Modeling the risk of an emerging pathogen entering the Canadian blood supply.

BACKGROUND: As part of its risk management process, Canadian Blood Services (CBS) constructed mathematical models of how newly emerging pathogens might affect blood transfusion recipients. STUDY DESIGN AND METHODS: CBS convened an expert panel including medical, health economics, analytical, risk management, and insurance professionals to examine multiple data sources. The model for emerging pathogen risk included separate modules to calculate the frequency and severity of infections from transfusion-transmitted agents that could cause either acute transient or chronic persistent infection. Important model input variables were annual number of components transfused, the presumed incidence and prevalence of a new agent, the time interval of recipient risk, recipient age and sex, projected recipient survival, rate of secondary infection, pathogen-induced morbidity, and the associated medical costs of such morbidity. RESULTS: In the 5-year time frame considered in the model, it was estimated that approximately 3500 recipient infections (two-SD range of 0 to 11,370 infections) could occur from an emerging pathogen that establishes a chronic infection in donors, with 60% of these due to red blood cell transfusion. The medical costs associated with recipient outcomes due to a catastrophic emerging pathogen could be lowered by 20% if an effective pathogen reduction method for either platelets or plasma were in place. CONCLUSION: This modeling exercise offers a framework for other blood services to construct similar models. It also provides a useful way to model the implementation of new blood safety interventions (e.g., pathogen reduction) on emerging pathogen risk.

Effect of a conjugated linoleic acid and omega-3 fatty acid mixture on body composition and adiponectin.

This study aimed to determine the effect of supplementation with conjugated linoleic acids (CLAs) plus n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) on body composition, adiposity, and hormone levels in young and older, lean and obese men. Young (31.4+/-3.9 years) lean (BMI, 23.6+/-1.5 kg/m2; n=13) and obese (BMI, 32.4+/-1.9 kg/m2; n=12) and older (56.5+/-4.6 years) lean (BMI, 23.6+/-1.5 kg/m2; n=20) and obese (BMI, 32.0+/-1.6 kg/m2; n=14) men participated in a double-blind placebo-controlled, randomized crossover study. Subjects received either 6 g/day control fat or 3 g/day CLA (50:50 cis-9, trans-11:trans-10, cis-12) and 3 g/day n-3 LC-PUFA for 12 weeks with a 12-week wash-out period between crossovers. Body composition was assessed by dual-energy X-ray absorptiometry. Fasting adiponectin, leptin, glucose, and insulin concentrations were measured and insulin resistance estimated by homeostasis model assessment for insulin resistance (HOMA-IR). In the younger obese subjects, CLA plus n-3 LC-PUFA supplementation compared with control fat did not result in increased abdominal fat and raised both fat-free mass (2.4%) and adiponectin levels (12%). CLA plus n-3 LC-PUFA showed no significant effects on HOMA-IR in any group but did increase fasting glucose in older obese subjects. In summary, supplementation with CLA plus n-3 LC-PUFA prevents increased abdominal fat mass and raises fat-free mass and adiponectin levels in younger obese individuals without deleteriously affecting insulin sensitivity, whereas these parameters in young and older lean and older obese individuals were unaffected, apart from increased fasting glucose in older obese men.