An association between bacterial genotype combined with a high-vancomycin minimum inhibitory concentration and risk of endocarditis in methicillin-resistant Staphylococcus aureus bloodstream infection.

INTRODUCTION: Antimicrobial resistance and bacterial virulence factors may increase the risk of hematogenous complications during methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI). This study reports on the impact of increasing vancomycin minimum inhibitory concentrations (V-MICs) and MRSA clone type on risk of hematogenous complications from MRSA BSI during implementation of an effective MRSA control program. METHODS: In sum, spa typing, staphylococcal cassette chromosome mec allotyping, and vancomycin and teicoplanin MICs were performed on 821 consecutive MRSA bloodstream isolates from 1999 to 2009. Prospectively collected data, including focus of infection, were available for 695 clinically significant cases. Logistic and multinomial logistic regression was used to determine the association between clone type, vancomycin MIC (V-MIC), and focus of infection. RESULTS: MRSA BSIs decreased by ∼90% during the 11 years. Typing placed isolates into 3 clonal complex (CC) groups that had different population median V-MICs (CC30, 0.5 µg/mL [n = 349]; CC22, 0.75 µg/mL [n = 272]; non-CC22/30, 1.5 µg/mL [n = 199]). There was a progressive increase in the proportion of isolates with a V-MIC above baseline median in each clonal group and a disproportionate fall in the clone group with lowest median V-MIC (CC30). In contrast, there were no increases in teicoplanin MICs. High V-MIC CC22 isolates (1.5-2 µg/mL) were strongly associated with endocarditis (odds ratio, 12; 95% confidence interval, 3.72-38.9) and with a septic metastasis after catheter-related BSI (odds ratio, 106; 95% confidence interval, 12.6-883) compared with other clone type/V-MIC combinations. CONCLUSIONS: An interaction between clone type and V-MIC can influence the risk of endocarditis associated with MRSA BSI, implying involvement of both therapeutic and host-pathogen factors.

Economic burden of intracranial vascular malformations in adults: prospective population-based study.

BACKGROUND AND PURPOSE: Although intracranial vascular malformations (IVMs) are the leading cause of intracerebral hemorrhage (ICH) in young adults, there has not been a cost-of-illness study on an unselected cohort. METHODS: We measured the direct healthcare costs (inpatient, outpatient, intervention, and brain imaging) incurred by every adult within 3 years after their first presentation with a brain arteriovenous malformation (AVM) or cavernous malformation (CM) in a prospective, population-based study. We estimated the indirect cost of lost productivity for the whole cohort over the same period by projecting questionnaire responses from living consenting adults. RESULTS: 369 adults (AVM=229 [62%], CM=140 [38%]) incurred healthcare costs of pound 5.96 million over 3 years, of which AVMs accounted for 90%, inpatient care accounted for 75%, and the first year of care accounted for 69%. Median 3-year healthcare costs were statistically significantly higher for adults presenting with ICH, aged <65 years, receiving interventional treatment, and adults with AVMs rather than CMs ( pound 15,784 versus pound 1385, P<0.0005). Healthcare costs diminished with increasing AVM nidus size (P=0.005). Mean 3-year costs of lost productivity per questionnaire respondent (n=145) were pound 17,111 for AVMs and pound 6752 for CMs (P=0.1), and the projected 3-year cost of lost productivity for all 369 adults was pound 8.7 million. CONCLUSIONS: The costs of healthcare and lost productivity attributable to IVMs are considerable, and highest in those aged <65 years, presenting with ICH, receiving interventional treatment, and harboring AVMs rather than CMs. Long-term studies of the cost-effectiveness of interventional treatment are needed.

The Utility of Blood and Bone Marrow Films and Trephine Biopsy Sections in the Diagnosis of Parasitic Infections.

The laboratory haematologist has a role in the diagnosis of parasitic infections. Peripheral blood examination is critical in the diagnosis of malaria, babesiosis, filariasis and trypanosomiasis. Bone marrow examination is important in the diagnosis of leishmaniasis and occasionally leads to the diagnosis of other parasitic infections. The detection of eosinophilia or iron deficiency anaemia can alert the laboratory haematologist or physician to the possibility of parasitic infection. In addition to morphological skills, an adequate clinical history is important for speedy and accurate diagnosis, particularly in non-endemic areas.