2023-2024 Infectious Diseases Clinical Fellows


Mirian Vanesa Garcia Rivera

Mirian Vanesa Garcia Rivera, MD - Chief Fellow

I was born and raised in Lima, Peru. Our healthcare system is centralized and as such, all complicated cases from the Amazon Basin and the High Sierra areas were seen and managed in our capital. As a medical intern, I was versed in many tropical diseases and their complications. The desire to advance my medical education brought me to the USA. My journey included time in Pennsylvania, Vermont, New Hampshire, and New York. Early on I was actively involved in cultural advocacy, education to minority groups and working as part of the medical staff for a free clinic for underserved, uninsured, and foreigners. My residency program in Internal Medicine in Queens, NY afforded me the opportunity to continue my passion for Infectious Disease, serving a diverse population with multiple comorbidities from numerous nursing homes patients to the underserved, multicultural surrounding communities. We often managed patients with Candida Auris, disseminated tuberculosis, undiagnosed AIDS, septic shock and malaria. Good collaboration, communication, and leadership were vital to getting through my most challenging moments during the pandemic. I have had incredible opportunities to learn with peers and patients from a variety of cultures, languages, ethnicities, and nationalities that reshaped my perspective in life personally and professionally. In my free time I like to explore different cuisines, swim and play volleyball with family and friends. I chose the University of Colorado for its academic and global reputation in ID as well as its location in a vibrant city.

Nnamdi Nwafo, MD, MPH

Nnamdi Nwafo, MD, MPH

I attended medical school at University of Nigeria, then practiced in Nigeria for a time before moving to Brooklyn, NY, for Internal Medicine Residency training. After residency, I worked as a Hospitalist in South Dakota (Rapid City) and Colorado, obtaining a Master’s Degree in Public Health at University of Colorado along the way. The COVID pandemic played a major role in choosing this new step in my career, and I am excited to be back at University of Colorado for ID Fellowship. I have always enjoyed caring for acutely ill patients, and I have interests in sepsis and critical care. I also look forward to exploring the Transplant ID and ID Oncology fields. Outside work, I enjoy traveling with my family and seeing new places. I love sports and talk shows in sports, and I play lawn tennis and soccer when I get the chance. And I listen to audio books… everyday, every time (literally).

Chad McCormick, MD

Chad McCormick, MD


Zachary Cantor

Zachary Cantor, DO

My name is Zachary Cantor, I am from Detroit, Michigan. I went to medical school at Touro University Nevada and completed my residency at Detroit Medical Center/Wayne State University. I love all things ID but am particularly interested in HIV/primary care. I enjoy having continuity of care and seeing my patients' health improve over time. Outside of work, if the weather is nice, I'm almost certainly on the golf course. Otherwise, I love doing anything active and seeing live music. 

Braden Sciarra

Braden Sciarra, MD

I was born and raised in Southern Indiana and completed my undergraduate degree in chemistry at Butler University in Indianapolis, IN. After college I stayed in Indiana where I completed my medical training at Indiana University School of Medicine. While in medical school I had the opportunity to work closely with physician leaders within the Division of Infectious Diseases, and completed international health rotations in Eldoret, Kenya. Next I travelled to Milwaukee, WI to complete residency in Internal Medicine & Pediatrics. During my training I developed an interest in HIV medicine and improving access to care for persons living with HIV. In my spare time I enjoy hiking, travel, and exploring new restaurants and breweries. 

Sawyer Ricker

Sawyer Ricker, MD

I was raised in Texas and have traveled to most US states during trips with my family and friends, as well as for my professional medical life. I also have traveled to several oversea scenic/outdoor destinations such as New Zealand and Iceland, and I studied for medical school in Grenada. I enjoy staying active through outdoor activities such as hiking, kayaking, and swimming as well as through sports such as snowboarding, frisbee, and tennis. I also partake in a good amount of less adrenaline-fueled activities such as playing videogames and indulging in sci-fi/fantasy media (namely reading or TV). I have many other interests which include attending concers, history, playing electric guitar, and martial arts. Overall, I consider myself a well-rounded person with a broad range of interests. After my ID fellowship, I plan on pursuing a critical care fellowship to become ID/Crit certified. 

Maxwell Witt

Maxwell Witt, MD

I grew up in the San Francisco Bay Area. As the son of an ID Physician, I was exposed to the field at an early age. (Sorry, terrible pun). I studied public health as an undergrad at UC Berkeley, and I did research on the pertussis vaccine's effectiveness during the epidemic in 2009-10 as well as studies evaluating the effectiveness of Hepatitis C medications within the Kaiser system. Before medical school, I did a fellowship as an analyst with the Health Resources and Services Administration (HRSA) Division of Transplantation, where I focused on improving the use of marginal donated kidneys, but also helped with the division's response to Zika virus. I went to medical school at the University of Michigan and completed my residency at University of New Mexico. My academic interests include host-pathogen interactions and hospital epidemiology. I also have a lot of interest in vector borne disease. Outside of medicine, my interests include mechanical work (Vintage cars mainly) and aviation. I recently finished my pilot's license, after having refurbished a small plane as part of a flying club I started with a friend. 

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Infectious Diseases (SOM)

CU Anschutz

Research Complex II

12700 East 19th Avenue

Mail Stop B168

Aurora, CO 80045


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