Clinical Care Providers, HIV County Program

Johns Hopkins HIV Service County Program

Our team of HIV specialists is composed of physicians, nurse practitioners, physician assistants, nurses, and case managers who offer the most recent treatments and help you to manage your healthcare.

Clinical Care Providers and Staff

David Griffith, MD – Medical Director, Clinical Associate

David Griffith, MD received his MD from the University of Maryland. He completed a residency in combined internal medicine and pediatrics at the University of Rochester, followed by fellowships in Pediatric and Adult Infectious Diseases at Johns Hopkins University. He is board certified by the American Board of Internal Medicine and American Board of Pediatrics.

Iryne Zziwa-Kabenge-MSN-CRNP – Nurse Practitioner

Iryne Nakato Zziwa-Kabenge, CRNP graduated from the University of Maryland, School of Nursing with a BSN in 1997 and in 2008 attained a Masters in Nursing from Johns Hopkins University, School of Nursing. She joined Johns Hopkins University in 2008 doing work with sexual health at the Baltimore City Health Department from 2008-2012. In 2012, she joined the Johns Hopkins AIDS Service County program and currently provides HIV specialized care to patients enrolled in the County program. She is credentialed through the American Nurses Credentialing Center (ANCC) and with the American Academy of HIV Specialists.

Sarah Rives Gray, MPH, CRNP, FNP-BC – Nurse Practitioner

Sarah Rives Gray, CRNP, joined the HIV County Program in 2023. She has worked in a variety of capacities in HIV programs since 2007, and graduated from the Columbia University School of Nursing as a family nurse practitioner in 2012. She comes to the HIV County Program from the Baltimore City Health Department where she was from 2015-2023, most recently as the Medical Director for HIV/PrEP/HepC in the Sexual Health Clinics.

Emily Murrill, PA-C – Physician Assistant

Emily Murrill, PA-C, joined the HIV County Program in 2024. She graduated from Weill Cornell Graduate School of Medical Sciences PA Program in 2018 and has previously worked in primary care and oncology settings. Emily is also a provider of pre-exposure prophylaxis (PrEP) through Johns Hopkins, to prevent transmission of HIV and is working to expand PrEP access in Baltimore county and surrounding county areas.

Sheri Mancini, RN – Senior Clinical Nurse

Sheri Mancini, R.N. joined the Johns Hopkins AIDS service in 1988 as a clinic nurse. In 2000 she expanded her role to include nurse educator for the Project LINK adherence program. She became a member of the Johns Hopkins County Program in 2013.

Stephanie Bosley, RN – Clinical Nurse

Stephanie Bosley, RN, started her nursing career in 1997 as a staff nurse in the Cardiac ICU at Johns Hopkins Bayview Medical Center. Since then, she has worked in various specialties, including medical-surgical, oncology, telemetry, and public health nursing. She came to the Moore ID Clinic as a clinic nurse in 2012, and worked in the clinic as it became the John G. Bartlett Specialty Practice. She continued her work there until 2023, when she joined the Johns Hopkins HIV County Service Program.

Michelle Pollard, MEd, BSN, LC-ADC, CCM – Clinical Case Manager 

Michelle Pollard, CCM joined Johns Hopkins AIDS Service in 2015 as a Clinical Case Manager. She comes with over 25-years of extensive training / skills in nursing, human service, social work, mental health, substance abuse, and vocation. Her passion lies in client advocacy, ensuring every client has a voice / choice in their health care, resources to meet their medical / psychosocial goals, and to reduce barriers that interfere with communal stability. As a clinical case manager, she remains on a mission to end new HIV/AIDS diagnosis, stop transmission, and stop stigma through education, communication, and medical management.

Kereen (Candy) McCullough – Office Manager, Senior Clinical Program Coordinator 

Ms. McCullough received her Bachelor’s degree in Health Services Management from University of Maryland, University College. She is currently pursuing a Master’s degree in Health Care Management. Kereen joined the HIV/AIDS county program in 2003. She has over 21 years of experience with infectious diseases office management.

Pay a Bill

Johns Hopkins has simplified our billing statement. You will receive one bill for your care at Johns Hopkins Medicine. Questions? Call Customer Service, 1-855-662-3017

Online Payment

By Phone: 1-855-662-3017

By Mail: Mail you check or money order payable to Johns Hopkins Medicine, along with the coupon at the bottom of your statement.

OPAT Clinic Locations

Johns Hopkins Bayview Medical Center, Infectious Diseases Clinic
BMO – Blue Canopy, 01 Level
4940 Eastern Avenue Baltimore, MD 21224


Rockland Physician Practice at Greenspring Station
Johns Hopkins Falls Concourse
10751 Falls Road, Suite 412
Lutherville, MD  21093


John G. Bartlett Specialty Practice
The Park Building, Ground Floor
1717 E. Monument Street
Baltimore, MD  21205


Charitable Giving

The Michael Del Bianco Fund provides direct funding for HIV patient care needs not supported by other means, such as medications, housing, or other expenses.

Michael Del Bianco Fund

John Bartlett Specialty Practice Fund supports clinical activities for the entire ID practice, including patient and staff activities.

John Bartlett Specialty Practice Fund

Dr. John Bartlett HIV/AIDS Fund supports young trainees and junior faculty in the division, helping them transition to their independent careers.

Dr. John Bartlett HIV/AIDS Fund