scholarly journals Utility of Nontraditional Data Sources for Early Detection of Influenza

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.

scholarly journals Effects of School Holidays on Seasonal Influenza in South Korea, 2014–2016

2020 ◽  
Vol 222 (5) ◽  
pp. 832-835 ◽  
Author(s):  
Sukhyun Ryu ◽  
Sheikh Taslim Ali ◽  
Benjamin J Cowling ◽  
Eric H Y Lau
Keyword(s):  
South Korea ◽  
Seasonal Influenza ◽  
School Closure ◽  
Surveillance Data ◽  
Influenza Surveillance ◽  
School Closures ◽  
School Aged Children ◽  
Severe Influenza ◽  
Influenza Transmission

Abstract School closures are considered as a potential nonpharmaceutical intervention to mitigate severe influenza epidemics and pandemics. In this study, we assessed the effects of scheduled school closure on influenza transmission using influenza surveillance data before, during, and after spring breaks in South Korea, 2014–2016. During the spring breaks, influenza transmission was reduced by 27%–39%, while the overall reduction in transmissibility was estimated to be 6%–23%, with greater effects observed among school-aged children.

scholarly journals Increased urbanization reduced the effectiveness of school closures on seasonal influenza epidemics in China

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hao Lei ◽  
Hangjin Jiang ◽  
Nan Zhang ◽  
Xiaoli Duan ◽  
Tao Chen ◽  
...  
Keyword(s):  
Seasonal Influenza ◽  
Southern China ◽  
Social Contact ◽  
School Closure ◽  
Surveillance Data ◽  
Reproductive Number ◽  
Influenza Surveillance ◽  
Sirs Model ◽  
Influenza Transmission ◽  
The Impact

Abstract Background School closure is a common mitigation strategy during severe influenza epidemics and pandemics. However, the effectiveness of this strategy remains controversial. In this study, we aimed to explore the effectiveness of school closure on seasonal influenza epidemics in provincial-level administrative divisions (PLADs) with varying urbanization rates in China. Methods This study analyzed influenza surveillance data between 2010 and 2019 provided by the Chinese National Influenza Center. Taking into consideration the climate, this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China. The effect of school closure on influenza transmission was evaluated by the reduction of the effective reproductive number of seasonal influenza during school winter breaks compared with that before school winter breaks. An age-structured Susceptible-Infected-Recovered-Susceptible (SIRS) model was built to model influenza transmission in different levels of urbanization. Parameters were determined using the surveillance data via robust Bayesian method. Results Between 2010 and 2019, in the less urbanized provinces: Hebei, Zhejiang, Jiangsu and Anhui, during school winter breaks, the effective reproductive number of seasonal influenza epidemics reduced 14.6% [95% confidential interval (CI): 6.2–22.9%], 9.6% (95% CI: 2.5–16.6%), 7.3% (95% CI: 0.1–14.4%) and 8.2% (95% CI: 1.1–15.3%) respectively. However, in the highly urbanized cities: Beijing, Tianjin and Shanghai, it reduced only 5.2% (95% CI: -0.7–11.2%), 4.1% (95% CI: -0.9–9.1%) and 3.9% (95% CI: -1.6–9.4%) respectively. In China, urbanization is associated with decreased proportion of children and increased social contact. According to the SIRS model, both factors could reduce the impact of school closure on seasonal influenza epidemics, and the proportion of children in the population is thought to be the dominant influencing factor. Conclusions Effectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns. School closure should be recommended in the low urbanized regions in China in the influenza seasons. Graphical abstract

scholarly journals Evaluation of Point of Need Diagnostic Tests for Use in California Influenza Outbreaks

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Ashlynn Daughton ◽  
Alina Deshpande
Keyword(s):  
Data Streams ◽  
Surveillance System ◽  
Laboratory Data ◽  
Developed Countries ◽  
The United States ◽  
Diagnostic Tools ◽  
Influenza Surveillance ◽  
Mortality Data ◽  
Surveillance Systems ◽  
Influenza Outbreaks

Because of the potential threats flu viruses pose, the United States, like many developed countries, has a very well established flu surveillance system consisting of 10 components collecting laboratory data, mortality data, hospitalization data and sentinel outpatient care data. Currently, this surveillance system is estimated to lag behind the actual seasonal outbreak by one to two weeks. As new data streams come online, it is important to understand what added benefit they bring to the flu surveillance system complex. For data streams to be effective, they should provide data in a more timely fashion or provide additional data that current surveillance systems cannot provide. Two multiplexed diagnostic tools designed to test syndromically relevant pathogens and wirelessly upload data for rapid integration and interpretation were evaluated to see how they fit into the influenza surveillance scheme in California.

scholarly journals Modeling influenza seasonality in the tropics and subtropics

2021 ◽  
Vol 17 (6) ◽  
pp. e1009050
Author(s):  
Haokun Yuan ◽  
Sarah C. Kramer ◽  
Eric H. Y. Lau ◽  
Benjamin J. Cowling ◽  
Wan Yang
Keyword(s):  
Hong Kong ◽  
Mechanistic Model ◽  
Seasonal Pattern ◽  
Influenza Viruses ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Influenza Surveillance ◽  
Influenza Epidemic ◽  
Influenza Transmission ◽  
The Impact

Climate drivers such as humidity and temperature may play a key role in influenza seasonal transmission dynamics. Such a relationship has been well defined for temperate regions. However, to date no models capable of capturing the diverse seasonal pattern in tropical and subtropical climates exist. In addition, multiple influenza viruses could cocirculate and shape epidemic dynamics. Here we construct seven mechanistic epidemic models to test the effect of two major climate drivers (humidity and temperature) and multi-strain co-circulation on influenza transmission in Hong Kong, an influenza epidemic center located in the subtropics. Based on model fit to long-term influenza surveillance data from 1998 to 2018, we found that a simple model incorporating the effect of both humidity and temperature best recreated the influenza epidemic patterns observed in Hong Kong. The model quantifies a bimodal effect of absolute humidity on influenza transmission where both low and very high humidity levels facilitate transmission quadratically; the model also quantifies the monotonic but nonlinear relationship with temperature. In addition, model results suggest that, at the population level, a shorter immunity period can approximate the co-circulation of influenza virus (sub)types. The basic reproductive number R0 estimated by the best-fit model is also consistent with laboratory influenza survival and transmission studies under various combinations of humidity and temperature levels. Overall, our study has developed a simple mechanistic model capable of quantifying the impact of climate drivers on influenza transmission in (sub)tropical regions. This model can be applied to improve influenza forecasting in the (sub)tropics in the future.

scholarly journals Detecting influenza and emerging avian influenza virus by influenza and pneumonia surveillance systems in a large city in China, 2005 to 2016

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiaorong Guo ◽  
Dong Yang ◽  
Ruchun Liu ◽  
Yaman Li ◽  
Qingqing Hu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Surveillance System ◽  
Large City ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Incident Cases ◽  
Death Cases

Abstract Background Detecting avian influenza virus has become an important public health strategy for controlling the emerging infectious disease. Methods The HIS (hospital information system) modified influenza surveillance system (ISS) and a newly built pneumonia surveillance system (PSS) were used to monitor the influenza viruses in Changsha City, China. The ISS was used to monitor outpatients in two sentinel hospitals and to detect mild influenza and avian influenza cases, and PSS was used to monitor inpatients in 49 hospitals and to detect severe and death influenza cases. Results From 2005 to 2016, there were 3,551,917 outpatients monitored by the ISS system, among whom 126,076 were influenza-like illness (ILI) cases, with the ILI proportion (ILI%) of 3.55%. After the HIS was used, the reported incident cases of ILI and ILI% were increased significantly. From March, 2009 to September, 2016, there were 5,491,560 inpatient cases monitored by the PSS system, among which 362,743 were pneumonia cases, with a proportion of 6.61%. Among pneumonia cases, about 10.55% (38,260/362,743) of cases were severe or death cases. The pneumonia incidence increased each year in the city. Among 15 avian influenza cases reported from January, 2005 to September, 2016, there were 26.7% (4/15) mild cases detected by the HIS-modified ISS system, while 60.0% (9/15) were severe or death cases detected by the PSS system. Two H5N1 severe cases were missed by the ISS system in January, 2009 when the PSS system was not available. Conclusions The HIS was able to improve the efficiency of the ISS for monitoring ILI and emerging avian influenza virus. However, the efficiency of the system needs to be verified in a wider area for a longer time span in China.

Absenteeism in schools during the 2009 influenza A(H1N1) pandemic: a useful tool for early detection of influenza activity in the community?

2011 ◽  
Vol 140 (7) ◽  
pp. 1328-1336 ◽  
Author(s):  
E. O. KARA ◽  
A. J. ELLIOT ◽  
H. BAGNALL ◽  
D. G. F. FOORD ◽  
R. PNAISER ◽  
...  
Keyword(s):  
Syndromic Surveillance ◽  
Influenza A ◽  
Laboratory Data ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
H1n1 Pandemic ◽  
School Absenteeism ◽  
Sentinel Network ◽  
Influenza A H1n1 ◽  
Influenza Activity

SUMMARYCertain influenza outbreaks, including the 2009 influenza A(H1N1) pandemic, can predominantly affect school-age children. Therefore the use of school absenteeism data has been considered as a potential tool for providing early warning of increasing influenza activity in the community. This study retrospectively evaluates the usefulness of these data by comparing them with existing syndromic surveillance systems and laboratory data. Weekly mean percentages of absenteeism in 373 state schools (children aged 4–18 years) in Birmingham, UK, from September 2006 to September 2009, were compared with established syndromic surveillance systems including a telephone health helpline, a general practitioner sentinel network and laboratory data for influenza. Correlation coefficients were used to examine the relationship between each syndromic system. In June 2009, school absenteeism generally peaked concomitantly with the existing influenza surveillance systems in England. Weekly school absenteeism surveillance would not have detected pandemic influenza A(H1N1) earlier but daily absenteeism data and the development of baselines could improve the timeliness of the system.

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

2019 ◽  
Vol 24 (45) ◽  
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.

scholarly journals Modeling Influenza Seasonality in the Tropics and Subtropics

2021 ◽  
Author(s):  
Haokun Yuan ◽  
Sarah C. Kramer ◽  
Eric H. Y. Lau ◽  
Benjamin J. Cowling ◽  
Wan Yang
Keyword(s):  
Hong Kong ◽  
Mechanistic Model ◽  
Seasonal Pattern ◽  
Influenza Viruses ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Influenza Surveillance ◽  
Influenza Epidemic ◽  
Influenza Transmission ◽  
The Impact

AbstractClimate drivers such as humidity and temperature may play a key role in influenza seasonal transmission dynamics. Such a relationship has been well defined for temperate regions. However, to date no models capable of capturing the diverse seasonal pattern in tropical and subtropical climates exist. In addition, multiple influenza viruses could cocirculate and shape epidemic dynamics. Here we construct seven mechanistic epidemic models to test the effect of two major climate drivers (humidity and temperature) and multi-strain co-circulation on influenza transmission in Hong Kong, an influenza epidemic center located in the subtropics. Based on model fit to long-term influenza surveillance data from 1998 to 2018, we found that a simple model incorporating the effect of both humidity and temperature best recreated the influenza epidemic patterns observed in Hong Kong. The model quantifies a bimodal effect of absolute humidity on influenza transmission where both low and very high humidity levels facilitate transmission quadratically; the model also quantifies the monotonic but nonlinear relationship with temperature. In addition, model results suggest that, at the population level, a shorter immunity period can approximate the co-circulation of influenza virus (sub)types. The basic reproductive number R0 estimated by the best-fit model is also consistent with laboratory influenza survival and transmission studies under various combinations of humidity and temperature levels. Overall, our study has developed a simple mechanistic model capable of quantifying the impact of climate drivers on influenza transmission in (sub)tropical regions. This model can be applied to improve influenza forecasting in the (sub)tropics in the future.

scholarly journals A New Influenza-Tracking Smartphone App (Flu-Report) Based on a Self-Administered Questionnaire: Cross-Sectional Study (Preprint)

2018 ◽  
Author(s):  
Kazutoshi Fujibayashi ◽  
Hiromizu Takahashi ◽  
Mika Tanei ◽  
Yuki Uehara ◽  
Hirohide Yokokawa ◽  
...  
Keyword(s):  
Early Detection ◽  
Surveillance System ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Basic Information ◽  
Information And Communications Technologies ◽  
Communications Technologies ◽  
Influenza Activity ◽  
Influenza Outbreaks ◽  
Self Administered Questionnaire

BACKGROUND Influenza infections can spread rapidly, and influenza outbreaks are a major public health concern worldwide. Early detection of signs of an influenza pandemic is important to prevent global outbreaks. Development of information and communications technologies for influenza surveillance, including participatory surveillance systems involving lay users, has recently increased. Many of these systems can estimate influenza activity faster than the conventional influenza surveillance systems. Unfortunately, few of these influenza-tracking systems are available in Japan. OBJECTIVE This study aimed to evaluate the flu-tracking ability of Flu-Report, a new influenza-tracking mobile phone app that uses a self-administered questionnaire for the early detection of influenza activity. METHODS Flu-Report was used to collect influenza-related information (ie, dates on which influenza infections were diagnosed) from November 2016 to March 2017. Participants were adult volunteers from throughout Japan, who also provided information about their cohabiting family members. The utility of Flu-Report was evaluated by comparison with the conventional influenza surveillance information and basic information from an existing large-scale influenza-tracking system (an automatic surveillance system based on electronic records of prescription drug purchases). RESULTS Information was obtained through Flu-Report for approximately 10,094 volunteers. In total, 2134 participants were aged <20 years, 6958 were aged 20-59 years, and 1002 were aged ≥60 years. Between November 2016 and March 2017, 347 participants reported they had influenza or an influenza-like illness in the 2016 season. Flu-Report-derived influenza infection time series data displayed a good correlation with basic information obtained from the existing influenza surveillance system (rho, ρ=.65, P=.001). However, the influenza morbidity ratio for our participants was approximately 25% of the mean influenza morbidity ratio for the Japanese population. The Flu-Report influenza morbidity ratio was 5.06% (108/2134) among those aged <20 years, 3.16% (220/6958) among those aged 20-59 years, and 0.59% (6/1002) among those aged ≥60 years. In contrast, influenza morbidity ratios for Japanese individuals aged <20 years, 20-59 years, and ≥60 years were recently estimated at 31.97% to 37.90%, 8.16% to 9.07%, and 2.71% to 4.39%, respectively. CONCLUSIONS Flu-Report supports easy access to near real-time information about influenza activity via the accumulation of self-administered questionnaires. However, Flu-Report users may be influenced by selection bias, which is a common issue associated with surveillance using information and communications technologies. Despite this, Flu-Report has the potential to provide basic data that could help detect influenza outbreaks.

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

2006 ◽  
Vol 11 (10) ◽  
pp. 11-12 ◽  
Author(s):  
A Mazick ◽  
A H Christiansen ◽  
S Samuelsson ◽  
K Mølbak
Keyword(s):  
Chronic Illness ◽  
Influenza Vaccine ◽  
Age Groups ◽  
Pneumococcal Vaccination ◽  
Case Control ◽  
Vaccination Status ◽  
Sentinel Surveillance ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Survey Questionnaires

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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