Endocarditis Due To Gram-Negative Bacilli At A French Teaching Hospital Over A 6-Year Period: Clinical Characteristics And Outcome

Background: Infective endocarditis (IE) due to gram-negative bacilli (GNB) is rare. However, several studies described a change in the epidemiological profile of patients within the past few years. Methods: We reviewed all cases diagnosed and followed in the infectious diseases ward of a French teaching hospital in Paris between 2009 and 2014, inclusive. Results: Among the 17 patients with definite GNB-IE (11 male, mean age 54 years), 12 (70%) were due to non-HACEK GNB and 5 (30%) to HACEK group GNB. A prosthetic valve was involved in 10 cases (8 in non-HACEK and 2 in HACEK group). Escherichia coli (4/12 patients) and Pseudomonas aeruginosa (3/12 patients) were the most common pathogens in the first group; all the pathogens in the second group were Haemophilus spp. One-third of the patients with non-HACEK GNB had nosocomial IE, whereas injection drug use-related infections were rare (2/12). All patients with HACEK infection had at least one complication (intracardiac abscess, stroke or other systemic embolization). All patients were treated by antibiotic combination therapy during a median time of 42 days (interquartile range (IQR) = 42-42) and 10 (59%) underwent cardiac surgery. One death at 9 months was observed in the non-HACEK group. Conclusions: Regarding HACEK IE, this report supports the frequent association with vascular complications. Regarding non-HACEK GNB IE, this report supports the increasing proportion of nosocomial infections. We reported a high proportion of surgery in the therapeutic management of both HACEK and non-HACEK groups associated with no in-hospital mortality.