Nocardial infection
Nocardia asteroides, Nocardia brasiliensis.
Found worldwide in soil and decaying organic material
Access to humans33 - 50% immunocompromised Transplant (45%), long term use of steroids Lymphoma / leukemia, HIV, post splenectomy
Pathogenicity
Human defencesOpportunistic infection
DiagnosisSubacute or chronic abscess
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 abscessThe CNS is infected in about 1/3 of all cases. Nocardial Brain Abscess
Therapeutic strategy