Rhodococcus equi causing bacteremia in an adult with acute leukemia

We have reported a case of isolated bacteremia due to Rhodococcus equi in an immunocompromised, non-HIV-infected patient with acute leukemia. This patient's illness demonstrates a rare presentation of an emerging opportunistic pathogen that may be potentially acquired via exposure to domestic horses or their habitat during periods of aggressive chemotherapeutic administration. The infection was successfully eradicated by treatment with erythromycin and rifampin. Counseling immunocompromised patients inclined to participate in recreational activities involving potential risks of exposure to this pathogen would seem to be a reasonable, but unproven, preventive intervention.