[Long term survival after Rhodococcus equi pneumonia in a patient with human immunodeficiency virus infection in the era of highly active antiretroviral therapy: case report and review].

Before highly active antiretroviral therapy (HAART) has become available, antibiotic treatment was usually unable to eradicate Rhodococcus (R.) equi infection in HIV-infected patients, although some clinical improvement could be observed in most cases. There are limited data on the outcome of treatment of R. equi pneumonia in the HAART era. We report on a 52-year-old HIV-infected man who presented in poor general condition with an extensive lung cavitation lesion caused by R. equi. The patient recalled exposure to horses on several occasions. R. equi was cultured from the sputum and the isolate was sensitive to imipenem vancomycin, co-trimoxazole, erythromycin, azithromycin, ciprofloxacin and rifampicin. The CD4+ lymphocyte count was 5 cells/mm3 (0.9%) and his plasma HIV-1 RNA viral load was 101000 copies/mL. The patient was successfully treated with a combination of antibiotics that included azithromycin both as part of an initial and suppressive regimen together with antiretroviral treatment. Surgery was not needed and the patient had no relapse for more than five years after the diagnosis and for more than 3 years of suppressive therapy discontinuation. Our literature search revealed 27 patients treated for R. equi infection in the HAART era. However, details on antimicrobial treatment were given in only 3 cases. The optimal drug regimen and duration of treatment for R. equi pneumonia have not yet been established. Because drug resistance may occur during single agent therapy, it has been suggested that at least two antibiotics to which R. equi is susceptible be given. The recommended choices usually include imipenem, antipseudomonal aminoglycosides, erythromycin or azithromycin, vancomycin, rifampin, and levofloxacin. To our knowledge this is the first documented case of long term remission of R. equi pneumonia in an HIV-infected man treated with azithromycin as part of his antibiotic regimen and HAART.