No abstract

The genus Nocardia includes aerobic actinomycetes causing disease in both humans and animals. Nocardiosis is a rare bacterial infection, but the incidence of human disease has increased in the recent years in association with an increasing population of immune-compromised hosts and the improved methods for detection and identification of Nocardia spp. in the clinical laboratory. All those situations of immune-system compromise are conditions associated with increased risk, especially when cell-mediated immunity is involved. The prognosis depends both upon the immediacy of therapy initiation, concomitant disorders and the immune status of the patient. Recently cases of multi-drug resistance nocardiosis and the epidemiology and drug susceptibility of less common Nocardia species have been described. In HIV positive patients pulmonary nocardiosis, the most common clinical presentation, has a low reported prevalence of 0.3%, and it is not considered an AIDS-defining disease. The difficulties in isolation, the non-specific clinical and radiologic presentation, and the widespread use of cotrimoxazole (TMP/SMX) prophylaxis could be responsible for this low prevalence. In this paper, it is described a rare and fatal case of systemic nocardiosis arising with chest pain in a patient with a severe immune deficiency, unaware of his HIV positivity. Systemic nocardiosis is generally caused by N. asteroids and the prognosis is good, but in patients with AIDS, mortality in disseminated forms with central nervous system involvement is more than 50%.