Magnetofluidic platform for rapid multiplexed screening of SARS-CoV-2 variants and respiratory pathogens

The rise of highly transmissible SARS-CoV-2 variants brings new challenges and concerns with vaccine efficacy, diagnostic sensitivity, and public health responses in the fight to end the pandemic. Widespread detection of variant strains will be critical to inform policy decisions to mitigate further spread, and post-pandemic multiplexed screening of respiratory viruses will be necessary to properly manage patients presenting with similar respiratory symptoms. In this work, we have developed a portable, magnetofluidic cartridge platform for automated PCR testing in <30 min. Cartridges were designed for multiplexed detection of SARS-CoV-2 with either distinctive variant mutations or with Influenza A and B. The platform demonstrated a limit of detection down to 2 copies/μL SARS-CoV-2 RNA with successful identification of B.1.1.7 and B.1.351 variants. The multiplexed SARS-CoV-2/Flu assay was validated using archived clinical nasopharyngeal swab eluates (n = 116) with an overall sensitivity/specificity of 98.1%/95.2%, 85.7%/100%, 100%/98.2%, respectively, for SARS-CoV-2, Influenza A, and Influenza B. Further testing with saliva (n = 14) demonstrated successful detection of all SARS-CoV-2 positive samples with no false-positives.

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Epidemiology of Respiratory Pathogens among Elderly Nursing Home Residents with Acute Respiratory Infections in Corsica, France, 2013–2017

BioMed Research International ◽

10.1155/2017/1423718 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Shirley Masse ◽

Lisandru Capai ◽

Alessandra Falchi

Keyword(s):

Nursing Home ◽

Influenza A ◽

Respiratory Infections ◽

Nursing Home Residents ◽

Respiratory Viruses ◽

Sudden Onset ◽

Influenza Viruses ◽

Influenza B ◽

Acute Respiratory Infections ◽

Respiratory Pathogens

Background. The current study aims to describe the demographical and clinical characteristics of elderly nursing home (NH) residents with acute respiratory infections (ARIs) during four winter seasons (2013/2014–2016/2017), as well as the microbiological etiology of these infections. Methods. Seventeen NHs with at least one ARI resident in Corsica, France, were included. An ARI resident was defined as a resident developing a sudden onset of any constitutional symptoms in addition to any respiratory signs. Nasopharyngeal swabs from ARI residents were screened for the presence of 21 respiratory agents, including seasonal influenza viruses. Results. Of the 107 ARI residents enrolled from NHs, 61 (57%) were positive for at least one of the 21 respiratory pathogens. Forty-one (38.3%) of the 107 ARI residents had influenza: 38 (92%) were positive for influenza A (100% A(H3N2)) and three (8%) for influenza B/Victoria. Axillary fever (≥38°C) was significantly more common among patients infected with influenza A(H3N2). Conclusion. The circulation of seasonal respiratory viruses other than influenza A(H3N2) seems to be sporadic among elderly NH residents. Investigating the circulation of respiratory viruses in nonwinter seasons seems to be important in order to understand better the dynamic of their year-round circulation in NHs.

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1791. Novel Metabolomics Approach for the Diagnosis of Respiratory Viruses Directly from Nasopharyngeal Specimens

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1654 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S660-S660

Author(s):

Catherine Hogan ◽

Anthony T Le ◽

Justin Mak ◽

Malaya Kumar. Sahoo ◽

Tina Cowan ◽

...

Keyword(s):

Host Cell ◽

Influenza A ◽

Component Analysis ◽

Respiratory Viruses ◽

Primary Component ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Compound Identification ◽

Influenza A H1n1 ◽

Syncytial Virus

Abstract Background Respiratory virus infections are important causes of morbidity and mortality among pediatric and adult patients. These viruses infect respiratory epithelial cells, where they may induce specific metabolite alterations. As a proof-of-concept, we investigate the novel use of liquid chromatography (LC) combined with quadrupole time-of-flight mass spectrometry (Q-TOF) for the study of host cell metabolite alterations to diagnose and differentiate respiratory viruses. Methods We studied nasopharyngeal swab samples positive for respiratory viruses by the eSensor Respiratory Viral Panel (GenMark Diagnostics, Carlsbad, CA). Banked, frozen samples (−80°C) stored in viral transport media were retrieved and thawed. Aliquots of 100 μL were centrifuged at 13.3 × g for 15 minutes, and the filtrate was analyzed by Agilent 6545 Quadrupole LC/Q-TOF (Agilent Technologies, Santa Clara, CA). Compounds were separated using a novel column arrangement based on hydrophobicity and charge using a quaternary solvent manager, followed by accurate mass analysis by LC/Q-TOF. Agilent Mass Profiler 3D principal component analysis was performed, and compound identification was completed using the METLIN metabolite database. Results A total of 235 specimens were tested by LC/Q-TOF, including 195 positive specimens [including adenovirus, coronavirus, influenza A H1N1 and H3N2, influenza B, human metapneumovirus, parainfluenza viruses 1, 2, 3, and 4, respiratory syncytial virus (RSV), and rhinovirus] as well as 40 negative clinical specimens. LC/Q-TOF primary component analysis (PCA) allowed preliminary identification of key metabolites that distinguished all virus-positive specimens compared with the negative group, and differentiated respiratory viruses from one another including between influenza A 2009 H1N1 and H3N2 subtypes (Figure 1). Conclusion Preliminary data from our LC/Q-TOF analysis show that respiratory viruses exhibit different host cell metabolomic profiles that allow viral differentiation to the species level, and for influenza A virus, the subtype level. This metabolomic approach has substantial potential for diagnostic applications in infectious diseases directly from patient samples, and may be eventually adapted for point-of-care testing. Disclosures All authors: No reported disclosures.

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Mortality Following Isolation of Various Respiratory Viruses in Nursing Home Residents

Infection Control and Hospital Epidemiology ◽

10.1086/501589 ◽

1999 ◽

Vol 20 (12) ◽

pp. 812-815 ◽

Cited By ~ 33

Author(s):

Paul J. Drinka ◽

Stefan Gravenstein ◽

Elizabeth Langer ◽

Peggy Krause ◽

Peter Shult

Keyword(s):

Nursing Home ◽

Influenza A ◽

Skilled Nursing Facility ◽

Nursing Home Residents ◽

Respiratory Illness ◽

Respiratory Viruses ◽

Influenza B ◽

Respiratory Pathogens ◽

Syncytial Virus ◽

Viral Respiratory

AbstractObjective:To compare mortality following isolation of influenza A to mortality following isolation of other respiratory viruses in a nursing home.Setting:The Wisconsin Veterans Home, a 688-bed skilled nursing facility for veterans and their spouses.Participants:All residents with respiratory viral isolates obtained between 1988 and 1999.Design:Thirty-day mortality was determined following each culture-proven illness.Results:Thirty-day mortality following isolation of viral respiratory pathogens was 4.7% (15/322) for influenza A 5.4% (7/129) for influenza B; 6.1% (3/49) for parainfluenza type 1; 0% (0/26) for parainfluenza types 2,3, and 4; 0% (0/26) for respiratory syncytial virus (RSV); and 1.6% (1/61) for rhinovirus.Conclusions:Mortality following isolation of certain other respiratory viruses may be comparable to that following influenza A (although influenza A mortality might be higher without vaccination and antiviral agents). The use of uniform secretion precautions for all viral respiratory illness deserves consideration in nursing homes.

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Multicenter Evaluation of the QIAstat-Dx Respiratory Panel for Detection of Viruses and Bacteria in Nasopharyngeal Swab Specimens

Journal of Clinical Microbiology ◽

10.1128/jcm.00155-20 ◽

2020 ◽

Vol 58 (5) ◽

Cited By ~ 5

Author(s):

Amy L. Leber ◽

Jan Gorm Lisby ◽

Glen Hansen ◽

Ryan F. Relich ◽

Uffe Vest Schneider ◽

...

Keyword(s):

Influenza A ◽

Parainfluenza Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Respiratory Pathogens ◽

Content Type ◽

Percent Agreement ◽

Influenza A H1n1 ◽

Syncytial Virus

ABSTRACT The QIAstat-Dx Respiratory Panel (QIAstat-Dx RP) is a multiplex in vitro diagnostic test for the qualitative detection of 20 pathogens directly from nasopharyngeal swab (NPS) specimens. The assay is performed using a simple sample-to-answer platform with results available in approximately 69 min. The pathogens identified are adenovirus, coronavirus 229E, coronavirus HKU1, coronavirus NL63, coronavirus OC43, human metapneumovirus A and B, influenza A, influenza A H1, influenza A H3, influenza A H1N1/2009, influenza B, parainfluenza virus 1, parainfluenza virus 2, parainfluenza virus 3, parainfluenza virus 4, rhinovirus/enterovirus, respiratory syncytial virus A and B, Bordetella pertussis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. This multicenter evaluation provides data obtained from 1,994 prospectively collected and 310 retrospectively collected (archived) NPS specimens with performance compared to that of the BioFire FilmArray Respiratory Panel, version 1.7. The overall percent agreement between QIAstat-Dx RP and the comparator testing was 99.5%. In the prospective cohort, the QIAstat-Dx RP demonstrated a positive percent agreement of 94.0% or greater for the detection of all but four analytes: coronaviruses 229E, NL63, and OC43 and rhinovirus/enterovirus. The test also demonstrated a negative percent agreement of ≥97.9% for all analytes. The QIAstat-Dx RP is a robust and accurate assay for rapid, comprehensive testing for respiratory pathogens.

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Coinfections with Respiratory Pathogens among COVID-19 Patients in Korea

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2021/6651045 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Kyoung Ho Roh ◽

Yu Kyung Kim ◽

Shin-Woo Kim ◽

Eun-Rim Kang ◽

Yong-Jin Yang ◽

...

Keyword(s):

Influenza A ◽

Pathogen Detection ◽

Respiratory Virus ◽

Respiratory Viruses ◽

Diagnostic Value ◽

Respiratory Pathogen ◽

Nasopharyngeal Swab ◽

Respiratory Pathogens ◽

Oropharyngeal Swab ◽

Syncytial Virus

The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in upper and lower respiratory specimens and coinfection with other respiratory pathogens in patients with coronavirus disease 2019 (COVID-19) was investigated. Study subjects (N = 342) were retrospectively enrolled after being confirmed as SARS-CoV-2 positive, and their nasopharyngeal swab (NPS), oropharyngeal swab (OPS), and sputum specimens were restored for SARS-CoV-2 retesting and respiratory pathogen detection. The majority of the subjects (96.5%, N = 330) were confirmed as SARS-CoV-2 positive using NPS/OPS specimens. Among the COVID-19 patients (N = 342), 7.9% (N = 27) and 0.9% (N = 3) were coinfected with respiratory viruses and Mycoplasma pneumoniae, respectively, yielding an 8.8% (N = 30) overall respiratory pathogen coinfection rate. Of the respiratory virus coinfection cases (N = 27), 92.6% (N = 25) were coinfected with a single respiratory virus and 7.4% (N = 2) with two viruses (metapneumovirus/adenovirus and rhinovirus/bocavirus). No triple coinfections of other respiratory viruses or bacteria with SARS-CoV-2 were detected. Respiratory viruses coinfected in the patients with COVID-19 were as follows: rhinovirus (N = 7, 2.1%), respiratory syncytial virus A and B (N = 6, 1.8%), non-SARS-CoV-2 coronaviruses (229E, NL63, and OC43, N = 5, 1.5%), metapneumovirus (N = 4, 1.2%), influenza A (N = 3, 0.9%), adenovirus (N = 3, 0.9%), and bocavirus (N = 1, 0.3%). In conclusion, the diagnostic value of utilizing NPS/OPS specimens is excellent, and, as the first report in Korea, coinfection with respiratory pathogens was detected at a rate of 8.8% in patients with COVID-19.

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Verification of a Novel Multiplex PCR Respiratory Virus Panel in a US Biocontainment Unit

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqz112.013 ◽

2019 ◽

Vol 152 (Supplement_1) ◽

pp. S7-S7

Author(s):

Christina L Dean ◽

Emily Alvey ◽

Crystal Evans ◽

Charles Hill ◽

Eileen Burd ◽

...

Keyword(s):

Influenza A ◽

Respiratory Virus ◽

Limit Of Detection ◽

Communicable Disease ◽

Control Sample ◽

The United States ◽

Clinical Samples ◽

Influenza B ◽

Respiratory Pathogens ◽

Syncytial Virus

Abstract Emerging infectious diseases carry unique logistical, financial, and clinical ramifications. Rapid diagnostic testing methods can alleviate some of these challenges by providing definitive diagnoses earlier in the clinical course, leading to appropriate targeted therapy, cost savings, and improved patient outcomes. The BioFire FilmArray Respiratory Panel 2 plus (RP2plus; bioMérieux, Marcy l’Etoile, France) is a multiplexed nucleic acid test for detection of Middle East respiratory syndrome coronavirus (MERS-CoV) and 14 common viral and 4 bacterial respiratory pathogens in nasopharyngeal swabs obtained from those meeting MERS-CoV epidemiological criteria. The aim of this study was to verify the FilmArray RP2plus for use in our biocontainment unit. Of note, the RP2plus is FDA approved but not currently available for sale in the United States. Eight patient samples were tested with known results (GenMark Respiratory Virus Panel [RVP] or Cepheid Xpert Flu/RSV). We had concordant results between the platforms for samples containing influenza A, respiratory syncytial virus (RSV), parainfluenza virus 2, rhinovirus, and a negative sample. We evaluated two influenza B samples from two different patients. The FilmArray RP2plus did not detect influenza B in one of the patient samples. The sample was exhausted and repeat testing could not be performed. A second rhinovirus sample was not detected by the RP2plus, but Coronavirus 229E was detected in this sample, a virus not detected by the RVP. The sample was repeated and again did not detect rhinovirus. Further investigation into this discrepancy revealed that rhinovirus was originally detected by RVP at a signal of 34.4 nA (repeat of 46.9 nA). The concordant rhinovirus sample had a signal of 226.7 nA by RVP, which was much higher than the discrepant sample. Because of the low signal by RVP in the discrepant sample, perhaps the viral load was below the limit of detection of the RP2plus. All other quality control sample pools passed verification testing, including day-to-day and operator variance. It is not uncommon for a person under investigation (PUI) for a highly communicable disease to be evaluated in our facility. The performance of the RP2plus test on clinical samples showed acceptable concordance with our current means of testing for respiratory pathogens. The RP2plus will eliminate challenges implicated in storing and transporting specimens to an off-site lab, facilitate quicker turnaround time, and streamline the often cumbersome, complex protocols and practices required to work up a serious communicable disease.

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152. Sharp Decline in Rates of Community Respiratory Viral Infections Among NIH Clinical Center Patients During the COVID-19 Pandemic

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.152 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S91-S92

Author(s):

Michele Woolbert ◽

Ninet Sinaii ◽

Christine Spalding ◽

David K Henderson ◽

Tara N Palmore

Keyword(s):

Multiplex Pcr ◽

Influenza A ◽

Respiratory Viruses ◽

Mitigation Measures ◽

Respiratory Pathogen ◽

Influenza B ◽

Respiratory Pathogens ◽

Symptom Screening ◽

Clinical Center ◽

Annual Range

Abstract Background During the first year of the COVID-19 pandemic, nonpharmaceutical interventions had a broad impact on viral transmission apart from SARS-CoV-2. The NIH Clinical Center has used the BioFire FilmArray multiplex PCR respiratory pathogen panel (RPP) for evaluation of upper respiratory symptoms since 2014. Beginning in 3/20, respiratory samples from symptomatic patients were tested by SARS-CoV-2 PCR and the RPP. We performed a retrospective study comparing frequency and rates of community respiratory viruses detected by RPP from 1/14 through 3/21. Methods Results of RPPs from nasopharyngeal swabs/washes, bronchoalveolar lavages, and bronchial washes were included. Results from viral challenge studies were excluded. Charts were reviewed to determine whether repeat positives for the same virus within 12 months represented new infections; repeats from the same infection were excluded. A quantitative data analysis was completed using cross tabulations; comparisons were done using mixed models, applying Dunnett’s correction for multiplicity. Results A total of 3,329 patients underwent 8,122 RPPs from 1/14 through 3/21. Frequency of all respiratory pathogens declined from an annual range of 0.88-1.97% from 1/14-3/20 to 0.29% in 4/20-3/21 (p < 0.001). Individual viral pathogens declined sharply in frequency during the pandemic, with zero cases of influenza A/B, parainfluenza, or metapneumovirus detected from 4/20-3/21. One case each of adenovirus, RSV, CoV OC43, and CoV HKU1 were detected in 4/20-3/21. Rhino/enterovirus detection continued, but with a substantially lower frequency of 4.27% in 4/20-3/21, compared with an annual range of 8.65-18.28% from 1/14-3/20 (p < 0.001). Frequency of detection of all respiratory pathogens tested using the Biofire FilmArray multiplex PCR respiratory pathogen panel from January 2014 through March 2021. The frequency of pathogen detection from April 2020 through March 2021 declined substantially in comparison with previous years. Frequency of detection of influenza A, influenza B, rhinovirus/enterovirus, parainfluenza (1, 2, 3, 4), and respiratory syncytial virus from January 2014 through March 2021. The frequency of detection of these pathogens declined sharply starting in April 2020. Conclusion During the pandemic, the burden of viral respiratory infections detected among patients at the NIH Clinical Center improved considerably. This reprieve was likely thanks to the layered COVID-19 prevention and mitigation measures implemented in the community and the hospital: masking, distancing, symptom screening, isolation and testing symptomatic persons. As COVID-19 vaccination allows relaxation of masking, community transmission of respiratory viruses will likely resume; continued mask-wearing in the hospital may provide an enduring benefit by preventing nosocomial transmission. Disclosures Tara N. Palmore, MD, Nothing to disclose

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153. Gone Are the Other Respiratory Viruses During COVID…but the Rhinovirus/Enterovirus “Cockroach” Persists!

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.153 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S92-S93

Author(s):

Jasjit Singh ◽

Beth Huff ◽

Delma Nieves ◽

Wendi Gornick

Keyword(s):

Influenza A ◽

Viral Infections ◽

Respiratory Viruses ◽

Return To School ◽

Influenza B ◽

Respiratory Pathogens ◽

Free Standing ◽

California Department ◽

Syncytial Virus ◽

Healthcare Associated

Abstract Background In a typical winter respiratory season, Influenza A, Influenza B, Respiratory Syncytial Virus (RSV) and human Metapneumovirus (hMPV) infections are common in pediatrics. During the COVID-19 pandemic, we noted a marked decrease in all except for Rhinovirus/Enterovirus at our free-standing quaternary level children’s hospital. Methods We prospectively reviewed all patients with positive testing for viral respiratory pathogens from October 1, 2018 through May 29, 2021. Testing was done by polymerase chain reaction (PCR) (BioFire® FilmArray® Respiratory 2 Panel, UT) and by SARS-CoV-2 PCR testing (Cepheid®, CA). The latter may have been done for pre-procedure or admission screening. We submitted 74 specimens to the California Department Public Health (CDPH) for definitive identification and serotyping analysis. Results The number of Rhinovirus/Enterovirus (RV/EV) infections was compared with Influenza A & B, RSV, and hMPV over the past 3 years. There was a 152% increase in RV/EV from 2018-2019 to 2020-2021 with near absence of other respiratory viruses (Figure 1). In 2020-2021, RV/EV (N=877, 84%) made up a larger percentage of all viral etiologies compared to 2018-2019 (N=348, 11%) (Figure 2). Healthcare acquired infections (HAI) due to respiratory viruses decreased in 2020-2021 compared to both of the prior seasons, though all cases were due to RV/EV (Figure 3). There were no RV/EV associated deaths. Of 74 submitted, CDPH did typing on 24 samples; all were found to be rhinovirus (RV). Figure 1. High-Risk Winter Viral Infections 2019-2021. Figure 2. Distribution of Winter Viral Pathogens 2018-2019 Compared to 2020-2021 Season. Figure 3. Winter Viral Healthcare Associated Infections 2019-2021. Conclusion We experienced a marked increase in RV/EV during COVID precautions, despite a near absence of other common respiratory viruses. This was reflected in both our community data and HAI due to respiratory viruses. There was a marked increase in RV/EV starting with week 18 (Figure 4). We hypothesize this is due to schools’ re-opening. Understanding RV epidemiology and transmission is important, as it may inform return to school and work protocols for the upcoming respiratory viral season. Figure 4. Rhinovirus/Enterovirus by Week for the 2020-2021 Season. Disclosures All Authors: No reported disclosures

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The viral aetiology of influenza-like illnesses in Kampala and Entebbe, Uganda, 2008

African Journal of Laboratory Medicine ◽

10.4102/ajlm.v2i1.65 ◽

2013 ◽

Vol 2 (1) ◽

Cited By ~ 2

Author(s):

Stephen Balinandi ◽

Barnabas Bakamutumaho ◽

John T. Kayiwa ◽

Juliette Ongus ◽

Joseph Oundo ◽

...

Keyword(s):

Influenza A ◽

Management Strategies ◽

Respiratory Viruses ◽

Cross Sectional Study ◽

Parainfluenza Virus ◽

Influenza B Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Cross Sectional ◽

Syncytial Virus

Background: As the threat of zoonoses and the emergence of pandemic-prone respiratory viruses increases, there is a need to establish baseline information on the incidence of endemic pathogens in countries worldwide.Objectives: To investigate the presence of viruses associated with influenza-like illnesses (ILI) in Uganda.Methods: A cross-sectional study was conducted in which nasopharyngeal swab specimens were collected from patients diagnosed with ILI in Kampala and Entebbe between 14 August2008 – 15 December 2008. A multiplex polymerase chain reaction assay for detecting 12 respiratory viruses was used.Results: A total of 369 patients (52.3% females) was enrolled; the median age was 6 years (range1–70). One or more respiratory viruses were detected in 172 (46.6%) cases and their prevalence were influenza A virus (19.2%), adenovirus (8.7%), human rhinovirus A (7.9%), coronavirusOC43 (4.3%), parainfluenza virus 1 (2.7%), parainfluenza virus 3 (2.7%), influenza B virus (2.2%),respiratory syncytial virus B (2.2%), human metapneumovirus (1.4%), respiratory syncytialvirus A (1.1%), parainfluenza virus 2 (0.5%) and coronavirus 229E (0.5%). There were 24 (14.0%) mixed infections.Conclusions: This study identified some of the respiratory viruses associated with ILI in Uganda.The circulation of some of the viruses was previously unknown in the study population. These results are useful in order to guide future surveillance and case management strategies involving respiratory illnesses in Uganda.

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Influenza A and B viruses in the population of Vojvodina, Serbia

Archives of Biological Sciences ◽

10.2298/abs1401043r ◽

2014 ◽

Vol 66 (1) ◽

pp. 43-50 ◽

Cited By ~ 2

Author(s):

J. Radovanov ◽

V. Milosevic ◽

I. Hrnjakovic ◽

V. Petrovic ◽

M. Ristic ◽

...

Keyword(s):

Influenza A ◽

Respiratory Infections ◽

Influenza Viruses ◽

Influenza B Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Influenza A Viruses ◽

B Virus ◽

Life Threatening ◽

Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

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