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

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.

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

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.

Influenza Project in Myanmar

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.

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

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.

scholarly journals Morbidity patterns associated with seasonal influenza A/H1N1in Swaziland

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Vusie Lokotfwako ◽  
Nhlanhla Nhlabatsi ◽  
Phinda Khumalo ◽  
Siphiwe Shongwe ◽  
Bongani Tsabedze ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Index Case ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Epidemic Disease ◽  
Influenza A H1n1 ◽  
Private Laboratory

ObjectiveTo establish morbidity patterns of influenza A/H1N1 in Swaziland from 10th July to 15th August 2017.IntroductionInfluenza infection is caused by the influenza virus, a single-stranded RNA virus belonging to the Orthomyxoviridae family. Influenza viruses are classified as types A, B and C. Influenza A and B viruses can cause epidemic disease in humans and type C viruses usually cause a mild, cold-like illness. The influenza virus spreads rapidly around the world in seasonal epidemics, resulting in significant morbidity and mortality. On the 10th of July 2017, a case of confirmed Influenza A/H1N1 was reported through the immediate disease notification system from a private hospital in the Hhohho region. A 49 year old female was diagnosed of Influenza A/H1N1 after presenting with flu-like symptoms. Contacts of the index case were followed and further positive cases were identified.MethodsUpon identification of the index case, the rapid response teams conducted further investigations. Two nasal swaps from each sample were taken and sent to a private laboratory in South Africa for the detection of the virus RNA using RT-PCR to assess for the presence Influenza A, B and Influenza A/H1N1. Further laboratory results were sourced from a private laboratory to monitor trends of influenza. Data was captured and analyzed in STATA version 12 from STATA cooperation. Descriptive statistics were carried out using means and standard deviations. The Pearson Chi square test and student t test were used to test for any possible association between influenza A/H1N1 and the explanatory variables (age and sex).ResultsSurveillance data captured between 10th July 2017 and 15th August 2017 indicated that a total of 87 patients had their samples taken for laboratory confirmation. There were 45 females and 42 males and the mean age was 27 years (SD= 17). At least 25 of the 87 patients tested positive for influenza A while only 1 tested positive for influenza B. The prevalence of influenza A/H1N1 was 16%. The prevalence of influenza A/H1N1 among males was 19% compared to 13% in females; however the difference was not statistically significant (p=0.469). There was no association noted between age and influenza A/H1N1 (p=427). Upon further sub-typing results indicated that the circulating strain was influenza A/H1N1 pdm 09 strain which is a seasonal influenza. The epidemic task forces held weekly and ad-hoc meetings to provide feedback to principals and health messaging to the general population to allay anxiety.ConclusionsThough WHO has classified the influenza A/H1N1 strain pdm 0029 as a seasonal influenza, surveillance remains important for early detection and management. There is therefore an urgent need to set up sentinel sites to monitor and understand the circulating influenza strains. Health promotion remains crucial to dispel anxiety as the general public still link any influenza to the 2009 pandemic influenza. Finally the Ministry of Health should consider introducing influenza vaccines into the routine immunization schedule especially for children.References1. Global Epidemiological Surveillance Standards for Influenza. 2014 [cited 2015 15 April]; Available from: http://www.who.int/influenza/resources/documents/influenza_surveillance_manual/en/.2. Human cases of influenza at the human-animal interface, 2013. Wkly Epidemiol Rec, 2014.89(28): p. 309-20.3. WHO Global Influenza Surveillance Network. Manual for the laboratory diagnosis and virological surveillance of influenza. 2011 [cited 2015 April27]; Available from: http://www.who.int/influenza/gisrs_laboratory/manual_diagnosis_surveillance_influenza/en/.

scholarly journals Report on influenza viruses received and tested by the Melbourne WHO Collaborating Centre for Reference and Research on Influenza in 2019

2021 ◽  
Vol 45 ◽  
Author(s):  
Heidi Peck ◽  
Jean Moselen ◽  
Sook Kwan Brown ◽  
Megan Triantafilou ◽  
Hilda Lau ◽  
...  
Keyword(s):  
Influenza A ◽  
Seasonal Influenza ◽  
Significant Proportion ◽  
Influenza Viruses ◽  
World Health ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Surveillance And Response ◽  
Influenza A H1n1 ◽  
Potential Use

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 9,266 human influenza positive samples during 2019. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties. Selected viruses were propagated in qualified cells or embryonated hen’s eggs for potential use in seasonal influenza virus vaccines. In 2019, influenza A(H3N2) viruses predominated over influenza A(H1N1)pdm09 and B viruses, accounting for a total of 51% of all viruses analysed. The majority of A(H1N1)pdm09, A(H3N2) 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 2019. However, phylogenetic analysis indicated that a significant proportion of circulating A(H3N2) viruses had undergone genetic drift relative to the WHO recommended vaccine strain for 2019. Of 5,301 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, four A(H1N1)pdm09 viruses showed highly reduced inhibition with oseltamivir, one A(H1N1)pdm09 virus showed highly reduced inhibition with zanamivir and three B/Victoria viruses showed highly reduced inhibition with zanamivir.

scholarly journals Evaluation of four real-time PCR assays for detection of influenza A(H1N1)v viruses

2009 ◽  
Vol 14 (22) ◽  
Author(s):  
J Ellis ◽  
M Iturriza ◽  
R Allan ◽  
A Bermingham ◽  
K Brown ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Concurrent Use ◽  
Influenza A H1n1 ◽  
Similar Range ◽  
Pcr Assays

The sensitivity and specificity of four real-time PCR assays (HPA A(H1)v, CDC A (H1)v, HPA A(N1)v and NVRL S-OIV assays) was evaluated for detection of influenza A(H1N1)v viruses. Nose and throat swab samples containing influenza A(H1N1)v viruses, seasonal influenza AH3N2, AH1N1, influenza B viruses, or negative for influenza viruses were tested by the four assays. Specificity was also analysed using influenza A viruses of different subtypes and non-related respiratory viruses. The sensitivities and specificities of the four assays were in a similar range and suitable for diagnostic use. The HPA (H1)v and the S-OIV assays were the most sensitive assays for use as a first line test, but the S-OIV assay was less specific, detecting all avian subtypes of influenza A viruses tested. The results of this study demonstrate that the concurrent use of primary diagnostic and confirmatory assays provides rapid and accurate assessment of confirmed cases, and allows appropriate management of patients.

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

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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