Case-control study of household contacts to examine immunological protection from Bordetella pertussis transmission - study protocol.

BACKGROUND: There is mounting evidence that the recent resurgence of pertussis in many countries is in part related to the acellular vaccine, which has been administered in Canada since 1997. This vaccine elicits a different cell-mediated immune response than the previously used whole-cell vaccine, and its effectiveness wanes over time. The aim of this study is to understand the immunological, demographic and clinical factors that mediate protection from pertussis on exposure. METHODS: This is a household case-control study protocol. Following notification of an index case in a household, a study team will conduct a home visit to collect data and biological specimens. The study team will return to the household 8 weeks from the onset of illness in the index case. The Th1, Th2 and Th17 responses, cytokine expression, IgG subclass, blood cell counts and presence of Bordetella pertussis will be determined. We will use laboratory and statistical analyses to determine immunological differences between contacts who are infected with B. pertussis and contacts who remain healthy, and to determine which clinical and demographic covariates are associated with a reduced risk of infection. INTERPRETATION: The results of this study will be essential for understanding the immune response required for protection from infection with B. pertussis and will contribute to our understanding of the shortcomings of the current vaccine.

A new approach to improving healthcare personnel influenza immunization programs: a randomized controlled trial.

BACKGROUND: Healthcare personnel influenza immunization rates remain sub-optimal. Following multiple studies and expert consultations, the "Successful Influenza Immunization Programs for Healthcare Personnel: A Guide for Program Planners" was produced. This trial assessed the impact of the Guide with facilitation in improving healthcare personnel influenza immunization rates in Canadian healthcare organizations. METHODS: A sample of 26 healthcare organizations across six Canadian provinces (ON, MB, NS, BC, SK, NL) was randomized to Intervention (n=13) or Control groups (n=13). Baseline influenza immunization rates were obtained for 2008-2009; the study groups were followed over two subsequent influenza seasons. The Intervention group received the Guide, facilitation support through workshops for managers and ongoing support. The Control groups conducted programs as usual. The Groups were compared using their reported influenza healthcare personnel influenza immunization rates and scores from a program assessment questionnaire. FINDINGS: Twenty-six organizations agreed to participate. 35% (9/26) of sites were acute care hospitals, 19% (5/26) continuing care, long-term care organizations or nursing homes, and 46% (12/26) were mixed acute care hospitals and long-term care or regional health authorities. The median rate of influenza immunization among healthcare personnel for the Intervention group was 43%, 44%, and 51% at three points in time respectively, and in the CONTROL GROUP: 62%, 57%, and 55% respectively. No significant differences were observed between the groups at the three points in time. However, there was a 7% increase in the median rates between the Baseline Year and Year Two in the Intervention group, and a 6% decrease in the CONTROL GROUP over the same time period, which was statistically significant (0.071 versus -0.058, p < 0.001). INTERPRETATION: This pragmatic randomized trial of the Guide with facilitation of its implementation improved healthcare personnel immunization rates, but these rates continued to be sub-optimal and below rates achievable in programs requiring personnel to be immunized. TRIAL REGISTRATION: ClinicalTrials.gov NCT01207518.

Live liver donors' risk thresholds: risking a life to save a life.

BACKGROUND: There is still some controversy regarding the ethical issues involved in live donor liver transplantation (LDLT) and there is uncertainty on the range of perioperative morbidity and mortality risks that donors will consider acceptable. METHODS: This study analysed donors' inclinations towards LDLT using decision analysis techniques based on the probability trade-off (PTO) method. Adult individuals with an emotional or biological relationship with a patient affected by end-stage liver disease were enrolled. Of 122 potential candidates, 100 were included in this study. RESULTS: The vast majority of participants (93%) supported LDLT. The most important factor influencing participants' decisions was their wish to improve the recipient's chance of living a longer life. Participants chose to become donors if the recipient was required to wait longer than a mean ± standard deviation (SD) of 6 ± 5 months for a cadaveric graft, if the mean ± SD probability of survival was at least 46 ± 30% at 1 month and at least 36 ± 29% at 1 year, and if the recipient's life could be prolonged for a mean ± SD of at least 11 ± 22 months. CONCLUSIONS: Potential donors were risk takers and were willing to donate when given the opportunity. They accepted significant risks, especially if they had a close emotional relationship with the recipient.