Using sentinel surveillance to monitor effectiveness of influenza vaccine is feasible: A pilot study in Denmark

The influenza vaccine for the season 2003/04 did not contain the circulating A(H3N2)/Fujian virus strain. Vaccine effectiveness (VE) estimates were needed but unavailable. We explored whether or not laboratory based influenza surveillance can be used to estimate VE. We carried out a case-control study nested within Danish sentinel surveillance. A case was defined as a person aged 25 or above with A(H3N2)/Fujian/411/02 influenza. Four controls per case, matched on age groups and time, were selected from clients of sentinel practitioners (SP) who reported cases. SPs collected the following data in structured one-page questionnaires: vaccination status, chronic illness and previous pneumococcal vaccination. We sent postal survey questionnaires to participating SPs to assess acceptability and simplicity of data collection. Twenty four cases were identified. Data from 19 case-control sets were analysed. One control was excluded because information on vaccination status was missing. Two of the 19 cases and 11 of 75 controls had been vaccinated against influenza. The VE adjusted for chronic illness was 33% (95% CI 0%–88%) and 37% (95% CI 0%–89%) when excluding 5 controls with influenza-like illness. Twenty two SPs returned survey questionnaires. Fifteen of 17 SPs reported that it was easy to find controls. SPs collected data through interviews and clinical notes, spending 1 to 5 minutes per case and 5 to 15 minutes for all four controls. Nineteen of 22 SPs considered the amount of time they spent on the study to be acceptable, 17 said that they would like to participate again, and none ruled out further participation. Le contrôle de l’EV au sein des systèmes de surveillance sentinelle est faisable. Les nombres restreints de notre étude limitent l’interprétation de l’EV. Une étude étendue à l’échelle européenne, comprenant plusieurs pays, pourrait surmonter cette limitation et offrir des évaluations de l’efficacité vaccinale plus tôt dans la saison, pour différents groupes d’âge et pour des souches virales émergentes, incluant les sous-types nouveaux et pandémiques. Monitoring VE within sentinel surveillance systems is feasible. The small numbers in our study limit interpretation of VE. Expansion to a European multicountry study could overcome this limitation and provide VE estimates earlier in the season, for different age groups and emerging virus strains, including new and pandemic subtypes.

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Utility of Nontraditional Data Sources for Early Detection of Influenza

Online Journal of Public Health Informatics ◽

10.5210/ojphi.v9i1.7636 ◽

2017 ◽

Vol 9 (1) ◽

Author(s):

Shari Barlow ◽

Jonathan Temte ◽

Yenlik Zheteyeva ◽

Ashley Fowlkes ◽

Carrie Reed ◽

...

Keyword(s):

Age Groups ◽

School Closure ◽

Influenza Viruses ◽

Influenza Surveillance ◽

Surveillance Systems ◽

School Absenteeism ◽

School Closures ◽

School Based ◽

Influenza Transmission ◽

Influenza Outbreaks

ObjectiveThis session will provide an overview of the current systemsfor influenza surveillance; review the role of schools in influenzatransmission; discuss relationships between school closures, schoolabsenteeism, and influenza transmission; and explore the usefulnessof school absenteeism and unplanned school closure monitoring forearly detection of influenza in schools and broader communities.IntroductionInfluenza surveillance is conducted through a complex networkof laboratory and epidemiologic systems essential for estimatingpopulation burden of disease, selecting influenza vaccine viruses,and detecting novel influenza viruses with pandemic potential (1).Influenza surveillance faces numerous challenges, such as constantlychanging influenza viruses, substantial variability in the number ofaffected people and the severity of disease, nonspecific symptoms,and need for laboratory testing to confirm diagnosis. Exploringadditional components that provide morbidity information mayenhance current influenza surveillance.School-aged children have the highest influenza incidence ratesamong all age groups. Due to the close interaction of children inschools and subsequent introduction of influenza into households,it is recognized that schools can serve as amplification points ofinfluenza transmission in communities. For this reason, pandemicpreparedness recommendations include possible pre-emptive schoolclosures, before transmission is widespread within a school system orbroader community, to slow influenza transmission until appropriatevaccines become available. During seasonal influenza epidemics,school closures are usually reactive, implemented in response tohigh absenteeism of students and staff after the disease is alreadywidespread in the community. Reactive closures are often too late toreduce influenza transmission and are ineffective.To enhance timely influenza detection, a variety of nontraditionaldata sources have been explored. School absenteeism was suggestedby several research groups to improve school-based influenzasurveillance. A study conducted in Japan demonstrated that influenza-associated absenteeism can predict influenza outbreaks with highsensitivity and specificity (2). Another study found the use of all-causes absenteeism to be too nonspecific for utility in influenzasurveillance (3). Creation of school-based early warning systemsfor pandemic influenza remains an interest, and further studies areneeded. The panel will discuss how school-based surveillance cancomplement existing influenza surveillance systems.

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Evaluation of the Influenza Sentinel Surveillance System in the Democratic Republic of Congo, 2012-2015

10.21203/rs.2.10330/v1 ◽

2019 ◽

Author(s):

Pélagie Diambalula Babakazo ◽

Joelle Kabamba-Tshilobo ◽

Emile Okitolonda Wemakoy ◽

Léopold Lubula ◽

Léonie Kitoko Manya ◽

...

Keyword(s):

Data Quality ◽

Surveillance System ◽

Democratic Republic ◽

Democratic Republic Of Congo ◽

Sentinel Surveillance ◽

World Health ◽

Influenza Surveillance ◽

Surveillance Systems ◽

Republic Of Congo ◽

Sentinel Surveillance System

Abstract Background The World Health Organization recommends periodic evaluations of influenza surveillance systems to identify areas for improvement and provide evidence of data reliability for policymaking. However, data about the performance of established influenza surveillance systems are limited in Africa, including in the Democratic Republic of Congo (DRC). Methods We used the Centers for Disease Control and Prevention guidelines to evaluate the performance of the influenza sentinel surveillance system (ISSS) in DRC during 2012-2015. The performance of the system was evaluated using eight surveillance attributes: (i) data quality and completeness for key variables, (ii) timeliness, (iii) representativeness, (iv) flexibility, (v) simplicity, (vi) acceptability, (vii) stability and (viii) utility. For each attribute, specific indicators were developed and described using quantitative and qualitative methods. Scores for each indicator were as follows: <60% weak performance; 60-79% moderate performance; ≥80% good performance. Results During 2012-2015, we enrolled and tested 4,339 patients with influenza-like illness (ILI) and 2,869 patients with severe acute respiratory illness (SARI) from 11 sentinel sites situated in 5 of 11 provinces. Influenza viruses were detected in 446 (10.3%) samples from patients with ILI and in 151 (5.5%) samples from patients with SARI with higher detection during December-May. Data quality and completeness was >90% for all evaluated indicators. Other strengths of the system were timeliness, representativeness, simplicity, stability and utility that scored >70% each. Flexibility and acceptability had moderate to week performance. It was reported that the ISSS contributed to: (i) a better understanding of the epidemiology, circulating patterns and proportional contribution of influenza virus among patients with ILI or SARI; (ii) acquisition of new key competences related to influenza surveillance and diagnosis; and (iii) continuous education of surveillance staff and clinicians at sentinel sites about influenza. However, due to limited resources no actions were undertaken to mitigate the impact of seasonal influenza epidemics. Conclusions The system performed overall satisfactorily and provided reliable and timely data about influenza circulation in DRC. The simplicity of the system contributed to its stability. A better use of the available data could be made to inform and promote prevention interventions especially among the most vulnerable groups.

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Estimation of the incidence of MRSA patients: evaluation of a surveillance system using health insurance claim data

Epidemiology and Infection ◽

10.1017/s0950268816000674 ◽

2016 ◽

Vol 144 (11) ◽

pp. 2260-2267 ◽

Cited By ~ 2

Author(s):

S. TANIHARA ◽

S. SUZUKI

Keyword(s):

Health Insurance ◽

Surveillance System ◽

Age Groups ◽

Claim Data ◽

Sentinel Surveillance ◽

Surveillance Systems ◽

Insurance Claim ◽

Medical Facilities ◽

Insurance Claim Data ◽

Using Data

SUMMARYBecause sentinel surveillance systems cannot obtain information about patients who visit non-sentinel medical facilities, the characteristics of patients identified by these systems may be biased. In this study, we evaluated the representativeness of a methicillin-resistant Staphylococcus aureus (MRSA) surveillance system using health insurance claim (HIC) data, which does not depend on physician notification. We calculated the age-specific incidence of MRSA patients using data from the Japan Nosocomial Infections Surveillance (JANIS) programme, which is based on sentinel surveillance systems, and inpatient HICs submitted to employee health insurance organizations in 2011, and then computed age-specific incidence ratios between the HIC and JANIS data. Age-specific MRSA incidence in both datasets followed J-shaped curves with similar shapes. For all age groups, the ratios between HIC and JANIS data were around 10. These findings indicate that JANIS notification of MRSA cases was not affected by patients’ age.

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Performance of surveillance case definitions for respiratory syncytial virus infections through the sentinel influenza surveillance system, Portugal, 2010 to 2018

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.45.1900140 ◽

2019 ◽

Vol 24 (45) ◽

Cited By ~ 2

Author(s):

Emma Sáez-López ◽

Pedro Pechirra ◽

Inês Costa ◽

Paula Cristóvão ◽

Patrícia Conde ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Characteristic Curve ◽

Age Groups ◽

Case Definition ◽

Influenza Surveillance ◽

Surveillance Systems ◽

The European Union ◽

Case Definitions ◽

Rsv Infection ◽

Syncytial Virus

Background Well-established influenza surveillance systems (ISS) can be used for respiratory syncytial virus (RSV) surveillance. In Portugal, RSV cases are detected through the ISS using the European Union (EU) influenza-like illness (ILI) case definition. Aim To investigate clinical predictors for RSV infection and how three case definitions (EU ILI, a modified EU acute respiratory infection, and one respiratory symptom) performed in detecting RSV infections in Portugal. Methods This observational retrospective study used epidemiological and laboratory surveillance data (October 2010–May 2018). Associations between clinical characteristics and RSV detection were analysed using logistic regression. Accuracy of case definitions was assessed through sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). A 0.05 significance level was accepted. Results The study involved 6,523 persons, including 190 (2.9%) RSV cases. Among 183 cases with age information, RSV infection was significantly more frequent among individuals < 5 years (n = 23; 12.6%) and ≥ 65 years (n = 45; 24.6%) compared with other age groups (p < 0.0001). Cough (odds ratio (OR): 2.4; 95% confidence interval (CI): 1.2–6.5) was the best RSV-infection predictor considering all age groups, while shortness of breath was particularly associated with RSV-positivity among ≤ 14 year olds (OR: 6.7; 95% CI: 2.6–17.4 for 0–4 year olds and OR: 6.7; 95% CI: 1.5–28.8 for 5–14 year olds). Systemic symptoms were significantly associated with RSV-negative and influenza-positive cases. None of the case definitions were suitable to detect RSV infections (AUC = 0.51). Conclusion To avoid underestimating the RSV disease burden, RSV surveillance within the Portuguese sentinel ISS would require a more sensitive case definition than ILI and, even a different case definition according to age.

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Evaluation of the Influenza Sentinel Surveillance System in the Democratic Republic of Congo, 2012-2015

10.21203/rs.2.12209/v3 ◽

2019 ◽

Author(s):

Pelagie Diambalula Babakazo ◽

Joelle Kabamba-Tshilobo ◽

Emile Okitolonda Wemakoy ◽

Léopold Lubula ◽

Léonie Kitoko Manya ◽

...

Keyword(s):

Data Quality ◽

Surveillance System ◽

Democratic Republic ◽

Democratic Republic Of Congo ◽

Sentinel Surveillance ◽

World Health ◽

Influenza Surveillance ◽

Surveillance Systems ◽

Republic Of Congo ◽

Sentinel Surveillance System

Abstract Background The World Health Organization recommends periodic evaluations of influenza surveillance systems to identify areas for improvement and provide evidence of data reliability for policymaking. However, data about the performance of established influenza surveillance systems are limited in Africa, including in the Democratic Republic of Congo (DRC). Methods We used the Centers for Disease Control and Prevention guidelines to evaluate the performance of the influenza sentinel surveillance system (ISSS) in DRC during 2012-2015. The performance of the system was evaluated using eight surveillance attributes: (i) data quality and completeness for key variables, (ii) timeliness, (iii) representativeness, (iv) flexibility, (v) simplicity, (vi) acceptability, (vii) stability and (viii) utility. For each attribute, specific indicators were developed and described using quantitative and qualitative methods. Scores for each indicator were as follows: <60% weak performance; 60-79% moderate performance; ≥80% good performance. Results During 2012-2015, we enrolled and tested 4,339 patients with influenza-like illness (ILI) and 2,869 patients with severe acute respiratory illness (SARI) from 11 sentinel sites situated in 5 of 11 provinces. Influenza viruses were detected in 446 (10.3%) samples from patients with ILI and in 151 (5.5%) samples from patients with SARI with higher detection during December-May. Data quality and completeness was >90% for all evaluated indicators. Other strengths of the system were timeliness, simplicity, stability and utility that scored >70% each. Representativeness, flexibility and acceptability had moderate performance. It was reported that the ISSS contributed to: (i) a better understanding of the epidemiology, circulating patterns and proportional contribution of influenza virus among patients with ILI or SARI; (ii) acquisition of new key competences related to influenza surveillance and diagnosis; and (iii) continuous education of surveillance staff and clinicians at sentinel sites about influenza. However, due to limited resources no actions were undertaken to mitigate the impact of seasonal influenza epidemics. Conclusions The system performed overall satisfactorily and provided reliable and timely data about influenza circulation in DRC. The simplicity of the system contributed to its stability. A better use of the available data could be made to inform and promote prevention interventions especially among the most vulnerable groups.

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Identifying early changes in influenza vaccination uptake following a government funded immunisation program using a participatory community surveillance program

Communicable Diseases Intelligence ◽

10.33321/cdi.2020.44.57 ◽

2020 ◽

Vol 44 ◽

Author(s):

Sarah A Moberley ◽

Sandra J Carlson ◽

David N Durrheim ◽

Craig B Dalton

Keyword(s):

Influenza Vaccine ◽

Surveillance System ◽

Vaccine Coverage ◽

Age Groups ◽

Influenza Surveillance ◽

Surveillance Program ◽

Community Based ◽

Influenza Like Illness ◽

National Immunisation ◽

The University

Following Australia’s severe influenza season in 2017, the health departments of the states and territories commenced funding in 2018 of influenza vaccine for all children aged six months to five years. As the national immunisation register has recently been extended to include recording of vaccination for all age groups, Australia’s community-based influenza-like illness (ILI) surveillance system, Flutracking, was used to explore influenza vaccine coverage in participants. Flutracking participants respond to a weekly survey about ILI from April to October each year. Participants report their influenza vaccine status with the current year’s vaccine in the first weekly survey, and if unvaccinated (or unknown), participants are prompted with the question weekly until the end of the Flutracking season. Detailed methods for Flutracking are available elsewhere.1 Self-reported vaccine coverage by age group (<5 years, 5 to 17 years, 18 to 64 years and ≥65 years) was calculated at 21 October (timing of the final 2018 Flutracking survey) for participants who had completed at least one survey in 2018. The five-year average was calculated for the percentage vaccinated at the end of the Flutracking survey for the years 2013 to 2017, and compared to 2018. Flutracking received ethics approval from the University of Newcastle (# 06/03/22.403) in 2006. In 2009 the program applied to the University of Newcastle to exit the ethics committee review as Flutracking had been incorporated into the national influenza surveillance system. The total number of participants completing at least one survey increased from 18,437 in 2013 to 45,532 in 2018. Flutracking participants are more likely to be female (59.8% compared to 50.4%) and more likely to have completed a postgraduate degree (22.6% compared to 3.6%) than the general Australian population.2 A relatively large proportion of Flutracking participants are health care workers, working face to face with patients (17.5%). Keywords: flutracking, vaccine coverage, influenza vaccine, influenza like illness, community based surveillance

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Seasonal Influenza Vaccine Effectiveness in People With Asthma: A National Test-Negative Design Case-Control Study

Clinical Infectious Diseases ◽

10.1093/cid/ciz1086 ◽

2019 ◽

Vol 71 (7) ◽

pp. e94-e104

Author(s):

Eleftheria Vasileiou ◽

Aziz Sheikh ◽

Chris C Butler ◽

Chris Robertson ◽

Kimberley Kavanagh ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza Vaccination ◽

Case Control Study ◽

Influenza Infection ◽

Age Groups ◽

Case Control ◽

Vaccine Effectiveness ◽

Vaccine Uptake ◽

Individual Patient Level ◽

Control Study

Abstract Background Influenza infection is a trigger of asthma attacks. Influenza vaccination can potentially reduce the incidence of influenza in people with asthma, but uptake remains persistently low, partially reflecting concerns about vaccine effectiveness (VE). Methods We conducted a test-negative designed case-control study to estimate the effectiveness of influenza vaccine in people with asthma in Scotland over 6 seasons (2010/2011 to 2015/2016). We used individual patient–level data from 223 practices, which yielded 1 830 772 patient-years of data that were linked with virological (n = 5910 swabs) data. Results Vaccination was associated with an overall 55.0% (95% confidence interval [CI], 45.8–62.7) risk reduction of laboratory-confirmed influenza infections in people with asthma over 6 seasons. There were substantial variations in VE between seasons, influenza strains, and age groups. The highest VE (76.1%; 95% CI, 55.6–87.1) was found in the 2010/2011 season, when the A(H1N1) strain dominated and there was a good antigenic vaccine match. High protection was observed against the A(H1N1) (eg, 2010/2011; 70.7%; 95% CI, 32.5–87.3) and B strains (eg, 2010/2011; 83.2%; 95% CI, 44.3–94.9), but there was lower protection for the A(H3N2) strain (eg, 2014/2015; 26.4%; 95% CI, −12.0 to 51.6). The highest VE against all viral strains was observed in adults aged 18–54 years (57.0%; 95% CI, 42.3–68.0). Conclusions Influenza vaccination gave meaningful protection against laboratory-confirmed influenza in people with asthma across all seasons. Strategies to boost influenza vaccine uptake have the potential to substantially reduce influenza-triggered asthma attacks.

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Mid-season influenza vaccine effectiveness 2011–2012: A Department of Defense Global, Laboratory-based, Influenza Surveillance System case–control study estimate

Vaccine ◽

10.1016/j.vaccine.2013.01.022 ◽

2013 ◽

Vol 31 (13) ◽

pp. 1651-1655 ◽

Cited By ~ 4

Author(s):

Victor H. MacIntosh ◽

Katie J. Tastad ◽

Angelia A. Eick-Cost

Keyword(s):

Influenza Vaccine ◽

Department Of Defense ◽

Surveillance System ◽

Case Control Study ◽

Case Control ◽

Vaccine Effectiveness ◽

Influenza Surveillance ◽

Control Study

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Impact of influenza vaccination programmes among the elderly population on primary care, Portugal, Spain and the Netherlands: 2015/16 to 2017/18 influenza seasons

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.45.1900268 ◽

2019 ◽

Vol 24 (45) ◽

Author(s):

Ausenda Machado ◽

Clara Mazagatos ◽

Frederika Dijkstra ◽

Irina Kislaya ◽

Alin Gherasim ◽

...

Keyword(s):

Primary Care ◽

The Netherlands ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Vaccination Programme ◽

Vaccine Coverage ◽

The Elderly ◽

Influenza Surveillance ◽

Surveillance Systems ◽

The Impact

Background To increase the acceptability of influenza vaccine, it is important to quantify the overall benefits of the vaccination programme. Aim To assess the impact of influenza vaccination in Portugal, Spain and the Netherlands, we estimated the number of medically attended influenza-confirmed cases (MAICC) in primary care averted in the seasons 2015/16 to 2017/18 among those ≥ 65 years. Methods We used an ecological approach to estimate vaccination impact. We compared the number of observed MAICC (n) to the estimated number that would have occurred without the vaccination programme (N). To estimate N, we used: (i) MAICC estimated from influenza surveillance systems, (ii) vaccine coverage, (iii) pooled (sub)type-specific influenza vaccine effectiveness estimates for seasons 2015/16 to 2017/18, weighted by the proportion of virus circulation in each season and country. We estimated the number of MAICC averted (NAE) and the prevented fraction (PF) by the vaccination programme. Results The annual average of NAE in the population ≥ 65 years was 33, 58 and 204 MAICC per 100,000 in Portugal, Spain and the Netherlands, respectively. On average, influenza vaccination prevented 10.7%, 10.9% and 14.2% of potential influenza MAICC each season in these countries. The lowest PF was in 2016/17 (4.9–6.1%) with an NAE ranging from 24 to 69 per 100,000. Conclusions Our results suggest that influenza vaccination programmes reduced a substantial number of MAICC. Together with studies on hospitalisations and deaths averted by influenza vaccination programmes, this will contribute to the evaluation of the impact of vaccination strategies and strengthen public health communication.

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