scholarly journals Characteristics of seasonal influenza A and B in Latin America: Influenza surveillance data from ten countries

PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0174592 ◽  
Author(s):  
Saverio Caini ◽  
Wladimir J. Alonso ◽  
Angel Balmaseda ◽  
Alfredo Bruno ◽  
Patricia Bustos ◽  
...  
Keyword(s):  
Latin America ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Surveillance Data ◽  
Influenza Surveillance

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.

Hospitalization of pregnant women with pandemic A(H1N1) 2009 influenza in Canada

2011 ◽  
Vol 140 (7) ◽  
pp. 1316-1327 ◽  
Author(s):  
E. ROLLAND-HARRIS ◽  
J. VACHON ◽  
R. KROPP ◽  
J. FROOD ◽  
K. MORRIS ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Comparison Group ◽  
Health Agency ◽  
Reproductive Age ◽  
Influenza Surveillance ◽  
Historical Comparison ◽  
Influenza A H1n1

SUMMARYThis article describes the epidemiology of pandemic A(H1N1) 2009 influenza in all Canadian pregnant women admitted to hospital, and compares it with historical inter-pandemic influenza activity. We used weekly hospitalization and death counts of laboratory-confirmed pandemic A(H1N1) influenza cases reported to the Public Health Agency of Canada's (PHAC) 2009–2010 national pandemic influenza surveillance programme. Pregnant women infected and admitted with the pandemic strain were described and compared with: (1) confirmed admissions of all women of reproductive age; (2) all admitted cases reported to PHAC; and (3) to a historical average of inter-pandemic seasonal influenza admissions, and pneumonia and influenza (P&I) admissions for pregnant women. During the pandemic, 263 pregnant women with confirmed infections were admitted; four died in their third trimester. The median age for admitted pregnant cases was 27·5 years, which is consistent with the median age of the 3-year historical inter-pandemic pregnant comparison group. Aboriginal women appeared to be overrepresented but ethnicity was unavailable for 15·2% of all pregnant cases. Overall admission volumes were higher than those for seasonal influenza in the historical comparison group but were lower than those for P&I admissions. Despite increased admission volumes, severe outcomes in pregnant women were proportionally fewer than in all cases admitted for influenza A(H1N1) infection during the pandemic.

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 What will the next influenza season bring about: seasonal influenza or the new A(H1N1)v? An analysis of German influenza surveillance data

2009 ◽  
Vol 14 (32) ◽  
Author(s):  
H Uphoff ◽  
S Geis ◽  
A Grüber ◽  
A M Hauri
Keyword(s):  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza Season ◽  
Influenza Viruses ◽  
Moderate Intensity ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Low Intensity ◽  
Influenza A H1n1 ◽  
Using Data

For the next influenza season (winter 2009-10) the relative contributions to virus circulation and influenza-associated morbidity of the seasonal influenza viruses A(H3N2), A(H1N1) and B, and the new influenza A(H1N1)v are still unknown. We estimated the chances of seasonal influenza to circulate during the upcoming season using data of the German influenza sentinel scheme from 1992 to 2009. We calculated type and subtype-specific indices for past exposure and the corresponding morbidity indices for each season. For the upcoming season 2009-10 our model suggests that it is unlikely that influenza A(H3N2) will circulate with more than a low intensity, seasonal A(H1N1) with more than a low to moderate intensity, and influenza B with more than a low to median intensity. The probability of a competitive circulation of seasonal influenza A with the new A(H1N1)v is low, increasing the chance for the latter to dominate the next influenza season in Germany.

scholarly journals Integrating patient and whole genome sequencing data to provide insights into the epidemiology of seasonal influenza A(H3N2) viruses

2017 ◽  
Author(s):  
Emily J. Goldstein ◽  
William T. Harvey ◽  
Gavin S. Wilkie ◽  
Samantha J. Shepherd ◽  
Alasdair R. MacLean ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Epidemiological Data ◽  
Respiratory Illness ◽  
Influenza Surveillance ◽  
Whole Genome Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data

AbstractGenetic surveillance of seasonal influenza is largely focused upon sequencing of the haemagglutinin gene. Consequently, our understanding of the contribution of the remaining seven gene segments to the evolution and epidemiological dynamics of seasonal influenza is relatively limited. The increased availability of next generation sequencing technologies allows rapid and economic whole genome sequencing (WGS). Here, 150 influenza A(H3N2) positive clinical specimens with linked epidemiological data, from the 2014/15 season in Scotland, were sequenced directly using both Sanger sequencing of the HA1 region and WGS using the Illumina MiSeq platform. Sequences generated by both methods were highly consistent and WGS provided on average >90% whole genome coverage. As reported in other European countries during 2014/15, all strains belonged to genetic group 3C, with subgroup 3C.2a predominating. Inter-subgroup reassortants were identified (9%), including three 3C.3 viruses descended from a single reassortment event, which had persisted in the population. Significant phylogenetic associations with cases of severe acute respiratory illness observed herein warrant further investigation. Severe cases were also more likely to be associated with reassortant viruses (odds ratio: 4.4 (1.3-15.5)) and occur later in the season. These results suggest that increased levels of WGS, linked to clinical and epidemiological data, could improve influenza surveillance.

scholarly journals Forecasting type-specific seasonal influenza after 26 weeks in the United States using influenza activities in other countries

2019 ◽  
Author(s):  
S. B. Choi ◽  
J. Kim ◽  
I. Ahn
Keyword(s):  
United States ◽  
Time Series ◽  
Deep Learning ◽  
Seasonal Influenza ◽  
Prediction Models ◽  
Time Lag ◽  
The United States ◽  
Surveillance Data ◽  
Influenza Surveillance ◽  
The U.S

AbstractTo identify countries that have seasonal patterns similar to the time series of influenza surveillance data in the United States and other countries, and to forecast the 2018–2019 seasonal influenza outbreak in the U.S. using linear regression, auto regressive integrated moving average, and deep learning. We collected the surveillance data of 164 countries from 2010 to 2018 using the FluNet database. Data for influenza-like illness (ILI) in the U.S. were collected from the Fluview database. This cross-correlation study identified the time lag between the two time-series. Deep learning was performed to forecast ILI, total influenza, A, and B viruses after 26 weeks in the U.S. The seasonal influenza patterns in Australia and Chile showed a high correlation with those of the U.S. 22 weeks and 28 weeks earlier, respectively. The R2 score of DNN models for ILI for validation set in 2015–2019 was 0.722 despite how hard it is to forecast 26 weeks ahead. Our prediction models forecast that the ILI for the U.S. in 2018–2019 may be later and less severe than those in 2017–2018, judging from the influenza activity for Australia and Chile in 2018. It allows to estimate peak timing, peak intensity, and type-specific influenza activities for next season at 40th week. The correlation for seasonal influenza among Australia, Chile, and the U.S. could be used to decide on influenza vaccine strategy six months ahead in the U.S.

scholarly journals Report on influenza viruses received and tested by the Melbourne WHO Collaborating Centre for Reference and Research on Influenza in 2017

2019 ◽  
Vol 43 ◽  
Author(s):  
Merryn Roe ◽  
Matthew Kaye ◽  
Pina Iannello ◽  
Hilda Lau ◽  
Iwona Buettner ◽  
...  
Keyword(s):  
Influenza A ◽  
Seasonal Influenza ◽  
Vaccine Virus ◽  
Influenza Viruses ◽  
World Health ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Neuraminidase Inhibitors ◽  
Response System ◽  
Surveillance And Response

As part of its role in the World Health Organization’s (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received a record total of 5866 human influenza positive samples during 2017. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties and were propagated in qualified cells and hens’ eggs for use as potential seasonal influenza vaccine virus candidates. In 2017, influenza A(H3) viruses predominated over influenza A(H1)pdm09 and B viruses, accounting for a total of 54% of all viruses analysed. The majority of A(H1)pdm09, A(H3) and influenza B viruses analysed at the Centre were found to be antigenically similar to the respective WHO recommended vaccine strains for the Southern Hemisphere in 2017. However, phylogenetic analysis indicated that the majority of circulating A(H3) viruses had undergone genetic drift relative to the WHO recommended vaccine strain for 2017. Of 3733 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, only two A(H1)pdm09 viruses and one A(H3) virus showed highly reduced inhibition by oseltamivir, while just one A(H1)pdm09 virus showed highly reduced inhibition by zanamivir.

scholarly journals Future Pandemic Influenza Virus Detection Relies on the Existing Influenza Surveillance Systems: A Perspective from Australia and New Zealand

2019 ◽  
Vol 4 (4) ◽  
pp. 121
Author(s):  
Lance C. Jennings ◽  
Ian G. Barr
Keyword(s):  
New Zealand ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Control Strategies ◽  
Influenza Pandemic ◽  
Virus Detection ◽  
World Health ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Influenza A H1n1

The anniversary of the 1918–1919 influenza pandemic has allowed a refocusing on the global burden of influenza and the importance of co-ordinated international surveillance for both seasonal influenza and the identification of control strategies for future pandemics. Since the introduction of the International Health Regulations (IHR), progress had been slow, until the emergence of the novel influenza A(H1N1)2009 virus and its global spread, which has led to the World Health Organization (WHO) developing a series of guidance documents on global influenza surveillance procedures, severity and risk assessments, and essential measurements for the determination of national pandemic responses. However, the greatest burden of disease from influenza occurs between pandemics during seasonal influenza outbreaks and epidemics. Both Australia and New Zealand utilise seasonal influenza surveillance to support national influenza awareness programs focused on seasonal influenza vaccination education and promotion. These programs also serve to promote the importance of pandemic preparedness.

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