Legionnaires' disease and HIV infection: An opportunistic infection?

BACKGROUND AND OBJECTIVE: Legionella infections are not frequent in HIV-infected patients, although clinical manifestations and outcome are particularly severe in this subset. This manuscript analyzes the clinical features and immunological situation of HIV-infected patients with Legionnaires' disease (LD). PATIENTS AND METHOD: The clinical files of HIV-infected patients diagnosed with LD from 1983 to December 2003 were reviewed. The incidence of hospital-acquired Legionella pneumonia (HALF) from 1997-2000 in HIV-infected patients was compared with that of non infected patients. RESULTS: Eighteen patients were included. 72.2% were diagnosed by the Legionella urinary antigen assay. The incidence of HALF in HIV-infected and non infected patients was 0.3 and 0.25/1000 admissions/year, respectively (p = 0.42). 83.3% received appropriate antibiotic treatment at the Emergency department. The mean lymphocyte CD4 count was 348.1/μl, 53.8% had an undetectable viral load and 64.7% were on antiretroviral therapy. 72.2% were smokers, 38.8% had cancer and 16.7% were on chemotherapy. 93.8% had cough, 75% dyspnea, 62.5% extrarespiratory symptoms, 76.5% increased AST, 50% increased CK and 56.3% hyponatremia. Moreover, 50% developed bilateral pulmonary infiltrates, 83.3% respiratory failure and 22.2% died. CONCLUSIONS: Although LD is not more frequent in HIV-infected than in non infected patients, its clinical severity suggests that it is an opportunistic infection.