Epidemiological survey of the first case of vancomycin-resistant Staphylococcus aureus infection in Europe.

We report on the follow-up and epidemiological study triggered by the isolation of the first vancomycin-resistant Staphylococcus aureus (VRSA) detected in Europe. The patient and 53 close contacts were screened for S. aureus colonization and all isolates recovered were characterized by multiple molecular typing methods. The VRSA remained confined to the infected foot of the patient and was not detected in any of the close contacts. Nasal colonization with S. aureus was detected in 20 subjects, of whom 15 carried methicilin-susceptible isolates with the remaining five harbouring methicilin-resistant S. aureus (MRSA). The majority of the isolates belonged to clones that have been previously shown to be prevalent in Portugal, both in the hospital setting and in the community. Only one isolate, an MRSA, was closely related to the VRSA. Like most of the characterized VRSA isolates from other countries, the VRSA isolated in Portugal belonged to clonal complex (CC) 5. Despite the absence of VRSA dissemination, the recent increase in the incidence of lineages belonging to CC5 in some European countries, including Portugal, may result in more frequent opportunities for the emergence of VRSA.

Cardiac valve calcification in haemodialysis patients: role of calcium-phosphate metabolism.

BACKGROUND: Cardiac valve calcification (VC) has been detected with increased frequency in haemodialysis (HD) patients, making it necessary to determine the potential pathogenic factors in uraemic patients. METHODS: A total of 92 chronic HD patients (39 female, 53 male) and 92 age and gender-matched nondialysis control subjects were evaluated by echocardiography and a severity score for VC was determined. Calcium phosphate metabolism was evaluated at the beginning of haemodialysis. RESULTS: We found a greater prevalence of VC in dialysis patients than in normal patients (mitral annulus 44.5% vs 10%, P = 0.02; aortic annulus 52% vs 4.3%, P = 0.01). HD patients with mitral calcification were found to be older than patients without calcification, were on long-term renal replacement therapy, had longer duration of predialysis arterial hypertension, had greater values of the highest value of mean calcium phosphate product in 6 successive months (CaxP) and the highest absolute value of calcium-phosphate product (CaxPmax). We also found a positive correlation between calcification score, age, and CaxP. No correlation was found between actual VC and arterial hypertension or parathyroid hormone. Multiple stepwise regression analysis selected age and CaxP as the most predictive parameters for mitral calcification (r = 0.47). Mitral calcification was associated more frequently with rhythm and cardiac conduction defects, valvular insufficiency and with peripheral vascular calcification. Aortic calcification was correlated with age (r = 0.42) and longer duration of predialysis arterial hypertension. CONCLUSION: Our study confirmed an increased prevalence of VC in HD patients and selected age and calcium phosphate product as the most predictive parameters. These findings support careful monitoring of calcium metabolism beginning at the early stages of end-stage renal failure to reduce the risk of heart disease.