Objective: Nocardiosis is a common opportunistic infection found in both immunocompromised and immunocompetent patients. The clinical manifestations, underlying diseases, radiologic findings, antimicrobial susceptibility and treatment of nocardial infection are presented here.
Method: A retrospective study at Srinagarind Hospital, Khon Kaen in Thailand was performed. Medical records from 1996-2001 were reviewed.
Results: There were 81 cases of nocardiosis during the study period but data of only 70 cases were available. 80% of cases were male. The mean age was 39.7+/-14.9 years. Underlying diseases were found in 80%, of which HIV infection was the most common (34.3%). The common clinical findings were fever, cough, and cutaneous abscess. The most common clinical syndrome was pleuropulmonary infection (44.3%), followed by skin and soft tissue infection (22.8%). Multiorgan dissemination was found in 11.4% of cases. The chest X-rays were abnormal in 46 cases (65.7%); alveolar and reticulonodular infiltration was common. Only 70% had positive cultures for Nocardia spp. The resistance rate of Nocardia isolates to trimethoprim-sulfamethoxazole (TMP-SMX) was very high (57.9%) in this study. Most of the patients (85.7%) were treated with antimicrobials, of which TMP-SMX was commonly used. In-hospital mortality was 20%. Most of the cases who died had dissemination, brain abscesses or infection with TMP-SMX-resistant strains. The long-term prognosis was good, with a treatment success rate of 93.75%.
Conclusion: Nocardiosis is a common opportunistic infection in many immunocompromised conditions. It can present with various clinical syndromes, especially pleuropulmonary infection. Culture may not yield the organism but modified acid-fast staining is very helpful in diagnosis. Drug susceptibility testing should be performed due to increasing resistance to TMP-SMX.