Epidemiologic and microbiologic aspects of 33 osteitis and anaerobes.

We analyzed 33 cases of osteitis or infectious osteoarthritis in which biop sies had isolated one or several anaerobic bacteria. The diagnosis of anaer obic infection was definitive if the anaerobes had been isolated from relia ble perioperative biopsies or at least two unreliable biopsies (fistula, ne edle biopsy), and on the condition that the different results were correlat ed. One hundred and eighteen bacteria were isolated from the 33 patients, o f which 81 were purely anaerobic bacteria, i.e., 2.39 bacteri per patient ( including 20 Peptostreptococus, 16 Prevotella, 12 Bacteroides, of which six were in the fragilis group, ten Propionibacterium acnes and eight Fusobact erium nucleatum). Twenty-four cases of osteitis were caused by mixed infect ions (73%), and nine (27%) were exclusively due to anaerobes, of which seve n were monomicrobic. We analyzed the infections and the distribution of bac terial etiologies according to the localization, method of contamination an d the risk factors. (C) 2000 Editions scientifiques et medicales Elsevier S AS.