Is cotrimoxazole prophylaxis still reliable for the prevention of nocardiosis?

Abstract number: P1547

Muñoz P., Marin M., Valerio M., Cercenado E., Guinea J., Martín-Rabadán P., Radice C., Fernández-Cruz A., Bouza E.

Background: Clinical and microbiological spectrum of nocardiosis has changed recently due to the widespread use of cotrimoxazole (SXT) prophylaxis, the emergence of new types of immunosuppressed patients (pts) and the improved identification of the isolates by means of molecular techniques.

Objective: To establish the incidence and the microbiological and clinical characteristics of nocardiosis in a general hospital over the last 12 years.

Methods: Review of the clinical records of all pts with Nocardia spp. cultured from a clinical specimen between 1995 and 2006. Nocardia isolates were identified with classic procedures and by hsp65 PCR-RFLP. MICs of SXT, minocycline, imipenem, meropenem, linezolid and amikacin were determined following the CLSI microdilution method.

Results:Nocardia was recovered from 43 patients. Six were considered colonised. All had severe underlying pulmonary pathology and were treated with antimicrobials (6) or corticosteroids (4). Colonising species corresponded to N. farcinica, N. nova and N. asteroides.

Invasive nocardiosis was diagnosed in 37 pts; 86.5% were men and mean age was 55.8±17.3 y.o. The most common underlying condition was HIV infection (10 pts; 27%), followed by neoplasic disease (4 pts; 21.6%), COPD (8 pts; 21.6%), autoimmune diseases (8 pts; 21.6%) and solid organ transplantation (7; 18.9%). Most important risk factor was corticosteroids administration (23 pts; 62.2%). Nocardiosis was disseminated in 5 cases (13.5%), pulmonary in 70.3%, cutaneous in 8.1%, affected the CNS in 5.4%, and caused otomastoiditis in 1 case (2.7%).

Species were: N. asteroides VI 45.9%, N. farcinica 24.3%, N. otitidiscaviarum 10.8% and N. nova 5.4%. Antimicrobial resistance rates were: SXT 8.3%, meropenem 16.6%, imipenem 11.2%, mynocicline, linezolid and amikacin 0%. Nocardiosis occurred while the patients were on SXT prophylaxis in 11 pts (29.7%) and the strains isolated in those pts were susceptible to SXT in 33 (91.6%) and resistant in 3 (8.3%)(SXT susceptibility not known in one strain). Overall, 13 pts died (21.6%) and related-mortality was 21.6% (8 pts).

Conclusions: Our results show important changes occurring in nocardiosis in recent years. HIV infection is presently the most common underlying condition and species different from N. asteroides account for more than half of the infections. Moreover, cotrimoxazole prophylaxis should not be relied upon as universally protective.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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