Meet the Team

Melissa McCallum, RN, BScN, MN

GHHN Executive Director

Melissa McCallum, Executive Director, Greater Hamilton Health Network, possesses over 15 years of progressive healthcare experience and planning. She completed her undergraduate Bachelor of Science honors Nursing Degree at McMaster University and Master of Nursing degree with an educational focus. Melissa has been involved in health system planning and integration activities across community, hospital, and social sectors. Clinically, Melissa is a BScN trained emergency nurse.

Martina Rozsa

GHHN Executive Lead Home Care

Martina is a transformational leader with over 25 years of progressive experience in leading teams through large scale integration initiatives across healthcare sectors. Her diverse background as a Senior Leader in operations, strategic planning and quality and risk is a significant asset in supporting the GHHN as it embarks on the journey of delivering Home Care to its residents and patients. 

Martina received her BScN from McMaster University, and also holds a MScHA, and Certificate in Executive Community Leadership from Rotman School of Management. Martina is passionate about breaking down silos to improve the patient and provider experience and isn’t afraid to take risks with new and  innovative ways of delivering high quality care.

Brad van den Heuvel

GHHN Director of Physician Recruitment

Brad’s passion for health workforce planning is central to his work, and he brings over a decade of experience in physician recruitment and retention to the GHHN.  

His experience with the Ontario Physician Locum Programs at HealthForceOntario (now Ontario Health) involved working closely with physicians and hospital leadership to prevent emergency department closures and ensure adequate specialist coverage throughout the province. In addition to leading process improvement initiatives and conducting departmental assessments Brad also provided operational oversight to the Northern Specialist Locum Programs.  

His more recent role in Family Medicine Recruitment with Hamilton Physicians has involved working with a broad network of healthcare professionals and community stakeholders to address physician staffing challenges and attract qualified candidates to the area.   

As the Director, Physician Recruitment with the GHHN Brad will continue this important work and will provide support and input on special projects aimed at improving the availability and quality of care in the Hamilton area.  

Megan Lynch

GHHN Manager of Priority Populations

Received her Bachelor of Science in Nursing from McMaster University and Master of Education from Brock University. She has over 15 years of experience as a Registered Nurse working in Hamilton for Public Health. As a health care practitioner, she has experience in health care system change, health promotion, and communication working in tobacco cessation at the local, LHIN, and provincial levels. She also served as the Lead Public Health Nurse with long-term care and retirement homes, congregate living, shelters and other workplaces for the COVID Outbreak team.

As Manager of Priority Populations of the GHHN, Megan will be leading the priority population working groups, planning strategic directions and working with stakeholders to co-design integrated models of care.

Sarah Precious, MLCE, CYW, RSSW

GHHN Manager of Engagement and Communications

Sarah brings 20 years of experience in the non profit health and social service sectors, with eight years of experience in post secondary education.  Sarah teaches part time at McMaster University and holds a Master of Leadership and Community Engagement. Sarah brings experience in research, facilitation, communications, public speaking and project management.

As the Manager of Communications and Engagement for the GHHN, Sarah will be the lead in implementing and overseeing the communications and engagement strategies.  Working with the community, diverse stakeholders and those with lived and living experience to co-develop innovative ways to transform services and systems to better serve people.

Marijke Jurriaans

GHHN Manager of Primary Care and Environmental Sustainability

Marijke loves living in her Gantt Charts! Beyond her passion for organization and balancing scopes, budgets, and schedules, she also focuses on ensuring all projects utilize an EDI and Environmentally Sustainable lens.

Marijke’s portfolio includes Primary Care and Environmental Sustainability. Marijke holds a Bachelor of Health Sciences and Master of Science (Global Health) from McMaster University and obtained her Project Management Certificate from the University of Toronto.



Kiran Sidhu

GHHN Operations Lead

Studied Digital Enterprise Management at the University of Toronto. She previously worked as a Global Mobility Advisor at KPMG where she assisted with international and domestic relocations. Kiran also worked as a Destination Manager for All Points Relocation Services. Her experience includes working in marketing, project management, operations and event management in Canada and the UK.

As Operations Lead for the GHHN, Kiran will be responsible for administration and project support for the team as well as support in areas of quality improvement, organizational development, and communications. This is a shared position with the Hamilton Family Health Team.

Ceara Holditch

GHHN Project Manager, Digital Health

Ceara brings a diverse skillset to her projects with a passion for written communication, change management, and strategic development. Her portfolio includes managing projects through the project lifecycle, maintaining the work plan for the Digital Health Secretariat, and supporting the development of proposals for joint GHHN initiatives. She also holds a concurrent role as a Project Manager at St. Joseph’s Healthcare Hamilton, where she leads various virtual care projects. 

Ceara graduated summa cum laude from McMaster University with an Honours Bachelor of Arts degree in English and Classics. She also graduated on the President’s Honor Roll at Fanshawe College where she received a Graduate Certificate in Project Management. She is currently working towards her PMP certification. 

Ryan Janssen, RP

GHHN Project Manager, Health Equity, Haldimand, and Mental Health and Addictions

Ryan Janssen is a Registered Psychotherapist living on land covered by the Between the Lakes Treaty in east Hamilton.  Ryan‘s experiences working in various mental health and addictions roles in community, tertiary, and primary care settings fostered a desire to impact that part of health which is socially determined; and led to leadership over projects pertaining to health equity and population health.

Ryan maintains active involvement in his community in many ways.  He holds a Combined Honours BA in both psychology and sociology and a Masters in clinical counselling.  Ryan will provide project management support for the GHHN in the areas of mental health and addictions, health equity, and Haldimand.

Heather Shaw

GHHN Manager, Integrated Health Pathways and System Navigation

Heather Shaw is a seasoned Registered Nurse with a Bachelor of Science from McMaster University and a Graduate of Charles Sturt University, Master of Nursing with a focus on leadership. She has a diverse clinical background, as she has worked in many clinical settings, both in acute care and community, to support a strong working knowledge of the Ontario Healthcare System. As a health care practitioner, she has experience in education, leadership, change management and risk management, health promotion, healthcare system change, quality management, strategic planning, and engaging patients as partners in healthcare. Heather is passionate about education and teaches part-time at Conestoga College. Heather has been involved in health system planning and integration activities, most recently with eHealth Centre of Excellence, as the Engagement and Adoption Lead, Acute Care, Central Ontario, eReferral.

In her current role with the Greater Hamilton Health Network as the Navigation and Digital Access Lead, she will be leading both provincial and regional digital work.

Anna Burns

GHHN Coordinator of Engagement and Communication

As the Engagement and Communications Coordinator, Anna will be supporting the development of communications plans and strategies. She completed her Bachelors Degree in Media Studies with a focus in Public Relations at the University of Guelph-Humber. Anna joins us with marketing experience in non-profit organizations and is passionate about community outreach.


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Get In Touch

If you would like to get in touch with the Greater Hamilton Health Network staff, please email us at info@ghhn.caDo you need an interpreter to connect with us? Contact us and we’ll book one for you!

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Meet the GHHN Patient Advisors

Ike Agbassi

Patient Advisor


David Cooke

Patient Advisor

Barbara Dolanjski

Patient Advisor

Janice Duda-Kosar

Patient Advisor


Sue Wilkins

Patient Advisor


John Fleming

Patient Advisor

Angela Frisina

Patient Advisor


Anita Gombos Hill

Patient Advisor

Bernice King

Patient Advisor, Patient Family CarePartner Leadership Network Co-Chair 

Mia LaRonde

Ruth Morris

Patient Advisor

photograph of joe pedulla

Bonnie Pataran

Patient Advisor

photograph of joe pedulla

Jodi Rock

Patient Advisor

Leila Ryan

Patient Advisor


Angie Tracz

Patient Advisor

Murray Walz

Patient Advisor, Patient Family CarePartner Leadership Network Co-Chair