Incidence of Chronic Pulmonary Aspergillosis in Patients with Suspected or Confirmed NTM and TB-A Population-Based Retrospective Cohort Study

Chronic pulmonary aspergillosis (CPA) is a severe and underdiagnosed pulmonary fungal infection with a significant overlap in symptoms and imaging findings of mycobacterium tuberculosis (TB) and non-tuberculous mycobacterium (NTM). Infection with TB or NTM is a predisposing underlying condition for CPA in approximately one-third of patients. A previously published study from Uganda showed increased incidence and complication rate of CPA with respect to pre-existing radiographic cavitation in a post-treatment TB population. The aim of this study was to investigate the incidence of CPA in a low-endemic population of confirmed or suspected TB and NTM patients. We manually reviewed 172 patients referred on suspicion or for treatment of TB or NTM at the Department of Respiratory Medicine, Odense University Hospital during the period of 1 January 2018 to 31 December 2020. We found no CPA amongst TB patients as opposed to an incidence of 8.2% (n = 4) in NTM-infected patients. We identified possible investigatory differences in Aspergillus blood sample screening protocols depending on NTM or TB, initiated at the Department of Respiratory Medicine at Odense University Hospital. A focused screening and investigatory protocol in NTM patients with persisting or developing symptoms is warranted in relation to suspected CPA.