[Pathogenic role of Acinetobacter spp during HIV infection]

In order to assess the clinical role of bacterial complications due to Acinetobacter spp. during HIV disease, a retrospective survey of clinical and microbiological data of 2221 HIV-infected patients hospitalised during the past 10 years was carried out, evaluating all episodes of Acinetobacter spp. infection according to several epidemiological, clinical and therapeutic variables. Eleven patients of 2221 (0.5%) suffered from Acinetobacter spp. disease: sepsis in 5 cases, and urinary, respiratory tract disease and bacteremic pneumonia in three, two, and one patient respectively. A. calcoaceticus was responsible in 4 cases, A. lwoffii in three, and Acinetobacter spp. in the 4 remaining cases; 4 patients experienced a polymicrobial infection, and 7 had a prior diagnosis of full-blown AIDS. All patients had a severe HIV-related immunodeficiency (mean CD4+ lymphocyte count 118.2 +/- 45.3 cells/microl). Compared with other localizations, sepsis was related to a lower mean CD4+ cell count (p<.001), and a more frequent occurrence of leucopenia-neutropenia (p<.005). Disease episodes diagnosed after the first 72 hours of hospitalisation (deemed no- socomial in origin), proved more frequent than community-acquired ones (9 cases versus 2), affected predominantly patients with AIDS and neutropenia, and were frequent1y associated with bacteremia (p<.04) The use of broad spectrum antibiotics, corticosteroids and cotrimoxazole, was recognized during the month preceding the diagnosis of Acinetobacter spp. disease, in 6, 4, and 8 cases, respectively. One patient only had an indwelling intravascular catheter, while no recent history of surgery, intensive care, or other invasive procedures was found. At in vitro susceptibility studies, bacterial isolates showed complete resistance to ampicillin and cephalothin, and low sensitivity to second-generation cephalosporins, while a higher susceptibility rate was revealed towards ceftazidime, netilmicin, amikacin, and quinolones, followed by cotrimoxazole and piperacillin. A prompt and appropriate antimicrobial therapy (mostly carried out with cephalosporins and aminoglycosides), led all patients to a clinical and microbiological cure within 6-1.3 days, in the absence of mortality or relapses. As opportunist pathogens with a predominant nosocomial origin, Acinetobacter spp. organisms may be responsible for an appreciable morbidity in patients with HIV disease, especially when additional risk factors (immunodeficiency, underlying diseases, and hospitalisation) are present. Notwithstanding the high drug resistance profile of the majority of isolated organisms, a timely diagnosis and a treatment based on in vitro assays, contribute to avoid recurrences and potentially life-threatening complications.