEFEDA nurse practitioners and PAs and provides patient education. Stacey has conducted research, published journal articles, and is a member of Sigma Theta Tau, the international nursing honor society.
Raquel Villavicencio, M.D.
Dr. Raquel Villavicencio is triple-board-certified in Endocrinology, Internal Medicine, and Obesity Medicine. Prior to her current role, she served as a primary care physician, hospitalist, and preoperative assessment practitioner. Dr. Villavicencio is a member of the Endocrine Society and the Menopause Society. She also earned a Certificate in Comprehensive Care for Persons with Diabetes from the Endocrine Society and is a certified Prevent T2 lifestyle coach. Dr. Villavicencio speaks both English and Spanish.
Khurram Wadud, M.D.
To Dr. Khurram Wadud, endocrinology is more than a profession—it’s personal. Several of Dr. Wadud’s family members suffered from diabetes and thyroid issues, making him keenly aware of the the toll these conditions can take. Dr. Wadud attended medical school in Pakistan, completed his residency at a hospital affiliated with Cornell University, followed by a fellowship in endocrinology at Saint Louis University. He is a fellow of the American Association of Clinical Endocrinologists and previously practiced at Indiana’s Marion General Hospital, where he was named “Doctor of the Year.”
Sujata Wagh, M.D.
Dr. Sujata Wagh is a board-certified endocrinologist with expertise in thyroid, parathyroid, adrenal, and pituitary disorders, as well as diabetes and osteoporosis.
She holds advanced certification in neck ultrasound (ECNU) and performs ultrasound-guided fine-needle aspirations.
She completed medical training in both India and the U.S., and has practiced in Florida and Colorado since 2005
Now based in Jacksonville, she emphasizes patient-centered care and collaborative treatment.
Outside of work, she enjoys outdoor sports and community service initiatives, particularly those supporting children with autism.
She holds advanced certification in neck ultrasound (ECNU) and performs ultrasound-guided fine-needle aspirations.
She completed medical training in both India and the U.S., and has practiced in Florida and Colorado since 2005
Now based in Jacksonville, she emphasizes patient-centered care and collaborative treatment.
Outside of work, she enjoys outdoor sports and community service initiatives, particularly those supporting children with autism.
Firas Warda, M.D.
Dr. Firas Warda was born in Syria, moving to Jacksonville, Florida in 2005. He earned his medical degree from St. George’s University School of Medicine. Dr. Warda completed training in Internal Medicine and Endocrine at the University of Florida College of Medicine, Jacksonville. Dr. Warda is an active contributor to clinical research at UF. He has also presented at national endocrinology conferences and has published numerous papers in national and international journals. Dr. Warda is known for providing compassionate care.
Gabrielle Du Sablon, PA
Gabrielle (Gabby) Du Sablon is a Certified Physician Assistant. Gabby attended Nova Southeastern University, where she received a Master of Medical Science. Prior to receiving her master’s degree, she attended the University of Central Florida, where she received a bachelor’s degree in health sciences. In her free time, Gabby enjoys being with family, traveling, and staying active.
Reach Out to NEFEDA Today.
NEW PATIENTS:
Please call us at 904-384-2240 to request an appointment.
EXISTING PATIENTS:
Please use our Patient Portal to request appointments or refills, pay a bill or send us a message. First-time users, signup for portal registration below. *All fields are required.
NEFEDA's CareTeam Superstars
