Pitfalls of rubella serology while on the brink of elimination: evaluation of national data, Belgium, 2017

Sofie Colman, Kris Vernelen, Bernard China, Dorien Van den Bossche, Laura Cornelissen, Marie-Luce Delforge, Marijke Reynders, Mario Berth, Melissa Depypere, Natasja Van Gasse, Sara Vijgen, Jos Van Acker, An Boel, Elizaveta Padalko

Research output: Contribution to journalA1: Web of Science-article

Abstract

BackgroundIn Belgium, rubella serology is frequently requested in women of childbearing age, despite high vaccination coverage and a near-absence of congenital rubella cases. Different test kits are available and should be standardised by an international standard preparation.AimTo analyse and compare rubella serology practices in Belgian laboratories.MethodsAs part of the mandatory External Quality Assessment programme for rubella serology in Belgium, the national public health institute, Sciensano, sent a voluntary questionnaire concerning anti-rubella IgM/IgG analyses in women aged 15 to 45 years in 2017 to 130 laboratories.ResultsThe questionnaire response rate was 83.8% (109/130). The majority of 169,494 IgG analyses were performed on Roche (55%), Abbott (17%) and Diasorin (13%) analysers. Not all laboratories used the proposed international cut-off of 10 IU/mL. Assumed median seroprevalence ranged from 76.3% with Liaison (Diasorin) to 96.3% with Modular (Roche). Despite very low rubella incidence in Belgium, 93 laboratories performed 85,957 IgM analyses, with 748 positive and 394 grey zone results. The National Reference Centre for Measles, Mumps and Rubella virus and the National Reference Centre for Congenital infections did not confirm any positive rubella cases in 2017.ConclusionThis retrospective analysis shows that rubella serology results may differ considerably according to the assay used. It is therefore important to use the same test when comparing results or performing follow-up testing. The number of anti-rubella IgM analyses was very high. Incorrect use of IgM for screening women of childbearing age can lead to unwarranted anxiety and overuse of confirmation tests.

Original languageEnglish
Article number2807
JournalEurosurveillance
Volume26
Issue number20
Number of pages9
ISSN1025-496X
DOIs
Publication statusPublished - 2021

Keywords

  • Antibodies, Viral
  • Belgium/epidemiology
  • Female
  • Humans
  • Measles-Mumps-Rubella Vaccine
  • Measles/diagnosis
  • Retrospective Studies
  • Rubella/diagnosis
  • Seroepidemiologic Studies

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