Acinetobacter infections in patients with human immunodeficiency virus infection: Microbiological and clinical epidemiology

Background: We evaluated the role of complications caused by Acinetobacter spp. in the setting of HIV infection. Methods: Clinical records of 1,923 co nsecutive HIV-infected patients hospitalized in a 9-year period were retros pectively reviewed, in order to identify all cases of Acinetobacter spp, co mplications, and to assess their occurrence and outcome according to severa l epidemiological, clinical and laboratory parameters. Results: Ten patient s out of 1,923 (0.52%) developed Acinetobacter spp. infections: sepsis in f our cases, urinary tract infection in three, pneumonia in two and septicaem ic pneumonia in the remaining patient. All patients were severely immunocom promised, as shown by a mean CD4+ lymphocyte count of 122 cells/mul and a f requent prior diagnosis of AIDS. As opposed to other infections, septicaemi a was associated with a significantly lower CD4+ cell count and a more freq uent occurrence of neutropenia. Hospital-acquired Acinetobacter spp. infect ions were significantly more frequent than community-acquired ones, and pre vailingly involved patients with AIDS and leucopenia, being responsible for frequent blood dissemination. Antimicrobial, corticosteroid and cotrimoxaz ole treatment were frequently carried out during the month preceding diseas e onset. Antibiotic susceptibility studies proved the complete resistance o f microbial isolates to ampicillin and cephalothin and poor sensitivity to second-generation cephalosporins and gentamicin, while greater susceptibili ty was shown to ceftazidime, netilmicin and amikacin, followed by piperacil lin, cotrimoxazole and quinolones.