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

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.

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Surveillance for Severe Acute Respiratory Infection as one approach to enhance Global Health Security in Indonesia

Health Science Journal of Indonesia ◽

10.22435/hsji.v9i1.473 ◽

2018 ◽

Vol 9 (1) ◽

pp. 8-13

Author(s):

Ira Wignjadiputro ◽

Ni Ketut Susilarini ◽

Catharina Yekti Praptiningsih ◽

Elvieda Sariwati ◽

Vivi Setiawaty ◽

...

Keyword(s):

Global Health ◽

Respiratory Infection ◽

Surveillance System ◽

Acute Respiratory Infection ◽

Influenza A ◽

Influenza Surveillance ◽

Influenza B ◽

Global Health Security ◽

Health Security ◽

Severe Acute Respiratory Infection

Latar Belakang: Sistem surveilans nasional untuk infeksi saluran pernafasan akut berat (SARI) dapatmemberikan informasi penting tentang sirkulasi virus influenza, menyediakan sistem untuk mengendalikankejadian luar biasa yang mengancam keamanan dan keselamatan masyarakat serta menyediakandata untuk sistem surveilans influenza global (GISRS). Kemampuan Indonesia untuk mendeteksi dan mengendalikanpenyakit menular penting untuk keamanan kesehatan dunia. Penelitian ini bertujuan untukmenilai sistem surveilans ISPA berat Indonesia (SIBI) dan pemanfaatan untuk memantau patogen prioritaslainnya sebagai upaya meningkatkan keamanan kesehatan global. Metode: penilaian atribut surveilans melalui review laporan, analisis data dan interview staff yang terlibatdalam sistem surveilans. Semua kasus yang memenuhi kriteria SARI pada bulan Mei 2013 – April 2015 ikutserta dalam penelitian. Data epidemiologi dan virologi dianalisis. Kelengkapan dan kemudahan sistem untukmencapai tujuan surveilans influenza dan mendukung surveilans penyakit infeksi baru (emerging) dikaji. Hasil: Sebanyak 1,806 kasus SARI dan 1,697 (94%) spesimen dilakukan pemeriksaan virus influenza.Sebanyak 200 (12%) positif influenza, terdiri dari 46% influenza A(H3N2), 18% A(H1N1)pdm09 dan 37%influenza B. Hasil penilaian terhadap sistem surveilans didapatkan kesesuaian pelaksanaan untuk semuaatribut surveilans melebihi target >80%, kelengkapan laporan online 95%, kesesuaian kasus terhadapdefinisi kasus 100%, kasus yang diambil spesimen 94% dan hasil laboratorium diinput ke database secaraonline 100%. Sistem surveilans untuk dengue dan infeksi arbovirus lainnya sudah terlaksana di unitrawat jalan dan gawat darurat di sentinel SARI surveilans. Kesimpulan: SIBI dapat disesuaikan untuk menggabungkan surveilans penyakit lain yang menunjukkankegunaan dan fleksibilitas dalam mendukung keamanan kesehatan global. Kata kunci: keamanan kesehatan global, surveilans, influenza, Indonesia AbstractBackground: The existing national surveillance system for severe acute respiratory infection (SARI) providescritical information on influenza virus circulation, provides a system to control influenza outbreaks that threatenthe safety and security of the population and feeds data into the global influenza surveillance and responsesystem (GISRS). Indonesia’s ability to detect and control communicable diseases is critical for global healthsecurity. The aim of this study was to assess the SARI surveillance system and utility for monitoring other prioritypathogens as an effort to enhance global health security. Methods: Surveillance attributes were assessed by reviewing records, data analysis and through interviewedwith staffs involved in the surveillance system. All patients at six sentinel hospitals who meet the SARI casedefinition during May 2013 – April 2015 were enrolled. Epidemiological and virological data were analyzed.The surveillance system utility for its influenza surveillance objectives and flexibility to support surveillance ofemerging infectious diseases were assessed. Resuts: A total of 1,806 SARI cases were reported of which 1,697 (94%) had specimens tested for influenza viruses.Of those tested, 200 (12%) were positive, of which 46% were influenza A(H3N2), 18% A(H1N1)pdm09and 37% influenza B viruses. The system exceeded the targets of >80% adherence for most attributes: 95% forcompleteness of online reporting, 100% for cases adhering to the case definition, 94% for cases with specimenscollected and 100% of laboratory results uploaded to the online database. A surveillance system for dengue andother arbovirus infections was established in the outpatient/emergency units at the SARI surveillance sentinel.Conclusion: SIBI was adjusted to incorporate surveillance for other priority diseases indicating its utility andflexibility to support global health security Keywords: Global Health Security, surveillance, influenza, Indonesia

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

Frontiers in Microbiology ◽

10.3389/fmicb.2021.713408 ◽

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 = < 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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Dual and Triple Infections With Influenza A and B Viruses: A Case-Control Study in Southern Brazil

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz221 ◽

2019 ◽

Vol 220 (6) ◽

pp. 961-968 ◽

Cited By ~ 6

Author(s):

Tatiana Schäffer Gregianini ◽

Ivana R Santos Varella ◽

Patricia Fisch ◽

Letícia Garay Martins ◽

Ana B G Veiga

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Clinical Symptoms ◽

Antiviral Treatment ◽

Influenza Virus Infection ◽

H3n2 Virus ◽

Influenza Surveillance ◽

Influenza B Virus ◽

Influenza B ◽

Influenza A H1n1

Abstract Influenza surveillance is important for disease control and should consider possible coinfection with different viruses, which can be associated with disease severity. This study analyzed 34 459 patients with respiratory infection from 2009 to 2018, of whom 8011 were positive for influenza A virus (IAV) or influenza B virus (IBV). We found 18 cases of dual influenza virus infection, including coinfection with 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09) and influenza A(H3N2) virus (1 case), A(H1N1)pdm09 and IBV (6 cases), A(H3N2) and IBV (8 cases), and nonsubtyped IAV and IBV (3 cases); and 1 case of triple infection with A(H3N2), A(H1N1)pdm09, and IBV. Compared with 76 monoinfected patients, coinfection was significantly associated with cardiopathy and death. Besides demographic characteristics and clinical symptoms, we assessed vaccination status, antiviral treatment, timeliness of antiviral use, hospitalization, and intensive care unit admission, but no significant differences were found between coinfected and monoinfected cases. Our findings indicate that influenza virus coinfection occurs more often than previously reported and that it can lead to a worse disease outcome.

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Influenza A(H1N1)pdm 2009 and influenza B virus co-infection in hospitalized and non-hospitalized patients during the 2015–2016 epidemic season in Israel

Journal of Clinical Virology ◽

10.1016/j.jcv.2017.01.002 ◽

2017 ◽

Vol 88 ◽

pp. 12-16 ◽

Cited By ~ 7

Author(s):

Rakefet Pando ◽

Yaron Drori ◽

Nehemya Friedman ◽

Aharona Glatman-Freedman ◽

Hanna Sefty ◽

...

Keyword(s):

Influenza A ◽

Hospitalized Patients ◽

Influenza B Virus ◽

Influenza B ◽

Epidemic Season ◽

Influenza A H1n1 ◽

B Virus

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Influenza Surveillance Among Children With Pneumonia Admitted to a District Hospital in Coastal Kenya, 2007–2010

The Journal of Infectious Diseases ◽

10.1093/infdis/jis536 ◽

2012 ◽

Vol 206 (suppl_1) ◽

pp. S61-S67 ◽

Cited By ~ 18

Author(s):

Clayton O. Onyango ◽

Regina Njeru ◽

Sidi Kazungu ◽

Rachel Achilla ◽

Wallace Bulimo ◽

...

Keyword(s):

Virus Infection ◽

Influenza A Virus ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

District Hospital ◽

Severe Pneumonia ◽

Influenza B Virus ◽

Influenza B ◽

Virus Subtype

Abstract Background Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders. Methods Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007–2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A, B, and C viruses by molecular methods. Outpatient children provided comparative data. Results Of 2002 admissions, influenza A virus infection was diagnosed in 3.5% (71), influenza B virus infection, in 0.9% (19); and influenza C virus infection, in 0.8% (11 of 1404 tested). Four patients with influenza died. Among outpatients, 13 of 331 (3.9%) with acute respiratory infection and 1 of 196 without acute respiratory infection were influenza positive. The annual incidence of severe or very severe pneumonia, of influenza (any type), and of influenza A, was 1321, 60, and 43 cases per 100 000 <5 years of age, respectively. Peak occurrence was in quarters 3–4 each year, and approximately 50% of cases involved infants: temporal association with bacteremia was absent. Hypoxia was more frequent among pneumonia cases involving influenza (odds ratio, 1.78; 95% confidence interval, 1.04–1.96). Influenza A virus subtypes were seasonal H3N2 (57%), seasonal H1N1 (12%), and 2009 pandemic H1N1 (7%). Conclusions The burden of influenza was small during 2007–2010 in this pediatric hospital in Kenya. Influenza A virus subtype H3N2 predominated, and 2009 pandemic influenza A virus subtype H1N1 had little impact.

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Epidemiological and clinical features of acute respiratory infections occurring in St. Petersburg during the 2017–2018 and 2018–2019 epidemic seasons

Journal Infectology ◽

10.22625/2072-6732-2021-13-2-53-60 ◽

2021 ◽

Vol 13 (2) ◽

pp. 53-60

Author(s):

D. A. Guzhov ◽

E. A. Elpaeva ◽

M. A. Egorova ◽

V. A. Eder ◽

I. L. Baranovskya ◽

...

Keyword(s):

Clinical Features ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

Bacterial Infections ◽

Respiratory Infections ◽

Influenza B Virus ◽

Influenza B ◽

Acute Respiratory Infections ◽

Pharyngeal Wall

Objective: to analyze the epidemiological and clinical features of acute respiratory infections occurring during the St. Petersburg 2017-2018 and 2018-2019 epidemic seasons.Materials and methods: the study included 457 patients, treated in St. Petersburg clinics from 2017-2019, displaying symptoms of acute respiratory infection (ARI), including evaluation of their clinical histories. Pathogen types were determined by polymerase chain reaction (PCR). Data analysis was carried out using mathematical statistics methods using the Statistica 10 software package (StatSoft Inc.).Results: in this study, we examined the epidemiological and clinical features of acute respiratory infections in St. Petersburg occurring during two epidemic seasons, 2017-2018 and 2018-2019. The 2017-2018 season was characterized by a prevalence of infections caused by influenza B viruses and influenza A subtype H3N2 viruses. In the 2018-2019 season, there was a greater number of acute respiratory viral infections (ARVIs) and infections caused by influenza A subtype H1N1pdm; influenza B virus was detected only in isolated cases. In the 2017-2018 sore throats and muscle aches were a characteristic symptom of influenza A H1N1pdm infections, of bacterial infections – only sore throats. It was shown that throat pain and vasodilation of the scleral and soft palate vessels were significantly more frequent in the 2017-2018 season, compared to the 2018-2019 season. Cough and redness of the posterior pharyngeal wall were hallmark signs of ARVIs in the 2018-2019 season.Conclusion: according to the data, each epidemic season is characterized not only by its own type-specific acute respiratory infection frequencies, but also by different clinical manifestation frequencies. For global monitoring, treatment effectiveness evaluation, and refined study of acute respiratory infection clinical features, it is advisable to use approaches which incorporate accurate, specific, and rapid molecular biological methods capable of identifying a broad range of pathogens.

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Epidemiological and clinical features of acute respiratory infections occurring in St. Petersburg during the 2017–2018 and 2018–2019 epidemic seasons

Journal Infectology ◽

10.22625/2072-6732-2020-12-4-65-71 ◽

2020 ◽

Vol 12 (4) ◽

pp. 65-71

Author(s):

D. A. Guzhov ◽

E. A. Elpaeva ◽

M. A. Egorova ◽

V. A. Eder ◽

I. L. Baranovskaya ◽

...

Keyword(s):

Clinical Features ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

Bacterial Infections ◽

Respiratory Infections ◽

Influenza B Virus ◽

Influenza B ◽

Acute Respiratory Infections ◽

Pharyngeal Wall

Objective: to analyze the epidemiological and clinical features of acute respiratory infections occurring during the St. Petersburg 2017–2018 and 2018–2019 epidemic seasons.Materials and methods: the study included 457 patients, treated in St. Petersburg clinics from 2017–2019, displaying symptoms of acute respiratory infection (ARI), including evaluation of their clinical histories. Pathogen types were determined by polymerase chain reaction (PCR). Data analysis was carried out using mathematical statistics methods using the Statistica 10 software package (StatSoft Inc.).Results: in this study, we examined the epidemiological and clinical features of acute respiratory infections in St. Petersburg occurring during two epidemic seasons, 2017–2018 and 2018–2019. The 2017–2018 season was characterized by a prevalence of infections caused by influenza B viruses and influenza A subtype H3N2 viruses. In the 2018–2019 season, there was a greater number of acute respiratory viral infections (ARVIs) and infections caused by influenza A subtype H1N1pdm; influenza B virus was detected only in isolated cases. In the 2017–2018 sore throats and muscle aches were a characteristic symptom of influenza A H1N1pdm infections, of bacterial infections – only sore throats. It was shown that throat pain and vasodilation of the scleral and soft palate vessels were significantly more frequent in the 2017–2018 season, compared to the 2018–2019 season. Cough and redness of the posterior pharyngeal wall were hallmark signs of ARVIs in the 2018–2019 season.Conclusion: according to the data, each epidemic season is characterized not only by its own type-specific acute respiratory infection frequencies, but also by different clinical manifestation frequencies. For global monitoring, treatment effectiveness evaluation, and refined study of acute respiratory infection clinical features, it is advisable to use approaches which incorporate accurate, specific, and rapid molecular biological methods capable of identifying a broad range of pathogens.

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Laboratory based Influenza sentinel surveillance in Pakistan At NIC, Islamabad 2007-2017

European Journal of Public Health ◽

10.1093/eurpub/ckz186.499 ◽

2019 ◽

Vol 29 (Supplement_4) ◽

Author(s):

F Bashir ◽

K Fawad Khan ◽

S Zafar Qureshi ◽

F Khaudaidad ◽

R Sonia

Keyword(s):

Influenza A ◽

Vaccine Development ◽

Sudden Onset ◽

Sentinel Surveillance ◽

Influenza Viruses ◽

H3n2 Virus ◽

Influenza Surveillance ◽

Influenza B ◽

Pandemic Preparedness ◽

Influenza A H1n1

Abstract Background A country-wide lab-based surveillance system for ILI and Severe Acute Respiratory Illness (SARI) with weekly sampling and reporting was established in 2008.This system was necessary for early detection of emerging novel influenza subtypes and timely response for influenza prevention and control. Objectives To assess the trends of Influenza-like-Illness(ILI) and to monitor the predominant circulating strains of influenza viruses through Lab based sentinel surveillance. Methods A cross-sectional study was conducted based on ten years (2007-2017) influenza surveillance data obtained from National Influenza Central Laboratory Pakistan (NICLP) from January to March 2018.Study was done from the data records and samples of suspected ILI patients and SARI patients received from all seven sentinel sites. An ILI case was defined as sudden onset of fever of ≥ 38 C° and cough, with onset within last 10 days, while patients with sudden onset of fever (>38 °C), cough/sore throat requiring hospital admission within 7 days were termed as SARI. Samples were tested at NICLP for confirmation of virus, typing and subtyping by RT-PCR. Results A total of 15885 samples were analyzed during ten years period, out of which 3475(21.9%) were found positive for influenza virus. Among positive samples 26(0.75%) were Influenza-A (H1N1), 550(38%) were A/H3N1,550(15.9%) were A/H3N1,1587(45.7%) were A/H1N1 pdm09and 1312(37.8%) were influenza B. Males were predominant(54%).Influenza Maximum cases were reported from age group 01->12 years(66%).Virus circulation was detected throughout the year along with few cases of seasonal A/H1N1 virus during late winter(January February) and spring(March). Influenza A/H3N2 virus circulation was mainly observed during summer months (August-October). Conclusions The findings of this study emphasize the need for continuous and comprehensive influenza surveillance to predict seasonal trends for vaccine development and to further fortify pandemic preparedness. Key messages The need for continuous and comprehensive influenza surveillance. Public health importance by pandemic preparedness.

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DETECTION OF INFLUENZA VIRUSES AMONG HOSPITALIZED CASES SUFFERING FROM SEVERE ACUTE RESPIRATORY ILLNESS (SARI) IN SANA’A CITY, YEMEN

Universal Journal of Pharmaceutical Research ◽

10.22270/ujpr.v4i4.296 ◽

2019 ◽

Author(s):

Dina Abdulljabbar Abdullah Al-Ademi ◽

Abdulilah Hussein Al-Harazi ◽

Hassan A. Al-Shamahy ◽

Bushra Mohammed Jaadan

Keyword(s):

Mortality Rate ◽

Influenza A ◽

Respiratory Illness ◽

Hospitalized Patients ◽

Influenza Viruses ◽

Influenza Surveillance ◽

Influenza B ◽

Acute Respiratory Illness ◽

Influenza A H1n1 ◽

Severe Acute Respiratory Illness

Influenza is a major cause of morbidity and mortality around the world. So national influenza surveillance have been important for understanding the epidemiology of influenza over time. The aims of this study were to determine the prevalence rate of influenza viruses among hospitalized patients with severe acute respiratory illness (SARI), identify circulating types and subtypes of influenza viruses among them, and determine the risk factors associated with SARI. A total of 320 hospitalized patients suffering from SARI at Al Joumhouri University hospital in Sana’a city were enrolled; and their age was ranged from < 1 year to ≥ 56 years. Both nasopharyngeal and oro-pharyngeal swabs were collected from each patient and tested by using rRT-PCR technique for the detection of influenza A, influenza B and subtypes of influenza A viruses (A/H1N1(2009) and A/H3N2). The crude prevalent rate of influenza viruses among SARI patients was 10.9%;the female rate was 12.4%, and the male rate was 9.9%. The rate of Flu A in the total SARI cases was 5.9% and for Flu B was 5%. In addition 3.8% of SARI patients were suffering from influenza A/H3N2, 2.2% from influenza A/H1N1(2009) infections; and the mortality rate for influenza infections was 17.1%. Also, a high mortality rate was occurred in influenza infections in age groups 36-45 years and 6-15 years. Also, there was a significant association between flu infection; and 46-55 years group (OR=2.8), Winter time (OR=17.5), cardiac diseases (OR=9.1), and diabetic mellitus (OR=3.7). In conclusion: both influenza A and B were represented as a causative agents of SARI, and Influenza A/H3N2 was present subtype followed by A/H1N1(2009). The frequency of influenza viruses ascertain among SARI patients in Yemen highlights the need for health authorities to develop strategies to reduce morbidity among at-risk population in the course of vaccine recommendation.

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Epidemiology of influenza: findings from surveillance system of 40 hospital in Thailand, 2010-2019

European Journal of Public Health ◽

10.1093/eurpub/ckaa165.1098 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

T Eamchotchawalit ◽

P Piyaraj ◽

P Narongdej ◽

S Charoensakulchai ◽

C Chanthowong

Keyword(s):

Real Time ◽

Surveillance System ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Viruses ◽

Cold Chain ◽

Influenza Surveillance ◽

Influenza B ◽

Private Hospitals ◽

Influenza A H1n1

Abstract Background Although recent efforts from some Asian countries to describe burden of influenza disease and seasonality, these data are missing for the vast majority, including the private section of Thailand. A near real-time laboratory-based influenza surveillance system, in a network of 40 hospitals was implemented aiming to determine influenza strains circulating in the private hospitals of Thailand and know characteristics, trend and burden of influenza viruses. Methods We obtained the data by monitoring patients with influenza-like illness (ILI) at a network of 40 private hospitals across Thailand. Throat-swab specimens in viral transport media were collected and transported within 24 h of collection using a cold-chain system. The respiratory samples were tested by rapid influenza diagnostic tests and real-time reverse transcription polymerase chain reaction. Results From January 2010 to November 2019, a total of 1,300,594 subjects were tested and 320,499 cases of influenza were identified. Of those positive cases, 116,317(36.3%) were influenza type B, 185,512(57.9%) were influenza A unspecified subtype, 8,833(2.7%) were influenza A(H1N1)pdm2009 and 6,371(1.9%) were seasonal influenza A(H3N2). Positive rate were 50.5 and 49.5 in female and male. Positivity rate was 41.4% in persons 15-49 years followed by 29.1% in 15-14 years, 17.6% in under five children and 11.7% in > 49 years. In 2018-2019 season, the highest positivity rate observed in February and March (39.3%) followed by April (34.2%) and January (32.3%) while the lowest positivity rate was in May (18.1%). Conclusions In Thailand, seasonal Influenza A(H3N2), Influenza A(H1N1)pdm2009 and Influenza B viruses were circulating during 2010-2019. In last season, positivity rate and number of cases peaked in February and March. Key messages Influenza is one of public health problems in Thailand. The need to introduce influenza vaccine and antivirus is important to prevent and treat the disease in future.

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