All of our highly specialized providers currently on staff are American Academy HIV Specialist (AAHIVS) certified, or training for the certification. They are constantly looking for ways to promote our services and hone their skills, conducting research and attending conferences and meetings. Together, they work to create a pertinent conversation on the developments of HIV, hepatitis C, and transgender health care. The program has grown rapidly from a single provider in 2011 to several HIV and hepatitis C specialists working at four separate locations in Riverside County and San Bernardino County. Their compassionate approach to treatment is well regarded by our patients.
If you would like to make an appointment, please call (760) 676.5800.
Clayton Barbour, MD
Medical Director of Specialty Services
Dr. Clayton Barbour graduated from the University of Miami School of Medicine in 1982 and subsequently completed his postgraduate medical education at the University of Florida School of Medicine. During his professional training in Miami, he was involved with caring for some of the first AIDS patients in the United States. In 1984, Dr. Barbour was one of the founding members of the AIDS Coalition Duval County, and then, almost a decade later, he established a practice at Davies Medical Center in the Castro District in San Francisco. There, he also served on the HIV Services Committee and the Community Consortium of Bay Area HIV Health Care Providers.
From September 1994 to June 2011, he served as the Medical Director for Desert AIDS Project’s HIV Health Center in Palm Springs. In his current position as the Medical Director of Specialty for Borrego Health, Dr. Barbour has been instrumental in redefining a medical program for the treatment of HIV/AIDS and chronic hepatitis C, and, more recently, the transgender care program.
Eric Shigeno, MD
Dr. Shigeno received a Bachelor of Arts in Biochemistry and Molecular Biology from U.C. Berkeley in 1998. He worked for a few years researching the role of dietary oxidants in mitigating the effects of chronic inflammation in cancer and aging before matriculating to medical school. Dr. Shigeno received his medical degree from Rush Medical College in 2005. He completed his internal medicine internship and residency training at Scripps Mercy Hospital in 2008 before completing a fellowship in infectious disease at the U.C. Davis in 2011. Dr. Shigeno takes a patient-centered approach to healthcare that empowers his patients to be actively involved in achieving optimal health.
Joseph Dahman, FNP
Joseph M. Dahman started his career working with HIV in 1994 as an RN Nurse Clinician at Jeffrey Goodman Special Care Clinic in Hollywood, California. He then moved on to AIDS Project Los Angeles (APLA), where he worked as an RN Case Manager for four years. He graduated in 2001 with a Master of Science in Nursing as a Family Nurse Practitioner. Following completion of his degree, Joseph spent nine years with Desert Aids Project and four years at Eisenhower Medical Center.
In 2013, Joseph was hired by Dr. Barbour to be one of the first providers for the Borrego Health Specialty Clinic, treating HIV, hepatitis C, and transgender patients.
Joseph is a member of the American Association of Nurse Practitioners (AANP) and a proud member of the Palm Springs Gay Men’s Chorus.
Patric Schine, FNP, DNP
Director of Transgender Services
Patric Schine has been working with the LGBT community for more than 20 years, with a focus on Transgender Medicine for the last 14 years. While in private practice in Phoenix, he served the largest transgender patient population in the state, with services including a free, monthly clinic for those patients who couldn’t afford office visits.
Among his many scholarly activities, Patric developed “Trans 101 for Providers: A Lecture on Medical Transgender Care” as an introduction to medical care for those who identify as transgender. He has lectured around the country, providing trans-competent recommendations to staff at major organizations that include VIIV healthcare. Patric earned his Masters of Nursing/Family Nurse Practitioner degree from the University of Phoenix in 2002 and completed his Doctor of Nursing Practice at Arizona State University in 2010, focusing on education about, and treatment of, sexually transmitted infections. He has been faculty with Brandman University in Irvine for 6 years, while most recently serving as Director of the Family Nurse Practitioner Program in the Marybelle and S. Paul Musco School of Nursing and Health Professions.
When not providing medical care or teaching, Patric enjoys spending time with his husband and young twin daughters, as they help their children develop into a new generation of people who will love and live, without the need to label others.
Robert Fontanilla, PA-C
Before earning his master’s degree as a certified physician assistant from Touro University California, Robert Fontanilla had a successful career in the pharmaceutical industry for many years, holding various positions, including Executive Account Consultant for HIV products. For his degree, Robert completed his clinical training at Indian Health Services, Dallas Methodist Medical Center, and various private practices in California, Arizona, and Texas. In addition to his role as a physician assistant, he holds a master’s in Public Health, with an emphasis in Global Health and completed his field study at a community hospital in Sucre, Bolivia, where he was involved in health education for patients and providers.
Upon joining Borrego Health Specialty Clinic, he began specializing in the treatment of hepatitis C, HIV, and transgender people. He lectures for Marshall B. Ketchum University and California Baptist University physician assistant programs and serves as a preceptor, teaching future medical providers about specialty health and patient care. Robert has presented for many conferences, county public health departments, and is a faculty member for Gilead Sciences.
Robert is a member of the Phi Theta Kappa academic honor society, the California Academy of Physician Assistants, American Academy of Physician Assistants, and American Academy of HIV Medicine.
Gennady "Henry" Nosovitsky, PA-C
Gennady “Henry” Nosovitsky, certified physician assistant, joined Borrego’s specialty clinic in June 2016. Gennady specializes in treating patients with HIV, hepatitis C, type 2 diabetes, gay men’s health, HIV Pre-Exposure Prophylaxis (PrEP), HIV Post Exposure Prophylaxis (PEP), sexually transmitted infections (including syphilis, gonorrhea, and chlamydia), general infectious disease, as well as seeing primary care patients. Additionally, Gennady has an interest in improving patients' HIV and other medication adherence by also focusing on mental health difficulties, such as attention deficit disorder (ADHD).
He completed his undergraduate work at California State University, Northridge, receiving a bachelor’s degree in biology, and received his physician assistant education from Pacific University in Hillsboro, Oregon. His clinical rotations included training in primary care, infectious disease, HIV care, pain management, dermatology, and correctional facility healthcare.
Due to Gennady’s interest in academia, he currently tutors PA students through distance learning and is looking forward to being involved with Borrego’s residency program and teaching residents and medical students on the topics of HIV, hepatitis C, and STDs. He has presented at conferences and to other clinicians on the topic of STDs, with emphasis on syphilis awareness, diagnosis, and management. Prior to joining Borrego, Gennady worked at the Desert AIDS Project.
Daniel Pearce, DO, BS
Dr. Daniel Pearce graduated with a Bachelor of Science degree in Biology, Honors in Research from the University of California, Irvine and with his medical degree from the College of Osteopathic Medicine and Surgery, Des Moines and then completed 4 years of training, graduating from his Internal Medicine Residency at Wayne State University, Detroit where he saw his first HIV patient in 1983. He worked in the Michigan Department of Corrections and then in multiple rural areas of the Dominican Republic where he learned Spanish. In San Diego, he completed an AIDS Mini-Residency at the University of California’s Owen Clinic in 1988.
He then moved on to Los Angeles as the Director of Research for AltaMed, and then Pomona—where he was an Associate Professor of Medicine at Western University of Health Sciences while being a hospitalist at Arrowhead Regional Medical Center. He then moved to the Department of Public Health for Riverside County as the main HIV specialist, and then to Borrego Health in San Bernardino, Riverside, and San Jacinto. He relieves the hospitalist on vacation at Malamulo Hospital, Malawi each year for a couple of weeks since 2011.
Dr. Pearce is a Clinical Associate Professor of Medicine at Loma Linda University and an Adjunct Professor of Internal Medicine and HIV at two institutions: Touro University-California College of Osteopathic Medicine and Midwestern University Arizona-College of Osteopathic Medicine. He has completed a national and two California academic clinical trial courses and has performed many clinical trials resulting in being the primary or co-author of 31 abstracts or posters, and 23 journal publications. He has written a monthly medical column for a Latino gay men’s publication for over 10 years.
Making sure each patient is heard and that their needs are met is a priority for him.
Ashraf Zadshir, MD
Director of Residency and Medical Education
Dr. Zadshir is the founder and Director of the Department of Residency and Medical Education of Borrego Health. She is a clinical assistant professor of family medicine at the Keck School of Medicine of the University of Southern California and clinical associate professor at the School of Medicine of St. George's University. In Addition, she is the EMC-FMR Assistant Program Director.
A native from Iran, Dr. Zadshir attended the Heinrich Heine University in Dusseldorf, Germany where she graduated with a medical degree. After that, she started her post-graduate training in internal medicine and rheumatology. In 2008, after completing her Family Medicine Residency Program at USC, she joined Borrego Health and, in 2009, became Borrego Health's Regional Medical Director for Riverside County. In 2012, Dr. Zadshir founded the Department of Residency and Medical Education at Borrego Health establishing a unique collaboration of Borrego Health with multiple residency programs Riverside.
Over their many combined years of experience, our staff members have cultivated a rare level of excellence in customer service. We are in constant communication with our patients, outside facilities, and providers, proving that a skilled staff serves as the perfect liaison between members in the community clinic system.
If you would like to make an appointment, please call (760) 676.5800.
Charles Marbley, RN, BSN
Vice President of Specialty Services
Charles Marbley, Vice President of Specialty Services for Borrego Health, has spent the last three years developing Borrego’s HIV, hepatitis C, and transgender specialty clinic services. His responsibilities include the creation and execution of annual business development plans; local and national collaborative research partnerships; and the evaluation of all facets of clinical improvements, operations, and financial returns. Prior to his current position, he was the Director of Corporate Compliance, where he was responsible for ensuring that the company’s business was conducted in compliance with professional standards and accepted business practices.
Throughout his time at Borrego Health, he has built a reputation for developing strong collaborative partnerships with other healthcare organizations. A calculated risk-taker with profound business development knowledge, Charles has championed the specialty clinic, doubling its size and services to the desert community. Currently, he is also the Co-Chairman for The Coachella Valley Community Research Initiative (CVCRI), a long-term research program focused on HIV and aging, with a special emphasis on patients sixty years of age and older. Charles holds a B.S. in Nursing from the University of San Francisco.
Demetria Robertson, RN BSN
Charge Nurse and Site Manager of Borrego Health Specialty Care Center
As the Clinic Manager and Charge Nurse of Borrego Health Specialty Care in Desert Hot Springs, Demetria Robertson brings over twenty years of nursing experience in various fields. She built her career from the ground up as a certified nursing assistant in a nursing home. Subsequently, she became an LVN and worked at Desert AIDS Project with Dr. Barbour and Joseph Dahman, FNP-C. From there, she became licensed as an RN and worked at several local hospitals doing perinatal care for seven years, additionally working in Home Health and Hospice Care. Demetria also taught for nine years as the Lead Clinical Instructor in the VN program at Copper Mountain College. While teaching, working and raising her son, she completed her bachelor’s in nursing science from Grand Canyon University in 2016.
Christopher Fairfield, LVN
Borrego Health Specialty Care Center
A proud new dad, Christopher Fairfield completed his Licensed Vocational Nurse (LVN) program at Copper Mountain College in 2011, graduating with an associate degree in science. Shortly after, he became licensed through the Board of Vocational Nursing and Psychiatric Technicians (BVNPT). He began his professional career as an assisted living nurse and gained further experience in hospice, palliative care, and skilled nursing. As the LVN for Borrego Health Specialty Clinic, his roles include administering vaccines and treatments, triaging patients on-site and over the phone, and assisting with rooming for visiting patients.
Diana Borunda, LVN
Stonewall Medical Center
Born and raised in Los Angeles, Diana was a medical assistant for eight years before returning to school in 2006, in order to study vocational nursing. In 2008, she became a licensed vocational nurse and moved to Cathedral City with her husband. Diana began her nursing career at Angel View, an intermediate care facility for developmentally delayed children, where she worked for almost two years before starting at Borrego Health. Here, she worked for three years at Centro Medico Coachella, then Desert Hot Springs Main Campus before moving to the Stonewall Medical Center in 2017. Her roles include administering medications, vaccines, triaging patients and patient education.