Staphylococcal versus Streptococcal infective endocarditis in a tertiary hospital in Belgium: epidemiology, clinical characteristics and outcome

Abstract

Infective endocarditis (IE) is a rare but serious illness associated with a high mortality. Staphylococcus spp and Streptococcus spp are the most frequent causative pathogens. In this study, we compared the epidemiology, clinical characteristics and outcomes of patients with Staphylococcal and Streptococcal IE in a tertiary hospital. Using our institutional database ‘Medical Explorer’, we collected all cases of IE retrospectively between January 2005 and December 2010 at the Cliniques Universitaires Saint Luc and then focused on Staphylococcal and Streptococcal IE. Of the 212 patients with IE included in our study, Staphylococcus spp accounted for 35.9% (76/212) of the cases, Streptococcus spp for 35.4% (75/212) and the remainder 18% (61/212) of cases were caused by other pathogens. Negative blood culture IE accounted for 10.4% of all cases. Demographic and clinical characteristics such as age, gender, fever, presence of a heart murmur, heart failure, nature of the affected valve, location of the endocarditis, duration of antibiotics, length of stay and complication were not different when comparing Staphylococcal and Streptococcal IE; only mortality differed. The mortality rate was 21.4 and 6.6% (p = 0.02) for Staphylococcal and Streptococcal IE, respectively. In the multivariate analysis, age >60 years, Staphylococcal IE, presence of complications and absence of surgery were independent risk factors for mortality.