Our dynamic team is a fusion of health educators, medical professionals, wellness coaches and travel enthusiasts, who are not only experts in their field, but passionate about using their skills and expertise to strengthen the global health workforce. 


Dr. Rasori, Medical Director

Phil Rasori, MD 

Dr. Rasori teaches and consults in the fields of international health and travel medicine. For the last twenty years, he has led accredited, wilderness medicine and travel medicine field seminars for physicians to all the continents including programs to Kenya, Tanzania, New Guinea, Peru, Costa Rica, Ecuador, India, Nepal, Bhutan, Brazil, Mexico, Guatemala, Thailand, Vietnam, and Antarctica.  He is a long time member of the Wilderness Medical Society and has lectured frequently at their national conferences since 1990.

For 18 years, Dr. Rasori taught travel medicine and international health as part of the Department of Family and Community Medicine at the University of California, San Francisco School of Medicine.

He is the current director of Global Survival International and the medical director of Village HopeCore International. He has been the medical director since l987.

MedTreks Owner

Ari Rasori, RN, FNP

Ari is a nurse practitioner passionate about wilderness and travel medicine. She has traveled extensively on six continents over the past 32 years, participated in several international health projects and guided on various international medical trips.  Ari is the director of Public Health Program Development at HopeCore and has founded the MedTreks Kenya program as a way to strengthen the training and collaboration for medical professionals interested in improving global health. She enjoys running annual trips to Kenya, bringing medical professionals from the US to do direct training and hands-on skills with the HopeCore medical staff. Ari has taught travel medicine and global health all over the world. She is an AWLS instructor and enjoys teaching courses in wilderness and travel medicine. She also loves leading yoga and surf retreats for medical professionals.  Ari Rasori is currently a nurse practitioner in the Emergency Department in Southern Oregon. She loves her job working with a wide spectrum of patients, but when she is not working or traveling, she enjoys hiking, skiing, camping, yoga, rafting, biking and spending time with friends in the outdoors.

Wilderness Medicine Instructor

Sheryl Olson, RN 

Sheryl Olson grew up in Wyoming and Colorado.  Instructed by her father, she gained a passion for being in the outdoors and fell in love with adventure.  Sheryl was a backpacking guide in the Colorado mountains for 10 summers.  After graduating from college, she practiced her nursing profession for over 40 years, including 10 years as an ICU/CCU nurse and 18 

years as  helicopter flight nurse.  Overlapping with her clinical career was her passion for educating others. For the past 25 years she has been a teacher/instructor of Wilderness Medicine and Wilderness Safety and Survival at conferences and on adventure trips world-wide.   She believes that education and adventure go hand in hand and has guided and instructed on treks to Everest Base Camp, Mt. Kilimanjaro, Mt. Blanc, Patagonia and other beautiful places in the world.  Rivers in Costa Rica, Chile, California, Oregon, and Montana are some of her favorite places to raft, kayak, and educate others who want to learn more about Wilderness Medicine! Sheryl makes her home in Manitou Springs, CO, and along with her husband Larry Moore, and together they continue to enjoy the outdoors of doors hiking, mountain biking, paddle-boarding, rafting, backpacking, and backcountry skiing.

Wilderness Medicine CME Instructor

Dr. Christopher Van Tilburg

Christopher Van Tilburg is an American physician, rescue mountaineer, and award-winning author of 11 books, including two previous mountain rescue memoirs. Dr. Van Tilburg works in the emergency room, in clinic, and at a ski resort at the base of Oregon’s legendary, lethal Mount Hood. He is

 medical director for four search and rescue teams, chair of Mountain Rescue Association’s Medical Committee, and a USA delegate to the International Commission for Alpine Rescue. He serves as the local Public Health Officer and Medical Examiner. He has worked as an expedition physician on six continents, as a cruise ship doctor, and as team leader on five humanitarian medical trips to Haiti.

From the Wilderness Medical Society, he received the Dian Simpkins Award for Service in 2011, the Haiti Humanitarian Research Award in 2013, and the Ice Axe Award for Service in 2014. He is emeritus editor of Travel Medicine News and emeritus editor of Wilderness Medicine Magazine.

Wilderness Medicine CME Faculty

Brad L. Bennett, PhD, Paramedic, FAWM, FACSM, Captain, Medical Service Corps, U.S. Navy (Ret)  

Dr. Bennett is an applied physiologist who spent 27 years in the U.S. Navy conducting biomedical research, development, and medical education & training of military operational personnel serving in austere environments.  He has researched and taught the prevention and treatment of environmental hazards such as heat, cold, altitude and undersea medicine. He trained as a Navy Department Deep Sea Diving Officer and is a Master Diver, PADI. He is an adjunct Professor and former Vice Chairman, Military and Emergency Medicine Department, F. Edward Hébert School of

Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland. He served as President, Wilderness Medical Society, and has served on the Committee on Tactical Combat Casualty Care, Dept of Defense since 2003. Currently Dr. Bennett serves as a Section Editor, Wilderness and Environmental Medicine journal, and writes a quarterly article on tactical (trauma) medicine and other articles for the Wilderness Medicine Magazine. He is an avid traveler, and a nature and underwater photographer. He currently resides on the York River in Virginia, and is often found boating and kayaking.

Lainey Yu MD

Lainey Yu, MD

Elaine (Lainey) Yu is a Bay Area native who grew up in the mountains and on the water. She found her passion for wilderness medicine during medical school and is currently living her dream as a wilderness medicine fellow at UCSD. When not working in the ED or teaching everyone around her about wilderness medicine, she can be found on a cliffside, in the mountains, or underwater. ⁠She is an AWLS instructor for MedTreks. 

Medical Spanish Faculty

Dr. Mila Rojas, Medical Spanish Faculty

Milagros Rojas is a medical doctor from Venezuela. She has been part of the Endocrine-Metabolic Research Center “Dr. Félix Gómez” for over nine years and her curiosity as a medical researcher has led her to become interested in numerous topics. Her work has been published in different peer-reviewed journals and she is especially interested in mental health and psychiatry. Mila is all about empowering others with knowledge, which has led her to work as a creator of continued education resources as well as content designed for the general public. Her curiosity doesn’t end with medicine, she has traveled through the Americas, getting to know the people and medical practices in countries such as Colombia, Argentina, and Costa Rica. She loves immersing herself in new cultures and exploring the beautiful landscapes as well as trying delicious food everywhere she goes.

MedTreks Faculty

Deepika Goyal MedTreks Faculty

Deepika Goyal, RN, FNP, PHD, MedTreks Kenya Faculty 

Dr. Goyal obtained a Bachelor of Science in Nursing, Master of Science in Nursing, and her Family Nurse Practitioner Certificate at San Jose State University (SJSU). She obtained a PhD in Nursing from the University of California, San Francisco. She has been working as a family nurse practitioner since 2002 and teaching at SJSU since 2007. Dr. Goyal is a nurse educator, family nurse practitioner, and researcher who is passionate about maternal child health, in particular, mental health among underrepresented and minority women

Dr. Goyal’s research continues to add to the postpartum mental health narrative regarding minority women’s experience, mental health help-seeking behavior, and preferred management of perinatal depression. Her research findings provide clinicians with the information they need to provide culturally-informed care in an effort to promote optimal maternal-child well-being outcomes. Dr. Goyal continues to be an instrumental part of our clinical education team, providing ongoing presentations and hands-on skills training to our staff in Kenya.

Jan Zachry

Jan Zachry, MBA, RN, MedTreks Kenya Faculty

Jan Zachry is the vice president, chief operations executive/administrator for Scripps Memorial Hospital Encinitas. She is a registered nurse with an MBA and more than 20 years of progressive management responsibility for multiple clinical, diagnostic and ancillary services, including nursing, cardiology, emergency, and radiology for tertiary healthcare systems and community hospitals. For the past three years, Jan has joined MedTreks as faculty for MedTreks Kenya working with Village HopeCore International in Kenya. She has been instrumental in training the HopeCore staff on topics such as leadership, change management, healthcare delivery, well-child assessments, first aid and care of the newborn. Previously, Jan Zachry volunteered her time and expertise in Nepal Health Care project where she consulted on the creation of an intensive care unit for a government hospital located in a densely populated agricultural community outside Kathmandu. She trained 45 physicians and nurses in critical care protocols. Jan continues to volunteer her time and expertise as MedTreks Kenya faculty.

Debi Solberg, RN. MedTreks Kenya Faculty 

Debi is excited to join MedTreks Kenya as a volunteer faculty, sharing her background in teaching, training and working in high intensity hospitals. Debi’s experience as an RN for 40+ years includes working in the ED, Trauma ICU, Burn ICU, PACU, and as a Flight nurse. She is experienced with emergency management and operations, having worked with the Washington-1 Disaster Medical Assistance Team for nearly 30 years where she was the Administrative Officer and chief RN, deploying to multiple natural manmade disasters, including 9/11. Debi has an immense love of nursing and international travel which came about after volunteer trips to Peru and Nepal. Since then, she’s received her Master’s in Nursing, and has continued teaching ACLS and CPR as well as finding volunteer opportunities whenever possible. When not working, Debi is taking drum lessons, rowing when possible, and traveling. She is grateful for the continued opportunity to work with MedTreks International.

Anne Riitho

Anne Riitho

MedTreks Kenya Faculty 

Anne is deeply committed to supporting vulnerable populations and has a decade of experience living and working in Kenya. Anne was awarded her Master’s degree in Health, Community and Development from the London School of Economics, where she presented a thesis on factors that facilitate men’s use of HIV testing and treatment services in Nairobi, Kenya. Anne has previous experience working in the developing world with grassroots NGOs, in Boston working for an international public health consulting organization, and still actively supports a Kenyan children’s home. She enjoys working with people to improve the health in their communities, as well as developing systems within organizations to improve program implementation. Anne joined Village HopeCore International as a Global Public Health Fellow in 2014 and worked in this role until taking on the role of Managing Director in 2016. In 2017, Anne transitioned to the Director of Program Development for HopeCore. Anne is passionate about sharing her love of travel and Kenya with others and currently resides in Nairobi.

Jenny Dengler MedTreks Faculty

Jennifer Dengler, PA-C, MedTreks Kenya Faculty 

Currently a physician assistant in Southern Oregon working in Urgent Care with a background in Family Practice and Emergency Medicine. Jennifer is an officer in the United States Army Reserve where she is commissioned as a physician assistant. Jennifer is currently working on her Doctorate in Global Health Sciences through Nova Southeastern in Florida, has a Masters of Science in Cellular Molecular Nutrition from the University of North Carolina at Greensboro, and completed her Physician Assistant Studies from Pennsylvania College of Technology. Jennifer has a passion for wilderness travel, improving health care in developing nations while creating a sustainable infrastructure, and disaster medicine. When she has time she volunteers with Team Rubicon and enjoys travel with her family to explore nature and cultures of the world.

Winnie Wanjiru MedTreks Faculty

Winnie Wanjiru L Njuguna, MedTreks Kenya Faculty  

Winnie Wanjiru L Njuguna is an Advanced Paediatric Nurse Practitioner with a Masters Degree (Cum Laude) in Child Nursing from the University of Cape Town, South Africa. She works at the Gertrude’s Children’s Hospital, Kenya- Oncology unit and is a member of the Quality and Patient Safety team. She has over 15years of experience in pediatric Nursing, Accident and Emergency department and pediatric oncology. Winnie is passionate about improving the outcomes of children with cancer in the region through education of the clinical workforce and evidenced based practice. Winnie is a certified instructor for resuscitation courses such as Emergency Assessment and Treatment plus Admission care (ETAT+), Pediatric Immediate Life Support (PILs) and Newborn Life Support. She strives to ensure clinicians are equipped with the knowledge and skills for early recognition and prompt treatment of the seriously ill newborn and child.

Adventure Guide

Lynn Sullivan, MedTreks Kenya Faculty 

Lynn has been an adventurer all of her life, always looking to visit and experience the next “special place on this planet”.  She has traveled to more than 28 countries and still considers herself addicted to travel and adventure.  She had 11 years of emergency nursing experience that began in Compton, Los Angeles before she packed up all her worldly possessions and traveled around the world for a year.  She returned to the US and studied for her MS in nursing to become an FNP and has practiced in emergency medicine since graduating in 2005.  She has a passion for teaching and enjoys combining her love of travel with her emergency medicine skills.  She has a 15-year-old son and a life partner that she hopes to continue to travel the world with.

Yoga & Wellness Instructors

Erin O'Brien

Erin O’Brien, MedTreks Wellness Coach, Yoga Instructor & Retreat Leader 

Erin brings over a decade of experience teaching and leading experiential education. She completed a Masters degree in Education and has received over 500 hours of advanced training in yoga. When she is not leading retreats, you can find Erin snuggling her sweet baby boy Leo, teaching yoga, writing, designing websites, enjoying outdoor adventures & tending to her thriving garden.

Yoga Instructor

Angie Hanchett, RN. MedTreks Kenya Faculty, Yoga Instructor & Retreat Leader

Her passion for yoga began in the Bikram Yoga classroom 15 years ago. She has completed extensive workshops and participated in Bishnu Charan Gosh yoga cups. Her teaching certification is from Soma Yoga Institute and derives alignment concepts from the Anusara tradition. Angie strives to offer a well rounded practice that satisfies athletic cravings, mystical curiosities, and safe postural alignment in the body. Her personal yoga practice is the sacred cornerstone to her career as an emergency room nurse. She lives for ocean activities and started her passion for public safety with the San Diego Lifeguards. She loves teaching CPR/First Aid and learning about the cultural perspectives of healthcare in global settings. Her personal mission is to inspire wellness by empowering people with healthcare education. She is currently on a sabbatical sailing a 30 foot sailboat with her boyfriend in Baja California.

Sayulita Gold Yoga Instructor

Janalyn Rose, Yoga Instructor, Retreat Leader

Janalyn Rose has made it her life’s work to be a constant student and teacher of the ocean, the arts and yogic practice. Working as a lifeguard for 13 years, Janalyn fell in love with surfing and now offers a unique surf coaching experience incorporating oceanography and elements of surf therapy. Beginning her journey with Yoga as a result of injury, Janalyn has been teaching yoga for over 15 years specializing in yoga therapy and cultivating joy. A daughter of two Kodak lifers, Janalyn is passionate about capturing her ocean and yoga students as they are learning and evolving – as a photographer/videographer she strives to bring out confidence and ease in all of her subjects. Sayulita has been home for five years inspiring and bringing all of these passions under one umbrella – Sayulita Gold.



Garrett Means Garrett Means, EMT, CPT-1, MedTreks Kenya Global Health Intern

Garrett is passionate about connecting with local cultures to find ways that sustainably empower their health and maximize their resources. Having volunteered to serve impoverished communities throughout his life, he decided to transition away from his career in construction to find his calling in caring for the underserved. After working in global health NGO’s and local medical clinics with several disadvantaged communities across Tanzania, he was inspired to get a degree in neurobiology, physiology, and behavior while studying global health and poverty alleviation at UC Davis. He now works as an ER Tech in a rural Californian community while applying to applied psychology and global health programs to expand his capacity to serve. He is also working with the wonderful experts here at Village Hopecore and MedTreks on fulfilling their educational vision. He works both in-country and remotely with the team in Chogoria on creating and expanding our community health volunteer training program. Garrett spent 6 weeks in Chogoria working with MedTreks and HopeCore in 2019 and was instrumental in designing and implementing the online training program for our Community Health Workers at HopeCore. He continues to be part of our educational team and dedicates his internship time to creating improved health educational technologies and curriculum both online and in person. 

Britt UrbanBritt Urban, RN, MSN-S, MedTreks Kenya Intern  

Britt is a registered nurse and doula currently in her master’s program at the University of California at San Francisco (UCSF) for midwifery. Britt is an experienced birth professional passionate about each mama and partner having a supported birth and beyond. She works with expecting families and community from prenatal states to the postnatal journey. Britt’s passion is to support parents in creating an empowered and positive whole birth experience.

Britt holds an undergraduate degree from UC Santa Barbara, she has lived abroad twice, managed a non-profit in San Francisco and spent two years sailing around the world. When she returned home back to the Bay Area, California, she decided to settle into her passion for mothers and babies and became a doula in 2013. She runs her own business Urban Doula Collective in the Bay Area, supporting families throughout the entire birthing process. Britt joined our MedTreks team in the summer of 2019. She continues her support for MedTreks Kenya by helping to provide ongoing training opportunities for our staff in Kenya that focus specifically on maternal and newborn care.



MedTreks partners with Rasori Expeditions for several of the adventure travel & non-medical cultural trips. Rasori Expeditions is a recognized authority in international travel specializing in cultural experiences, socially responsible travel, and global journeys for the last 30 years. Many of the MedTreks trips are designed in collaboration with Rasori Expeditions.

Explore Egypt
Medical volunteer in Kenya meets with a patient at our clinic

MedTreks International has partnered with Village HopeCore International (HopeCore) for over 20 years, and MedTreks Kenya is the result of this fantastic partnership!

Our work and 20-year partnership with Village HopeCore International in Kenya has allowed us to assess our interventions continually. We regularly work with the staff in Kenya to collaborate on the most effective strategies and assistance our MedTreks teams can offer. Through this, we are assured that our programs and our interventions will be sustainable. For our programs to run well, we make sure to involve our Kenyan teams every step of the way.

Learn More

Partnering In

Adventure Travel & Global Health Experiences

MedTreks has 30 years of bringing groups and travelers around the world to experience cross-cultural medicine and witness the diversity of life in different corners of the planet. Through the years we have developed lasting friendships with our guides and tour operators. We partner with local outfitters who align with our responsible travel guidelines and regularly evaluate our trips to ensure they are executed within our sustainability principles.

Alaska Tatshenshini Expedition

Momentum River Expeditions

Our partners for river trips in California, Alaska & Idaho.
Medical Spanish Costa Rica

Nosara Spanish Institute

The Medical Spanish facility we partner with in Costa Rica
Mexico Retreat MedTreks

Sayulita Gold

MedTreks partners with retreat leader & host, Janalyn Rose of Sayulita Gold for the MedTreks Mexico Yoga Retreats

Boston College

Community Partner, Lynch School of Education and Development

All of our trips are designed with the goal of sustainability and building local capacity. At MedTreks we continually seek to identify ways in which our programs and trips can further support the cultures and communities where we run our trips and our courses.

We partner with local outfitters, tour operators and programs who align with our global health & responsible travel principles.

Interested in partnering with us for a trip, retreat or course?  We would love to learn more about what you do and where you work!

Work with Us
Humanitarian Medicine Team

“Alone we can do so little, together we can do so much”

~ Helen Keller