The impact of Ontario smoke-free legislation on secondhand smoke in enclosed public places.

Many studies have evaluated the impact of indoor smoking bans on secondhand smoke (SHS) exposure. No studies have assessed the impact of a smoking ban on SHS in enclosed areas outside separately ventilated, designated smoking rooms (DSRs). This study evaluated the overall impact of the Smoke-Free Ontario Act implemented May 31, 2006, on SHS in bars and coffee shops and the impact of banning DSRs on SHS outside DSRs. Air particulate matter (PM) and carcinogenic particulate polycyclic aromatic hydrocarbons (PPAH) were measured in May 2006 before the ban inside and outside DSRs in Toronto venues (13 coffee shops and 14 bars) that allowed smoking only in DSRs, and in Windsor venues (10 coffee shops and 10 bars) where smoking was allowed in shared spaces. Measurements were repeated 2 months post-ban. Air quality index values (AQIs) were calculated. Mixed model analysis was applied, taking into account measurement errors for repeated measures. Post ban, mean PM and PPAH levels were reduced by 87% (from 494 to 67 mm(2)/m(3)) and 94% (from 196 to 11 ng/m(3)), respectively, inside Toronto DSRs. Mean PM and PPAH levels were reduced by 10% (from 124 to 111 mm(2)/m(3)) and 46% (from 45 to 24 ng/m(3)), respectively, outside Toronto DSRs. In all Windsor venues, mean PM and PPAH levels were reduced by 83% (from 488 to 81 mm(2)/m(3)) and 90% (from 107 to 10 ng/m(3)), respectively. All reductions were statistically significant (p < 0.0001). In Toronto venues, the AQI was reduced from the "very unhealthy" range inside DSRs and the "moderate" range outside Toronto DSRs to the "good" range, and in Windsor venues from the "unhealthy for sensitive groups" range to the "good" range post-ban. Pre-ban PPAH levels including those outside Toronto DSRs may be associated with cardiovascular injury. DSRs did not provide adequate protection from SHS. The Smoke-Free Ontario Act produced a significant and firm reduction in SHS exposure in venues both with and without DSRs.

Assessment of a travel question to identify donors with risk of Trypanosoma cruzi: operational validity and field testing.

BACKGROUND: Because Trypanosoma cruzi (T. cruzi) infection in Canada and the United States is largely contracted in endemic countries, targeted testing of blood donors with risk travel may improve safety. The operational validity of a travel question suitable for donor screening was tested, and it was field-tested. STUDY DESIGN AND METHODS: After 1331 donors completed a short travel question, operational validity was assessed by detailed travel histories in face-to-face interviews. Two nationwide donor surveys were carried out assessing donor responses to similar travel questions in 2001 (13,623 donors) and in 2006 (20,037 donors). All donors in Toronto, Ontario, answered a travel question in 1997 and those born in or who spent 6 months or more in Mexico, Central America, or South America were tested for antibody to T. cruzi. RESULTS: There was 97.3 percent agreement between the travel question and detailed interviews, with 15 donors (1.1%) failing to acknowledge risk travel (false-negative questioning responses). Of these, 6 donors were born there and 7 others had less than 1 year of cumulative travel. In 2001 and 2006, there were 2.1 and 2.0 percent of donors with risk travel, respectively, but 16.5 and 11.2 percent of these donors were identified only because they were born there (travel not acknowledge). There were 1337 (1.6%) donors in Toronto in 1997 with risk travel and none were positive for the presence of T. cruzi antibody. CONCLUSION: Donors can answer a short question about cumulative time in Latin America with similar accuracy to detailed questioning, but screening questions should also include country of birth.

Declining hepatitis C rates in first-time blood donors: insight from surveillance and case-control risk factor studies.

BACKGROUND: Hepatitis C virus (HCV) rates have decreased steadily in first-time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported. STUDY DESIGN AND METHODS: Descriptive analysis of first-time blood donors by HCV positivity status and year (1993--2006), sex, and age was carried out. HCV-positive first-time donors and matched controls participated in a confidential scripted telephone interview about risk factors in 1993 through 1994 and in 2005 through 2006, and risk factors independently predicting HCV positivity were determined with multiple logistic regression. RESULTS: HCV-positive donations occurred most frequently in donors born between 1945 and 1964 and decreased in this birth cohort over time (p < 0.01). At present, most first-time donors (74%) are born after 1964. History of intravenous drug use, sex with an intravenous drug user, blood transfusion, and tattoo independently predicted (p < 0.01) HCV positivity in both periods (1993--1994 and 2005--2006). CONCLUSION: Most HCV-positive donors were born between 1945 and 1964, and the decline in HCV rates is associated primarily with this birth cohort. The key risk factors predicting HCV positivity did not change over the 13 years of the study. With approximately two-thirds of HCV-positive Canadians in the general population having been tested for HCV, potential donors may be aware of their HCV status and be likely to self-defer. This, and an increasing proportion of first-time donors born after 1964, may contribute to declining HCV rates in first-time donors.

Experience of a network of transfusion coordinators for blood conservation (Ontario Transfusion Coordinators [ONTraC]).

BACKGROUND: The experiences of the development of a provincial program to promote blood conservation are herein reported. STUDY DESIGN AND METHODS: Transfusion coordinators were placed in 23 Ontario hospitals. Anonymized laboratory and clinical information was collected in a defined number of all consecutive patients admitted for three designated procedures: knee arthroplasty, abdominal aortic aneurysm (AAA), and coronary artery bypass graft (CABG) surgery (n approximately 1100, 300, and 300 at each time period, respectively). RESULTS: Considerable interinstitutional variation was observed in the proportion of patients who received transfusions. At 12 months, and over the 24-month period of the project, most hospitals demonstrated decreased use of allogeneic blood; at 12 months an approximate 24 percent reduction in patients undergoing knee surgery, 14 percent in AAA, and 23 percent in CABG was obtained. In addition, patients who received transfusions received less allogeneic blood. Patients who did not receive allogeneic transfusions had lower postoperative infection rates (p < 0.05) and length of stay (p < 0.0001); allogeneic transfusion was an independent predictor of increased length of stay. The main blood conservation measures employed during this time were education, preoperative autologous donation, erythropoietin, and cell salvage. CONCLUSION: The implementation of a provincial network of transfusion coordinators was feasible and allogeneic transfusion rates declined over the period the program has been in place.

Face-to-face interviewing in predonation screening: lack of effect on detected human immunodeficiency virus and hepatitis C virus infections.

BACKGROUND: Predonation screening has become more elaborate over the years, while human immunodeficiency virus (HIV)- and hepatitis C virus (HCV)-positive donations have declined. The impact of face-to-face interviewing and of the format of the Donor Health Assessment Questionnaire (DHAQ) have not been evaluated. STUDY DESIGN AND METHODS: Canadian Blood Services DHAQ records between 1990 and 2004 were examined, and changes in them were tracked. The proportion of first-time donors permanently deferred for HIV or HCV risk, and the HIV and HCV rates per 100,000 donations, were calculated annually. Time-series analysis was used to determine whether major predonation screening changes had any effect on the HIV or HCV rates or permanent deferrals. RESULTS: In 1992, receiving money or drugs for sex was added to the DHAQ; otherwise, the content of high-risk questions changed little between 1990 and 2004. In 1997, the method of administration of the DHAQ changed from donor-completed to face-to-face interviewing for high-risk questions. Permanent deferrals for HIV or HCV risk factors and HIV and HCV rates in first-time donors decreased over this period. The HIV rates were close to 0 before 1997, whereas HCV rates decreased steadily through 2004. There was no interruption in rates in 1997 when the method of administration changed. CONCLUSION: Face-to-face interviewing for high-risk questions had no effect on HIV or HCV rates in first-time donations over 15 years of observation (during the latter 8 of which face-to-face interviewing was in place), and it did not increase permanent deferrals for HIV or HCV risk factors.

Predictive ability of sequential surveys in determining donor loss from increasingly stringent variant Creutzfeldt-Jakob disease deferral policies.

BACKGROUND: Predonation screening questions about travel increase the safety of the blood supply from diseases such as variant Creutzfeldt-Jakob disease (vCJD) and malaria. This study examines the ability of sequential surveys to predict actual travel deferrals and the operational validity of travel questions. STUDY DESIGN AND METHODS: To assess donor travel histories before implementing key deferral policies, two donor surveys were carried out at Canadian Blood Services collection sites in February 1999 (8026 donors) and March 2001 (13,623 donors). In-person interviews were carried out with 1530 donors to assess the operational validity of the short travel question. Time-series analysis was used to determine whether there was a change in deferrals when deferral policies were implemented. Predicted donor loss estimates based on survey results were compared with actual deferrals. RESULTS: Deferrals increased significantly (p < 0.05) when vCJD deferral policies were implemented in October 1999 and September 2001, but not in October 2000. Survey data accurately predicted deferrals 6 months after implementation from the initial policy (2.51% predicted vs. 2.51% actual), but there were fewer deferrals than predicted for the second (2.89% predicted vs. 2.26% actual, p < 0.01) and third deferral policies (3.10% predicted vs. 1.89% actual, p < 0.01). There was 96 percent agreement between donor responses to a short screening question and a detailed travel history. CONCLUSION: The initial survey accurately predicted the actual donor deferral rate, but the deferral rate was less than predicted for subsequent, more stringent donor deferral policies. Donors answered a short travel question suitable for donor screening similarly to a very detailed travel history.

Incidence and estimated rates of residual risk for HIV, hepatitis C, hepatitis B and human T-cell lymphotropic viruses in blood donors in Canada, 1990-2000.

BACKGROUND: Since 1990, the Canadian Red Cross Society and Canadian Blood Services have been testing blood donors for hepatitis C virus (HCV) antibody and HCV nucleic acids and have supplemented HIV antibody testing with p24 antigen testing. We report trends in the incidence of blood-transmissible viral markers and estimates of the risk of undetected infection in donors over the last decade. METHODS: We extracted anonymous donor and blood-transmissible disease information from the Canadian Blood Services National Epidemiology Donor Database for 8.9 million donations from 2.1 million donors between June 1990 and December 2000. The risk of transfusion-transmitted infection (or "residual risk") refers to the chance that an infected donation escapes detection because of a laboratory test's window period (i.e., the time between infection and detection of the virus by that test). We determined the probability of residual contamination of a unit of blood after testing by using the incidence/window period model, which is based on the incidence of infection in repeat donors and the window period for each laboratory test. The viral markers evaluated in the study were HIV, HCV, hepatitis B virus (HBV) and human T-cell lymphotropic virus (HTLV). RESULTS: Except for HBV, the transmissible-disease rates of the other evaluated viruses decreased over the study period, with less of a decrease for HTLV. In 2000, the transmissible-disease-positive rate per 100 000 donations was 0.38 for HIV, 16.83 for HCV, 12.40 for HBV and 1.77 for HTLV. The residual risk of HIV, HCV and HTLV decreased over the study period; the residual risk of HBV fluctuated throughout the decade. The current residual risk per million donations is 0.10 for HIV, 0.35 for HCV, 13.88 for HBV and 0.95 for HTLV. INTERPRETATION: Except for HBV, the estimated risk of undetected infection (residual risk) has decreased over time. The rates of transmissible disease and the probability of undetected transmission of infection are at par with, if not lower than, those reported for other industrialized countries.

Proceedings of a consensus conference: blood-borne HIV and hepatitis-optimizing the donor selection process.

Over the past several years, concern for the safety of blood transfusion has evolved from a primary focus on bacterial infections such as syphilis to viral infections including hepatitis B, C, and human immunodeficiency virus (HIV), and most recently, the theoretical risk of variant Creutzfeldt-Jakob Disease (vCJD). As a result of these changes, blood bankers have found themselves faced with the dilemma of balancing the rights of transfusion recipients to receive safe blood products, with the rights of individuals wishing to donate blood as an altruistic contribution to society.