The bidirectional butterfly effect reshaping patient care

Marisella Maribel Pillaca Horna, M.D., a pulmonologist from Peru, traveled to UAB as the first-ever physician in the Cassell Family Bidirectional Training Program. What she found here, and what she left behind, is already changing medicine on both sides of the world.

The X-ray machine was broken, again.

For Pillaca Horna, that sentence was not a crisis. It was Tuesday. During her pulmonology fellowship at a public hospital in Lima, Peru, she had grown accustomed to the absence: no timely imaging, rationed CT scans, outpatient cases waiting two to four months for a slot. Patients with suspected lung cancer or post-tuberculosis complications simply held on, because in the public health system, the pulmonology clinic always came last.

"When time is life," she said, "that can really change everything for a patient."

Faced with that reality, she did not complain. She problem-solved. And that instinct is exactly what the UAB Mary Heersink Institute for Global Health (MHIGH) was looking for.

The first of her kind

Pillaca Horna arrived at UAB as the inaugural physician participant in the Cassell Bidirectional Training Program, a collaboration between MHIGH and Socios en Salud, one of the most respected global health organizations working across South America. The program is built on a simple but radical premise: both institutions have something irreplaceable to teach the other.

"UAB has sent residents to Peru in the past to work alongside our teams on tuberculosis," she explains. "This year, they tried the opposite. I am the first one to arrive."

She says it with quiet pride. Selected through her work with Partners in Health, where she has spent her career building pulmonary rehabilitation programs for post-tuberculosis patients, Pillaca Horna brought to UAB a depth of clinical experience that cannot be replicated in a resource-rich environment. Peru carries one of the highest TB burdens in Latin America, and she has built her career around the patients left in its wake.

The investment that changed everything

Before her fellowship ended, Pillaca Horna made a decision that her colleagues would talk about for years. Frustrated by the daily battle for imaging access, she used her own money to purchase a Butterfly iQ, a handheld point-of-care ultrasound device smaller than a TV remote.

It was not a simple transition. Most of her attendings had never used point-of-care ultrasound, and introducing a new diagnostic paradigm meant navigating institutional skepticism alongside a full clinical workload. She navigated it anyway.

"Now, I use the ultrasound just like a stethoscope," she says. "Every day."

That sentence is worth sitting with. It speaks to a philosophy of care that is both profoundly practical and quietly visionary: meet the patient where they are, with whatever you have, and make it work.

Wide-eyed in the bronch lab

At UAB, Pillaca Horna moved through the institution like someone who came to see everything and intended to miss nothing. In just a few weeks, she rotated through the asthma, COPD, bronchiectasis, ILD, and interventional pulmonology clinics, and on free mornings, she sought out attendings and asked to join their rounds.

In the bronchoscopy lab in Jefferson Tower, she watched a robotic bronchoscopy procedure in real time, with a pathology team present. A level of integration that does not exist at her home institution.

"In every bronch lab here, you can have a CT during the procedure. In my country, I have access to one CT in the entire hospital. For me, that was... I mean, it was just unbelievable."

She also spent time with UAB's biomedical research team preparing for the American Thoracic Society conference and developing novel tools for early diagnosis of lung disease. The word "wow" came up more than once. Not as performance. As the genuine response of a clinician who has spent years mastering the art of doing more with less, I suddenly stand at the frontier of what more can look like.

What UAB can learn from Lima

The bidirectional nature of this program is not philosophical. It is clinical. When imaging is always available, pattern recognition and physical exam skills can atrophy. When every specialist is down the hall, integrative reasoning under pressure can go underdeveloped.

Pillaca Horna has spent her entire career sharpening exactly those capacities. She can anchor a diagnosis in physical findings when machines are unavailable. She can triage imaging decisions when access is rationed and time is short. She has built pulmonary rehabilitation programs from the ground up with minimal infrastructure and maximum community need.

For UAB faculty and trainees, working alongside her offers a window into a dimension of medicine that textbooks cannot illuminate: the ingenuity, resilience, and patient-centered commitment that emerge when ordering another scan simply is not an option.

Carrying it home

If you ask Pillaca Horna what she is taking back to Peru, and the list comes fast: multidisciplinary care models, advanced bronchoscopy techniques, structured clinical protocols, a culture of research woven into daily practice. She is already envisioning a future where point-of-care ultrasound, the tool she championed alone in Lima, becomes standard in pulmonology departments across the country.

"Having portable technology can improve bedside evaluations and clinical decision-making in settings where resources are limited," she says. "I see it as an investment in bringing more accessible diagnostic tools to my patients."

By the end of her rotation, she will return to Lima with new knowledge, new connections, and demonstrated proof that the exchange worked. That a physician trained in scarcity and one trained in abundance can meet in the middle and both come away richer.

The bidirectional aspect of the Cassell Training Program is still young. Pillaca Horna is its first participant. But if she is any indication of what this partnership can produce, the learning on both sides has barely begun.

Learn more about the program

UAB Mary Heersink Institute for Global Health
Cassell Family Bidirectional Training Program

Since a tuberculosis outbreak in Carabayllo in 1994, Socios En Salud has worked to expand access to TB treatment, including multidrug-resistant disease, reporting cure rates among the highest globally.

The Cassell Family Training Program connects UAB trainees with this work through two- to four-week rotations focused on maternal and child health, HIV, addiction medicine, and post-tuberculosis lung disease. The program covers travel, lodging, and fieldwork expenses for selected fellows fluent in English and Spanish.

Learn more about the program →