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Influenzaseizoen 2022/2023 in Nederland: langdurige circulatie van griepvirussen.

Fouchier, R., Meijer, A., Hooiveld, M., Eggink, D., Hoek, A.J. van, Gageldonk-Lafeber, R. van, Lange, M. de, Koopmans, M. Influenzaseizoen 2022/2023 in Nederland: langdurige circulatie van griepvirussen. Nederlands Tijdschrift voor Medische Microbiologie: 2024, 32(1), p. 29-36.
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The 2022/2023 influenza epidemic started in week 50 of 2022 and lasted until week 11 of 2023. Reports of
influenza-like illness (ILI) were only 4 weeks above the epidemic threshold of 5.8 persons with ILI per 10,000 population from week 51 onwards, but due to a rapid increase in influenzavirus detections in week 50 and continued high detection rates through week 11, it was still a fairly long epidemic.

Influenza A(H1N1)pdm09, A(H3N2) and B/Victoria line viruses were all detected frequently. Within each of these (sub)types, substantial genetic diversity was observed, but substantial antigenic drift was not seen. For the majority of viruses, there was no genetic or phenotypic evidence for resistance to available drugs. Two A(H1N1)pdm09 viruses had genetic markers in neuraminidase (S247N, D199G/H275Y)indicating resistance to neuraminidase inhibitors, one ofwhich could be cultured and confirmed phenotypically.

People who received the influenza vaccine this season had a 53 percent lower risk of influenza. After the influenza season, in August 2023, an A(H1N1)v swine influenza virus zoonosis was identified, without a demonstrable direct link with exposure to pigs.