Epidemiology

Etiology

Pathogen: Nocardia species (ubiquitous in soil worldwide)
- Reservoir: soil
- Gram positive with branching filaments
- Aerobe
- Weakly acid-fast staining (Ziehl-Neelsen stain) c
- Catalase positive
Risk factors
- Immunocompromise (e.g., due to HIV infection, organ transplant, glucocorticoid therapy, recent chemotherapy, diabetes mellitus)

Risk group: immunocompromised individuals
Clinical features
- Constitutional: fever, weight loss, anorexia, night sweats
- Respiratory (recurrent pneumonia): productive cough, dyspnea, pleuritic chest pain
- Pulmonary nocardiosis symptoms such as fever, chills, and weight loss are often mistaken for tuberculosis

First-line Tx:
- TMP-SMX high-dose (15-20 mg/kg/day of TMP component, IV or PO depending on severity). c
Severe, Disseminated, or CNS Disease:
- Combination therapy: TMP-SMX + Amikacin AND/OR a Carbapenem (e.g., Imipenem or Meropenem).
Duration of Therapy:
- Cutaneous: 3 months.
- Pulmonary: At least 6 months (immunocompetent).
- Immunocompromised or CNS disease: At least 12 months to prevent relapse.
Surgical Management:
- Drainage/resection of large empyemas or brain abscesses not responding to medical Tx.

tags	—
aliases	Nocardia