Frequency of Culture-proven Bacterial Infection and Radiographic Pneumonia in Pediatric Heart Transplant Recipients

Background: Infection is a leading cause of death after pediatric heart transplants (PHTs). Understanding of common pathogens is needed to guide testing strategies and empiric antibiotic use.

Methods: We conducted a 3-center retrospective study of PHT recipients ≤18 years old presenting to cardiology clinics or emergency departments (EDs) from 2010 to 2018 for evaluation of suspected infections within 2 years of transplant. Suspected infection was defined as (1) chief complaint of fever and/or (2) visit temperature ≥38 °C, and/or (3) blood culture obtained. The primary outcome was a culture-proven bacterial infection or radiographic pneumonia. Secondary outcomes included fluid-refractory septic shock, antibiotic resistance, respiratory viral infections and diagnostic testing. The unit of analysis was the encounter.

Results: Of 193 children meeting inclusion criteria, 108 (56.0%) had ≥1 visit for suspected infection. Of 258 total encounters, 88.8% occurred in the ED and 52.8% resulted in admission. Culture-proven bacterial infection (4.3%) or radiographic pneumonia (11.6%) was documented in 15.5% of encounters; 1 (0.4%) had bacteremia. Antibiotics were administered in 33.7% of encounters, and 3 (1.2%) required inotropic support for fluid-refractory shock. Viral testing was sent in 162 encounters (62.8%), and 52% detected viral pathogens. Clinical characteristics and routinely obtained laboratory testing were similar in encounters with and without culture-proven bacterial infection or radiographic pneumonia.

Conclusions: Over 15% of PHT recipients presenting with suspected infection had culture-proven bacterial infection or radiographic pneumonia. No single clinical or laboratory variable accurately identified these patients, potentially due to variability in testing. A more standardized approach could augment diagnostic and antimicrobial stewardship.