The microbiologic spectrum of dacryocystitis: a national study of acute versus chronic infection.

To examine the microbiologic spectrum of dacryocystitis, specifically characterizing differences between acute and chronic infection. National multicenter prospective study of the microbiologic spectrum of acute and chronic dacryocystitis based on culture results reported between March 2005 and March 2006. Chi-square analysis was used to compare differences between groups. Eighty-nine patients from 16 centers were included: 21 (23.6%) patients had acute infection and 68 (76.4%) had chronic infection. Of all 89 patients, there were 80 total culture isolates with 55 (68.8%) Gram-positive isolates, 23 (28.7%) Gram-negative isolates, and 2 (2.5%) Mycobacterium isolates. In the acute group, 18/23 (78.3%) were Gram-positive and 5/23 (21.7%) were Gram-negative. In the chronic group, 37/57 (64.9%) were Gram-positive, 18/57 (31.6%) were Gram-negative, and 2/57 (3.5%) were Mycobacterium isolates. The proportions of Gram-positive and Gram-negative organisms between groups revealed no statistically significant difference (p > 0.20). The frequency of methicillin-resistant Staphylococcus aureus (MRSA) in the acute group, 4/23 (17.4%), was greater than the chronic group, 1/57 (1.8%) (p ≤ 0.01). Gram-positive organisms were much more common than Gram-negative organisms overall, and the proportions did not differ significantly between the groups. Staphylococcus was the most common isolate in both groups, but there was a greater frequency of methicillin-resistant Staphylococcus aureus (MRSA) isolates in the acute group. The results of this study have important implications for the treatment of dacryocystitis.