Meet Our Team
Dr. Megan Hudson DMSc, PA-C
Founder
Dr. Megan Hudson is the proud founder of Global Health ImPAct.
Her 14 years of clinical experience and global health involvement has propelled her to create the same opportunities for other PAs across the globe. As the leader of GHI, Dr. Hudson is always reminding her team to be imPAct focused and ensuring that our global health experiences are sustainable and empowering to the communities we partner with.
Dr. Amy Bratten
Chief Academic Officer
Dr. Amy Bratten serves as the Provost of Academic Affairs and Workforce Education at Polk State College. Dr. Bratten brings a wealth of experience in the educational system as her career spans over 20 years and includes teaching in the middle school, high school, college, and university classrooms focusing on English literature, literacy development, English as another language, and teacher preparation. Dr. Bratten has taught in 8 countries, and believes deeply in global education creating well-rounded and empathetic individuals open to varied cultures and contexts.
Tiffany Grubbs, B.S., R.T.(T)
Chief Operations Officer
Tiffany serves as the COO of Global Health Impact, Inc., where she supports teams in creating transformative medical education opportunities for students in underserved communities around the globe. Tiffany’s leadership roles at Lakeland Regional Health in Oncology, Pediatrics, and Primary Care have leveraged her expertise to enhance patient care, positively impacting countless lives over her 14-year career in healthcare.
Katie Pierce PA-S
Director of Student Engagement
Katie is our secretary and a voting member on our Board of Directors. She is also currently a PA student at Barry University graduating in December of 2025! Katie has gone on several international service trips, including two led by GHI founder Megan Hudson, to Uganda, Africa visiting the Watoto Villages. Her desire to aid in launching Global Health Impact comes from a place of passion for serving the underserved, as well as seeing first-hand the influence of medical service trips. Throughout her PA education she believes her global experiences have equipped her with skills to be a stronger student, while also developing her into the compassionate and competent PA she hopes to become. She greatly encourages these kinds of experiences for all aspiring clinicians and truly believes in the impact these trips can have on those being served as well as on the serving students in their journey to become the best health care providers they can be!
Dr. Diana Cantero DMSc, PA-C
Director of Site Development
Dr. Diana Cantero is a Physician Associate from Los Angeles, California. She pursued her undergraduate studies at California State University Channel Islands, earning a Bachelor’s Degree in Biology. During her college years, Diana dedicated her time to volunteering at a local hospital and participated in a mission trip to aid the victims of Hurricane Katrina. This mission trip was a pivotal moment in Diana's life, inspiring her deep commitment to helping those in need. Following her undergraduate studies, Diana spent a summer shadowing at the clinic where her mother worked as a medical assistant. It was here that she discovered the Physician Associate profession and developed a passion for it. Motivated by this experience, Diana enrolled in the Keck School of Medicine of USC Physician Associate program, from which she graduated in 2014. During her time at USC, she demonstrated her leadership skills by organizing a medical mission trip to Honduras. On this mission trip, a clinic was set up to help a rural community, sparking Diana’s interest in global health. Since graduating, Dr. Cantero has been dedicated to the fields of Emergency Medicine and Urgent Care. In 2021, she decided to further her education by pursuing a Doctorate Degree, and in 2022, she graduated from the University of Lynchburg with a Doctor of Medical Science (DMSc). Her advanced degree and dedication to her profession led to her promotion to APP Regional Lead within her Urgent Care practice. In addition to her professional responsibilities, Dr. Cantero enjoys sharing her knowledge and experience by teaching Physician Associate students at USC. In her personal time, she loves to travel and spend quality time with her family.
Mary Showstark, BA, MPAS, FAWM, PhD, PA-C
Director of Global PA Advocacy
Mary Showstark is a Physician Associate/Assistant (PA), an Assistant Professor at Yale University, and an affiliate faculty member of the Yale Institute of Global Health. Showstark is involved in growing the healthcare workforce for the PA profession globally. She is Vice President for PAs for Global Health, a global ambassador to American Academy of PAs (AAPA), member of GACOPA, communications lead for International Academy of PA Educators, and consulted with the World Health Organization on the Global Framework for Universal Healthcare. She is also the creator of the International Federation of Physician Assistant/Physician Associate and Clinical Officer/Clinical Associate/Comparable Students’ Association (IFPACS). Showstark also spearheaded the curricula mapping of the PA/PA comparable professions around the world via LOOOP technology. She is also editor for JPAE’s Global Perspectives and creator of JAAPA’s Global Insights. Mary is also the Director of Virtual Interprofessional Education and on the Interprofessional.Global committee. She is also Chief Liaison Officer to Health Tech Without Borders and holds a PhD in Security and Intelligence Studies from the University of Buckingham. Mary Showstark is a physician associate with clinical experience in trauma surgery, emergency medicine, urgent care, disaster preparedness, wilderness, event, and mass gathering medicine. She has extensive experience with online education, group learning, organizational culture, and utilization of extended reality and artificial intelligence.
Ciara Calitri, MPAS, PA-C,
PA-C Pediatric Emergency Medicine
Director of Clinical Education
Ms. Calitri joined the South University, Tampa Physician Assistant Program full time in September of 2021 after working in pediatric emergency medicine. She earned a Master of Science in Physician Assistant in 2013 from South University, Tampa and worked serving the Tampa Bay community before transitioning into academics. Ms. Calitri is originally from New Jersey and graduated from Fordham University earning her Bachelor of Science. Her first position was at Johns Hopkins All Children’s Hospital in St. Petersburg, Florida, followed by positions with St. Joseph’s Hospital Main and South campuses in the Pediatric Emergency Department. During the global pandemic, Ms. Calitri worked in the Adult Emergency Department for months as a result of changes in patient volumes. She is proud of her alma mater, returning as an Adjunct Professor at South University, Tampa in 2018 and joining the faculty full time in 2021. Ms. Calitri is an active member of the American Academy of Physician Assistants (AAPA), Florida Academy of Physician Assistants (FAPA), and Society for Emergency Medicine Physician Assistants (SEMPA). She lives in Tampa with her husband and their three children.
Matthew Ard, PA-C
Board Member
Matthew is a compassionate and dedicated healthcare professional with over 25 years of experience as a Physician Assistant, specializing in underprivileged patient care and serving diverse ethnic communities. Currently, he holds multiple roles as an Emergency Medicine Physician Assistant, delivering care in rural emergency settings at facilities including Colquitt Regional Medical Center, Phoebe Physicians Group, and Memorial Satilla Health. Previously, he served as Clinic Medical Director of a Federally Qualified Health Center at Albany Area Primary Health Care’s South Albany Medical Center, where he led efforts to enhance healthcare access for underserved populations. His passion for serving disadvantaged communities extends beyond the U.S., evidenced by his participation in over 45 short-term medical missions worldwide. Matthew earned a Doctor of Health Sciences in Global Health from Nova Southeastern University, a Master of Physician Assistant Studies from the University of Nebraska Medical Center, and a Baccalaureate of Science in Physician Assistant Studies from Jefferson College of Health Sciences, complemented by earlier degrees in Food and Nutrition Science from The Florida State University and an Associate of Arts with Honors from Tallahassee Community College. Recognized with the 2005 National Health Service Corps Scholarship and the 2011 National Health Service Corps Loan Repayer award, he has consistently demonstrated a commitment to improving the health of disadvantaged populations. An active leader in his field, Matthew serves as Director at Large for the Georgia Association of Physician Assistants (2022–2024) and the Fellowship of Christian PAs (2021–Present), and as a Regional Contact Liaison for the former since 2013. He also contributes as a Clinical Assistant Professor at Arizona School of Health Sciences and a Clinical Lecturer at Florida State University’s College of Medicine School of PA Practice. Beyond his professional roles, Matthew is Vice President of Plowman Global Mission Inc. and serves on the boards of Global Health Initiatives (GHI) and the Christian Medical & Dental Associations/Global Health Outreach (CMDA/GHO), continuing his legacy of service through medical missions across countries such as Nicaragua, Guatemala, and Morocco."
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