The Epidemiological Trends of Opportunistic Infections Among Liver Transplant Recipients: A Population-Based Study

Introduction: Orthotopic liver transplantation (OLT) is a standard life-saving procedure for treating end-stage liver disease ESLD. The success of the OLT may be limited by opportunistic infectious complications. In this study, we aim to explore the epidemiological patterns of common opportunistic infections among OLT recipients. Methods: The data were obtained using a validated, large, multicenter database (Explorys Inc, Cleveland, OH, USA), an aggregate of pooled outpatient and inpatient records of 26 different healthcare systems, consisting of a total of 360 hospitals in the United States, and utilizing Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) for coding. A cohort of patients who underwent OLT was identified between 1999-2022. We measured the incidence rates of common opportunistic bacterial, viral, fungal, and parasitic infections and described the age-, gender- and race-based distribution. Associated conditions were also reported. For all analyses, a 2-sided P value of < 0.05 was considered statistically significant. Results: Among the 69,502,120 adult individuals in the database, 28,740 (4.1%) underwent OLT. Within the cohort, patients were more likely to be elderly, male, and Caucasian, Table 1. The most common opportunistic infections were cytomegalovirus (CMV), Candida, and Clostridium Difficile (C. Diff). Varicella-Zoster Virus (VZV), Methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. Conclusion: Viral and fungal (primarily candida) infections are the most common opportunistic infections, with drug-resistant bacterial infections emerging as a significant concern. Pre-transplant serological identification of donors and recipients is critical for infection risk assessment and the determination of antimicrobial prophylaxis. Therefore, it is crucial for liver transplant centers to devise robust strategies to mitigate such infections, using predicted infection risk, local antimicrobial resistance patterns, and judicious timing of prophylaxis. The further understanding and advancement of preventive, diagnostic, and therapeutic methods could markedly improve both the quality of life and survival rates of OLT recipients. Table 1. - The incidence of opportunistic infections following liver transplantation Opportunistic Infections Incidence rate Viral HHV-5 (CMV) 7.1% HHV-3 (VZV) 3.0% HBV 2.6% HCV 2.3% HSV 1.8% HHV-4 (EBV) 1.3% HIV 0.9% HAV 0.2% HTLV 0.2% West Nile Virus < 0.1% Fungal Candida 6.3% Aspergillus 0.7% Cryptococcus 0.3% Pneumocystis 0.2% Histoplasmosis 0.2% Coccidioidomycosis < 0.1% Nocardia < 0.1% Toxoplasma < 0.1% Bacterial Clostridium difficile 3.9% Methicillin-resistant Staphylococcus aureus (MRSA) 2.6% Pseudomonas 2.1% Streptococcus pyogenes 0.4% Syphilis 0.4% Tuberculosis 0.4% Streptococcus agalactiae 0.3% Vancomycin-resistant Enterococci (VRE) 0.3%