Johns Hopkins All Children's Hospital

Meet Our Team

The International Patient Services team provides patients and families with personalized care tailored to their needs.

Roberto Sosa, M.D. Neonatology

Dr. Sosa was named medical director of Johns Hopkins All Children’s International Program in 2013 after nearly 40 years as the leader of the hospital’s regional neonatology program. He has helped develop medical education and research projects in Latin America, including his native Guatemala, and participates in international conferences to provide education and foster clinical relationships with children’s health providers around the globe.
View Roberto’s Bio

Yadira Nuñez

Yadira Nuñez International Programs Director

Yadira Nuñez manages the Johns Hopkins All Children’s international patient services team, and supports Johns Hopkins International’s relationship management efforts in Latin America, the Caribbean and the Middle East. She joined the hospital staff in 2019. Previously, Yadira was the international business development and health care alliance manager focused on Latin America at Cook Children's Health Care system. She has a bachelor’s degree in business administration with a concentration in international business for Latin America from the University of Texas at Arlington.


Cristina Bozenhardt

Cristina Bozenhardt Senior International Care Coordinator

Cristina Bozenhardt has been with the Johns Hopkins All Children's International Program since 2013. She has extensive experience in case management and social services, and has worked with international and domestic patients throughout the Tampa Bay area. Cristina has lived and volunteered in several countries, making her very aware of different cultural needs and practices.


Nahed Dajani

Nahed Dajani Senior International Care Coordinator

Nahed Dajani has been an employee of Johns Hopkins All Children’s Hospital since 2007, and has extensive experience in health care administration, case management and marketing in both the United States and the Middle East. A native of Egypt, Nahed lived in both Egypt and Kuwait for many years. She is fluent in Arabic and is very familiar with the cultures and traditions of the Middle East North Africa (MENA) area.


Diana Retzer

Diana Retzer International Financial Coordinator

Diana Retzer has been an employee with Johns Hopkins All Children’s Hospital since 2002. She has extensive experience with the health insurance process, and has worked in patient access, admitting, registration and financial counseling. She brings invaluable knowledge of Johns Hopkins All Children’s internal culture and processes, which helps her to effectively assist international patient families in navigating insurance, billing and other financial information.