In the United States an estimated 500-1,000 new cases of Nocardia infection occur annually. An estimated 10%-15% of these patients also have HIV infection.
Severely immunocompromised persons (e.g., persons with malignancy, connective tissue disorders, bone marrow or solid organ transplantation, high-dose corticosteroid use, or HIV infection), alcoholism or pulmonary alveolar proteinosis, and males (ratio male:female = 3:1)
80% of the cases of nocardiosis show clinical features of invasive pulmonary infection, disseminated disease, or brain abscess; 20% show signs of cellulitis. In the United States an estimated 500 - 1,000 new cases of nocardiosis infection occur annually.