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Anna Chu,
Rachel Savage,
Don Willison,
Natasha S Crowcroft,
Laura C Rosella,
Doug Sider,
Jason Garay,
Ian Gemmill, Anne-Luise Winter,
Richard F Davies,
Ian Johnson
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ABSTRACT: BACKGROUND: Although an increasing number of studies are documenting uses of syndromic surveillance by front line public health, few detail the value added from linking syndromic data to public health decision-making. This study seeks to understand how syndromic data informed specific public health actions during the 2009 H1N1 pandemic. METHODS: Semi-structured telephone interviews were conducted with participants from Ontario's public health departments, the provincial ministry of health and federal public health agency to gather information about syndromic surveillance systems used and the role of syndromic data in informing specific public health actions taken during the pandemic. Responses were compared with how the same decisions were made by non-syndromic surveillance users. RESULTS: Findings from 56 interviews (82% response) show that syndromic data was most used for monitoring virus activity, measuring impact on the health care system and informing the opening of influenza assessment centres in several jurisdictions, and supporting communications and messaging, rather than its intended purpose of early outbreak detection. Syndromic data had limited impact on decisions that involved the operation of immunization clinics, school closures, sending information letters home with school children or providing recommendations to health care providers. Both syndromic surveillance users and non-users reported that guidance from the provincial ministry of health, communications with stakeholders and vaccine availability were driving factors in these public health decisions. CONCLUSIONS: Syndromic surveillance had limited use in decision-making during the 2009 H1N1 pandemic in Ontario. This study provides insights into the reasons why this occurred. Despite this, syndromic data were valued for providing situational awareness and confidence to support public communications and recommendations. Developing an understanding of how syndromic data is utilized during public health events provides valuable evidence to support future investments in public health surveillance.
BMC Public Health 10/2012; 12(1):929. · 2.00 Impact Factor
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ABSTRACT: Please cite this paper as: Peci et al. (2012) Community-acquired respiratory viruses and co-infection among patients of Ontario Sentinel practices, April 2009 to February 2010. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2012.00418.x. Background Respiratory viruses are known to cocirculate but this has not been described in detail during an influenza pandemic. Objectives To describe respiratory viruses, including co-infection and associated attributes such as age, sex or comorbidity, in patients presenting with influenza-like illness to a community sentinel network, during the pandemic A(H1N1)pdm09 in Ontario, Canada. Methods Respiratory samples and epidemiologic details were collected from 1018 patients with influenza-like illness as part of respiratory virus surveillance and a multiprovincial case-control study of influenza vaccine effectiveness. Results At least one virus was detected in 668 (65·6%) of 1018 samples; 512 (50·3%) had single infections and 156 (15·3%) co-infections. Of single infections, the most common viruses were influenza A in 304 (59·4%) samples of which 275 (90·5%) were influenza A(H1N1)pdm09, and enterovirus/rhinovirus in 149 (29·1%) samples. The most common co-infections were influenza A and respiratory syncytial virus B, and influenza A and enterovirus/rhinovirus. In multinomial logistic regression analyses adjusted for age, sex, comorbidity, and timeliness of sample collection, single infection was less often detected in the elderly and co-infection more often in patients <30 years of age. Co-infection, but not single infection, was more likely detected in patients who had a sample collected within 2 days of symptom onset as compared to 3-7 days. Conclusions Respiratory viral co-infections are commonly detected when using molecular techniques. Early sample collection increases likelihood of detection of co-infection. Further studies are needed to better understand the clinical significance of viral co-infection.
Influenza and Other Respiratory Viruses 08/2012; · 4.16 Impact Factor
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ABSTRACT: We report the impact of respiratory viruses on various outbreak settings by using surveillance data from the late first and second wave periods of the 2009 pandemic. A total of 278/345(78·5%) outbreaks tested positive for at least one respiratory virus by multiplex PCR. We detected A(H1N1)pdm09 in 20·6% of all reported outbreaks of which 54·9% were reported by camps, schools, and day cares (CSDs) and 29·6% by long-term care facilities (LCFTs), whereas enterovirus/human rhinovirus (ENT/HRV) accounted for 62% outbreaks of which 83·7% were reported by long-term care facilities (LCTFs). ENT/HRV was frequently identified in LTCF outbreaks involving elderly residents, whereas in CSDs, A(H1N1)pdm09 was primarily detected.
Influenza and Other Respiratory Viruses 02/2012; 6(3):e11-5. · 4.16 Impact Factor
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Rachel Savage,
Anna Chu,
Laura C Rosella,
Natasha S Crowcroft,
Monali Varia,
Michelle E Policarpio,
Norman G Vinson, Anne-Luise Winter,
Karen Hay,
Richard F Davies,
Ian Gemmill,
Don Willison,
Ian Johnson
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ABSTRACT: Despite the growing popularity of syndromic surveillance, little is known about if or how these systems are accepted, utilized and valued by end users. This study seeks to describe the use of syndromic surveillance systems in Ontario and users' perceptions of the value of these systems within the context of other surveillance systems.
Ontario's 36 public health units, the provincial ministry of health and federal public health agency completed a web survey to identify traditional and syndromic surveillance systems used routinely and during the pandemic and to describe system attributes and utility in monitoring pandemic activity and informing decision-making.
Syndromic surveillance systems are used by 20/38 (53%) organizations. For routine surveillance, laboratory, integrated Public Health Information System and school absenteeism data are the most frequently used sources. Laboratory data received the highest ratings for reliability, timeliness and accuracy ('very acceptable' by 92, 51 and 89%). Hospital/clinic screening data were rated as the most reliable and timely syndromic data source (50 and 43%) and ED visit data the most accurate (48%). During the pandemic, laboratory data were considered the most useful for monitoring the epidemiology and informing decision-making while ED screening and visit data were considered the most useful syndromic sources.
End user perceptions are valuable for identifying opportunities for improvement and guiding further investments in public health surveillance.
Journal of Public Health 12/2011; 34(2):195-202. · 2.06 Impact Factor
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Rachel Savage,
Michael Whelan,
Ian Johnson,
Elizabeth Rea,
Marie LaFreniere,
Laura C Rosella,
Freda Lam,
Tina Badiani, Anne-Luise Winter,
Deborah J Carr, [......],
Maureen Horn,
Kathleen Dooling,
Monali Varia,
Anne-Marie Holt,
Vidya Sunil,
Catherine Grift,
Eleanor Paget,
Michael King,
John Barbaro,
Natasha S Crowcroft
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ABSTRACT: Understanding transmission dynamics of the pandemic influenza A (H1N1) virus in various exposure settings and determining whether transmissibility differed from seasonal influenza viruses was a priority for decision making on mitigation strategies at the beginning of the pandemic. The objective of this study was to estimate household secondary attack rates for pandemic influenza in a susceptible population where control measures had yet to be implemented.
All Ontario local health units were invited to participate; seven health units volunteered. For all laboratory-confirmed cases reported between April 24 and June 18, 2009, participating health units performed contact tracing to detect secondary cases among household contacts. In total, 87 cases and 266 household contacts were included in this study. Secondary cases were defined as any household member with new onset of acute respiratory illness (fever or two or more respiratory symptoms) or influenza-like illness (fever plus one additional respiratory symptom). Attack rates were estimated using both case definitions.
Secondary attack rates were estimated at 10.3% (95% CI 6.8-14.7) for secondary cases with influenza-like illness and 20.2% (95% CI 15.4-25.6) for secondary cases with acute respiratory illness. For both case definitions, attack rates were significantly higher in children under 16 years than adults (25.4% and 42.4% compared to 7.6% and 17.2%). The median time between symptom onset in the primary case and the secondary case was estimated at 3.0 days.
Secondary attack rates for pandemic influenza A (H1N1) were comparable to seasonal influenza estimates suggesting similarities in transmission. High secondary attack rates in children provide additional support for increased susceptibility to infection.
BMC Public Health 01/2011; 11:234. · 2.00 Impact Factor
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Journal of the American Geriatrics Society 10/2010; 58(10):2036-8. · 3.74 Impact Factor
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Infection Control and Hospital Epidemiology 10/2010; 31(12):1300-2. · 3.67 Impact Factor
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ABSTRACT: Diagnostic difficulties may have led to underestimation of rhinovirus infections in long-term care facilities. Using surveillance data, we found that rhinovirus caused 59% (174/297) of respiratory outbreaks in these facilities during 6 months in 2009. Disease was sometimes severe. Molecular diagnostic testing can differentiate these outbreaks from other infections such as influenza.
Emerging Infectious Diseases 09/2010; 16(9):1463-5. · 6.79 Impact Factor
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Ashleigh R Tuite,
Amy L Greer,
Michael Whelan, Anne-Luise Winter,
Brenda Lee,
Ping Yan,
Jianhong Wu,
Seyed Moghadas,
David Buckeridge,
Babak Pourbohloul,
David N Fisman
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ABSTRACT: In the face of an influenza pandemic, accurate estimates of epidemiologic parameters are required to help guide decision-making. We sought to estimate epidemiologic parameters for pandemic H1N1 influenza using data from initial reports of laboratory-confirmed cases.
We obtained data on laboratory-confirmed cases of pandemic H1N1 influenza reported in the province of Ontario, Canada, with dates of symptom onset between Apr. 13 and June 20, 2009. Incubation periods and duration of symptoms were estimated and fit to parametric distributions. We used competing-risk models to estimate risk of hospital admission and case-fatality rates. We used a Markov Chain Monte Carlo model to simulate disease transmission.
The median incubation period was 4 days and the duration of symptoms was 7 days. Recovery was faster among patients less than 18 years old than among older patients (hazard ratio 1.23, 95% confidence interval 1.06-1.44). The risk of hospital admission was 4.5% (95% CI 3.8%-5.2%) and the case-fatality rate was 0.3% (95% CI 0.1%-0.5%). The risk of hospital admission was highest among patients less than 1 year old and those 65 years or older. Adults more than 50 years old comprised 7% of cases but accounted for 7 of 10 initial deaths (odds ratio 28.6, 95% confidence interval 7.3-111.2). From the simulation models, we estimated the following values (and 95% credible intervals): a mean basic reproductive number (R0, the number of new cases created by a single primary case in a susceptible population) of 1.31 (1.25-1.38), a mean latent period of 2.62 (2.28-3.12) days and a mean duration of infectiousness of 3.38 (2.06-4.69) days. From these values we estimated a serial interval (the average time from onset of infectiousness in a case to the onset of infectiousness in a person infected by that case) of 4-5 days.
The low estimates for R0 indicate that effective mitigation strategies may reduce the final epidemic impact of pandemic H1N1 influenza.
Canadian Medical Association Journal 12/2009; 182(2):131-6. · 8.22 Impact Factor
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ABSTRACT: Women are less likely than men to receive some stroke care interventions. It is not known whether gender differences in patient preferences explain some of the observed variations in stroke care delivery.
Outpatients with and without a history of cerebrovascular disease were recruited from stroke, vascular, and general internal medicine ambulatory clinics between September 2002 and October 2003. Self-administered surveys described hypothetical scenarios, and participants were asked if they would accept therapy with thrombolysis for acute ischemic stroke or carotid endarterectomy for secondary stroke prevention. The surveys also included questions on sociodemographic factors and decision-making preferences.
A total of 586 patients (45% women) completed the survey. Women were less likely than men to accept thrombolysis (79% vs. 86%, P=0.014), even after adjustment for other factors (adjusted odds ratio [OR] 0.58, 95% confidence interval [CI] 0.37-0.92). Women and men were equally likely to accept carotid endarterectomy (82% vs. 84%, P=0.502), even after adjustment for other factors (adjusted OR 0.94, 95% CI 0.58- 1.53). Women were less confident in their decisions, were more risk averse, and would have preferred more information to assist them in their decision-making.
No gender differences were found in patient preferences for carotid surgery. However, we observed gender differences in patient preferences for thrombolysis and in general attitudes toward stroke care decision-making. Health care providers should be aware that, compared with men, women may be more concerned about risks and may require more information before they make a decision.
Medical Care 02/2006; 44(1):70-80. · 3.41 Impact Factor
