Co-circulation of seasonal influenza A(H1N1)pdm09, A(H3N2) and B/Victoria lineage viruses with further genetic diversification, EU/EEA, 2022/23 influenza season.

BackgroundInfluenza viruses can cause large seasonal epidemics with high healthcare impact and severity as they continually change their virological properties such as genetic makeup over time.AimWe aimed to monitor the characteristics of circulating influenza viruses over the 2022/23 influenza season in the EU/EEA countries. In addition, we wanted to compare how closely the circulating viruses resemble the viral components selected for seasonal influenza vaccines, and whether the circulating viruses had acquired resistance to commonly used antiviral drugs.MethodsWe performed a descriptive analysis of the influenza virus detections and characterisations reported by National Influenza Centres (NIC) from the 30 EU/EEA countries from week 40/2022 to week 39/2023 to The European Surveillance System (TESSy) as part of the Global Influenza Surveillance and Response System (GISRS).ResultsIn the EU/EEA countries, the 2022/23 influenza season was characterised by co-circulation of A(H1N1)pdm09, A(H3N2) and B/Victoria-lineage viruses. The genetic evolution of these viruses continued and clade 6B.1A.5a.2a of A(H1N1)pdm09, 3C.2a1b.2a.2b of A(H3N2) and V1A.3a.2 of B/Victoria viruses dominated. Influenza B/Yamagata-lineage viruses were not reported.DiscussionThe World Health Organization (WHO) vaccine composition recommendation for the northern hemisphere 2023/24 season reflects the European virus evolution, with a change of the A(H1N1)pdm09 component, while keeping the A(H3N2) and B/Victoria-lineage components unchanged.

Parechovirus A Circulation and Testing Capacities in Europe, 2015-2021.

Parechovirus infections usually affect neonates and young children; manifestations vary from asymptomatic to life-threatening. We describe laboratory capacity in Europe for assessing parechovirus circulation, seasonality, and epidemiology. We used retrospective anonymized data collected from parechovirus infection case-patients identified in Europe during January 2015-December 2021. Of 21 laboratories from 18 countries that participated in the study, 16 (76%) laboratories with parechovirus detection capacity reported 1,845 positive samples; 12/16 (75%) with typing capability successfully identified 517 samples. Parechovirus A3 was the most common type (n = 278), followed by A1 (153), A6 (50), A4 (13), A5 (22), and A14 (1). Clinical data from 1,269 participants highlighted correlation of types A3, A4, and A5 with severe disease in neonates. We observed a wide capacity in Europe to detect, type, and analyze parechovirus data. To enhance surveillance and response for PeV outbreaks, sharing typing protocols and data on parechovirus-positive cases should be encouraged.

Systematic review of seroprevalence of SARS-CoV-2 antibodies and appraisal of evidence, prior to the widespread introduction of vaccine programmes in the WHO European Region, January-December 2020.

OBJECTIVES: Systematic review of SARS-CoV-2 seroprevalence studies undertaken in the WHO European Region to measure pre-existing and cumulative seropositivity prior to the roll out of vaccination programmes. DESIGN: A systematic review of the literature. DATA SOURCES: We searched MEDLINE, EMBASE and the preprint servers MedRxiv and BioRxiv in the WHO 'COVID-19 Global literature on coronavirus disease' database using a predefined search strategy. Articles were supplemented with unpublished WHO-supported Unity-aligned seroprevalence studies and other studies reported directly to WHO Regional Office for Europe and European Centre for Disease Prevention and Control. ELIGIBILITY CRITERIA: Studies published before the widespread implementation of COVID-19 vaccination programmes in January 2021 among the general population and blood donors, at national and regional levels. DATA EXTRACTION AND SYNTHESIS: At least two independent researchers extracted the eligible studies; a third researcher resolved any disagreements. Study risk of bias was assessed using a quality scoring system based on sample size, sampling and testing methodologies. RESULTS: In total, 111 studies from 26 countries published or conducted between 1 January 2020 and 31 December 2020 across the WHO European Region were included. A significant heterogeneity in implementation was noted across the studies, with a paucity of studies from the east of the Region. Sixty-four (58%) studies were assessed to be of medium to high risk of bias. Overall, SARS-CoV-2 seropositivity prior to widespread community circulation was very low. National seroprevalence estimates after circulation started ranged from 0% to 51.3% (median 2.2% (IQR 0.7-5.2%); n=124), while subnational estimates ranged from 0% to 52% (median 5.8% (IQR 2.3%-12%); n=101), with the highest estimates in areas following widespread local transmission. CONCLUSIONS: The low levels of SARS-CoV-2 antibody in most populations prior to the start of vaccine programmes underlines the critical importance of targeted vaccination of priority groups at risk of severe disease, while maintaining reduced levels of transmission to minimise population morbidity and mortality.

Comparative study between virus neutralisation testing and other serological methods detecting anti-SARS-CoV-2 antibodies in Europe, 2021.

One consequence of the ongoing coronavirus disease pandemic was the rapid development of both in-house and commercial serological assays detecting anti-SARS-CoV-2 antibodies, in an effort to reliably detect acute and past SARS-CoV-2 infections. It is crucial to evaluate the quality of these serological tests and consequently the sero-epidemiological studies that are performed with the respective tests. Here, we describe the set-up and results of a comparative study, in which a laboratory contracted by the European Centre for Disease Prevention and Control offered a centralised service to EU/EEA Member and pre-accession Member States to test representative serum specimens with known serological results, with the gold standard technique (virus neutralisation tests) to determine the presence of neutralising antibodies. Laboratories from 12 European countries shared 719 serum specimens with the contractor laboratory. We found that in-house serological tests detecting neutralising antibodies showed the highest percent agreement, both positive and negative, with the virus neutralisation test results. Despite extensive differences in virus neutralisation protocols neutralisation titres showed a strong correlation. From the commercial assays, the best positive percent agreement was found for SARS-CoV-2 IgG (sCOVG) (Siemens - Atellica IM Analyzer). Despite lower positive percent agreement of LIAISON SARS-CoV-2 TrimericS IgG kit (Diasorin Inc.), the obtained results showed relatively good correlation with neutralisation titres. The set-up of this study allowed for high comparability between laboratories and enabled laboratories that do not have the capacity or capability to perform VNTs themselves. Given the variety of in-house protocols detecting SARS-CoV-2 specific neutralising antibodies, including the virus strain, it could be of interest to select reference isolates for SARS-CoV-2 diagnostic to be made available for interested EU Member States and pre-accession countries.

Seasonality of respiratory syncytial virus and its association with meteorological factors in 13 European countries, week 40 2010 to week 39 2019.

BackgroundRespiratory syncytial virus (RSV) is the predominant cause of clinical pneumonia among infants and young children, often peaking during the winter months in temperate regions.AimTo describe RSV seasonality in 13 European countries and examine its association with meteorological factors.MethodsWe included weekly RSV seasonality data from 13 European countries between week 40 2010 and week 39 2019. Using local weighted regression method, we modelled weekly RSV activity with meteorological factors using data from the 2010/11 to the 2017/18 season. We predicted the weekly RSV activity of the 2018/19 season across 41 European countries and validated our prediction using empirical data.ResultsAll countries had annual wintertime RSV seasons with a longitudinal gradient in RSV onset (Pearson's correlation coefficient, r = 0.71, 95% CI: 0.60 to 0.80). The RSV season started 3.8 weeks later (95% CI: -0.5 to 8.0) in countries in the eastern vs western parts of Europe, and the duration ranged from 8-18 weeks across seasons and countries. Lower temperature and higher relative humidity were associated with higher RSV activity, with a 14-day lag time. Through external validation, the prediction error in RSV season onset was -2.4 ± 3.2 weeks. Similar longitudinal gradients in RSV onset were predicted by our model for the 2018/19 season (r = 0.45, 95% CI: 0.16 to 0.66).ConclusionMeteorological factors, such as temperature and relative humidity, could be used for early warning of RSV season onset. Our findings may inform healthcare services planning and optimisation of RSV immunisation strategies in Europe.

Point of Care Testing for Infectious Disease in Europe: A Scoping Review and Survey Study.

Background: Point of care testing (POCT) for infectious diseases is testing conducted near the patient. It allows clinicians to offer the most appropriate treatment more quickly. As POCT devices have increased in accuracy and become more cost-effective, their use has grown, but a systematic assessment of their use for clinical and public health management of infectious diseases in EU/EEA countries has not been previously undertaken. Methods: A scoping review of the literature on POCT in EU/ EEA countries as at November 2019, and a survey of key stakeholders. Results: 350 relevant articles were identified and 54 survey responses from 26 EU/EEA countries were analysed. POCT is available for a range of infectious diseases and in all countries responding to the survey (for at least one disease). POCT is commonly available for influenza, HIV/AIDS, Legionnaires' disease and malaria, where it is used in at least half of EU/EEA countries. While POCT has the potential to support many improvements to clinical care of infectious diseases (e.g., faster diagnosis, more appropriate use of antimicrobials), the results suggest POCT is infrequently used to support public health functions (e.g., disease surveillance and reporting). Conclusion: Although POCT is in use to some extent in all EU/EEA countries, the full benefits of POCT in wider public health functions have yet to be realised. Further research on barriers and facilitators to implementation is warranted.

Meta-analysis of the clinical performance of commercial SARS-CoV-2 nucleic acid and antibody tests up to 22 August 2020.

BackgroundReliable testing for SARS-CoV-2 is key for the management of the COVID-19 pandemic.AimWe estimate diagnostic accuracy for nucleic acid and antibody tests 5 months into the COVID-19 pandemic, and compare with manufacturer-reported accuracy.MethodsWe reviewed the clinical performance of SARS-CoV-2 nucleic acid and antibody tests based on 93,757 test results from 151 published studies and 20,205 new test results from 12 countries in the European Union and European Economic Area (EU/EEA).ResultsPooling the results and considering only results with 95% confidence interval width ≤ 5%, we found four nucleic acid tests, including one point-of-care test and three antibody tests, with a clinical sensitivity ≥ 95% for at least one target population (hospitalised, mild or asymptomatic, or unknown). Nine nucleic acid tests and 25 antibody tests, 12 of them point-of-care tests, had a clinical specificity of ≥ 98%. Three antibody tests achieved both thresholds. Evidence for nucleic acid point-of-care tests remains scarce at present, and sensitivity varied substantially. Study heterogeneity was low for eight of 14 sensitivity and 68 of 84 specificity results with confidence interval width ≤ 5%, and lower for nucleic acid tests than antibody tests. Manufacturer-reported clinical performance was significantly higher than independently assessed in 11 of 32 and four of 34 cases, respectively, for sensitivity and specificity, indicating a need for improvement in this area.ConclusionContinuous monitoring of clinical performance within more clearly defined target populations is needed.

Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe.

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.