Outbreak of invasive aspergillosis in heart transplant recipients: The role of screening computed tomography scans in asymptomatic patients and universal antifungal prophylaxis.

BACKGROUND: Delays in diagnosing pulmonary invasive aspergillosis (IA), a significant cause of morbidity and mortality among heart transplant recipients (HTRs), may impact on successful treatment. The appropriate screening strategy for IA in these patients remains undefined, particularly in the setting of nosocomial outbreaks. We describe our experience employing chest computed tomography (CT) scans as a screening method for IA. In addition, we comment on antimicrobial prophylaxis in HTRs in the setting of an outbreak.

METHODS: Screening CT scans of the chest and serum galactomannan (GM) were performed in HTRs during an outbreak that followed the index case of IA. Abnormal CT findings prompted a diagnostic workup. Antimicrobial prophylaxis for new transplants recipients included intravenous micafungin while hospitalized, followed by outpatient inhaled amphotericin B for up to 3 months.

RESULTS: During a 10-month period, five cases of IA were identified among HTRs. Two additional asymptomatic patients were diagnosed with IA among 15 asymptomatic HTRs who underwent screening chest CT scans. Among the five cases of IA in HTRs, two of five (40%) had a partial response and the other three failed voriconazole therapy. Complete response to voriconazole therapy assessed at 12 weeks was achieved in these two asymptomatic HTRs diagnosed via screening CTs. Serum GM was positive only in one of the symptomatic cases. The negative predictive value of CT scans was 100% (95% confidence interval, 71.5%-100%).

CONCLUSIONS: In an outbreak setting, screening CT scans of the chest may aid in early detection of asymptomatic HTRs with IA and improve outcome.