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

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.

Download Full-text

Influenza Project in Myanmar

Journal of Disaster Research ◽

10.20965/jdr.2014.p0842 ◽

2014 ◽

Vol 9 (5) ◽

pp. 842-847

Author(s):

Reiko Saito ◽

◽

Yadanar Kyaw ◽

Yi Yi Myint ◽

Clyde Dapat ◽

...

Keyword(s):

Influenza A ◽

Drug Susceptibility ◽

Influenza Viruses ◽

World Health ◽

Influenza Surveillance ◽

Influenza B ◽

Laboratory Capacity ◽

Influenza A H1n1 ◽

Resistant Strains ◽

Health Organization

The epidemiological study of influenza in Southeast Asia is limited. We surveyed influenza in Myanmar from 2007 to 2013. Nasopharyngeal swabs were collected from patients in the two cities of Yangon and Nay Pyi Taw. Samples were screened using rapid influenza diagnostic kits and identified by virus isolation. Isolates were characterized by cyclingprobe-based real-time PCR, drug susceptibility assay, and sequencing. Samples collected numbered 5,173, from which 1,686 influenza viruses were isolated during the seven-year study period. Of these, 187 strains were of seasonal influenza A(H1N1), 274 of influenza A(H1N1)pdm09, 791 of influenza A(H3N2), and 434 of influenza B. Interestingly, two zanamivir and amantadine-resistant strains each were detected in 2007 and 2008. These rare dual-resistant strains had a Q136K mutation in the NA protein and S31N substitution in the M2 protein. Our collaboration raised the influenza surveillance laboratory capacity in Myanmar and led Yangon’s National Health Laboratory – one of the nation’s leading research institutes – to being designated a National Influenza Center by the World Health Organization.

Download Full-text

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

Eurosurveillance ◽

10.2807/ese.14.32.19303-en ◽

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.

Download Full-text

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

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2017-16-1-7-15 ◽

2017 ◽

Vol 16 (1) ◽

pp. 7-15 ◽

Cited By ~ 2

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.

Download Full-text

Surveillance of influenza in the post-pandemic period in the Vojvodina, Serbia, October 2010 - May 2015

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh160901068r ◽

2017 ◽

Vol 145 (7-8) ◽

pp. 387-393

Author(s):

Mioljub Ristic ◽

Vesna Stojanovic ◽

Vesna Milosevic ◽

Jelena Radovanov ◽

Tihomir Dugandzija ◽

...

Keyword(s):

Influenza A ◽

Laboratory Data ◽

Weather Conditions ◽

Respiratory Illness ◽

Laboratory Method ◽

World Health ◽

School Age Children ◽

Influenza Surveillance ◽

Influenza B ◽

Influenza A H1n1

Introduction/Objective. In August 2010, World Health Organization declared the beginning of the postpandemic phase of influenza surveillance. The aim of this study was to evaluate the epidemiological and virological characteristics of influenza and correlation between the influenza occurrence and weather conditions. Methods. We used surveillance reports of influenza and laboratory data from October 2010 to May 2015. Data for the analysis were collected through sentinel surveillance of influenza-like illness (ILI), severe acute respiratory illness (SARI), acute respiratory distress syndrome, and by virological surveillance. The nasal and throat swabs from all influenza cases were performed by the PCR laboratory method. Results. During the observed period, the highest rates of ILI were registered during the 2010/11 and 2012/13 seasons, with influenza A (H1N1)pdm09 and influenza B being predominant, respectively. The highest weekly age-specific rates of ILI were registered in school-age children (ages 5?14). Out of 1,466 samples collected, 720 (49.1%) were laboratory confirmed as influenza, and influenza A virus was more frequently detected than influenza B. Among confirmed cases of influenza, participation of patients with SARI or ILI was nearly equal (46% vs. 44.1%). There was a weak correlation observed between the decrease in temperature and rainfall and the increase in influenza detection (? = -0.04214 vs. ? = -0.01545, respectively, p > 0.05). Conclusion. There is a need for continuous surveillance in order to predict seasonal trends and prepare for a timely response to influenza outbreak.

Download Full-text

Effect of Vaccination on Preventing Influenza-Associated Hospitalizations Among Children During a Severe Season Associated with B/Victoria Viruses, 2019-2020

Clinical Infectious Diseases ◽

10.1093/cid/ciab060 ◽

2021 ◽

Author(s):

Angela P Campbell ◽

Constance Ogokeh ◽

Geoffrey A Weinberg ◽

Julie A Boom ◽

Janet A Englund ◽

...

Keyword(s):

Influenza A ◽

Respiratory Illness ◽

Influenza Viruses ◽

Influenza B ◽

Surveillance Network ◽

Medical Centers ◽

Influenza A H1n1 ◽

Vaccination History ◽

Ed Visits ◽

Vaccine Surveillance

Abstract Background The 2019-2020 influenza season was characterized by early onset with B/Victoria followed by A(H1N1)pdm09 viruses. Emergence of new B/Victoria viruses raised concerns about possible vaccine mismatch. We estimated vaccine effectiveness (VE) against influenza-associated hospitalizations and emergency department (ED) visits among U.S. children. Methods We assessed VE among children 6 months–17 years with acute respiratory illness and ≥10 days of symptoms enrolled at 7 pediatric medical centers in the New Vaccine Surveillance Network. Combined mid-turbinate/throat swabs were tested for influenza virus using molecular assays. Vaccination history was collected from parental report, state immunization information systems, and/or provider records. We estimated VE from a test-negative design using logistic regression to compare odds of vaccination among children testing positive versus negative for influenza. Results Among 2029 inpatients, 335 (17%) were influenza positive: 37% with influenza B/Victoria alone and 44% with influenza A(H1N1)pdm09 alone.VE was 62% (95% confidence interval [CI], 52%–71%) for influenza-related hospitalization, 54% (95% CI, 33%–69%) for B/Victoria viruses and 64% (95% CI, 49%–75%) for A(H1N1)pdm09. Among 2102 ED patients, 671 (32%) were influenza positive: 47% with influenza B/Victoria alone and 42% with influenza A(H1N1)pdm09 alone. VE was 56% (95% CI, 46%–65%) for an influenza-related ED visit, 55% (95% CI, 40%–66%) for B/Victoria viruses and 53% (95% CI, 37%–65%) for A(H1N1)pdm09. Conclusions Influenza vaccination provided significant protection against laboratory-confirmed influenza-associated hospitalizations and ED visits associated with the two predominantly circulating influenza viruses among children, including against the emerging B/Victoria virus subclade.

Download Full-text

A multiplex one-step real-time RT-PCR assay for influenza surveillance

Eurosurveillance ◽

10.2807/ese.16.07.19798-en ◽

2011 ◽

Vol 16 (7) ◽

Author(s):

I Huber ◽

H Campe ◽

D Sebah ◽

C Hartberger ◽

R Konrad ◽

...

Keyword(s):

Real Time ◽

High Throughput ◽

Influenza A ◽

Multiplex Assay ◽

Influenza Viruses ◽

Influenza Surveillance ◽

Influenza B ◽

Rt Pcr ◽

Influenza A H1n1 ◽

One Step

For surveillance purposes real-time PCR assays for influenza viruses had to be adapted to the pandemic influenza A(H1N1)2009 strain. We combined published primers and probes for influenza A, influenza B and an internal amplification control with a detection system for influenza A(H1N1)2009 to set up a rapid, reliable, simple and cost-effective high-throughput multiplex one-step real-time RT-PCR. The workflow also includes automated sample preparation for high-throughput screening. The lower limit of detection of the multiplex assay was 3.5x102 RNA copies per PCR reaction. The diagnostic sensitivity of the multiplex assay was 87.7%, but increased to 99.4% for influenza-positive samples yielding Ct values of less than 34 cycles in the respective diagnostic assay. High specificity was confirmed by sequencing and correct detection of 15 reference samples from two quality assurance studies. The multiplex PCR was introduced for surveillance of samples from a network of general practitioners and paediatricians in Bavaria, Germany during the influenza pandemic of 2009. Comparison with surveillance data from reported cases proved the reliability of the multiplex assay for influenza surveillance programmes.

Download Full-text

Epidemiology of Influenza Viruses in Canada over the 2011–2012 to 2013–2014 Seasons: A Study from the Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research Network (CIRN)

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx163.735 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S314-S314

Author(s):

May Elsherif ◽

Todd Hatchette ◽

Jason Leblanc ◽

Lingyun Ye ◽

Melissa K Andrew ◽

...

Keyword(s):

Clinical Trials ◽

Health Research ◽

Influenza A ◽

Respiratory Illness ◽

Influenza Viruses ◽

Research Network ◽

Influenza B ◽

Acute Respiratory Illness ◽

Grant Recipient ◽

Research Grant

Abstract Background Influenza virus activity varies seasonally and within season. Epidemiology of serious influenza outcomes is contingent on the prevalent circulating strain/s and susceptible age group/s. Given the strain variability over the 2011–2012 through 2013–2014 seasons in Canada, this study examined the clinical and epidemiological profiles of different influenza strains causing adult hospitalizations. Methods During these three influenza seasons, the Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research Network (CIRN) enrolled adults hospitalized with acute respiratory illness across Canada. Nasopharyngeal swabs (NPs) from influenza cases were tested for strain characterization using real-time reverse transcriptase polymerase chain reaction (rtRT-PCR). A primary assay differentiated A and B influenza viruses. Subsequently, influenza A viruses were subtyped as H1N1 or H3N2, and influenza B lineages were differentiated as Victoria or Yamagata. Laboratory results were compared with patient demographic data and clinical outcomes. Results Over three consecutive influenza seasons, 3394 cases of hospitalized acute respiratory illness were laboratory-confirmed as influenza. At 72.4%, influenza A was predominant across all seasons, while influenza B caused 27.6%. Most of the influenza A cases were due to H3N2 (58.7%), while H1N1 accounted for 41.3%. For influenza B, the Yamagata lineage was predominant at 88.4% whereas the Victoria lineage accounted for 11.6%. Outcome analyses are presented for each influenza A subtype and influenza B lineage, overall and per season. Considering serious outcomes in patients ≥65, higher proportions of patients hospitalized with the H1N1 strain experienced intensive care unit (ICU) admission and need for mechanical ventilation, while higher proportions of patients hospitalized with B/Yamagata and H3N2 died within 30 days of admission. Conclusion Comprehensive collection of surveillance data paired with NP specimens by the CIRN SOS Network was conducive to broader understanding of influenza strain activity and associated outcomes at the subtype and lineage level. This data is important to make informed recommendations for the use of multicomponent influenza vaccines. Disclosures M. Elsherif, Canadian Institutes of Health Research: Investigator, Research grant. Public Health Agency of Canada: Investigator, Research grant. GSK: Investigator, Research grant. T. Hatchette, GSK: Grant Investigator, Grant recipient; Pfizer: Grant Investigator, Grant recipient. Abbvie: Speaker for a talk on biologics and risk of TB reactivation, Speaker honorarium.M. K. Andrew, GSK: Grant Investigator, Research grant. Pfizer: Grant Investigator, Research grant. Sanofi-Pasteur: Grant Investigator, Research grant. J. McElhaney, GSK Vaccines: Scientific Advisor, Speaker honorarium. A. Mcgeer, Hoffman La Roche: Investigator, Research grant. GSK: Investigator, Research grant. sanofi pasteur: Investigator, Research grant. J. Powis, Merck: Grant Investigator, Research grant. GSK: Grant Investigator, Research grant. Roche: Grant Investigator, Research grant. Synthetic Biologicals: Investigator, Research grant. M. Semret, GSK: Investigator, Research grant. Pfizer: Investigator, Research grant. S. Trottier, Canadian Institutes of Health Research: Investigator, Research grant. L. Valiquette, GSK: Investigator, Research grant. S. McNeil, GSK: Contract Clinical Trials and Grant Investigator, Research grant. Merck: Contract Clinical Trials and Speaker’s Bureau, Speaker honorarium. Novartis: Contract Clinical Trials, No personal renumeration. sanofi pasteur: Contract Clinical Trials, No personal renumeration

Download Full-text

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.

Download Full-text

Excess mortality is associated with influenza A (H1N1) in patients with severe acute respiratory illness

Journal of Clinical Virology ◽

10.1016/j.jcv.2019.05.003 ◽

2019 ◽

Vol 116 ◽

pp. 62-68 ◽

Cited By ~ 4

Author(s):

Suzana Margareth Lobo ◽

Aripuanã Sakurada Aranha Watanabe ◽

Maria Lúcia Machado Salomão ◽

Flavia Queiroz ◽

Joelma Vilafanha Gandolfi ◽

...

Keyword(s):

Influenza A ◽

Excess Mortality ◽

Respiratory Illness ◽

Acute Respiratory Illness ◽

Influenza A H1n1 ◽

Severe Acute Respiratory Illness

Download Full-text

Poor Vaccine Effectiveness against Influenza B-Related Severe Acute Respiratory Infection in a Temperate North Indian State (2019–2020): A Call for Further Data for Possible Vaccines with Closer Match

Vaccines ◽

10.3390/vaccines9101094 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1094

Author(s):

Hyder Mir ◽

Inaamul Haq ◽

Parvaiz A. Koul

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Respiratory Illness ◽

Vaccine Effectiveness ◽

Influenza Viruses ◽

Vaccine Uptake ◽

Influenza B ◽

Severe Acute Respiratory Infection ◽

Influenza A H1n1 ◽

Indian State

Influenza vaccine uptake in India is poor, and scant data exist regarding the effectiveness of influenza vaccine against hospitalization. Methods: From October 2019 to March 2020, vaccination status of 1219 patients (males n = 571, aged 5–107 years; median, 50 years) hospitalized with severe acute respiratory illness (SARI) was assessed. The patients were tested for influenza viruses and their subtypes by RT PCR. Sequencing of the HA gene was performed. Vaccine effectiveness (VE) against influenza subtypes was estimated by the test negative design. Results: A total of 336 (27.5%) patients were influenza-positive, with influenza B/Victoria accounting for 49.7% (n = 167), followed by influenza A/H1N1 (47.6%; n = 155) and influenza A/H3N2 (4.4%; n = 15). About 6.8% and 8.6% of the influenza-positive and influenza-negative patients, respectively, had been vaccinated. Adjusted VE for any influenza strain was 13% (95% CI −42 to 47), which for influenza B was 0%. HA sequencing revealed that influenza B samples mainly belonged to subclade V1A.3/133R with deletion of residues 163–165, as against the 2-aa deletion in influenza B/Colorado/06/2017 strain, contained in the vaccine. VE for influenza A/H1N1 was 55%. Conclusions: Poor VE due to a genetic mismatch between the circulating strain and the vaccine strain calls for efforts to reduce the mismatch.

Download Full-text