Clinical and microbiological characteristics of mycotic aneurysms in a medical center in southern Taiwan.
OBJECTIVE
Mycotic aneurysm poses a high risk of mortality. This study evaluated the demographic and clinical characteristics and outcomes of hospitalized patients with mycotic aneurysm.


METHODS
Patients with mycotic aneurysm hospitalized between March 1996 and May 2006 at a medical center in southern Taiwan were retrospectively analyzed.


RESULTS
Fifty two patients (38 men and 14 women; mean age, 64.5 +/- 15.6 years) were included. The leading underlying diseases were diabetes mellitus (40.4%), hypertension (21.2%), and renal disease and heart disease (19.2% each). The most common pathogens isolated from blood and/or resected tissue were Salmonella spp. (34.6%), Klebsiella pneumoniae (11.5%) and Staphylococcus aureus (11.5%). Mycotic aneurysms caused by Gram-negative bacilli were significantly more likely to occur in older patients (p=0.018) and at infrarenal sites (p=0.021). There were trends suggesting that mycotic aneurysms were more likely to be caused by Gram-negative bacilli in patients receiving steroid treatment and in those with underlying diabetes mellitus. Mycotic aneurysms caused by Gram-positive cocci were significantly more likely to occur in suprarenal arteries (p=0.048), especially intracranially (p=0.002), in younger patients (p=0.018) and in patients with concurrent endocarditis (p=0.008). The overall in-hospital mortality rate was 30.6%, and there was no significant difference in in-hospital mortality between mycotic aneurysms caused by Gram-negative bacilli and those due to Gram-positive cocci.


CONCLUSIONS
The relationship between the anatomic site of mycotic aneurysm and the spectrum of culprit bacteria may help clinicians promptly choose appropriate antibiotic regimens on an empirical basis. Further study is required to understand better the role of K. pneumoniae in mycotic aneurysm in Taiwan.
Hsu
Pao-Jen
PJ
Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan.
Lee
Chen-Hsiang
CH
Lee
Fan-Yen
FY
Liu
Jien-Wei
JW
D000368:Aged; D000369:Aged, 80 and over; D000785:Aneurysm, Infected / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D004755:Enterobacteriaceae / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D013210:Staphylococcus / Q000302:isolation & purification; D018709:Statistics, Nonparametric; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D013291:Streptococcus / Q000302:isolation & purification; D013624:Taiwan