Browsing by Subject "Influenza"

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  • Elf, Sonja; Auvinen, Pauliina; Jahn, Lisa; Liikonen, Karoliina; Sjöblom, Solveig; Saavalainen, Päivi; Mäki, Minna; Eboigbodin, Kevin E. (2018)
    Isothermal nucleic acid amplification methods can potentially shorten the amount of time required to diagnose influenza. We developed and evaluated a novel isothermal nucleic acid amplification method, RT-SIBA to rapidly detect and differentiate between influenza A and B viruses in a single reaction tube. The performance of the RT-SIBA Influenza assay was compared with two established RT-PCR methods. The sensitivities of the RT-SIBA, RealStar RT-PCR, and CDC RT-PCR assays for the detection of influenza A and B viruses in the clinical specimens were 98.8%, 100%, and 89.3%, respectively. All three assays demonstrated a specificity of 100%. The average time to positive result was significantly shorter with the RT-SIBA Influenza assay (90 min). The method can be run using battery-operated, portable devices with a small footprint and therefore has potential applications in both laboratory and near-patient settings. (C) 2018 Elsevier Inc. All rights reserved.
  • Sarkanen, Tomi O.; Alakuijala, Anniina P. E.; Dauvilliers, Yves A.; Partinen, Markku M. (2018)
    An increased incidence of narcolepsy was seen in many countries after the pandemic H1N1 influenza vaccination campaign in 2009-2010. The H1N1 vaccine - narcolepsy connection is based on observational studies that are prone to various biases, e.g., confounding by H1N1 infection, and ascertainment, recall and selection biases. A direct pathogenic link has, however, remained elusive. We conducted a systematic review and meta-analysis to analyze the magnitude of H1N1 vaccination related risk and to examine if there was any association with H1N1 infection itself. We searched all articles from PubMed, Web of Science and Scopus, and other relevant sources reporting the incidence and risk of post-vaccine narcolepsy. In our paper, we show that the risk appears to be limited to only one vaccine (Pandemrix (R)). During the first year after vaccination, the relative risk of narcolepsy was increased 5 to 14-fold in children and adolescents and 2 to 7-fold in adults. The vaccine attributable risk in children and adolescents was around 1 per 18,400 vaccine doses. Studies from Finland and Sweden also appear to demonstrate an extended risk of narcolepsy into the second year following vaccination, but such conclusions should be interpreted with a word of caution due to possible biases. Benefits of immunization outweigh the risk of vaccination-associated narcolepsy, which remains a rare disease. (C) 2017 Elsevier Ltd. All rights reserved.
  • Nystedt, Riikka (Helsingin yliopisto, 2017)
    Tutkimuksen tarkoitus: Vuonna 2009 esiintyi viimeksi maailmanlaajuinen influenssapandemia (niin kutsuttu sikainfluenssa), jonka aiheuttajaksi todettiin A(H1N1)-virusalatyyppi. Pandemian aikaan influenssaan voi sairastua huomattavan suuri määrä väestöstä, mikä kuormittaa erityisesti terveydenhuoltoa terveysasemien ja sairaaloiden palvelukapasiteettien rajallisuuden vuoksi. Tutkimuksen tarkoituksena oli perehtyä influenssaviruksiin sekä selvittää, kuinka influenssapandemiat kuormittavat terveydenhuollon palvelutoimintoja ja millaista materiaalien ja henkilöstön riittävyys oli pandemia-aaltojen aikaan vuonna 2009. Tutkimuksen perusteella pohditaan pandemian aiheuttamia haasteita terveydenhuollon toimivuudelle sekä pohditaan varautumista tuleviin vastaavanlaisiin pandemioihin. Materiaalit ja menetelmät: Sosiaali- ja terveysministeriön toimeksiantona lääninhallitukset keräsivät vuonna 2009 webropol-pohjaisella nettikyselyllä tietoa perus- ja erikoissairaanhoidon sekä sosiaalihuollon palvelujärjestelmän toimivuudesta pandemian huippuviikkoina Manner-Suomessa sekä Ahvenanmaalla. Kyselyillä selvitettiin työvoiman, materiaalien ja toimintaresurssien (tilat/laitteet) riittävyyttä, influenssapotilaiden määriä ja terveyskeskuksissa puhelinyhteydenottojen. Influenssaepidemia käynnistyi lokakuussa (viikot 41 - 42) ja huippu saavutettiin Pohjois-Suomessa viikkojen 43 - 45 aikana (loka-marraskuu) ja Etelä-Suomessa viikkojen 45 - 48 (marraskuu) aikana. Tulokset: Suomessa varmistettiin influenssaepidemian aikana 7669 influenssatapausta laboratoriokokein, mutta todellinen tartuntamäärä oli paljon suurempi. Influenssapandemiaan liittyi tavallista kausi-influenssaa vaikeampi taudinkuva. Seurantajakson aikana suurimmassa osassa lääneistä terveydenhuollon toimintakapasiteetit riittivät. Alueellisen epidemiahuipun aikaan sekä perusterveydenhuollon että erikoissairaanhoidon palvelut kuormittuivat ja erityisesti tehohoitopaikoista oli pulaa. Seurannan aikana puhelinyhteydenotot terveyskeskuksiin lisääntyvät voimakkaasti, mikä kuormitti palvelujärjestelmää. Joillakin alueilla oli nähtävissä myös henkilökuntapulan uhkaa. Johtopäätökset: Kansallista varautumissuunnitelmaa influenssapandemiaan päivitettiin vuoden 2009 pandemian jälkeen. Uudessa varautumissuunnitelmassa (2012) todetaan, että pandemian aikana koko terveydenhuollon resurssit ovat rajalliset, mutta erityisesti tehohoidon kapasiteetti ylittyy helposti. Korkeassa kuormitustilanteessa vähäinenkin potilasmäärän lisääntyminen voi merkittävästi vaikeuttaa teho-osastojen toimintaa. Varautumissuunnitelmassa todetaan myös influenssapotilaita hoitavan henkilökunnan rokottamisen tärkeys, jotta terveyden- ja sairaanhoito pysyy pandemiatilanteessa toimivana. Tällöin myös muiden henkilöryhmien ennuste paranee.
  • Efraim Investigators; Nine-I Study Grp; Martin-Loeches, Ignacio; Valkonen, Miia; Azoulay, Elie (2019)
    BackgroundIt is unclear whether influenza infection and associated co-infection are associated with patient-important outcomes in critically ill immunocompromised patients with acute respiratory failure.MethodsPreplanned secondary analysis of EFRAIM, a prospective cohort study of 68 hospitals in 16 countries. We included 1611 patients aged 18years or older with non-AIDS-related immunocompromise, who were admitted to the ICU with acute hypoxemic respiratory failure. The main exposure of interest was influenza infection status. The primary outcome of interest was all-cause hospital mortality, and secondary outcomes ICU length of stay (LOS) and 90-day mortality.ResultsInfluenza infection status was categorized into four groups: patients with influenza alone (n=95, 5.8%), patients with influenza plus pulmonary co-infection (n=58, 3.6%), patients with non-influenza pulmonary infection (n=820, 50.9%), and patients without pulmonary infection (n=638, 39.6%). Influenza infection status was associated with a requirement for intubation and with LOS in ICU (P
  • Martin-Loeches, Ignacio; Lemiale, Virginie; Geoghegan, Pierce; McMahon, Mary A; Pickkers, Peter; Soares, Marcio; Perner, Anders; Meyhoff, Tine S; Bukan, Ramin B; Rello, Jordi; Bauer, Philippe R; van de Louw, Andry; Taccone, Fabio S; Salluh, Jorge; Hemelaar, Pleun; Schellongowski, Peter; Rusinova, Katerina; Terzi, Nicolas; Mehta, Sangeeta; Antonelli, Massimo; Kouatchet, Achille; Klepstad, Pål; Valkonen, Miia; Landburg, Precious P; Barratt-Due, Andreas; Bruneel, Fabrice; Pène, Frédéric; Metaxa, Victoria; Moreau, Anne S; Souppart, Virginie; Burghi, Gaston; Girault, Christophe; Silva, Ulysses V A; Montini, Luca; Barbier, Francois; Nielsen, Lene B; Gaborit, Benjamin; Mokart, Djamel; Chevret, Sylvie; Azoulay, Elie (BioMed Central, 2019)
    Abstract Background It is unclear whether influenza infection and associated co-infection are associated with patient-important outcomes in critically ill immunocompromised patients with acute respiratory failure. Methods Preplanned secondary analysis of EFRAIM, a prospective cohort study of 68 hospitals in 16 countries. We included 1611 patients aged 18 years or older with non-AIDS-related immunocompromise, who were admitted to the ICU with acute hypoxemic respiratory failure. The main exposure of interest was influenza infection status. The primary outcome of interest was all-cause hospital mortality, and secondary outcomes ICU length of stay (LOS) and 90-day mortality. Results Influenza infection status was categorized into four groups: patients with influenza alone (n = 95, 5.8%), patients with influenza plus pulmonary co-infection (n = 58, 3.6%), patients with non-influenza pulmonary infection (n = 820, 50.9%), and patients without pulmonary infection (n = 638, 39.6%). Influenza infection status was associated with a requirement for intubation and with LOS in ICU (P < 0.001). Patients with influenza plus co-infection had the highest rates of intubation and longest ICU LOS. On crude analysis, influenza infection status was associated with ICU mortality (P < 0.001) but not hospital mortality (P = 0.09). Patients with influenza plus co-infection and patients with non-influenza infection alone had similar ICU mortality (41% and 37% respectively) that was higher than patients with influenza alone or those without infection (33% and 26% respectively). A propensity score-matched analysis did not show a difference in hospital mortality attributable to influenza infection (OR = 1.01, 95%CI 0.90–1.13, P = 0.85). Age, severity scores, ARDS, and performance status were all associated with ICU, hospital, and 90-day mortality. Conclusions Category of infectious etiology of respiratory failure (influenza, non-influenza, influenza plus co-infection, and non-infectious) was associated with ICU but not hospital mortality. In a propensity score-matched analysis, influenza infection was not associated with the primary outcome of hospital mortality. Overall, influenza infection alone may not be an independent risk factor for hospital mortality in immunosuppressed patients.
  • Baum, Ulrike; Kulathinal, Sangita; Auranen, Kari (2021)
    Background: Non-sensitive and non-specific observation of outcomes in time-to-event data affects event counts as well as the risk sets, thus, biasing the estimation of hazard ratios. We investigate how imperfect observation of incident events affects the estimation of vaccine effectiveness based on hazard ratios. Methods: Imperfect time-to-event data contain two classes of events: a portion of the true events of interest; and false-positive events mistakenly recorded as events of interest. We develop an estimation method utilising a weighted partial likelihood and probabilistic deletion of false-positive events and assuming the sensitivity and the false-positive rate are known. The performance of the method is evaluated using simulated and Finnish register data. Results: The novel method enables unbiased semiparametric estimation of hazard ratios from imperfect time-to-event data. False-positive rates that are small can be approximated to be zero without inducing bias. The method is robust to misspecification of the sensitivity as long as the ratio of the sensitivity in the vaccinated and the unvaccinated is specified correctly and the cumulative risk of the true event is small. Conclusions: The weighted partial likelihood can be used to adjust for outcome measurement errors in the estimation of hazard ratios and effectiveness but requires specifying the sensitivity and the false-positive rate. In absence of exact information about these parameters, the method works as a tool for assessing the potential magnitude of bias given a range of likely parameter values.
  • Baum, Ulrike; Kulathinal, Sangita; Auranen, Kari (BioMed Central, 2021)
    Abstract Background Non-sensitive and non-specific observation of outcomes in time-to-event data affects event counts as well as the risk sets, thus, biasing the estimation of hazard ratios. We investigate how imperfect observation of incident events affects the estimation of vaccine effectiveness based on hazard ratios. Methods Imperfect time-to-event data contain two classes of events: a portion of the true events of interest; and false-positive events mistakenly recorded as events of interest. We develop an estimation method utilising a weighted partial likelihood and probabilistic deletion of false-positive events and assuming the sensitivity and the false-positive rate are known. The performance of the method is evaluated using simulated and Finnish register data. Results The novel method enables unbiased semiparametric estimation of hazard ratios from imperfect time-to-event data. False-positive rates that are small can be approximated to be zero without inducing bias. The method is robust to misspecification of the sensitivity as long as the ratio of the sensitivity in the vaccinated and the unvaccinated is specified correctly and the cumulative risk of the true event is small. Conclusions The weighted partial likelihood can be used to adjust for outcome measurement errors in the estimation of hazard ratios and effectiveness but requires specifying the sensitivity and the false-positive rate. In absence of exact information about these parameters, the method works as a tool for assessing the potential magnitude of bias given a range of likely parameter values.
  • Hemilä, Harri (2013)
    Feedback to the following Cochrane review: Jefferson T, et al.: Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. Cochrane Database Syst Rev. 2012 Jan 18;1:CD008965 http://www.ncbi.nlm.nih.gov/pubmed/22258996