Endocarditis in the Mediterranean Basin

Abstract

Infective endocarditis is a severe disease with high mortality. Despite a global trend towards an increase in staphylococcal aetiologies, in older patients and a decrease in viridans streptococci, we have observed in recent studies great epidemiologic disparities between countries. In order to evaluate these differences among Mediterranean countries, we performed a PubMed search of infective endocarditis case series for each country. Data were available for 13 of the 18 Mediterranean countries. Despite great differences in diagnostic strategies, we could classify countries into three groups. In northern countries, patients are older (>50 years old), have a high rate of prosthetic valves or cardiac electronic implantable devices and the main causative agent is Staphylococcus aureus. In southern countries, patients are younger (<40 years old), rheumatic heart disease remains a major risk factor (45-93%), viridans streptococci are the main pathogens, zoonotic and arthropod-borne agents are frequent and blood culture-negative endocarditis remains highly prevalent. Eastern Mediterranean countries exhibit an intermediate situation: patients are 45 to 60 years old, the incidence of rheumatic heart disease ranges from 8% to 66%, viridans streptococci play a predominant role and zoonotic and arthropod-borne diseases, in particular brucellosis, are identified in up to 12% of cases.

Keywords: Diagnosis; Mediterranean Sea; endocarditis; epidemiology; zoonoses.

Fig. 1

Map of Mediterranean area showing distribution of aetiologic agents and age range of patients with infective endocarditis according to country.

Fig. 2

Principal component analysis (factor map) comparing Mediterranean countries using following infective endocarditis characteristics: patient age, ratio of rheumatic heart disease and percentages of Staphylococcus aureus, coagulase-negative staphylococci, viridans streptococci, Streptococcus gallolyticus, Enterococcus spp., nonfermentative Gram-negative bacteria, Enterobacteriaceae, HACEK (Haemophilus, Aggregatibacter (previously Actinobacillus), Cardiobacterium, Eikenella, Kingella), zoonotic and arthropod-borne bacteria, fungi and other microorganisms. ALG, Algeria; EGY, Egypt; FRA, France; GRE, Greece; ISR, Israel; ITA, Italy; MOR, Morocco; SPA, Spain; TUN, Tunisia; TUR, Turkey.

Fig. 3

Surgery vs. mortality rates in published series of infective endocarditis in Mediterranean countries. Series for which either surgery and/or mortality rates were not available and those that included only patients requiring admission to intensive care unit were not included. Shown are tendency curve, its equation and correlation coefficient.