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Background and Objectives: There is a growing infectious syphilis outbreak in Western Canada. Although blood donors are screened for syphilis risks, some blood donors will still be confirmed test‐positive for syphilis. This study compares the characteristics of confirmed test‐positive syphilis donations in both Western Canada and Eastern Canada, November 2022–August 2023. Materials and Methods: Donors were defined as Western or Eastern Canadian. Blood donations were tested for syphilis using the PK‐TP assay (Beckman Coulter PK7300 Automated Microplate System). Confirmatory Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) assays were performed by one of two reference laboratories. An RPR titre ≥1:8 was used as a proxy for possible infectious syphilis. Results: Rates of laboratory‐confirmed syphilis were higher in Western (n = 43, 13.4/100,000 donations) versus Eastern donors (n = 19, 4.7/100,000 donations; Fisher's exact test, two‐sided, p ≤ 0.0001). Most syphilis confirmations were in first‐time donors (Western Canada n = 31/43, 72.1%, Eastern Canada 12/19, 63.2%). Conclusion: Although rates of laboratory‐confirmed syphilis were higher in Western versus Eastern donors, Western donors did not have higher rates of infectious syphilis. Further studies might assess whether donors with laboratory‐confirmed syphilis understood pre‐donation screening questions or were completely unaware of a past infection. [ABSTRACT FROM AUTHOR]

Background: In Canada the time deferral for gay, bisexual, and other men who have sex with men (gbMSM) was progressively shortened (lifetime, 5 years, 1 year, 3 months). Here we describe trends in syphilis rates (a potential sexual risk marker) and risk behaviors from blood donors in the past 12 years. Study Design and Methods: Syphilis positivity in 10,288,322 whole blood donations (January 1, 2010–September 10, 2022) and gbMSM deferral time periods, donation status, age, and sex were analyzed with logistic regression. Overall, 26.9% syphilis positive and 42.2% controls (matched 1:4) participated in risk factor interviews analyzed by logistic regression. Results: Syphilis rates were higher in first‐time donors (OR 27.0, 95% CI 22.1–33.0), in males (OR 2.3, 1.9–2.8) and with the 3‐month deferral (OR 3.4, 2.6–4.3) during which the increase was greater for first‐time males (p <.001) but similar for male and female repeat donors (p >.05). Among first‐time donors, histories of intravenous drug use (OR 11.7, 2.0–69.5), male‐to‐male sex 7.8 (2.0–30.2) and birth in a high prevalence country (OR 7.6, 4.4–13.0) predicted syphilis positivity; among repeat donors, history of male‐to‐male sex (OR 33.5, CI 3.5–317.0). All but 1 gbMSM syphilis‐positive donors were noncompliant with the gbMSM deferral. About a quarter of first‐time interviewed case donors had history of syphilis; 44% were born in a high‐prevalence country. Conclusion: Rising syphilis rates in donors correlates with the general population epidemic. Recent infection rates rose similarly in males and females. GbMSM history may contribute to donor syphilis rates but shortening time deferrals appears unrelated. [ABSTRACT FROM AUTHOR]

The main aim of this study was to compare the response to trivalent inactivated influenza vaccine in children who received a kidney transplant and were on steroid-free versus steroid-based immunosuppression. Groups: 1. Kidney transplant recipients on steroid-free immunosuppression (n=27); 2. Kidney transplant recipients on steroid-based immunosuppression (n=39); 3. Healthy controls (n=21). Hemagglutination inhibition titers against 2007-2008 A/H1N1 and A/H3N2 and B strains were measured before and 8 weeks postvaccination. Postvaccination geometric mean titers to A/H1N1 were significantly lower among both transplant groups than controls (p=0.025 and 0.015, respectively). Postvaccination titers to H3N2 and B strains were not statistically different between groups. Proportions of participants developing seroprotection were not different among groups. Both kidney transplant groups seroconverted less than controls for A/H1N1 (p=0.0002) and were no different from controls for B. For A/H3N2, the steroid-free group had the weakest seroconversion (p=0.008), possibly due to mycophenolate-enhanced exposure and a younger age. Overall, children after kidney transplantation demonstrated a good serologic response to the inactivated influenza vaccine although somewhat lower than controls. Steroid-free immunosuppression did not seem to present an advantage in antibody response. Data on inactivated influenza vaccine safety and efficacy was collected and demonstrated absence of acute rejection or laboratory-proven influenza for 6 months postvaccination.