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.Peer reviewe

Seasonal and inter-seasonal RSV activity in the European Region during the COVID-19 pandemic from autumn 2020 to summer 2022

© 2023 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.Background: The emergence of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in early 2020 and subsequent implementation of public health and social measures (PHSM) disrupted the epidemiology of respiratory viruses. This work describes the epidemiology of respiratory syncytial virus (RSV) observed during two winter seasons (weeks 40–20) and inter-seasonal periods (weeks 21–39) during the pandemic between October 2020 and September 2022. Methods: Using data submitted to The European Surveillance System (TESSy) by countries or territories in the World Health Organization (WHO) European Region between weeks 40/2020 and 39/2022, we aggregated country-specific weekly RSV counts of sentinel, non-sentinel and Severe Acute Respiratory Infection (SARI) surveillance specimens and calculated percentage positivity. Results for both 2020/21 and 2021/22 seasons and inter-seasons were compared with pre-pandemic 2016/17 to 2019/20 seasons and inter-seasons. Results: Although more specimens were tested than in pre-COVID-19 pandemic seasons, very few RSV detections were reported during the 2020/21 season in all surveillance systems. During the 2021 inter-season, a gradual increase in detections was observed in all systems. In 2021/22, all systems saw early peaks of RSV infection, and during the 2022 inter-seasonal period, patterns of detections were closer to those seen before the COVID-19 pandemic. Conclusion: RSV surveillance continued throughout the COVID-19 pandemic, with an initial reduction in transmission, followed by very high and out-of-season RSV circulation (summer 2021) and then an early start of the 2021/22 season. As of the 2022/23 season, RSV circulation had not yet normalised.Peer reviewe

Problems of Epidemiological Surveillance of West Nile Fever in Ukraine

ObjectiveTo define the problems of epidemiological surveillance of West Nile fever (WNF) in Ukraine.IntroductionFlaviviridae are one of the most widespread arboviruses in Ukraine. Mosquitoes are vectors of WNF in a majority of cases due to bites during swimming, fishing, work in suburban areas and outdoor recreation without use of individual protection from mosquitoes.A study of the species composition of bloodsucking mosquitoes is conducted in Ukraine. Existence of natural foci of WNF viruses has been well-proven all over the territory of Ukraine by testing IgG antibodies in different groups of population, including children [1]. Also, infection of mosquitoes (RNA found in Culex pipiens (including Culex pipiens f. molestus, Culiseta annulata)) was registered. Infection of I. ricinus and D. reticulates was also determined, and it acts as a factor for circulation of virus in the wild too [2].MethodsStatistical, serological and epidemiological methods were used during the study. Serological tests included reactions with IgM and IgG antibody in human serum performed using immunofluorescent and ELISA methods.ResultsIn Ukraine, the causative agent of WNF is detected in all landscapes. It is the main arboviral infection in the forest-steppe zone (53.1 % among all arboviral infections). Enzootic territories are located in 18 regions, 47 administrative districts, and 63 settlements.The majority of natural foci of WNF is located in the Dnieper left-bank steppes, and also in North-Western and Western forest-steppes. The enzootic territories are located on the East of steppe zone and on the East of forest-steppes. The smallest number of natural foci is registered in the Dnieper right-bank part of the steppes. Enzootic territories are absent in Chernivtsi, Chernihiv, Sumy, Ternopil, Luhansk, Kirovohrad Oblasts and Kyiv. Most of them are located in Zaporizhzhia with 9 administrative districts and 16 settlements; in Rivno Oblast - 7 and 9; in Kherson - 5 and 4, and in Poltava Oblasts - 2 and 4 respectively [3].During the period from 2007 to 2016, 86 cases of WNF were registered. WNF was registered in 7 oblasts (Zaporizhzhya - 40 cases, Poltava - 24, Donetsk - 16, Mykolaiv- 3, Kherson, Kharkiv, Zhytomyr Oblasts - one case in each) [4].Registration of WNF cases separately from other viral hemorrhagic fevers has been conducted in the country since 2010 (official registration of total amount of viral hemorrhagic fevers has been performed since 2005).In enzootic territories, 2 cases of the diseases were registered and were associated with ticks bites. The strains of WNV were detected in bloodsucking mosquitoes in Rivne and Zaporizhzhia Oblasts and in tick samples of Ixodes genus collected in Lviv Oblast (probably may be found in other species of tick (Argasidae and Gamazoidea) where the causative agent is kept in natural foci under unfavorable conditions).Laboratory diagnostics was conducted (mainly retrospectively) in Zaporizhzhia, Poltava, Donetsk Oblastss. All diagnoses (exception Mykolaiv Oblast in 2011, data is absent) were laboratory confirmed, including 10 cases confirmed in the State Institution Lviv Research Institute of Epidemiology and Hygiene of the Ministry of Health of Ukraine, and 3 more cases were confirmed by a private laboratory [2].In total, 129 samples of blood sera collected from patients with clinical manifestations of a fever of unknown origin were delivered to the Laboratory of Virology of Ukrainian Center for Diseases Control and Monitoring during 2016-2017. Samples were investigated using the immunofluorescent and enzyme immunoassay methods including immunoblot. West Nile virus markers such as IgM/IgG antibodies have been detected in 4 cases (Poltava oblast) [4].ConclusionsMainly, single cases were registered. It is caused by insufficient level of diagnostics in most of the regions, as a result, diseases pass under other diagnoses. Migratory birds (3 flyways of migratory birds pass through Ukraine) and local animals (crows, jackdaws, doves and other) may be the possible reservoirs of causative agent of WNF. Laboratory diagnostics need to be improved and more attention should be paid to testing of samples of blood serum from patients with suspected WNF.References[1] Rusev I.T., Zakusilo V.M., Vinnuk V.D. Bloodsucking mosquitoes of urbanized biocenosis and their role are in circulation of viruses of West Nile fever. Series are "Biology, chemistry". issue 24 (63). 2011. No. 2. p. 240-248.[2] Lozinskyi I.M., Beletska G.V., Drul O.S., Fedoruck V.I., Kozlovskyi M.M., Rogochiy E.G., Sholomey M.V., Ben I.I., Shulgan A.M./Epidemic situation of Western Nile fever in Ukraine. Magazine of infectology, issue 6, No. 2, 2014 Appendix 66-65.[3] Official data of state statistic form of the Ministry of Health.[4] Data of the State Institution Ukrainian center for Diseases Control and Monitoring of the Ministry of Health of Ukraine

Prevalence of Hantaviruses Harbored by Murid Rodents in Northwestern Ukraine and Discovery of a Novel Puumala Virus Strain

In Europe, two species of hantaviruses, Puumala orthohantavirus (PUUV) and Dobrava orthohantavirus (DOBV), cause hemorrhagic fever with renal syndrome in humans. The rodent reservoirs for these viruses are common throughout Ukraine, and hence, the goal of this study was to identify the species and strains of hantaviruses circulating in this region. We conducted surveillance of small rodent populations in a rural region in northwestern Ukraine approximately 30 km from Poland. From the 424 small mammals captured, we identified nine species, of which the most abundant were Myodes glareolus, the bank vole (45%); Apodemus flavicollis, the yellow-necked mouse (29%); and Apodemus agrarius, the striped field mouse (14.6%) Using an indirect immunofluorescence assay, 15.7%, 20.5%, and 33.9% of the sera from M. glareolus, A. glareolus, and A. flavicollis were positive for hantaviral antibodies, respectively. Additionally, we detected antibodies to the hantaviral antigen in one Microtus arvalis, one Mus musculus, and one Sorex minutus. We screened the lung tissue for hantaviral RNA using next-generation sequencing and identified PUUV sequences in 25 small mammals, including 23 M. glareolus, 1 M. musculus, and 1 A. flavicollis, but we were unable to detect DOBV sequences in any of our A. agrarius specimens. The percent identity matrix and Bayesian phylogenetic analyses of the S-segment of PUUV from 14 M. glareolus lungs suggest the highest similarity (92–95% nucleotide or 99–100% amino acid) with the Latvian lineage. This new genetic information will contribute to future molecular surveillance of human cases in Ukraine

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

Predominance of influenza virus A(H3N2) 3C.2a1b and A(H1N1)pdm09 6B.1A5A genetic subclades in the WHO European Region, 2018–2019

Network authors: Portugal - Raquel Guiomar, Pedro Pechirra, National Influenza Reference Laboratory, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, Lisbon, PortugalBackground: The 2018/2019 influenza season in the WHO European Region was dominated by influenza A (H1N1)pdm09 and (H3N2) viruses, with very few influenza B viruses detected. Methods: Countries in the European Region reported virus characterization data to The European Surveillance System for weeks 40/2018 to 20/2019. These virus antigenic and genetic characterization and haemagglutinin (HA) sequence data were analysed to describe and assess circulating viruses relative to the 2018/2019 vaccine virus components for the northern hemisphere. Results: Thirty countries reported 4776 viruses characterized genetically and 3311 viruses antigenically. All genetically characterized A(H1N1)pdm09 viruses fell in subclade 6B.1A, of which 90% carried the amino acid substitution S183P in the HA gene. Antigenic data indicated that circulating A(H1N1)pdm09 viruses were similar to the 2018/2019 vaccine virus. Genetic data showed that A(H3N2) viruses mostly fell in clade 3C.2a (75%) and 90% of which were subclade 3C.2a1b. A lower proportion fell in clade 3C.3a (23%) and were antigenically distinct from the vaccine virus. All B/Victoria viruses belonged to clade 1A; 30% carried a double amino acid deletion in HA and were genetically and antigenically similar to the vaccine virus component, while 55% carried a triple amino acid deletion or no deletion in HA; these were antigenically distinct from each other and from the vaccine component. All B/Yamagata viruses belonged to clade 3 and were antigenically similar to the virus component in the quadrivalent vaccine for 2018/2019. Conclusions: A simultaneous circulation of genetically and antigenically diverse A(H3N2) and B/Victoria viruses was observed and represented a challenge to vaccine strain selection.Highlights: Co-circulation of different clades/subclades of influenza A viruses in 2018/2019 in the Region; Most circulating A(H1N1)pdm09 viruses (6B.1A) carried S183P in hemagglutinin; Genetically heterogeneous A(H3N2) viruses, with co-circulation of clades 3C.2a and 3C.3a; Antigenically distinct A(H3N2) clade 3C.3a viruses were increasingly detected until 02/2019 and then decreased; Co-circulation of genetically and antigenically diverse A(H3N2) strains challenges vaccine strain selection.info:eu-repo/semantics/publishedVersio