Christopher Sikora

Transmission of pandemic influenza A (H1N1) 2009 within households: Edmonton, Canada

BACKGROUND In April 2009, a novel influenza A, subtype H1N1, now referred to as the Pandemic (H1N1) 2009 virus (pH1N1), began circulating in countries around the world. Describing the transmission characteristics of this novel influenza A virus is important to predict current, and future, disease spread. The Public Health response to the first wave of pH1N1 in Alberta focused on the identification and management of secondary cases within households. OBJECTIVES The purpose of this study was to describe transmission characteristics of pH1N1 in households in Edmonton, the capital city of Alberta, during the first wave, and to identify the serial interval and secondary attack rate (SAR) in this setting. STUDY DESIGN This is a prospective analysis of pH1N1 household transmission within 87 urban Canadian households between April 30 and June 9, 2009; with each household having at least one laboratory-confirmed case. The secondary attack rate was calculated in the 262 household contacts using a weighted average by number of susceptible individuals in each household. The serial interval, or time to illness in secondary cases, was analyzed using survival analysis with a Weibull model. RESULTS Within the 87 households, 42 (48.3%) had no secondary cases develop; 25 (28.7%) had one secondary case develop; and 20 (22.9%) had more than one secondary case develop. The secondary attack rate did not decrease with increasing household size and households with two members exhibited the lowest secondary attack rate at 14.1%. Children under the age of 19, and individuals with an underlying medical condition, were at increased risk (p<0.05) of becoming a secondary case. The overall secondary attack rate among the 262 susceptible household contacts was 30.2% (95% CI: 12.6-52.2). The median serial interval for pH1N1 transmission was 3.4 days (95% CI: 2.9-3.9). CONCLUSIONS The identified transmission characteristics of pH1N1 among Canadian households differ slightly from other previously reported North American estimates, but are in keeping with historical transmission rates of pandemic influenza viruses.

Time and motion study to compare electronic and hybrid data collection systems during the pandemic (H1N1) 2009 influenza vaccination campaign.

During the pandemic (H1N1) 2009 vaccination campaign, vaccine providers collected immunization data using hybrid (paper-based and electronic methods) and electronic data systems. We measured staff time in seconds spent on data collection tasks to compare system efficiencies. The sample consisted of 38 organizations across nine Canadian provinces/territories. The total mean data collection times per client were 104 s (electronic system), 143 s (hybrid system with electronic registration) and 172 s (hybrid system with paper registration). Electronic registration and record keeping were faster than paper-based methods; these findings should be used to improve data collection for future influenza seasons.

Perceptions of immunization information systems for collecting pandemic H1N1 immunization data within Canada's public health community: A qualitative study

BackgroundImmunization information systems (IISs) are electronic registries used to monitor individual vaccination status and assess vaccine coverage. IISs are currently not widely used across Canada, where health jurisdictions employ a range of approaches to capture influenza immunization information. Conducted in advance of the 2009 H1N1 vaccination campaign, the objectives of this study were to understand the perceived value of individual-level data and IISs for influenza control, identify ideal system functions, and explore barriers to implementation.MethodsIn July and August 2009, semi-structured interviews were conducted with key informants engaged in vaccine delivery and/or pandemic planning at regional, provincial/territorial and federal levels across Canada. Key informants were recruited using a combination of convenience and snowball sampling methodologies. Qualitative analysis was used to extract themes from interview content.ResultsPatient management, assessment of vaccine coverage, and evaluation of safety and effectiveness were identified as public health priorities that would be achieved in a more timely manner, and with greater accuracy, through the use of an IIS. Features described as ideal included system flexibility, rapid data entry, and universality. Financial and human resource constraints as well as coordination between immunization providers were expressed as barriers to implementation.ConclusionsIISs were perceived as valuable by key informants for strengthening management capacity and improving evaluation of both seasonal and pandemic influenza vaccination campaigns. However, certain implementation restrictions may need to be overcome for these benefits to be achieved.

Pan-Canadian assessment of pandemic immunization data collection: study methodology

BackgroundThe collection of individual-level pandemic (H1N1) 2009 influenza immunization data was considered important to facilitate optimal vaccine delivery and accurate assessment of vaccine coverage. These data are also critical for research aimed at evaluating the new vaccines safety and effectiveness. Systems used to collect immunization data include manual approaches in which data are collected and retained on paper, electronic systems in which data are captured on computer at the point of vaccination and hybrid systems which are comprised of both computerized and manual data collection components. This studys objective was to compare the efficiencies and perceptions of data collection methods employed during Canadas pandemic (H1N1) 2009 influenza vaccination campaign.Methods/DesignA pan-Canadian observational study was conducted in a convenience sample of public health clinics and healthcare institutions during the H1N1 vaccination campaign in the fall of 2009. The study design consisted of three stages: Stage 1 involved passive observation of the sites layout, processes and client flow; Stage 2 entailed timing site staff on 20 clients through five core immunization tasks: i) client registration, ii) medical history collection, iii) medical history review, iv) vaccine administration record keeping and v) preparation of proof of vaccine administration for the client; in Stage 3, site staff completed a questionnaire regarding perceived usability of the sites data collection approach. Before the national study began, a pilot study was conducted in three seasonal influenza vaccination sites in Ontario, to both test that the proposed methodology was logistically feasible and to determine inter-rater reliability in the measurements of the research staff. Comparative analyses will be conducted across the range of data collection methods with respect to time required to collect immunization data, number and type of individual-level data elements collected, and clinic staff perceptions of the usability of the method employed at their site, using analysis of variance (ANOVA).DiscussionVarious data collection methods were employed at immunization sites across Canada during the pandemic (H1N1) 2009 influenza vaccination campaign. Our comparison of methods can facilitate planning an efficient, coordinated approach for collecting immunization data in future influenza seasons.

The Impact of Standardized Decision Support on Syndromic Surveillance in Alberta

This study examined the impact of standardized decision supports to improve school absenteeism surveillance. Two public health zones in Alberta, Canada, participated. The intervention zone received additional alerts and applied a standard response protocol. The control zone continued with their usual practice. During the study period, the intervention zone received 246 alerts, detected 19 outbreaks and reported 39 instances of public health action. The control zone reported 20 alerts, detected 16 outbreaks and no additional actions. The intervention required additional staff time. The findings suggest that using standardized decision supports results in better surveillance but only when resources were provided.