Epidemiology of non-multiresistant methicillin-resistant Staphylococcus aureus infection in Queensland, Australia: associations with indigenous populations and Panton-Valentine leukocidin.

The purpose of this study was to determine the extent of the spread of epidemic clones of non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA) and the epidemiology of resultant infections throughout the state of Queensland. We collected a sample of clinical isolates of nmMRSA from laboratories serving public hospitals and clinics throughout the state. Three hundred isolates were typed and tested for the presence of Panton-Valentine leukocidin (PVL) genes and demographic and clinical data were collected from associated cases. Fifteen percent of S. aureus isolates were nmMRSA and 69% of these belonged to PVL-positive clones, predominantly ST93 and CC30. Low numbers of USA300- and USA400-like isolates were also present. Infections due to PVL-positive strains were much less frequently acquired in hospital (3.4%) than those due to PVL-negative nmMRSA (23.7%). Thirty-seven percent of cases were in indigenous people who make up only 3.6% of the general population. The proportion of cases with PVL-positive, but non-negative isolates decreased progressively with age, suggesting that immunity to PVL might be an important determinant of protection. nmMRSA strains are present throughout Queensland and cause infections in both community and healthcare settings.

Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study.

OBJECTIVES: The purpose of this study was to determine long-term outcome in adults with congenitally corrected transposition of the great arteries (CCTGA), with particular emphasis on systemic ventricular dysfunction and congestive heart failure (CHF). BACKGROUND: Patients with CCTGA have the anatomical right ventricle as their systemic pumping chamber, with ventricular dysfunction and CHF being relatively common in older adults. METHODS: Retrospective analysis of records of 182 patients from 19 institutions were reviewed to determine current status and possible risk factors for systemic ventricular dysfunction and CHF. Factors considered included age, gender, associated cardiac defects, operative history, heart block, arrhythmias and tricuspid (i.e., systemic atrioventricular) regurgitation (TR). RESULTS: Both CHF and systemic ventricular dysfunction were common in groups with or without associated cardiac lesions. By age 45, 67% of patients with associated lesions had CHF, and 25% of patients without associated lesions had this complication. The rates of systemic ventricular dysfunction and CHF were higher with increasing age, the presence of significant associated cardiac lesions, history of arrhythmia, pacemaker implantation, prior surgery of any type, and particularly with tricuspid valvuloplasty or replacement. Aortic regurgitation (a previously unreported problem) was also relatively common in this patient population. CONCLUSIONS: Patients with CCTGA are increasingly subject to CHF with advancing age; this complication is extremely common by the fourth and fifth decades. Tricuspid (systemic atrioventricular) valvular regurgitation is strongly associated with RV (anatomical right ventricle connected to aorta in CCTGA patients; systemic ventricle in CCTGA) dysfunction and CHF; whether it is causative or a secondary complication remains speculative.