The incidence rate of IE is between 2-7.9 per 100,000 people2, 3, and has remained stable4. Although relatively rare, IE continues to be characterized by increased morbidity and mortality and is now the third or fourth most common life-threatening infection syndrome.5 In 2010, IE was associated with 1.58 million disability-adjusted life-years or years of healthy life lost, as a result of death and nonfatal illness or impairment worldwide 6. The demographics of patients affected by IE have shifted in recent years, with an increase in mean patient age, an increase in the proportion of patients with prosthetic valves and other cardiac devices, and a decrease in the proportion of patients with rheumatic heart disease 6, 7. The average age of the patients in this study was 40.7 years old, 49.1% of the patients were over 40 years old, and 65.2% of the patients were male,and congenital heart disease (CHD) is the most common cardiac disease history that showed in IE patients, a same idea we could find in the research of Fefer P, which considered no-rheumatic valvular heart disease of the elderly was the most common underlying factor.8
In this study , lung infection is the leading clinical features in IE patients without heart disease history,. It was similar to the studies of Aylin Tugcu.9.Electrocardiogram showed that valvular vegetations were mainly generated in the left heart, and most of them were accompanied with varying degrees regurgitation. Some infectious markers, such as CRP, erythrocyte sedimentation rate, and neutrophil, may contribute to early detection of the disease.10 In this study, more than 50% patients accompany with WBC, N% ESR, PCT and CRP increased , infectious indicators may be used as an auxiliary basis for the diagnosis of infective endocarditis4, 11. .However, due to the poor specificity of various infectious indicators4, pathogen culture and electrocardiogram are required as the final basis for the diagnosis of IE12
Staphylococcus spp is the most common cause of IE, followed by Streptococci spp13, 14.Staphylococcus spp associate IE has became increasingly common in most industrialized countries because of increased medical intervention5; meanwhile Streptococci spp has became less15, 16. the presence of S. aureus bacteremia should be considered a major criterion, regardless of whether the infection is nosocomially acquired or whether a removable source of infection is present17. In the studies from Spain18, more than one third of IE cases were related to medical treatment, and the main pathogen of these patients was staphylococcus, however, pathogens may vary in different areas.11, 19, 20. in our study, the most common pathogen was Streptococcus viridans (20.7%), followed by staphylococcus aureus 18.0%.This prevalence pattern differs significantly from studies before. This may be related to economic development21. Patients of our research selected crowd in the southwest China where economic level and medical conditions is weak5, few patients had medical treatment. Study from Jerusalem22 shows that staphylococcus often exists in medical care IE patients while more streptococci is found from community infection. Study from Lauren Hartman et al. showed that23 staphylococcus aureus is the most common in patients with IDU-IE, while streptococcus is more common in patients without IDU-IE, only 1 patient had IDU history In our study. Above may be the reasons for the difference in distribution of pathogens. It is also reported21 that this difference may be due to adhesion molecules from Streptococcus viridans and staphylococcus aureus, which are related to the presence of surface adhesion factors on valve surfaces or in favor of bacterial colonization.
Indicate in European endocarditis management guidance, only for part of patients with congenital heart disease or valvular surgery, preventive use of antibiotics was necessary,10 Empirical treatment may include vancomycin or ampicillin/ Sulbactam and aminoglycosides24, but ultimately antibiotic treatment options need to be based on antibiotic sensitive test. In this study, neither staphylococcus nor streptococcus showed resistance to vancomycin, vancomycin could be used as a preventive treatment antibiotic. The resistance rate of staphylococcus and streptococcus to erythromycin, azithromycin, clindamycin and tetracycline are all over 30%, and it is not recommended to use in the experience of treatment.
To further explore the impact of the major death factors, the following information is included in the analysis model: gender, age ≥ 60 years, history of heart disease, PVE, Vegetative site and some lab data. Our results indicates that only history of heart disease is major risk factors for the prognosis of IE patients(OR:0.01,95%CI:0.08-0.68),while some study indicated that age ≥ 60 years (OR = 6.861, 0.94–50.1), congestive heart failure (OR = 8.854, 1.34–54.7), diabetes (OR = 7.224, 1.17–44.7), and Staphylococcus aureus or negative tuberculosis infection (OR = 18.81, 2.39–148.2) were major risk factors for the prognosis of IE patients. 21 This may be related to regional differences in studies.