scholarly journals Pandemic H1N1 influenza surveillance in Victoria, Australia, April – September, 2009

2009 ◽  
Vol 14 (42) ◽  
Author(s):  
J E Fielding ◽  
N Higgins ◽  
J E Gregory ◽  
K A Grant ◽  
M G Catton ◽  
...  
Keyword(s):  
General Practitioner ◽  
Surveillance System ◽  
Influenza A ◽  
Sentinel Surveillance ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Pandemic H1n1 ◽  
First Case ◽  
Influenza A H1n1 ◽  
Sentinel Surveillance System

Victoria was the first Australian state to report widespread transmission of pandemic H1N1 2009 influenza. Notifiable laboratory-confirmed influenza and a general practitioner sentinel surveillance system measuring influenza-like illness (ILI), including laboratory confirmation of influenza as the cause of ILI, were used to assess the pandemic. The pandemic influenza A(H1N1)v virus quickly became the dominant circulating strain and notification rates were highest in children and young adults. Despite a high number of notified cases, comparison of ILI rates suggested the season peaked in late June, was similar in magnitude to 2003 and 2007 and less severe than 1997. The majority of clinical presentations were mild, but one quarter of hospitalised cases required admission to intensive care. Given the low proportion of imported cases in the Victorian pandemic, the rapid increase in cases with no travel history and the low median age of cases notified during the phases of intense surveillance, we suggest there may have been silent importations of pandemic virus into Victoria before the first case was recognised. The usefulness of a general practitioner sentinel surveillance system to provide a comparable assessment of influenza and ILI activity over time was clearly demonstrated, and the need for similar hospital and mortality surveillance systems for influenza in Victoria was highlighted.

scholarly journals Implementation of Real-Time Laboratory-Based Influenza Surveillance System, Thailand

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Phunlerd Piyaraj ◽  
Nira Pet-hoi ◽  
Chaiyos Kunanusont ◽  
Supanee Sangiamsak ◽  
Somsak Wankijcharoen ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Influenza Virus ◽  
Real Time ◽  
Surveillance System ◽  
Influenza A ◽  
Medical Services ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Private Hospitals ◽  
Influenza A H1n1

Objective: We describe the Bangkok Dusit Medical Services Surveillance System (BDMS-SS) and use of surveillance efforts for influenza as an example of surveillance capability in near real-time among a network of 20 hospitals in the Bangkok Dusit Medical Services group (BDMS).Introduction: Influenza is one of the significant causes of morbidity and mortality globally. Previous studies have demonstrated the benefit of laboratory surveillance and its capability to accurately detect influenza outbreaks earlier than syndromic surveillance.1-3 Current laboratory surveillance has an approximately 4-week lag due to laboratory test turn-around time, data collection and data analysis. As part of strengthening influenza virus surveillance in response to the 2009 influenza A (H1N1) pandemic, the real-time laboratory-based influenza surveillance system, the Bangkok Dusit Medical Services Surveillance System (BDMS-SS), was developed in 2010 by the Bangkok Health Research Center (BHRC). The primary objective of the BDMS-SS is to alert relevant stakeholders on the incidence trends of the influenza virus. Type-specific results along with patient demographic and geographic information were available to physicians and uploaded for public health awareness within 24 hours after patient nasopharyngeal swab was collected. This system advances early warning and supports better decision making during infectious disease events.2 The BDMS-SS operates all year round collecting results of all routinely tested respiratory clinical samples from participating hospitals from the largest group of private hospitals in Thailand.Methods: The BDMS has a comprehensive network of laboratory, epidemiologic, and early warning surveillance systems which represents the largest body of information from private hospitals across Thailand. Hospitals and clinical laboratories have deployed automatic reporting mechanisms since 2010 and have effectively improved timeliness of laboratory data reporting. In April 2017, the capacity of near real-time influenza surveillance in BDMS was found to have a demonstrated and sustainable capability.Results: From October 2010 to April 2017, a total of 482,789 subjects were tested and 86,110 (17.8%) cases of influenza were identified. Of those who tested positive for influenza they were aged <2 years old (4.6%), 2-4 year old (10.9%), 5-14 years old (29.8%), 15-49 years old (41.9%), 50-64 years old (8.3%) and >65 years old (3.7%). Approximately 50% of subjects were male and female. Of these, 40,552 (47.0%) were influenza type B, 31,412 (36.4%) were influenza A unspecified subtype, 6,181 (7.2%) were influenza A H1N1, 4,001 (4.6%) were influenza A H3N2, 3,835 (4.4%) were influenza A seasonal and 196 (0.4%) were respiratory syncytial virus (RSV).The number of influenza-positive specimens reported by the real-time influenza surveillance system were from week 40, 2015 to week 39, 2016. A total of 117,867 subjects were tested and 17,572 (14.91%) cases tested positive for the influenza virus (Figure 1). Based on the long-term monitoring of collected information, this system can delineate the epidemiologic pattern of circulating viruses in near real-time manner, which clearly shows annual peaks in winter dominated by influenza subtype B in 2015-1016 season. This surveillance system helps to provide near real-time reporting, enabling rapid implementation of control measures for influenza outbreaks.Conclusions: This surveillance system was the first real-time, daily reporting surveillance system to report on the largest data base of private hospitals in Thailand and provides timely reports and feedback to all stakeholders. It provides an important supplement to the routine influenza surveillance system in Thailand. This illustrates a high level of awareness and willingness among the BDMS hospital network to report emerging infectious diseases, and highlights the robust and sensitive nature of BDMS’s surveillance system. This system demonstrates the flexibility of the surveillance systems in BDMS to evaluate to emerging infectious disease and major communicable diseases. Through participation in the Thailand influenza surveillance network, BDMS can more actively collaborate with national counterparts and use its expertise to strengthen global and regional surveillance capacity in Southeast Asia, in order to secure advances for a world safe and secure from infectious disease. Furthermore, this system can be quickly adapted and used to monitor future influenzas pandemics and other major outbreaks of respiratory infectious disease, including novel pathogens.

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

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.

scholarly journals Enhancement of the Influenza Surveillance System in the Russian Federation: the Main Results of the Sentinel Surveillance for Influenza and other Acute Respiratory Viral Infections

2017 ◽  
Vol 16 (1) ◽  
pp. 7-15 ◽  
Author(s):  
A. A. Sominina ◽  
E. A. Smorodintseva ◽  
K. A. Stolyarov ◽  
A. A. Mel'nikova
Keyword(s):  
Respiratory Infection ◽  
Surveillance System ◽  
Acute Respiratory Infection ◽  
Influenza A ◽  
Hospitalized Patients ◽  
Sentinel Surveillance ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A H1n1

Existing influenza surveillance system is constantly improved to obtain comprehensive information for understanding of continuously changing situation with the influenza, which is a consequence of the highest variability of the pathogen, its ability to reassortment and the imminence of emergence a new shift-variants of the virus that could cause the next pandemic events. For this purpose, since the 2010 - 2011 epidemic season, in addition to the traditional surveillance system (TS) a new well standardized sentinel surveillance system (SS) for rapid clinical and epidemiological data obtaining was introduced in Russia. A total 7812 hospitalized patients with severe acute respiratory infection (SARI) and 9854 outpatients with influenza-like illness and acute respiratory infection (ILI/ARI) were investigated during the 6-year period in SS. Percent of SARI among all hospitalized patients ranged from 1.7 to 3.1%; about 5.3 - 7.5% SARI patients were placed in the Intensive Care Unit. Etiological monitoring using PCR showed influenza spread trends in SS similar to those registered in the TS: a clear predominance of influenza A (H1N1) pdm09 among SARI and ILI/ARI in 2010 - 2011 and 2015 - 2016 epidemic seasons, influenza A (H3N2) in the epidemic seasons 2011 - 2012 and 2014 - 2015, the co-circulation of these pathogens in 2012 - 2013, 2013 - 2014 seasons in Russia. SARI caused by influenza B virus were detected less frequently than influenza A but increased influenza B activity was registered in the epidemic of 2014 -2015, when Yamagata lineage changed suddenly for the Victorian one. The average frequency of influenza diagnosis among SARI between the seasons varied in the range 12.5 - 27.1%, at the peak of the epidemic it reached 44.8 - 73.5% and was the highest during the season with active circulation of influenza A (H1N1) pdm09 virus. The rate of influenza diagnosis among ILI/ARI has always been lower than that among SARI. Studies have also shown the importance of rhinovirus, RS-virus and parainfluenza infections in SARI development. The frequency of registration of coronaviruses, metapneumovirus and bocavirus infection was very low in SARI and ILI/ARI. It was found that in all studied seasons most of SARI patients with influenza have not been vaccinated. Among ILI/ARI outpatients with influenza, the frequency of vaccinated individuals for the entire period of the study was estimated as 10.1%, which was 4.2 times higher than that in SARI, where only 2.4% of patients were vaccinated. In addition, it was found that for all six seasons the SARI patients with influenza were treated with antivirals drugs 2 times less often compared to outpatients. Analysis of data on concomitant diseases and conditions in SARI patients with influenza confirmed the leading role of pregnancy as a risk factor for hospitalization in all influenza epidemics, irrespective of their etiology. In addition, diabetes and cardiovascular disease were recognized as risk factors for influenza associated SARI development.

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

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.

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

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, 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.

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

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, 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.

scholarly journals Electronic real-time surveillance for influenza-like illness: experience from the 2009 influenza A(H1N1) pandemic in Denmark

2011 ◽  
Vol 16 (3) ◽  
Author(s):  
K M Harder ◽  
P H Andersen ◽  
I Bæhr ◽  
L P Nielsen ◽  
S Ethelberg ◽  
...  
Keyword(s):  
Real Time ◽  
Surveillance System ◽  
Influenza A ◽  
Daily Basis ◽  
Influenza Surveillance ◽  
Situational Analysis ◽  
Influenza Like Illness ◽  
Electronic Reporting ◽  
Influenza A H1n1 ◽  
Sentinel Surveillance System

To enhance surveillance for influenza-like illness (ILI) in Denmark, a year-round electronic reporting system was established in collaboration with the Danish medical on-call service (DMOS). In order to achieve real-time surveillance of ILI, a checkbox for ILI was inserted in the electronic health record and a system for daily transfer of data to the national surveillance centre was implemented. The weekly number of all consultations in DMOS was around 60,000, and activity of ILI peaked in week 46 of 2009 when 9.5% of 73,723 consultations were classified as ILI. The incidence of ILI reached a maximum on 16 November 2009 for individuals between five and 24 years of age, followed by peaks in children under five years, adults aged between 25 and 64 years and on 27 November in senior citizens (65 years old or older). In addition to the established influenza surveillance system, this novel system was useful because it was timelier than the sentinel surveillance system and allowed for a detailed situational analysis including subgroup analysis on a daily basis.

scholarly journals Evaluation of the influenza sentinel surveillance system in the Democratic Republic of Congo, 2012–2015

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Pélagie 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 4339 patients with influenza-like illness (ILI) and 2869 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.

scholarly journals Influenza surveillance during the post-pandemic influenza 2010/11 season in Greece, 04 October 2010 to 22 May 2011

2011 ◽  
Vol 16 (44) ◽  
Author(s):  
M Athanasiou ◽  
A Baka ◽  
A Andreopoulou ◽  
G Spala ◽  
K Karageorgou ◽  
...  
Keyword(s):  
Pandemic Influenza ◽  
Influenza A ◽  
Influenza Season ◽  
Fatal Outcome ◽  
Sentinel Surveillance ◽  
Influenza Surveillance ◽  
Surveillance Systems ◽  
Influenza A H1n1 ◽  
Clinical Illness ◽  
Population Mortality

In this manuscript, we summarise the experience of Greece during the post-pandemic influenza season 2010/11 from 04 October 2010 to 22 May 2011. The spread of the disease and its impact were monitored using multiple surveillance systems, such as sentinel surveillance, virological surveillance and all-cause mortality surveillance. We also focus on the characteristics of laboratory-confirmed severe influenza cases who required admission to an intensive care unit (ICU) (n=368), and/or with a fatal outcome (n=180). The influenza-like illness rate reported from sentinel surveillance started rising in early January 2011 and peaked between 31 January and 6 February 2011. The total number of ICU admissions was higher in the post-pandemic influenza season than during the pandemic period causing a lot of pressure on ICUs. The overall population mortality rate due to influenza A(H1N1)2009 was higher than during the pandemic period (15.9 vs 13.2 fatal cases per million, p=0.087). Our data suggest that the severity of clinical illness in the first post-pandemic influenza season was comparable or even higher than during the pandemic.

scholarly journals A Comprehensive Molecular and Epidemiological Characterization of Influenza Viruses Circulating 2016–2020 in North Macedonia

2021 ◽  
Vol 12 ◽  
Author(s):  
Maja Kuzmanovska ◽  
Golubinka Boshevska ◽  
Elizabeta Janchevska ◽  
Teodora Buzharova ◽  
Milica Simova ◽  
...  
Keyword(s):  
Surveillance System ◽  
Influenza A ◽  
Phylogenetic Analyses ◽  
Sentinel Surveillance ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Receptor Binding Site ◽  
Routine Surveillance ◽  
Influenza A H1n1

Influenza viruses know no boundaries, representing an example of rapid virus evolution combined with pressure exerted by the host’s immune system. Seasonal influenza causes 4–50 million symptomatic cases in the EU/EEA each year, with a global death toll reaching 650,000 deaths. That being the case, in 2014 North Macedonia introduced the sentinel surveillance in addition to the existing influenza surveillance in order to obtain more precise data on the burden of disease, circulating viruses and to implement timely preventive measures. The aims of this study were to give a comprehensive virological and epidemiological overview of four influenza seasons (2016–2020), assess the frequency and distribution of influenza circulating in North Macedonia and to carry out molecular and phylogenetic analyses of the hemagglutinin (HA) and neuraminidase (NA) genes of influenza A(H1N1)pdm09, A(H3N2) from ILI and SARI patients. Our results showed that out of 1,632 tested samples, 46.4% were influenza positive, with influenza A(H1N1)pdm09 accounting for the majority of cases (44%), followed by influenza B (32%) and A(H3N2) (17%). By comparing the sentinel surveillance system to the routine surveillance system, we showed that the newly applied system works efficiently and gives great results in the selection of cases. Statistically significant differences (p = &lt; 0.0000001) were observed when comparing the number of reported ILI cases among patients aged 0–4, 5–14, 15–29, and 30–64 years to the reference age group. The phylogenetic analysis of the HA sequences unveiled the resemblance of mutations circulating seasonally worldwide, with a vast majority of circulating viruses belonging to subclade 6B.1A. The PROVEAN analysis showed that the D187A substitution in the receptor binding site (RBS) of the A(H1N1)pdm09 HA has a deleterious effect on the its function. The A(H3N2) viruses fell into the 3C.2a and 3C.3a throughout the analyzed seasons. Molecular characterization revealed that various substitutions in the A(H3N2) viruses gradually replaced the parental variant in subsequent seasons before becoming the dominant variant. With the introduction of sentinel surveillance, accompanied by the advances made in whole-genome sequencing and vaccine therapeutics, public health officials can now modify their approach in disease management and intervene effectively and in a timely manner to prevent major morbidity and mortality from influenza.

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