Pulmonary infection in patients with severe fever with thrombocytopenia syndrome: A multicentre observational study

Co-infection in patients with severe fever with thrombocytopenia syndrome (SFTS) has been reported, posing a serious threat to survival and treatment. We aimed to systematically investigate the SFTS associated pulmonary infection, particularly invasive pulmonary fungal infection (IPFI). During April 2019 to October 2021, we conducted a multicentre observational study on adult hospitalized patients confirmed with SFTS from three tertiary hospital in central China. Demographic, clinical and laboratory data of patients were collected and re-assessed. A total of 443 patients (51.7% were male sex) were included for analysis with median age of 65-year-old. Among them, 190 (42.9%) patients met the criteria for pulmonary infection. Pulmonary infection was associated with shorter survival time (p < 0.0001 by log-rank test), and adjusted hazard ratio was 1.729 [95% confidence interval, 1.076-2.780] (p = 0.024). Age (odds ratio (OR) 1.040 [1.019-1.062], p < 0.001), time from onset to admission (OR 1.163 [1.070-1.264], p < 0.001), having severe status (OR 3.166 [2.020-4.962], p < 0.001) and symptoms of skin change (OR 2.361 [1.049-5.316], p < 0.001) at admission and receiving intravenous immunoglobin (OR 2.185 [1.337-3.569], p = 0.002) were independent risk factors for the occurrence of pulmonary infection. A total of 70 (15.8%) patients were defined as IPFI. Multivariate analysis showed that time from onset to admission (OR 1.117 [1.016-1.229], p = 0.022), severe status (OR 5.737 [3.054-10.779], p < 0.001), having smoking history (OR 3.178 [1.251-8.070], p = 0.015) and autoimmunity disease (OR 7.855 [1.632-37.796], p = 0.010), receiving intravenous immunoglobin (OR 3.270 [1.424-7.508], p = 0.005) were independent risk factors for the occurrence of IPFI. In SFTS patients with pulmonary infection, white blood count <2.09 × 10⁹ per L (OR 11.064 [3.708-33.012], p < 0.001) and CD3⁺ CD4⁺ T cell count <104.0 per μL (OR 10.429 [3.395-32.038], p < 0.001) could independently predict IPFI. This study showed the high prevalence and poor outcomes of pulmonary infection and IPFI in patients with SFTS. These findings highlighted the need for active surveillance of fungal pathogens and early antifungal treatment in patients with SFTS.