Staphylococcus lugdunensis infective endocarditis: a literature review and analysis of risk factors.

BACKGROUND/PURPOSE Infective endocarditis caused by Staphylococcus lugdunensis is a rare disease. Since its first description in 1988, there have only been a few reports of this disease and the causative organism. These publications were primarily case reports and brief case series. We conducted a literature review to identify the nature of the disease and its risk factors. METHODS We retrospectively reviewed the cases reported between 1988 and 2008 by searching the relevant literature using the keywords "endocarditis" and "Staphylococcus lugdunensis" in the Medline database. All cases included met the definition of the modified Duke criteria. RESULTS For the period 1988-2008, 67 cases from 27 articles were reviewed. The mean age of individuals was 53.9 years. Left-sided valvular endocarditis represented 52 (82.5%) of cases and native-valve endocarditis was evident in 48 (78.7%) of cases. A large proportion (82%) of 50 S. lugdunensis strains were susceptible to penicillin. Valve replacement operations were performed in 42 (66.7%) patients and the mortality rate was 38.8%. Univariate analysis showed a higher mortality rate in patients aged more than 50 years, those treated before 1995, those treated with antibiotics alone, and those with growth not detected by echocardiography. Medical treatment alone was the independent risk factor for mortality by multivariate analysis. CONCLUSION S. lugdunensis endocarditis led to substantial morbidity and mortality. Detailed microbiological identification, echocardiography evaluation, and valve replacement may improve the clinical outcome of individuals with S. lugdunensis endocarditis.