Meet Our Faculty!

Thank you for your interest in Fitchburg Family Medicine.  Feel free to contact any of our faculty any time to learn more!

You can also read more about the personal biographies of faculty members who have been interviewed in our residency newsletters!


Nicholas Apostoleris, PhD
Fitchburg Residency Behavioral Science Director
Associate Residency Director
Assistant Professor
Worcester State Hospital/UMass Medical School, Dept. of Psychiatry Internship, 1999
Clark University, Clinical Psychology Ph.D., 2000
UMass Medical School Fellowship, Primary Care Clinical Psychology, 2001
Areas of Interest and Research: Dr. Apostoleris teaches research methodology and behavioral science, consults with medical providers, provides direct patient care,and supervises the program's post-doctoral fellowship in Primary Care Psychology. Areas of clinical interest include substance abuse and dual diagnosis issues, severe psychopathology, and child assessment. Areas of research interest include intrinsic motivation, home education, and psychological factors related to health outcomes.


Margarita Castro-Zarraga, MD
The Brooklyn Hospital Center (Residency)
College of Medicine, University of the Philippines Manila
Professional Affiliations: American Academy of Family Physicians and the American Heart Association
Areas of Interest and Research: Adult congenital heart disease, female sexual dysfunction, herbal medicine, meditation, raw food vitamins, student education in family medicine
About UMass: "UMass has given me the opportunity to practice academic full-spectrum family medicine in the service of an underserved population. It is an honor to be working along side
such gifted and genuine professionals. When you find the job that gets you up and excited in the morning, that is the greatest blessing."
Personal Facts: "I had a stint as a movie jockey on a local cable channel over one summer when I was a teenager…I learned Vipassana meditation, essentially "body scanning" --- helps me discipline my mind and deal with stress."


Felix Chang, MD
Assistant Professor and Inpatient Service Director
Guayaquil University School of Medicine in Ecuador, 1986
UMass Fitchburg Family Medicine Residency, 2006
Areas of Interest and Research: Dr. Chang completed his training at the Fitchburg Family Medicine Residency Program in 2006. He remains on faculty at the Residency. He serves a Latin outreach program at the Leominster FHC. As director of the residency's Family Medicine Inpatient Service, Dr. Chang supervises morning report and rounds and lectures frequently on topics related to inpatient medicine, maternity and pediatrics. Dr. Chang is fluent in English, Spanish and Portuguese.


Cheryl DiVito, DO
Osteopathic Residency Director
University of New England College of Osteopathic Medicine, 2002
University of Massachusetts Family Medicine Residency Program, Fitchburg, MA, 2005
Areas of Interest and Research: Dr. DiVito completed her training at the Fitchburg Family Medicine Residency Program in September, 2005. She remains on the faculty at the residency. Dr. DiVito directs the osteopathic residency and also directs the maternity curriculum.

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James J. Ledwith, MD, FAAFP
Residency Director and Assistant Professor
College of William and Mary, 1979
Medical College of Virginia/Virginia Commonwealth University, MD, 1983
Family Practice Residency at The Toledo Hospital, OH, 1986
Areas of Interest and Research: Clinical interests include chronic disease management, preventive services, obesity, substance abuse and suboxone therapy. I love delivering babies! Practice-based research interests include patient safety and care improvement.
Hometown: Numerous homes in my youth in MA, NJ, and PA, but Tappahannock, VA became hometown for me and my children. I am currently settled in Franklin, MA. 
About UMass Fitchburg:  "After 19 years of clinical practice before coming to UMass, I maintain a passion for community service and for the care of patients with a focus on health maintenance and systems implementation to enhance safe, accessible, comprehensive service. When I made the move to UMass, I shopped for a residency that was community-oriented and expressed care for its members, patients and staff like family. I found what I was looking for in Fitchburg!" 
Personal Facts: "My wife Lauren keeps my life in balance and my three children keep me active. Hobbies (often conflicting) include good food, reading, fitness, visiting the Cape, and protecting my home from the enthusiastic exploration of our new lab pup, Cassie. One day, with no kids' sports and school events, and with house renovations completed, I'll dust off my golf clubs or perhaps join another medical mission team."
Community Involvement: Dr. Ledwith also serves as the Medical Director of the Epworth Free Clinic in Worcester.


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Beth Kurtz Mazyck, MD, FAAFP
Associate Clinical Professor
Director of Medical Education
Senior VP of Clinical Services, Community Health Connections, Inc.
1979 University of Oregon, Eugene
1984 George Washington University School of Health Sciences, Washington, DC
1987 Dwight David Eisenhower Army Medical Center, Fort Gordon, GA
Areas of Interest and Research: Women’s Health, Clinical Ethics, Community Health
Hometown: Hanover, NH
About UMass Fitchburg: "UMass Fitchburg is a great place to train. The education is wonderful, the variety of opportunities outstanding, and the resident support is unmatched at any residency."
Why Family Medicine? "I wanted the opportunity to really get to know my patients and be involved in their lives. I needed to know that I was helping them remain healthy, not just recover from being sick. Also, the thought of doing the same thing over and over and over again (as with subspecialty practices) just seemed too BORING!  Besides, Family Docs are the nicest group of docs you could ever want to work with!"
Personal Facts: "I hate to be bored, but am rarely bored since I married my husband, acquired 3 teenage sons, then had 3 more children!  Now I have not only 6 children, but 5 grandchildren…no time for boredom! I love to travel, but with 6 children I don’t have the money to travel, so I have stayed in the Army – free trips to Iraq, Kosovo, Bolivia, and Guatemala (among others.)"
Community Involvement: Dr. Mazyck is the Deputy Commander of Clinical Services for the 399th Combat Support Hospital and has served in Iraq and Kosovo. She has also served on overseas humanitarian missions in Bolivia, Guatemala, Malawi and with the Indian Health Services. In addition, Dr. Mazyck has organized and provided leadership for the Regional Public Health Coalition for Northern Worcester County.   


Kristen Kavulich McCarthy, DO
Assistant Professor
Marist College (Poughkeepsie, NY), 2004
Lake Erie College of Osteopathic Medicine (LECOM), Erie, PA - 2009
UMass Fitchburg Family Medicine Residency, 2012
Hometown: Wappingers Falls, NY
Areas of Interest and Research: Osteopathic Manipulative Medicine (OMM/OMT), nutrition and healthy living, integrative medicine, acupuncture, resident and student education, continuity
of care in family medicine and caring for the whole family 
About UMass Fitchburg: "UMass offers a well-rounded training in family medicine, which prepared me to care for all kinds of patients. i enjoyed it so much, I decided to join as faculty after graduation. It's a supportive atmosphere and I enjoy working with a variety of talented providers and educators, working in an underserved community."
Personal Facts: "I love snowboarding, being active and outdoors (running, yoga, hiking( and traveling. I am passionate about live music and travel all across the country to attend various concerts (especially the Dave Matthews Band.) I'm also crazy about dogs!"

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Peter C. McConarty, MD
Associate Professor, FMCH, University of Massachusetts Medical School
Harvard College, 1969
University of Rochester School of Medicine and Dentistry, 1973
University of California San Francisco General, Residency, 1976
Areas of Interest and Research: Diabetes, care of underserved populations, collaborative primary care, assisting patients in behavior change, care of chronic disease, furthering the demise of the current non-system of healthcare
Hometown: Easton, MA
About UMass Fitchburg: "Fitchburg is a manageable size, has enormous unmet medical need, a very involved and supportive medical community and a Community Health Center committed to being part of the solution."
Why Family Medicine? "Family Medicine represented the last, best hope for reform of a dysfunctional medical delivery system when I chose a residency in 1973, and it still does today."
Community Involvement: Member, Physicians of a National Health program; Campaign worker for President Barack Obama, Senator Jeanne Shaheen, Mass Governor Deval Patrick, Fitchburg Mayor Lisa Wong and candidate John Kerry.


Abhijeet A. Patil, MD, MS
Assistant Professor
Fellowship, Geriatric Medicine, University Of Massachusetts, Worcester, MA 
Residency, Family Medicine, Hennepin County Medical Center, Minneapolis, MN
Master of Science, Exercise and Sports Studies and Sports Psychology, Miami University, Oxford, OH
Grant Medical College, Mumbai, MH, India
Professional Affiliations: American Academy of Family Physicians, American Geriatrics Society, Massachusetts Medical Society
Areas of Interest and Research: 1. Impassioned advocate for improvement of quality of life of the elderly population, through evidence based and compassionate geriatric medicine. 2. Global health: Social determinants of health and its impact on the health and provision of high qualiy health care to the vulnerable 3. Helping patients and families in complex decision making in heath care
4. Patient and community empowerment 5. e-health & m-Health. 6. Chronic disease management with an interdisciplinary and integrated approach.
About UMass Fitchburg: A wonderful place for quality health care education for professionals and health care provisions for patients. One of the few places where patient centered care is at the core of its vision.
Personal Facts: I believe in, ‘Change the Man In The Mirror, to Change The World for Better’ and follow Sir Rudolf Virchow’s philosophy; ‘The physicians are the natural attorneys of the poor and it's their obligation to point out problems and to attempt their theoretical solutions’. I am a founder of ‘i-PACE’ (i-Partners in All Inclusive Community Empowerment), a NGO in India, working for Education, Health and Environment for All! I am also an avid badminton and cricket player, and I love to paint!



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Michele P. Pugnaire, M.D.
Associate Professor of Family Medicine and Community Health
Vice Dean for Undergraduate Medical Education, University of Massachusetts Medical School

Areas of Interest and Research:
Dr. Pugnaire is responsible for providing leadership for curriculum development, implementation, and evaluation in undergraduate medical education. She has served as Associate Dean for Admissions and Assistant Dean for Student Advising. During the past 15 years, Dr. Pugnaire has served in a variety of administrative and teaching positions in the Department of Family Medicine, and is currently Project Director for the Macy Initiative in Health Communication grant at UMass Medical School as well as Principal Investigator for the Pfizer Sexual Health in Undergraduate Medical School Curricula and AAMC/John A. Hartford Foundation Enhancing Gerontology and Geriatrics Medicine Education in Undergraduate Medical Education grants.

Her education interests and achievements include faculty development in student advising, technology in teaching, the McQ Standardized Family curriculum, and the expansion of the standardized family across three clerkships as the principal investigator for a UME 21 Associate Partnership grant. Dr. Pugnaire is the recipient of numerous teaching awards and maintains a community-based clinical practice in family medicine with the UMass Fitchburg Family Medicine Residency Program.



Katherine Riggert, DO, MS
Faculty, UMASS Fitchburg Family Medicine Residency
Faculty, UMASS Sports Medicine Fellowship Program
University of South Florida
University of New England College of Osteopathic Medicine
Middlesex Hospital Family Medicine Residency, Middletown, CT
UMASS Sports Medicine Fellowship
Areas of Interest and Research: Sports medicine, endurance sports performance, medical issues & sports injuries in the female, pediatric, & master athlete populations; health behavior changes
Hometown: Sudbury, MA
About UMass Fitchburg: "UMass Fitchburg has supportive faculty with many diverse interests."
Why Family Medicine? "Family medicine provided the ideal foundation, broad-based & well-rounded, on which to become a primary care sports medicine specialist."
Personal Facts: "I had a past life as a professional bicycle racer before going to medical school. Cycling and running are two my favorite activities." 

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J. Herbert Stevenson, MD
Associate Professor
Director, Sports Medicine
Director, Sports Medicine Fellowship Program
University of Vermont College of Medicine, 1998
University of Massachusetts Family Practice Residency, Worcester, 2001
Sports Medicine Fellowship, University of Connecticut, 2002
Areas of Interest and Research:  Dr. Stevenson's clinical areas of interest include: sports medicine, evidence-based medicine, and implementation of technology in medical training and at the point of care.

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Barbara G. Sullivan, FNP-BC, Family Nurse Practitioner
MS - UMass-Amherst, 1995
ANCC - Credentialed
American Association of Nurse Practitioners - Member
Massachusetts Coalition of Nurse Practitioners - Member
American Association of Home Care Physicians - Member
Health Care for the Homeless Clinicians Network - Member
Personal Facts: Prior to coming to the family practice residency, Barbara worked as a family nurse practitioner in private internal medicine and family practices.
Community Involvement: Barbara has also worked at Boston Health Care for the Homeless and has worked with the GI Rights Hotline. As an RN, Barbara worked at the Homeless Outreach and Advocacy Project in Worcester, MA, and in community health and homecare for 15 years. Her special interests include providing care for the homeless and other underserved populations, cross-cultural issues, and women's health.


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Kathleen Sweeney, MD
Chief Medical Officer, Community Health Connections
University of Rochester School of Medicine
Residency at UMASS Family Practice
Personal Facts: "4 kids; 1 husband. I live in an old farmhouse with horses, gardens and a maple sugar bush."
Community Involvement: Dr. Sweeney has been active with the Wachusett Regional School Committee, the Boys and Girls Club of Leominster, MA, the Genesis Club of Worcester and the Princeton Youth Soccer Association.

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Stefan Topolski, MD, Assistant Professor
Country Doctor at Trailside Health
Director of Caring in Community Inc., 501 (c) 3  
Medical Director at Overlook Hospice
Med-Psych Officer at VA Leeds
Chief Programmer for the CottageMed Global EMR
Brandeis University, 1991
University of Maryland School of Medicine 
Research in Complexity and Alternative Medicine, 1996
The Western Pennsylvania FP Residency, 1999
Areas of Interest and Research: Medical ethics, history of medicine, philosophy of science, enlightened management, complex systems science, creativity and humanity in medicine, appopriate technology for sustainable development, country doctoring and the house call, affordable access to caring healers and he future of family medicine.
Hometown: Liberty, Maine
Personal Facts: "A jack of all trades...who enjoys almost everything except extreme heights, large livestock and sinking at sea."
About UMass Fitchburg: A radical talented faculty with incredible mental health resources to carrying George Engel's biopsychosocial ideal of health into the 21st century.
Why Family Medicine? "For every old-fashioned, high-minded reason that you’ve already heard. Family Medicine is the only western medicine which cares for the whole person their whole life. From before birth to after death we are the profession equipped and trusted to address any pain, bringing comfort to all suffering."
Community Involvement: "I have deeply immersed myself in underserved communities for a quarter century living and volunteering in Catholic Worker soup kitchens in Boston and Baltimore, social working among factory and migrant farm workers in Salisbury and Nassawadox, serving religious medical missions in Antigua, Guatemala and Ahuas, Honduras, working with homeless men and women in cities large and small, visiting local classrooms encouraging healthy living and the value of education, developing elder outreach programs in rural western Massachusetts, and encouraging local, personal, creative solutions without government distortion of individual humane intentions."