Introduction: Influenza is usually a self-limited illness in healthy adults, but influenza virus infection can cause severe illness in certain high-risk groups like solid organ transplant recipients (SOTR). We aimed to evaluate the clinical results of SOTR with influenza admitted to the intensive care unit (ICU).
Materials and Methods: Data of SOTR with influenza related ICU admission in a single center were analyzed between May 2016 to September 2019 retrospectively. Demographics, type of influenza virus, treatment duration, complications and mortality in ICU were assessed.
Results: A total of 115 cases of influenza with SOTR were hospitalized. Out of these 17, %35 were female and 1 was a pediatric patient admitted to ICU due to acute respiratory failure. The median age of 17 patients consisting of 11 kidney and 6 liver recipients was 41 years (range 12-81years). Seven (41%) patients were in chronic rejection. Mean APACHE II and SOFA scores at ICU admission were 17±7.1 and 6.6±2.0 respectively. Except for one patient (<3 months), all were infected with influenza in the late period (>1 year) after transplantation. While real-time polymerase chain reaction (PCR) test was positive in 13 (76.5%) patients, other 4 (23.5%) were diagnosed with rapid antigen testing. The subtypes of influenza were revealed as: 2 (11.8%) influenza A, 13 (76.5%) influenza B, 2 (11.8%) influenza A and B. Simultaneous respiratory syncytial virus (RSV) positivity was seen in 9 SOTR (1 influenza A, 1 influenza A and B, 7 influenza B). Five patients were isolated due to extensively drug-resistant infections. Oseltamivir treatment was applied 5 or 10 days according to disease severity which was 58.8% and 41.2% respectively. Three (17.6%) patients received invasive mechanical ventilation and 10 (58.8%) high flow oxygen therapy for acute respiratory failure. Eight (47.0%) had vasopressor support due to shock and 7 (41.1%) patients received renal replacement therapy. The length of ICU and hospital stay were as 5.6±7.6 days and 18.2±19.0 days respectively. According to APACHE II scoring, mean predicted mortality was 17.0%, while 2 (11.7%) actual deaths were observed.
Discussion: Most of the patients admitted to ICU for influenza were infected after the first year. Influenza B subtype was more common than A, and this was high in RSV accompaniment.
Conclusion: Our study highlightes that, when the symptoms of influenza appear in high risk groups like solid organ transplant recipients, the early initiation of antiviral therapy can be a significantly lifesaving approach.