2024 Volume 52 Issue 2 Pages 19-26
Nocardia are actinomycetes species that primarily causes infections of the lungs and skin. We investigated 25 cases of Nocardia infection diagnosed at St. Marianna University Yokohama Seibu Hospital between November 2005 and March 2019. Sixteen patients（64%）were men, and 22 were aged 70 years or older（median age 76 years）. The sites of infection were in the lungs only in 20 cases, the lungs and pleural effusion in 2, bronchi in 1, and the lungs and urinary tract in 1; the remaining case showed systemic dissemination. The underlying diseases included cancer in 2 cases, collagen disease in 5, hematologic disease in 6, and other respiratory disease in 15; no underlying disease was identified in the remaining 3 cases. There were cases with multiple underlying diseases. Common findings on chest CT were nodules, consolidation, cavities, and bronchiectasis.
Among the 15 patients who received antibiotics, 8 recovered from infection and another relapsed after showing improvement. The treatment outcome is unknown for the remaining 7 patients due to transferring to other hospitals. Although 9 of the 25（36%）patients died, none died due to Nocardia infection. In this study, Nocardia infection was more prevalent among the elderly and men, and among those with underlying diseases. It is difficult to identify by imaging findings, so it is important to remember Nocardia as a potential cause of opportunistic infection and to perform culture tests.
