SESSION TITLE: Infectious Disease Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Nocardiosis is bacterial infection caused by gram positive filamentous rods called Nocardia which tend to strike the lungs, brain and skin. The risk of nocardial infection is increased in immunocompromised patients, particularly those with defects in cell-mediated immunity. Nocardia was first reported as a complication of HIV infection in 1985. It is an uncommon opportunistic pathogen in HIV and is usually associated with advanced immunosuppression and high mortality. Pulmonary Nocardia presents as localized or diffuse pneumonias, which may be accompanied by cavitation, abscess formation, pleural effusion or empyema. Here we report an unusual presentation of pulmonary nocardia as pyopneumothorax and diagnosis of the same in resource limited setting.
CASE PRESENTATION: 41 year old male with no significant past medical history presented with shortness of breath and cough for 15 days. Review of systems was positive for low grade fever, significant weight loss and decreased appetite for 3 months. Patient is weaver by occupation with a smoking history of 12.5 pack years. He is sexually active with one female partner and denied any drug abuse. On examination, he was pale, dehydrated and cachectic. Vital signs showed tachycardia, tachypnea and oxygen saturation of 91% on room air. Breath sounds were diminished on the left side of chest. Other systems were unremarkable. Laboratory testing revealed hemoglobin 6.2 g/dl, WBC 8600/μL, platelet 150,000/μL, BUN 103 mg/dl and serum creatinine 1.8 mg/dl. Serum electrolytes and hepatic function panel were normal except for low albumin of 3 g/dl. Chest x-ray showed pyopneumothorax on the left side without mediastinal shift. Chest tube was placed emergently which drained 100 cc of purulent material. Further workup confirmed HIV infection with a CD4 count of 26 cells /μL. Pleural fluid analysis showed acid fast filamentous rods by Kinyoun procedure. Aerobic culture grew Nocardia, however further speciation was not done. Screening and diagnostic testing for mycobacterium tuberculosis were negative. After the pesumptive diagnosis of Nocardia with staining, treatment was initiated with high dose intravenous trimethoprim-sulfamethoxazole and amikacin. Clinical improvement was seen in 1 week and antibiotic therapy was switched to oral trimethoprim-sulfamethoxazole. Anti-retroviral therapy was started and patient’s CD4 count improved to 206 cells /μL in 6 months.
DISCUSSION: Nocardia are branching, beaded, filamentous bacteria, ubiquitous in soil. Important characteristics of nocardial infection are its ability to disseminate to any organ and tendency to progress or relapse despite appropriate therapy which makes early diagnosis and treatment crucial. It usually appears in advanced immunodeficiency with CD4 cell count less than 50 cells/μL in approximately 50% to 85% cases. It is also more common in patients not on active treatment for HIV, and in one case series report 37% of patients with Nocardia infection had undiagnosed HIV infection. It is often complicated by coinfections like Mycobacterium tuberculosis, Mycobacterium Avium Complex, Pseudomonas aeruginosa and Pneumocystis jiroveci making diagnosis difficult. Diagnosis is established by isolation and identification of the organism from a clinical specimen. First line of treatment is trimethoprim-sulfamethoxazole. However combination therapy with Amikacin, imipenem or third generation cephalosporins is warranted in patients with severe infection and also prolonged course of antibiotics is recommended because of the relapsing nature of the disease.
CONCLUSIONS: This case highlights the unusual presentation of nocardia as pyopneumothorax. Often there is delay in diagnosis due to its low incidence, nonspecific clinical presentation and relatively difficult culture. In a resource limited country like India, diagnosis can be made with acid fast staining and aerobic culture. Prompt initiation of treatment is life-saving and can prevent dissemination of the disease.
Reference #1: AS King, PhD, JG Castro, MD and GCK Dow, MD. Nocardia farcinica lung abscess presenting in the context of advanced HIV infection: Spontaneous resolution in response to highly active antiretroviral therapy alone. Can J Infect Dis Med Microbiol. 2009 Autumn; 20(3): e103-e106.
Reference #2: Uttamchandani RB, Daikos GL, Reyes RR, et al. Nocardiosis in 30 patients with advanced human immunodeficiency virus infection: clinical features and outcome. Clin Infect Dis 1994; 18:348.
DISCLOSURE: The following authors have nothing to disclose: Aswini Kumar, Aswanth Reddy, Kumar Satagopan
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