Epidemiology of chronic pulmonary aspergillosis: A nationwide descriptive study

Background: Chronic pulmonary aspergillosis (CPA) has recently gained attention owing to its substantial health burden. However, the precise epidemiology and prognosis of the disease are still unclear due to the lack of a nationwide descriptive analysis. This study aimed to elucidate the epidemiology of patients with CPA and to investigate their prognosis.

Methods: Using a national administrative database covering >99% of the population in Japan, we calculated the nationwide incidence and prevalence of CPA from 2016 to 2022. Additionally, we clarified the survival rate of patients diagnosed with CPA and identified independent prognostic factors using multivariate Cox proportional hazard analysis.

Results: During the study period, while the prevalence of CPA remained stable at 9.0-9.5 per 100,000 persons, its incidence declined to 2.1 from 3.5 per 100,000 person-years. The 1-, 3-, and 5-year survival rates were 65%, 48%, and 41%, respectively. During the year of CPA onset, approximately 50% of patients received oral corticosteroids (OCS) at least once, while about 30% underwent frequent OCS treatment (≥4 times per year) within the same timeframe. Increased mortality was independently associated with older age (>65 years) (hazard ratio [HR], 2.65; 95% confidence interval (CI), 2.54-2.77), males (1.24; 1.20-1.29), a history of chronic obstructive pulmonary disease (1.05; 1.02-1.09), lung cancer (1.12; 1.06-1.18); and ILD (1.19; 1.14-1.24); and frequent OCS use (1.13; 1.09-1.17). Conversely, decreased mortality was associated with a history of tuberculosis (HR, 0.81; 95% CI, 0.76-0.86), non-tuberculous mycobacteria (0.91; 0.86-0.96), and other chronic pulmonary diseases (0.89; 0.85-0.92).

Conclusions: The incidence of CPA decreased over the past decade, although the prevalence was stable and much higher than that in European countries. Moreover, the patients' prognosis was poor. Physicians should be vigilant about CPA onset in patients with specific high-risk underlying pulmonary conditions.