Nocardial infection

Nocardia asteroides, Nocardia brasiliensis.

Found worldwide in soil and decaying organic material 

Access to humans Susceptible hosts

33 - 50% immunocompromised  Transplant (45%), long term use of steroids Lymphoma / leukemia, HIV, post splenectomy 

Pathogenicity

Opportunistic infection

Human defences Pathology

 Subacute or chronic abscess 

Diagnosis Clinical infections 

Lungs most common site of involvement -- 70-80% of cases Pulmonary nocardiosis -- subacute (may have acute onset in immunocompromised hosts) cough, sputum, fever , anorexia , wt. loss CXR >> variable infiltrates , nodules, cavities 

However, dissemination to nearly every organ has been reported i.e., kidney, bone, muscle, peritonitis, endocarditis 
Extrapulmonary dissemination typically presents as subacute or chronic abscess 

The CNS is infected in about 1/3 of all cases. Nocardial Brain Abscess 

Therapeutic strategy

Prevention