An unusual cause of infection in immunocompetent individuals: A case series

<b>Introduction:</b> Nocardia can cause&nbsp;pneumonia especially in immunocompromised individuals. We present a case series of 4 immunocompetent patients who were diagnosed as pulmonary nocardiosis. <b>Discussion:</b> People with depressed cell mediated immunity are at very high risk of nocardia infection including those with lymphoma, HIV, transplant recepients or those on long term steroids. Inhalation is the primary route of exposure.more often its presentation is subacute or chronic with productive cough, dyspnoea, chest pain, haemoptysis, fever, weight loss and progressive fatigue. Chest X-ray can be variable with focal or multifocal disease with nodules/infiltrates/ cavitatory lesions.radiological differentials include filamentous fungi and other mycobacterial disease. Sputum/BAL gram stain/ culture aid in diagnosis. In our case series, all the patients were immunocompetent. Most had a acute / subacute presentation with left lung being commonly involved. All our patients had an underlying bronchiectasis. Though it wasnt diagnosed in routine testing, bronchoalveolar lavage proved the diagnosis. All the patients responded to cotrimoxazole and showed a radiological resolution.&nbsp;In patients with CNS or extra pulmonary/ severe infection, combination treatment is recommended with cotrimoxazole plus imipenem. In immunocompromised host, mortality is around 41 percent for pulmonary nocardiosis, but its as high as 100 percent for CNS nocardiosis. In a study by Steinbrink et al, mortality in immunocompetent host was around 7%. <b>Conclusion:</b> Immunocompetent patients presenting with pneumonia/ nodular opacities should be evaluated for nocardiosis especially if they have underlying bronchiectasis to avoid morbidity and complications.